2024-03-28T10:56:00Zhttps://www.repo.uni-hannover.de/oai/requestoai:www.repo.uni-hannover.de:123456789/1142022-12-02T15:12:32Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:510
2015-11-02T10:32:37Z
urn:hdl:123456789/114
Discrete R-symmetries and anomaly universality in heterotic orbifolds
Bizet, Nana G. Cabo
Kobayashi, Tatsuo
Peña, Damián K. Mayorga
Parameswaran, Susha L.
Schmitz, Matthias
Zavala, Ivonne
Wilson Line
Orbifold Model
Low Energy Effective Field Theory
Geometrical Symmetry
String Theory
Finite Symmetry
Explicit Computation
Heterotic String
Superstrings
Conformal Field Model
We study discrete R-symmetries, which appear in the 4D low energy effective field theory derived from heterotic orbifold models. We derive the R-symmetries directly from the geometrical symmetries of the orbifolds. In particular, we obtain the corresponding R-charges by requiring that the couplings be invariant under these symmetries. This allows for a more general treatment than the explicit computations of correlation functions made previously by the authors, including models with discrete Wilson lines, and orbifold symmetries beyond plane-by-plane rotational invariance. The R-charges obtained in this manner differ from those derived in earlier explicit computations. We study the anomalies associated with these R-symmetries, and comment on the results.
2015-11-02T10:32:37Z
2015-11-02T10:32:37Z
2014
Article
Text
Bizet, Nana G. Cabo; Kobayashi, Tatsuo; Peña, Damián K. Mayorga; Parameswaran, Susha L.; Schmitz, Matthias; Zavala, Ivonne: Discrete R-symmetries and anomaly universality in heterotic orbifolds. In: Journal of High Energy Physics 2014 (2014), Nr. 2. DOI: http://dx.doi.org/10.1007/JHEP02(2014)098
http://www.repo.uni-hannover.de/handle/123456789/114
http://dx.doi.org/10.15488/96
eng
Journal of High Energy Physics 2014 (2014), Nr. 2
http://arxiv.org/abs/1308.5669
http://arxiv.org/abs/1308.5669v2
1029-8479
http://dx.doi.org/10.1007/JHEP02(2014)098
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
New York : Springer
oai:www.repo.uni-hannover.de:123456789/2072022-12-13T15:12:26Zcom_123456789_1col_123456789_3ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-02-02T12:03:11Z
urn:hdl:123456789/207
Estimation of Measurement Uncertainty of kinematic TLS Observation Process by means of Monte-Carlo Methods
Alkhatib, Hamza
Kutterer, Hansjörg
Monte Carlo simulation
kinematic terrestrial laserscanning
uncertainty modeling
In many cases, the uncertainty of output quantities may be computed by assuming that the distribution represented by the result of measurement and its associated standard uncertainty is a Gaussian. This assumption may be unjustified and the uncertainty of the output quantities determined in this way may be incorrect. One tool to deal with different distribution functions of the input parameters and the resulting mixed-distribution of the output quantities is given through the Monte Carlo techniques. The resulting empirical distribution can be used to approximate the theoretical distribution of the output quantities. All required moments of different orders can then be numerically determined. To evaluate the procedure of derivation and evaluation of output parameter uncertainties outlined in this paper, a case study of kinematic terrestrial laserscanning (k-TLS) will be discussed. This study deals with two main topics: the refined simulation of different configurations by taking different input parameters with diverse probability functions for the uncertainty model into account, and the statistical analysis of the real data in order to improve the physical observation models in case of k-TLS. The solution of both problems is essential for the highly sensitive and physically meaningful application of k-TLS techniques for monitoring of, e. g., large structures such as bridges.
2016-02-02T12:03:11Z
2016-02-02T12:03:11Z
2013-05-18
Article
Text
Alkhatib, Hamza; Kutterer, Hansjörg: Estimation of Measurement Uncertainty of kinematic TLS Observation Process by means of Monte-Carlo Methods. In: Journal of Applied Geodesy 7 (2013), Nr. 2, S. 125-134. DOI: http://dx.doi.org/10.1515/jag-2013-0044
http://www.repo.uni-hannover.de/handle/123456789/207
http://dx.doi.org/10.15488/185
eng
Journal of Applied Geodesy 7 (2013), Nr. 2
1862-9024
1862-9016
http://dx.doi.org/10.1515/jag-2013-0044
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/2082022-12-13T15:12:26Zcom_123456789_1col_123456789_3ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-02-02T12:03:11Z
urn:hdl:123456789/208
Uncertainty modeling of random and systematic errors by means of Monte Carlo and fuzzy techniques
Alkhatib, Hamza
Neumann, Ingo
Kutterer, Hansjörg
GUM
Monte Carlo methods
fuzzy methods
The standard reference in uncertainty modeling is the “Guide to the Expression of Uncertainty in Measurement (GUM)”. GUM groups the occurring uncertain quantities into “Type A” and “Type B”. Uncertainties of “Type A” are determined with the classical statistical methods, while “Type B” is subject to other uncertainties which are obtained by experience and knowledge about an instrument or a measurement process. Both types of uncertainty can have random and systematic error components. Our study focuses on a detailed comparison of probability and fuzzy-random approaches for handling and propagating the different uncertainties, especially those of “Type B”. Whereas a probabilistic approach treats all uncertainties as having a random nature, the fuzzy technique distinguishes between random and deterministic errors. In the fuzzy-random approach the random components are modeled in a stochastic framework, and the deterministic uncertainties are treated by means of a range-of-values search problem. The applied procedure is outlined showing both the theory and a numerical example for the evaluation of uncertainties in an application for terrestrial laserscanning (TLS).
2016-02-02T12:03:11Z
2016-02-02T12:03:11Z
2009-06-15
Article
Text
Alkhatib, Hamza; Neumann, Ingo; Kutterer, Hansjörg: Uncertainty modeling of random and systematic errors by means of Monte Carlo and fuzzy techniques. In: Journal of Applied Geodesy 3 (2009), Nr. 2, S: 67-79. DOI: http://dx.doi.org/10.1515/JAG.2009.008
http://www.repo.uni-hannover.de/handle/123456789/208
http://dx.doi.org/10.15488/186
eng
Journal of Applied Geodesy 3 (2009), Nr. 2
1862-9024
1862-9016
http://dx.doi.org/10.1515/JAG.2009.008
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/2252022-12-13T15:12:26Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-02-11T09:04:21Z
urn:hdl:123456789/225
Well-posedness, blow-up phenomena, and global solutions for the b-equation
Escher, Joachim
Yin, Zhaoyang
degasperis-procesi equation
shallow-water equation
camassa-holm equation
korteweg-de-vries
integrable equation
peakon solutions
weak solutions
cauchy-problem
wave solutions
shock-waves
In the paper we first establish the local well-posedness for a family of nonlinear dispersive equations, the so called b-equation. Then we describe the precise blow-up scenario. Moreover, we prove that for the b-equation we do have the coexistence of global in time solutions and blow-up phenomena: Depending on the initial data solutions may exist for ever, while other data force the solution to produce a singularity in finite time. Finally, we prove the uniqueness and existence of global weak solution to the equation provided the initial data satisfy certain sign conditions.
2016-02-11T09:04:21Z
2016-02-11T09:04:21Z
2008-10-29
Article
Text
Escher, Joachim; Yin, Zhaoyang: Well-posedness, blow-up phenomena, and global solutions for the b-equation. In: Journal für die reine und angewandte Mathematik 2008 (2008), Nr. 624, S. 51-80. DOI: http://dx.doi.org/10.1515/CRELLE.2008.080
http://www.repo.uni-hannover.de/handle/123456789/225
http://dx.doi.org/10.15488/203
eng
Journal für die reine und angewandte Mathematik 2008 (2008), Nr. 624
1435-5345
0075-4102
http://dx.doi.org/10.1515/CRELLE.2008.080
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/2262022-12-13T15:12:26Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-02-11T09:04:22Z
urn:hdl:123456789/226
A K-theoretic proof of Boutet de Monvel's index theorem for boundary value problems
Melo, Severino T.
Schick, Thomas
Schrohe, Elmar
algebra
operators
calculus
We study the C*-closure U of the algebra of all operators of order and class zero in Boutet de Monvel's calculus on a compact connected manifold X with boundary partial derivative X not equal phi. We find short exact sequences in K-theory 0 -> K-i (C(X)) -> K-i(U/R) ->(P) K1-i(C-0(T*X degrees)) -> 0, i = 0,1, which split, so that K-i(U/R) congruent to K-i(C(X)) circle plus K1-i(Co(T*X degrees)). Using only simple K-theoretic arguments and the Atiyah-Singer index theorem, we show that the Fredhohn index of an elliptic element in A is given by ind A = ind(t)(p[A])), where [A] is the class of A in K-1(U/R) and ind(t) is the topological index, a relation first established by Boutet de Monvel by different methods.
2016-02-11T09:04:22Z
2016-02-11T09:04:22Z
2006-12-07
Article
Text
Melo, Severino T.; Schick, Thomas; Schrohe, Elmar: A K-theoretic proof of Boutet de Monvel's index theorem for boundary value problems. In: Journal für die reine und angewandte Mathematik 2006 (2006), Nr. 599, S. 217-233. DOI: http://dx.doi.org/10.1515/CRELLE.2006.083
http://www.repo.uni-hannover.de/handle/123456789/226
http://dx.doi.org/10.15488/204
eng
Journal für die reine und angewandte Mathematik 2006 (2006), Nr. 599
1435-5345
0075-4102
http://dx.doi.org/10.1515/CRELLE.2006.083
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/2282022-12-13T15:12:26Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-02-11T09:04:22Z
urn:hdl:123456789/228
Analytic solutions for a Stefan problem with Gibbs-Thomson correction
Escher, Joachim
Pruss, Jan
Simonett, Gieri
phase-transition problems
free-boundary
parabolic equations
classical-solutions
space variables
weak solutions
continuity
regularity
temperature
operators
We provide existence of a unique smooth solution for a class of one- and two-phase Stefan problems with Gibbs-Thomson correction in arbitrary space dimensions. In addition, it is shown that the moving interface depends analytically on the temporal and spatial variables. Of crucial importance for the analysis is the property of maximal L-p-regularity for the linearized problem, which is fully developed in this paper as well.
2016-02-11T09:04:22Z
2016-02-11T09:04:22Z
2003
Article
Text
Escher, Joachim; Pruss, Jan; Simonett, Gieri: Analytic solutions for a Stefan problem with Gibbs-Thomson correction. In: Journal für die reine und angewandte Mathematik 2003 (2003), Nr. 563, S. 1-52. Doi: http://dx.doi.org/10.1515/crll.2003.082
http://www.repo.uni-hannover.de/handle/123456789/228
https://doi.org/10.15488/206
eng
Journal für die reine und angewandte Mathematik 2003 (2003), Nr. 563
1435-5345
0075-4102
http://dx.doi.org/10.1515/crll.2003.082
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/2302022-12-13T15:12:26Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-02-11T09:04:22Z
urn:hdl:123456789/230
Degenerations of Prym varieties
Alexeev, V.
Birkenhake, C.
Hulek, Klaus
Prym variety
algebra
applied mathematics
Let (C, l) be a stable curve with an involution. Following a classical construction one can define its Prym variety P, which in this case turns out to be a semiabelian group variety and usually not complete. In this paper we study the question whether there are "good" compactifications of P in analogy to compactified Jacobians. The answer to this question depends on whether we consider degenerations of principally polarized Prym varieties or degenerations with the induced (non-principal) polarization. We describe degeneration data of such degenerations. The main application of our theory lies in the case of degenerations of principally polarized Prym varieties where we ask whether such a degeneration depends on a given one-parameter family containing (C, l) or not. This allows us to determine the indeterminacy locus of the Prym map.
2016-02-11T09:04:22Z
2016-02-11T09:04:22Z
2002
Article
Text
Alexeev, V.; Birkenhake, C.; Hulek, Klaus: Degenerations of Prym varieties. In: Journal für die reine und angewandte Mathematik 2002 (2002), Nr. 553, S. 73-116. DOI: http://dx.doi.org/10.1515/crll.2002.103
http://www.repo.uni-hannover.de/handle/123456789/230
http://dx.doi.org/10.15488/208
eng
Journal für die reine und angewandte Mathematik 2002 (2002), Nr. 553
1435-5345
0075-4102
http://dx.doi.org/10.1515/crll.2002.103
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/2382022-12-13T15:12:26Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-02-16T08:10:45Z
urn:hdl:123456789/238
The modularity of the Barth-Nieto quintic and its relatives
Hulek, Klaus
Spandaw, J.
van Geemen, B.
van Straten, D.
Calabi-Yau
algebra
applied mathematis
The moduli space of (1, 3)-polarized abelian surfaces with full level-2 structure is birational to a double cover of the Barth Nieto quintic. Barth and Nieto have shown that these varieties have Calabi-Yau models Z and Y, respectively. In this paper we apply the Weil conjectures to show that Y and Z are rigid and we prove that the L-function of their common third e A tale cohomology group is modular, as predicted by a conjecture of Fontaine and Mazur. The corresponding modular form is the unique normalized cusp form of weight 4 for the group Gamma(1)(6). By Tate's conjecture, this should imply that Y, the fibred square of the universal elliptic curve S-1(6), and Verrill's rigid Calabi-Yau ZA(3), which all have the same L-function, are in correspondence over Q. We show that this is indeed the case by giving explicit maps.
2016-02-16T08:10:45Z
2016-02-16T08:10:45Z
2001-08
Article
Text
Hulek, Klaus; Spandaw, J.; van Geemen, B.; van Straten, D.: The modularity of the Barth-Nieto quintic and its relatives. In: Advances in Geometry 1 (2001), Nr. 3, S. 263-289. DOI: http://dx.doi.org/10.1515/advg.2001.017
http://www.repo.uni-hannover.de/handle/123456789/238
http://dx.doi.org/10.15488/216
eng
Advances in Geometry 1 (2001), Nr. 3
1615-7168
1615-715X
http://dx.doi.org/10.1515/advg.2001.017
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/2572022-12-13T15:12:26Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-03-04T11:42:36Z
urn:hdl:123456789/257
On positive solutions of some system of reaction-diffusion equations with nonlocal initial conditions
Walker, Christoph
lotka competition model
differential-equations
population-dynamics
steady-states
predator-prey
bifurcation
pairs
The paper focuses on positive solutions to a coupled system of parabolic equations with nonlocal initial conditions. Such equations arise as steady-state equations in an age-structured predator-prey model with diffusion. By using global bifurcation techniques, we describe the structure of the set of positive solutions with respect to two parameters measuring the intensities of the fertility of the species. In particular, we establish co-existence steady-states, i.e. solutions which are nonnegative and nontrivial in both components.
2016-03-04T11:42:36Z
2016-03-04T11:42:36Z
2011-11
Article
Text
Walker, Christoph: On positive solutions of some system of reaction-diffusion equations with nonlocal initial conditions. In: Journal für die reine und angewandte Mathematik 2011 (2011), Nr. 660, S. 149-179. DOI: http://dx.doi.org/10.1515/CRELLE.2011.074
http://www.repo.uni-hannover.de/handle/123456789/257
http://dx.doi.org/10.15488/235
eng
Journal für die reine und angewandte Mathematik 2011 (2011), Nr. 660
1435-5345
0075-4102
http://dx.doi.org/10.1515/CRELLE.2011.074
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/2582022-12-13T15:12:26Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-03-04T11:42:37Z
urn:hdl:123456789/258
Seminormal forms and Gram determinants for cellular algebras
Mathas, Andrew
Soriano, Marcos
algebra
Cayley-Hamilton theorem
This paper develops an abstract framework for constructing ‘‘seminormal forms’’ for cellular algebras. That is, given a cellular R-algebra A which is equipped with a family of JM-elements we give a general technique for constructing orthogonal bases for A, and for all of its irreducible representations, when the JM-elements separate A. The seminormal forms for A are defined over the field of fractions of R. Significantly, we show that the Gram determinant of each irreducible A-module is equal to a product of certain structure constants coming from the seminormal basis of A. In the non-separated case we use our seminormal forms to give an explicit basis for a block decomposition of A.
2016-03-04T11:42:37Z
2016-03-04T11:42:37Z
2008-06
Article
Text
Mathas, Andrew; Soriano, Marcos: Seminormal forms and Gram determinants for cellular algebras. In: Journal für die reine und angewandte Mathematik 2008 (2008), Nr. 619, S. 141-173. DOI: http://dx.doi.org/10.1515/CRELLE.2008.042
http://www.repo.uni-hannover.de/handle/123456789/258
http://dx.doi.org/10.15488/236
eng
Journal für die reine und angewandte Mathematik 2008 (2008), Nr. 619
1435-5345
0075-4102
http://dx.doi.org/10.1515/CRELLE.2008.042
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/3142022-12-02T15:17:13Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:610ddc:510ddc:570
2016-06-13T15:13:59Z
urn:hdl:123456789/314
Scanning Laser Optical Tomography Resolves Structural Plasticity during Regeneration in an Insect Brain
Eickhoff, Rene
Lorbeer, Raoul-Amadeus
Scheiblich, Hannah
Heisterkamp, Alexander
Meyer, Heiko
Stern, Michael
Bicker, Gerd
projection tomography
schistocerca-gregaria
gene-expression
mushroom bodies
axonal regeneration
locusta-migratoria
tympanal nerve
desert locust
antennal lobe
microscopy
Background: Optical Projection Tomography (OPT) is a microscopic technique that generates three dimensional images from whole mount samples the size of which exceeds the maximum focal depth of confocal laser scanning microscopes. As an advancement of conventional emission-OPT, Scanning Laser Optical Tomography (SLOTy) allows simultaneous detection of fluorescence and absorbance with high sensitivity. In the present study, we employ SLOTy in a paradigm of brain plasticity in an insect model system. Methodology: We visualize and quantify volumetric changes in sensory information procession centers in the adult locust, Locusta migratoria. Olfactory receptor neurons, which project from the antenna into the brain, are axotomized by crushing the antennal nerve or ablating the entire antenna. We follow the resulting degeneration and regeneration in the olfactory centers (antennal lobes and mushroom bodies) by measuring their size in reconstructed SLOTy images with respect to the untreated control side. Within three weeks post treatment antennal lobes with ablated antennae lose as much as 60% of their initial volume. In contrast, antennal lobes with crushed antennal nerves initially shrink as well, but regain size back to normal within three weeks. The combined application of transmission-and fluorescence projections of Neurobiotin labeled axotomized fibers confirms that recovery of normal size is restored by regenerated afferents. Remarkably, SLOTy images reveal that degeneration of olfactory receptor axons has a trans-synaptic effect on second order brain centers and leads to size reduction of the mushroom body calyx. Conclusions: This study demonstrates that SLOTy is a suitable method for rapid screening of volumetric plasticity in insect brains and suggests its application also to vertebrate preparations.
2016-06-13T15:13:59Z
2016-06-13T15:13:59Z
2012-07-19
Article
Text
Eickhoff, Rene; Lorbeer, Raoul-Amadeus; Scheiblich, Hannah; Heisterkamp, Alexander; Meyer, Heiko et al.: Scanning Laser Optical Tomography Resolves Structural Plasticity during Regeneration in an Insect Brain. In: PloS ONE 7 (2012), Nr. 7, e41236. DOI: http://dx.doi.org/10.1371/journal.pone.0041236
http://www.repo.uni-hannover.de/handle/123456789/314
http://dx.doi.org/10.15488/292
eng
PLoS ONE 7 (2012), Nr. 7
1932-6203
http://dx.doi.org/10.1371/journal.pone.0041236
http://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
San Francisco : Public Library Science
oai:www.repo.uni-hannover.de:123456789/6282022-12-02T15:03:41Zcom_123456789_1col_123456789_4doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:600
2016-10-31T13:38:59Z
urn:hdl:123456789/628
Implementing second-order decision analysis: Concepts, algorithms, and tool
Larsson, Aron
Kuznetsova, Alina
Caster, Ola
Ekenberg, Love
systems sciences
communications system
WINPRE
PRIME method
We present implemented concepts and algorithms for a simulation approach to decision evaluation with second-order belief distributions in a common framework for interval decision analysis. The rationale behind this work is that decision analysis with interval-valued probabilities and utilities may lead to overlapping expected utility intervals yielding difficulties in discriminating between alternatives. By allowing for second-order belief distributions over interval-valued utility and probability statements these difficulties may not only be remedied but will also allow for decision evaluation concepts and techniques providing additional insight into a decision problem. The approach is based upon sets of linear constraints together with generation of random probability distributions and utility values from implicitly stated uniform second-order belief distributions over the polytopes given from the constraints. The result is an interactive method for decision evaluation with second-order belief distributions, complementing earlier methods for decision evaluation with interval-valued probabilities and utilities. The method has been implemented for trial use in a user oriented decision analysis software.
2016-10-31T13:38:59Z
2016-10-31T13:38:59Z
2014
Article
Text
Larsson, A.; Kuznetsova, Alina; Caster, O.; Ekenberg, L.: Implementing second-order decision analysis: Concepts, algorithms, and tool. In: Advances in Decision Sciences 2014 (2014), 519512. DOI: http://dx.doi.org/10.1155/2014/519512
http://www.repo.uni-hannover.de/handle/123456789/628
http://dx.doi.org/10.15488/604
eng
Advances in Decision Sciences 2014 (2014)
2090-3359
http://dx.doi.org/10.1155/2014/519512
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
New York, NY : Hindawi Publishing Corporation
oai:www.repo.uni-hannover.de:123456789/8442022-12-02T15:04:50Zcom_123456789_1col_123456789_6doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T07:23:06Z
urn:hdl:123456789/844
FEA-based optimisation of a clinching process with an open multiple-part die aimed at damage minimisation in CR240BH-AlSi10MnMg joints
Behrens, Bernd-Arno
Bouguecha, Anas
Vucetic, Milan
Hübner, Sven
Yilkiran, Deniz
Jin, Yilin
Peshekhodov, Ilya
Alloy steel
Cracks
Dies
Geometry
Bake hardening steels
Clinching process
Minimisation
Multiple parts
Optimisations
Tool designs
Aluminum alloys
The paper presents results of a FEA-based tool design optimisation for a clinching process with an open multiple-part die. The studied materials are the bake-hardening steel CR240BH (1.5 mm) on the punch side and the die-cast aluminium alloy AlSi10MnMg (2.95 mm) on the die side. The objective of the optimisation was to minimise probability of cracks that appear at the outer circumference of the bottom of the clinch joint in AlSi10MnMg. In the framework of the optimisation, it was possible to minimise crack probability by varying geometrical parameters of the tools though at the cost of slightly worse but still tolerable geometrical parameters of the clinch joint.
2016-12-16T07:23:06Z
2016-12-16T07:23:06Z
2015
Article
Text
Behrens, B.-A.; Bouguecha, A.; Vucetic, M.; Hubner, S.; Yilkiran, D. et al.: FEA-based optimisation of a clinching process with an open multiple-part die aimed at damage minimisation in CR240BH-AlSi10MnMg joints. In: MATEC Web of Conferences 21 (2015), 04009. DOI: https://doi.org/10.1051/matecconf/20152104009
http://www.repo.uni-hannover.de/handle/123456789/844
http://dx.doi.org/10.15488/820
eng
MATEC Web of Conferences 21 (2015)
2261236X
https://doi.org/10.1051/matecconf/20152104009
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Les Ulis : EDP Sciences
oai:www.repo.uni-hannover.de:123456789/8452022-12-02T15:04:50Zcom_123456789_1col_123456789_6doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T07:23:11Z
urn:hdl:123456789/845
Implementation of the Bai and Wierzbicki fracture criterion in QForm and its application for cold metal forming and deep drawing technology
Gladkov, Yury
Peshekhodov, Ilya
Vucetic, Milan
Bouguecha, Anas
Behrens, Bernd-Arno
Algorithms
Computer software
Deep drawing
Fracture
Metal drawing
Metal forming
Deep-drawing process
Fracture criteria
Fracture prediction
ITS applications
Metal-forming process
Drawing (forming)
The paper presents implementation of fracture prediction algorithm for a cold metal forming process simulation in the software QForm. Authors programmed the function for calculation of the criterion proposed by Bai and Wierzbicki. Obtained results of the simulation in QForm for a deep drawing process are compared with results of experiments. A good agreement between the simulation and experiment was achieved.
2016-12-16T07:23:11Z
2016-12-16T07:23:11Z
2015
Article
Text
Gladkov, Y.; Peshekhodov, I.; Vucetic, M.; Bouguecha, A.; Behrens, B.-A.: Implementation of the Bai and Wierzbicki fracture criterion in QForm and its application for cold metal forming and deep drawing technology. In: MATEC Web of Conferences 21 (2015), 12009. DOI: https://doi.org/10.1051/matecconf/20152112009
http://www.repo.uni-hannover.de/handle/123456789/845
http://dx.doi.org/10.15488/821
eng
MATEC Web of Conferences 21 (2015)
2261236X
https://doi.org/10.1051/matecconf/20152112009
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Les Ulis : EDP Sciences
oai:www.repo.uni-hannover.de:123456789/8592022-12-02T15:06:07Zcom_123456789_1col_123456789_6doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T07:50:13Z
urn:hdl:123456789/859
Inverse determination of constitutive equations and cutting force modelling for complex tools using oxley's predictive machining theory
Denkena, Berend
Grove, Thilo
Dittrich, Marc-André
Niederwestberg, D.
Lahres, M.
Force
Material
Simulation
Carbon
Carbon steel
Computation theory
Constitutive equations
Constitutive models
Cutting
Cutting tools
Inverse problems
Machining centers
Materials
Particle swarm optimization (PSO)
Complex tool geometry
Constitutive parameters
Material removal model
Simulation
Temperature calculation
Ultrahigh carbon steel
Undeformed chip thickness
Finite element method
In analysis of machining processes, finite element analysis is widely used to predict forces, stress distributions, temperatures and chip formation. However, constitutive models are not always available and simulation of cutting processes with complex tool geometries can lead to extensive computation time. This article presents an approach to determine constitutive parameters of the Johnson-Cook's flow stress model by inverse modelling as well as a methodology to predict process forces and temperatures for complex three-dimensional tools using Oxley's machining theory. In the first part of this study, an analytically based computer code combined with a particle swarm optimization (PSO) algorithm is used to identify constitutive models for 70MnVS4 and an aluminium-alloyed ultra-high-carbon steel (UHC-steel) from orthogonal milling experiments. In the second part, Oxley's predictive machining theory is coupled with a multi-dexel based material removal model. Contact zone information (width of cut, undeformed chip thickness, rake angle and cutting speed) are calculated for incremental segments on the cutting edge and used as input parameters for force and temperature calculations. Subsequently, process forces are predicted for machining using the inverse determined constitutive models and compared to actual force measurements. The suggested methodology has advantages regarding the computation time compared to finite element analyses.
2016-12-16T07:50:13Z
2016-12-16T07:50:13Z
2015
Article
Text
Denkena, B.; Grove, T.; Dittrich, M.A.; Niederwestberg, D.; Lahres, M.: Inverse determination of constitutive equations and cutting force modelling for complex tools using oxley's predictive machining theory. In: Procedia CIRP 31 (2015), S. 405-410. DOI: https://doi.org/10.1016/j.procir.2015.03.012
http://www.repo.uni-hannover.de/handle/123456789/859
http://dx.doi.org/10.15488/835
eng
Procedia CIRP 31 (2015)
22128271
https://doi.org/10.1016/j.procir.2015.03.012
https://creativecommons.org/licenses/by-nc-nd/4.0/
CC BY-NC-ND 4.0 Unported
Amsterdam : Elsevier
oai:www.repo.uni-hannover.de:123456789/8702023-04-17T15:25:14Zcom_123456789_1col_123456789_3doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T09:16:36Z
urn:hdl:123456789/870
DEM generation with short base length pleiades triplet
Jacobsen, Karsten
Topan, H.
Heipke, C.
Stilla, U.
Accuracy
Adjustment
DEM/DTM
Georeferencing
Performance
Radiometric
Space
Geometry
Image matching
Instrument scales
Rock mechanics
Systematic errors
Stereo image processing
An image triplet of Pleiades images covering the area of Zonguldak, Turkey has been investigated. The height to base relation of the first to the last image is just 1:4.5 and for the first and the second image 1:9. This is quite below the usual height to base relation of 1:1.6 for a typical stereo pair of space images. The corresponding small angle of convergence influences the possible vertical accuracy, but images with such a small angle of convergence are more similar to each other as images with larger convergence angles. This enables a better image matching, improving the vertical accuracy and compensating partially the influence of poor intersection geometry. Even over forest areas no matching gaps occurred. Height models are generated with different base configurations and compared with a reference height model. Pleiades images are distributed with 50cm ground sampling distance instead of the physical size of 70cm, the image quality justifies this zooming and also the geometric results are in the range of other space images with originally 50cm GSD. The image orientation by bias corrected Rational Polynomial Coefficients (RPC) is leading with more as 160 ground control points (GCP) to root mean square (RMS) differences slightly below 1.0 GSD of the distributed images (0.5m GSD). Only negligible systematic errors have been identified. With the combination of the first and last image a standard deviation of the generated height model of 1.6m, respectively for flat terrain close to 1.0m has been reached in relation to a reference height model. The small angle of convergence is not as much influencing the height accuracy as according to simple geometric relation.
2016-12-16T09:16:36Z
2016-12-16T09:16:36Z
2015
Article
Text
Jacobsen, K.; Topan, H.: DEM generation with short base length pleiades triplet. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2015), Nr. 3W2, S. 81-86. DOI: https://doi.org/10.5194/isprsarchives-XL-3-W2-81-2015
http://www.repo.uni-hannover.de/handle/123456789/870
http://dx.doi.org/10.15488/846
eng
PIA15+HRIGI15 – Joint ISPRS conference
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-3/W2
2194-9034
1682-1750
https://doi.org/10.5194/isprsarchives-XL-3-W2-81-2015
https://doi.org/10.5194/isprsarchives-xl-3-w2-81-2015
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/8712023-04-17T15:25:14Zcom_123456789_1col_123456789_3doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T09:16:38Z
urn:hdl:123456789/871
A graph based model for the detection of tidal channels using marked point processes
Schmidt, Alena
Rottensteiner, Franz
Sörgel, Uwe
Heipke, Christian
Paparoditis, N.
Raimond, A.-M.
Sithole, G.
Rabatel, G.
Çöltekin, A.
Rottensteiner, F.
Briottet, X.
Christophe, S.
Dowman, I.
Elberink, S.O.
Patanè, G.
Mallet, C.
Coast
Digital terrain models
Graph model
Marked point processes
RJMCMC
In this paper we propose a new method for the automatic extraction of tidal channels in digital terrain models (DTM) using a sampling approach based on marked point processes. In our model, the tidal channel system is represented by an undirected, acyclic graph. The graph is iteratively generated and fitted to the data using stochastic optimization based on a Reversible Jump Markov Chain Monte Carlo (RJMCMC) sampler and simulated annealing. The nodes of the graph represent junction points of the channel system and the edges straight line segments with a certain width in between. In each sampling step, the current configuration of nodes and edges is modified. The changes are accepted or rejected depending on the probability density function for the configuration which evaluates the conformity of the current status with a pre-defined model for tidal channels. In this model we favour high DTM gradient magnitudes at the edge borders and penalize a graph configuration consisting of non-connected components, overlapping segments and edges with atypical intersection angles. We present the method of our graph based model and show results for lidar data, which serve of a proof of concept of our approach.
2016-12-16T09:16:38Z
2016-12-16T09:16:38Z
2015
Article
Text
Schmidt, A.; Rottensteiner, F.; Soergel, U.; Heipke, C.: A graph based model for the detection of tidal channels using marked point processes. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2015), Nr. 3W3, S. 115-121. DOI: https://doi.org/10.5194/isprsarchives-XL-3-W3-115-2015
http://www.repo.uni-hannover.de/handle/123456789/871
http://dx.doi.org/10.15488/847
eng
ISPRS Geospatial Week 2015
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-3/W3
2194-9034
1682-1750
https://doi.org/10.5194/isprsarchives-XL-3-W3-115-2015
https://doi.org/10.5194/isprsarchives-xl-3-w3-115-2015
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/8722022-12-02T16:17:36Zcom_123456789_1col_123456789_3doc-type:BookPartdoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T09:16:38Z
urn:hdl:123456789/872
A stereo line matching technique for aerial images based on a pair-wise relation approach
Ok, A.O.
Wegner, Jan Dirk
Heipke, Christian
Rottensteiner, Franz
Sörgel, Uwe
Toprak, V.
Pair-wise line matching
Post-processing
Stereo aerial images
Image matching
Information science
Iterative methods
Urban growth
Aerial images
Dense urban areas
Line extraction
Line-matching
Post processing
Postprocessing algorithms
Relation-based
Voting schemes
Stereo image processing
In this study, we developed a new pair-wise relation based approach for the matching of line features from stereo aerial images. To solve the final matching inconsistencies, we propose an iterative pair based post-processing algorithm in which the matching inconsistencies are eliminated using three novel measures and a final similarity voting scheme. The approach is tested over four urban test sites with various built-up characteristics, and for all test sites, we achieved a stereo line matching performance of 98%. The overall results indicate that the proposed approach is highly robust for the line features extracted in (very) dense urban areas.
2016-12-16T09:16:38Z
2016-12-16T09:16:38Z
2010
BookPart
Text
Ok, A.O.; Wegner, J.D.; Heipke, C.; Rottensteiner, F.; Soergel, U. et al.: A stereo line matching technique for aerial images based on a pair-wise relation approach. In: Modeling of optical airborne and space borne sensors. Hannover : International Society for Photogrammetry and Remote Sensing, 2010 (The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; 38-1/W17), 7 S. https://www.isprs.org/proceedings/XXXVIII/1-W17/3_Ok.pdf
http://www.repo.uni-hannover.de/handle/123456789/872
http://dx.doi.org/10.15488/848
eng
Modeling of optical airborne and space borne sensors
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; 38-1/W17
2194-9034
1682-1750
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Hannover : International Society for Photogrammetry and Remote Sensing
oai:www.repo.uni-hannover.de:123456789/8732023-04-17T15:25:14Zcom_123456789_1col_123456789_3doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T09:16:38Z
urn:hdl:123456789/873
Contextual classification of point clouds using a two-stage CRF
Niemeyer, Joachim
Rottensteiner, Franz
Sörgel, Uwe
Heipke, Christian
Heipke, C.
Stilla, U.
Classification
Conditional Random Fields
Contextual
LiDAR
Point cloud
Clustering algorithms
Image segmentation
Optical radar
Random processes
Statistical tests
Classification features
Conditional random field
Contextual classification
Long range interactions
Point cloud
Urban
Urban classification
In this investigation, we address the task of airborne LiDAR point cloud labelling for urban areas by presenting a contextual classification methodology based on a Conditional Random Field (CRF). A two-stage CRF is set up: in a first step, a point-based CRF is applied. The resulting labellings are then used to generate a segmentation of the classified points using a Conditional Euclidean Clustering algorithm. This algorithm combines neighbouring points with the same object label into one segment. The second step comprises the classification of these segments, again with a CRF. As the number of the segments is much smaller than the number of points, it is computationally feasible to integrate long range interactions into this framework. Additionally, two different types of interactions are introduced: one for the local neighbourhood and another one operating on a coarser scale. This paper presents the entire processing chain. We show preliminary results achieved using the Vaihingen LiDAR dataset from the ISPRS Benchmark on Urban Classification and 3D Reconstruction, which consists of three test areas characterised by different and challenging conditions. The utilised classification features are described, and the advantages and remaining problems of our approach are discussed. We also compare our results to those generated by a point-based classification and show that a slight improvement is obtained with this first implementation.
2016-12-16T09:16:38Z
2016-12-16T09:16:38Z
2015
Article
Text
Niemeyer, J.; Rottensteiner, F.; Soergel, U.; Heipke, C.: Contextual classification of point clouds using a two-stage CRF. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2015), Nr. 3W2, S. 141-148. DOI: https://doi.org/10.5194/isprsarchives-XL-3-W2-141-2015
http://www.repo.uni-hannover.de/handle/123456789/873
http://dx.doi.org/10.15488/849
eng
PIA15+HRIGI15 – Joint ISPRS conference
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-3/W2
2194-9034
1682-1750
https://doi.org/10.5194/isprsarchives-XL-3-W2-141-2015
https://doi.org/10.5194/isprsarchives-xl-3-w2-141-2015
http://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/8772022-12-02T15:02:17Zcom_123456789_1col_123456789_3doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T09:39:04Z
urn:hdl:123456789/877
GPS-aided video tracking
Feuerhake, Udo
Brenner, Claus
Sester, Monika
Algorithm
Object tracking
Trajectory analysis, sensor and data fusion
Tracking moving objects is both challenging and important for a large variety of applications. Different technologies based on the global positioning system (GPS) and video or radio data are used to obtain the trajectories of the observed objects. However, in some use cases, they fail to provide sufficiently accurate, complete and correct data at the same time. In this work we present an approach for fusing GPS-and video-based tracking in order to exploit their individual advantages. In this way we aim to combine the reliability of GPS tracking with the high geometric accuracy of camera detection. For the fusion of the movement data provided by the different devices we use a hidden Markov model (HMM) formulation and the Viterbi algorithm to extract the most probable trajectories. In three experiments, we show that our approach is able to deal with challenging situations like occlusions or objects which are temporarily outside the monitored area. The results show the desired increase in terms of accuracy, completeness and correctness.
2016-12-16T09:39:04Z
2016-12-16T09:39:04Z
2015
Article
Text
Feuerhake, U., Brenner, C., Sester, M.: GPS-aided video tracking. In: ISPRS International Journal of Geo-Information 4 (2015), Nr. 3, S. 1317-1335. DOI: https://doi.org/10.3390/ijgi4031317
http://www.repo.uni-hannover.de/handle/123456789/877
https://doi.org/10.15488/853
eng
ISPRS International Journal of Geo-Information 4 (2015), Nr. 3
22209964
https://doi.org/10.3390/ijgi4031317
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Basel : MDPI AG
oai:www.repo.uni-hannover.de:123456789/8812022-12-02T15:04:49Zcom_123456789_1col_123456789_4doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-16T09:39:05Z
urn:hdl:123456789/881
A van Benthem theorem for modal team semantics
Kontinen, Juha
Müller, Julian-Steffen
Schnoor, Henning
Vollmer, Heribert
Bisimulation
Expressivity
Generalized dependence atom
Inclusion
Team semantics
Formal logic
Inclusions
Linearization
Reconfigurable hardware
Semantics
Dependence logic
Independence
Modal logic
Computer circuits
The famous van Benthem theorem states that modal logic corresponds exactly to the fragment of first-order logic that is invariant under bisimulation. In this article we prove an exact analogue of this theorem in the framework of modal dependence logic MDL and team semantics. We show that modal team logic MTL, extending MDL by classical negation, captures exactly the FO-definable bisimulation invariant properties of Kripke structures and teams. We also compare the expressive power of MTL to most of the variants and extensions of MDL recently studied in the area.
2016-12-16T09:39:05Z
2016-12-16T09:39:05Z
2015
Article
Text
Kontinen, J.; Müller, J.-S.; Schnoor, H.; Vollmer, H.: A van Benthem theorem for modal team semantics. In: Leibniz International Proceedings in Informatics, LIPIcs 41 (2015), S. 277-291. DOI: https://doi.org/10.4230/LIPIcs.CSL.2015.277
http://www.repo.uni-hannover.de/handle/123456789/881
http://dx.doi.org/10.15488/857
eng
Leibniz International Proceedings in Informatics, LIPIcs 41 (2015)
18688969
https://doi.org/10.4230/LIPIcs.CSL.2015.277
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Wadern : Schloss Dagstuhl- Leibniz-Zentrum für Informatik GmbH
oai:www.repo.uni-hannover.de:123456789/9052023-04-17T15:25:14Zcom_123456789_1col_123456789_3ddc:000doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-12-21T10:56:35Z
urn:hdl:123456789/905
Learning image descriptors for matching based on Haar features
Chen, Lin
Rottensteiner, Franz
Heipke, Christian
Paparoditis, N.
Schindler, K.
AdaBoost
Descriptor learning
Haar features
Image descriptors
Image matching
Pooling configuration
Adaptive boosting
Cascaded classifiers
Corresponding weights
Descriptors
Response functions
Training algorithms
This paper presents a new and fast binary descriptor for image matching learned from Haar features. The training uses AdaBoost; the weak learner is built on response function for Haar features, instead of histogram-type features. The weak classifier is selected from a large weak feature pool. The selected features have different feature type, scale and position within the patch, having correspond threshold value for weak classifiers. Besides, to cope with the fact in real matching that dissimilar matches are encountered much more often than similar matches, cascaded classifiers are trained to motivate training algorithms see a large number of dissimilar patch pairs. The final trained output are binary value vectors, namely descriptors, with corresponding weight and perceptron threshold for a strong classifier in every stage. We present preliminary results which serve as a proof-of-concept of the work.
2016-12-21T10:56:35Z
2016-12-21T10:56:35Z
2014
Article
Text
Chen, L.; Rottensteiner, F.; Heipke, C.: Learning image descriptors for matching based on Haar features. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2014), Nr. 3, S. 61-66. DOI: https://doi.org/10.5194/isprsarchives-XL-3-61-2014
http://www.repo.uni-hannover.de/handle/123456789/905
http://dx.doi.org/10.15488/881
eng
ISPRS Technical Commission III Symposium : 5 – 7 September 2014, Zurich, Switzerland
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-3
2194-9034
1682-1750
https://doi.org/10.5194/isprsarchives-XL-3-61-2014
https://doi.org/10.5194/isprsarchives-xl-3-61-2014
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/9092023-04-17T15:25:14Zcom_123456789_1col_123456789_3ddc:000ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-12-21T10:56:39Z
urn:hdl:123456789/909
Radiometric and geometric characteristics of pleiades images
Jacobsen, Karsten
Topan, H.
Cam, A.
Özendi, M.
Oruç, M.
Toth, C.
Jutzi, B.
Holm, T.
Adjustment
Georeferencing
Radiometric
Restitution
Space
Geometry
Image analysis
Image reconstruction
Image resolution
Optical transfer function
Pixels
Radiometry
Restoration
Stereo image processing
Image sampling
Pleiades images are distributed with 50cm ground sampling distance (GSD) even if the physical resolution for nadir images is just 70cm. By theory this should influence the effective GSD determined by means of point spread function at image edges. Nevertheless by edge enhancement the effective GSD can be improved, but this should cause enlarged image noise. Again image noise can be reduced by image restoration. Finally even optimized image restoration cannot improve the image information from 70cm to 50cm without loss of details, requiring a comparison of Pleiades image details with other very high resolution space images. The image noise has been determined by analysis of the whole images for any sub-area with 5 pixels times 5 pixels. Based on the standard deviation of grey values in the small sub-areas the image noise has been determined by frequency analysis. This leads to realistic results, checked by test targets. On the other hand the visual determination of image noise based on apparently homogenous sub-areas results in too high values because the human eye is not able to identify small grey value differences - it is limited to just approximately 40 grey value steps over the available gray value range, so small difference in grey values cannot be seen, enlarging results of a manual noise determination. A tri-stereo combination of Pleiades 1A in a mountainous, but partially urban, area has been analyzed and compared with images of the same area from WorldView-1, QuickBird and IKONOS. The image restoration of the Pleiades images is very good, so the effective image resolution resulted in a factor 1.0, meaning that the effective resolution corresponds to the nominal resolution of 50cm. This does not correspond to the physical resolution of 70cm, but by edge enhancement the steepness of the grey value profile across the edge can be enlarged, reducing the width of the point spread function. Without additional filtering edge enhancement enlarges the image noise, but the average image noise of approximately 1.0 grey values related to 8bit images is very small, not indicating the edge enhancement and the down sampling of the GSD from 70cm to 50cm. So the direct comparison with the other images has to give the answer if the image quality of Pleiades images is on similar level as corresponding to the nominal resolution. As expected with the image geometry there is no problem. This is the case for all used space images in the test area, where the point identification limits the accuracy of the scene orientation.
2016-12-21T10:56:39Z
2016-12-21T10:56:39Z
2014
Article
Text
Jacobsen, K.; Topan, H.; Cam, A.; Özendi, M.; Oruc, M.: Radiometric and geometric characteristics of pleiades images. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2014), Nr. 1, S. 173-177. DOI: https://doi.org/10.5194/isprsarchives-XL-1-173-2014
http://www.repo.uni-hannover.de/handle/123456789/909
http://dx.doi.org/10.15488/885
eng
ISPRS Technical Commission I Symposium, 17–20 November 2014, Denver, Colorado, USA
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-1
2194-9034
1682-1750
https://doi.org/10.5194/isprsarchives-XL-1-173-2014
https://doi.org/10.5194/isprsarchives-xl-1-173-2014
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/9102023-04-17T15:25:14Zcom_123456789_1col_123456789_3doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-12-21T10:56:39Z
urn:hdl:123456789/910
A dynamic Bayes Network for visual pedestrian tracking
Klinger, Tobias
Rottensteiner, Franz
Heipke, Christian
Paparoditis, N.
Schindler, K.
Classification
On-line
Reasoning
Tracking
Bayesian networks
Decision trees
Surface discharges
Adaptive classifiers
Generated trajectories
Pedestrian tracking
Probabilistic framework
Recursive estimation
Video
Classification (of information)
Many tracking systems rely on independent single frame detections that are handled as observations in a recursive estimation framework. If these observations are imprecise the generated trajectory is prone to be updated towards a wrong position. In contrary to existing methods our novel approach suggests a Dynamic Bayes Network in which the state vector of a recursive Bayes filter, as well as the location of the tracked object in the image are modelled as unknowns. These unknowns are estimated in a probabilistic framework taking into account a dynamic model, prior scene information, and a state-of-the-art pedestrian detector and classifier. The classifier is based on the Random Forests-algorithm and is capable of being trained incrementally so that new training samples can be incorporated at runtime. This allows the classifier to adapt to the changing appearance of a target and to unlearn outdated features. The approach is evaluated on a publicly available dataset captured in a challenging outdoor scenario. Using the adaptive classifier, our system is able to keep track of pedestrians over long distances while at the same time supporting the localisation of the people. The results show that the derived trajectories achieve a geometric accuracy superior to the one achieved by modelling the image positions as observations.
2016-12-21T10:56:39Z
2016-12-21T10:56:39Z
2014
Article
Text
Klinger, T.; Rottensteiner, F.; Heipke, C.: A dynamic Bayes Network for visual pedestrian tracking. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2014), Nr. 3, S. 145-150. DOI: https://doi.org/10.5194/isprsarchives-XL-3-145-2014
http://www.repo.uni-hannover.de/handle/123456789/910
http://dx.doi.org/10.15488/886
eng
ISPRS Technical Commission III Symposium : 5 – 7 September 2014, Zurich, Switzerland
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-3
2194-9034
1682-1750
https://doi.org/10.5194/isprsarchives-XL-3-145-2014
https://doi.org/10.5194/isprsarchives-xl-3-145-2014
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/9122023-04-17T15:25:14Zcom_123456789_1col_123456789_3ddc:000ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-12-21T10:56:39Z
urn:hdl:123456789/912
A global approach for image orientation using Lie algebraic rotation averaging and convex L∞ minimisation
Reich, Martin
Heipke, Christian
Paparoditis, N.
Schindler, K.
Bundle adjustment
Rotation averaging
Algebra
Convex optimization
Global optimization
Group theory
Parameter estimation
Rotation
Statistics
Bundle adjustments
Convex optimisation
Image orientation
Relative orientation
Riemannian manifold
Robust least squares
Special orthogonal group
Translation parameters
Lie groups
In this paper we present a new global image orientation approach for a set of multiple overlapping images with given homologous point tuples which is based on a two-step procedure. The approach is independent on initial values, robust with respect to outliers and yields the global minimum solution under relatively mild constraints. The first step of the approach consists of the estimation of global rotation parameters by averaging relative rotation estimates for image pairs (these are determined from the homologous points via the essential matrix in a pre-processing step). For the averaging we make use of algebraic group theory in which rotations, as part of the special orthogonal group SO(3), form a Lie group with a Riemannian manifold structure. This allows for a mapping to the local Euclidean tangent space of SO(3), the Lie algebra. In this space the redundancy of relative orientations is used to compute an average of the absolute rotation for each image and furthermore to detect and eliminate outliers. In the second step translation parameters and the object coordinates of the homologous points are estimated within a convex L∞ optimisation, in which the rotation parameters are kept fixed. As an optional third step the results can be used as initial values for a final bundle adjustment that does not suffer from bad initialisation and quickly converges to a globally optimal solution. We investigate our approach for global image orientation based on synthetic data. The results are compared to a robust least squares bundle adjustment. In this way we show that our approach is independent of initial values and more robust against outliers than a conventional bundle adjustment.
2016-12-21T10:56:39Z
2016-12-21T10:56:39Z
2014
Article
Text
Reich, M.; Heipke, C.: A global approach for image orientation using Lie algebraic rotation averaging and convex L∞ minimisation. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2014), Nr. 3, S. 265-272. DOI: https://doi.org/10.5194/isprsarchives-XL-3-265-2014
http://www.repo.uni-hannover.de/handle/123456789/912
http://dx.doi.org/10.15488/888
eng
ISPRS Technical Commission III Symposium : 5 – 7 September 2014, Zurich, Switzerland
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-3
2194-9034
1682-1750
https://doi.org/10.5194/isprsarchives-XL-3-265-2014
https://doi.org/10.5194/isprsarchives-xl-3-265-2014
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/9142023-04-17T15:25:14Zcom_123456789_1col_123456789_3ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-12-21T10:56:41Z
urn:hdl:123456789/914
Extraction of fluvial networks in lidar data using marked point processes
Schmidt, Alena
Rottensteiner, Franz
Sörgel, Uwe
Heipke, Christian
Paparoditis, N.
Schindler, K.
Coast
Lidar
Marked point processes
Networks
Coastal zones
Extraction
Geometry
Markov processes
Networks (circuits)
Optimization
Simulated annealing
Automatic extraction
Marked point process
Non-overlapping areas
Reversible jump Markov chain Monte Carlo
RJMCMC
Stochastic optimizations
Straight-line segments
Tidal channel networks
Optical radar
We propose a method for the automatic extraction of fluvial networks in lidar data with the aim to obtain a connected network represented by the fluvial channels' skeleton. For that purpose we develop a two-step approach. First, we fit rectangles to the data using a stochastic optimization based on a Reversible Jump Markov Chain Monte Carlo (RJMCMC) sampler and simulated annealing. High gradients on the rectangles' border and non-overlapping areas of the objects are introduced as model in the optimization process. In a second step, we determine the principal axes of the rectangles and their intersection points. Based on this a network graph is constructed in which nodes represent junction points or end points, respectively, and edges in-between straight line segments. We evaluate our method on lidar data with a tidal channel network and show some preliminary results.
2016-12-21T10:56:41Z
2016-12-21T10:56:41Z
2014
Article
Text
Schmidt, A.; Rottensteiner, F.; Soergel, U.; Heipke, C.: Extraction of fluvial networks in lidar data using marked point processes. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2014), Nr. 3, S. 297-304. DOI: https://doi.org/10.5194/isprsarchives-XL-3-297-2014
http://www.repo.uni-hannover.de/handle/123456789/914
http://dx.doi.org/10.15488/890
eng
ISPRS Technical Commission III Symposium : 5 – 7 September 2014, Zurich, Switzerland
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-3
2194-9034
1682-1750
https://doi.org/10.5194/isprsarchives-XL-3-297-2014
https://doi.org/10.5194/isprsarchives-xl-3-297-2014
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/9172022-12-02T15:03:40Zcom_123456789_1col_123456789_3ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-21T12:08:59Z
urn:hdl:123456789/917
Focused wave generation in laboratory flumes over uneven bottom
Fernández, Hernan
Venkatachalam, Sriram
Schimmels, Stefan
Budzik, Mariusz
Oumeraci, Hocine
Extreme waves
Nonlinear waves
Numerical wave tank
Self correcting method
Tsunami generation
Wave focusing
Coastal engineering
Control nonlinearities
Focusing
Tanks (containers)
Numerical wave tanks
Numerical methods
A proper design of offshore and coastal structures requires further knowledge about extreme wave events. Such waves are highly nonlinear and may occur unexpectedly due to diverse reasons. One of these reasons is wave-wave interaction and the wave focusing technique represents one option to generate extreme wave events in the laboratory. The underlying mechanism is the superimposition and phasing of wave components at a predefined location. To date, most of the existing methods to propagate target wave profile backwards to the position of the wave generator apply linear wave theory. The problem is that the generated waves with different frequencies generate new components which do not satisfy the linear dispersion relation. As a result, small changes in the wave board control signal generally induce large and random shifts in the resulting focused wave. This means that iterations are necessary to get the required wave profile at the correct position in the flume. In this study, a Self Correcting Method (SCM) is applied to optimize the control signal of the wave maker in a Numerical Wave Tank (NWT). The nonlinearities are included in the control signal and accurate wave focusing is obtained irrespective of the prevailing seabed topography (horizontal or sloping) and type of structure (reflective or absorbing). The performance of the proposed SCM is numerically investigated for a wide variety of scenarios and validated by scale model tests in the Large Wave Flume (Großer Wellen Kanal, GWK), Hannover, Germany. The strengths and limitations of the proposed SCM are discussed, including the potential for further developments.
2016-12-21T12:08:59Z
2016-12-21T12:08:59Z
2014
Article
Text
Fernández, H.; Venkatachalam, S.; Schimmels, S.; Budzik, M.; Oumeraci, H.: Focused wave generation in laboratory flumes over uneven bottom. In: Proceedings of the Coastal Engineering Conference 2014-January (2014), waves.32
http://www.repo.uni-hannover.de/handle/123456789/917
http://dx.doi.org/10.15488/893
eng
Proceedings of the Coastal Engineering Conference (2014)
01613782
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Reston : American Society of Civil Engineers (ASCE)
oai:www.repo.uni-hannover.de:123456789/9182022-12-02T15:02:17Zcom_123456789_1col_123456789_3ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-21T12:08:59Z
urn:hdl:123456789/918
Non-stationary flow around buildings during run-up of tsunami waves on a plain beach
Goseberg, Nils
Schlurmann, Torsten
Long wave
Obstacle
Tsunami
Wake angle
Wave run-up
Wave-structure interaction
Beaches
Coastal engineering
Wakes
Experimental investigations
Long waves
Non-stationary flows
Obstacle
Side-by-side arrangements
Spatiotemporal evolution
Wave-structure interaction
This paper presents an experimental investigation that focuses on some predominant flow features that arise around surface mounted vertical obstacles which are exposed to a transient flow. The flow under investigation is caused by a tsunami-like long wave that climbs up a 1:40 sloping plain beach. In this study the wave height in offshore waters is varied. A single obstacle of 10 cm width as well as side-by-side arrangement of two identical square obstacles with different spacing are considered at an approximate length scale of 1 in 100. The analysis reveals important flow features around the various obstacle configurations. Particular emphasize is laid on the spatiotemporal evolution of the wake angle that linearly increases over time irrespective of the obstacle spacing. The growth rate of the wake angle reciprocally depends on the gap ratio over the investigated range of g† = 0.0 to g† = 3.0.
2016-12-21T12:08:59Z
2016-12-21T12:08:59Z
2014
Article
Text
Goseberg, N.; Schlurmann, T.: Non-stationary flow around buildings during run-up of tsunami waves on a plain beach. In: Coastal Engineering Proceedings : Proceedings of the International Conference on Coastal Engineering 34 (2014), currents.21. DOI: https://doi.org/10.9753/icce.v34.currents.21
http://www.repo.uni-hannover.de/handle/123456789/918
http://dx.doi.org/10.15488/894
eng
Proceedings of the Coastal Engineering Conference (2014)
2156-1028
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Reston : American Society of Civil Engineers (ASCE)
oai:www.repo.uni-hannover.de:123456789/9202022-12-02T15:02:17Zcom_123456789_1col_123456789_3ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-21T12:08:59Z
urn:hdl:123456789/920
Long wave propagation, shoaling and run-up in nearshore areas
Sriram, V.
Didenkulova, I.
Schimmels, Stefan
Sergeeva, A.
Goseberg, Nils
Elongated solitons
Large-scale experimental facility
Long wave dynamics
Numerical simulation
Propagation
Run-up
Coastal engineering
Computer simulation
Nonlinear equations
Numerical models
Wave propagation
Experimental facilities
Fully nonlinear potential flow
KdV equations
Large wave flumes
Long waves
Nearshores
Nonlinear shallow water
Run-up
Solitons
This paper discusses the possibility to study propagation, shoaling and run-up of these waves over a slope in a 300-meter long large wave flume (GWK), Hannover. For this purpose long bell-shaped solitary waves (elongated solitons) of different amplitude and the same period of 30 s are generated. Experimental data of long wave propagation in the flume are compared with numerical simulations performed within the fully nonlinear potential flow theory and KdV equations. Shoaling and run-up of waves on different mild slopes is studied hypothetically using nonlinear shallow water theory. Conclusions about the feasibility of using large scale experimental facility (GWK) to study tsunami wave propagation and run-up are made.
2016-12-21T12:08:59Z
2016-12-21T12:08:59Z
2014
Article
Text
Sriram, V.; Didenkulova, I.; Schimmels, S.; Sergeeva, A.; Goseberg, N.: Long wave propagation, shoaling and run-up in nearshore areas. In: Proceedings of the Coastal Engineering Conference 2014-January (2014), currents.20
http://www.repo.uni-hannover.de/handle/123456789/920
http://dx.doi.org/10.15488/896
eng
Proceedings of the Coastal Engineering Conference (2014)
01613782
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Reston : American Society of Civil Engineers (ASCE)
oai:www.repo.uni-hannover.de:123456789/9212022-12-02T15:02:17Zcom_123456789_1col_123456789_3ddc:550doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510ddc:500
2016-12-21T12:09:00Z
urn:hdl:123456789/921
Influence of retention areas on the propagation of storm surges in the Weser estuary
Zorndt, Anna C.
Goseberg, Nils
Schlurmann, Torsten
Design water levels
Retention areas
Storm surges
Weser estuary
Catchments
Climate change
Coastal engineering
Floods
Fluid dynamics
Geometry
Hydraulic structures
Hydrodynamics
Levees
Shore protection
Storms
Water levels
Anthropogenic climate changes
Coastal protection
Design water level
High-resolution models
Low safety levels
Small-scale features
Storm surges
Estuaries
The hydrodynamics of estuaries are forced by the tides from the open sea and the river runoff from the catchment area. The hinterland is often low-lying and densely populated and must therefore be protected by dikes. Anthropogenic climate change poses new challenges to the coastal protection. However, changes in the geometry of the estuaries can have equally severe impacts on the deformation of a storm surge wave form when it propagates through the estuary. This affects the peak water levels and hence the design water levels. This contribution focuses on the influence of retention areas or forelands seaside of the main dike lines, which are protected by summer dikes against the less severe but more frequently occurring storm surges. This is shown at the example of a retention area in the Weser estuary, which has historically been the cite of a soccer stadium and thus hosts high values which stand in sharp contrast against the low safety level against flooding. The investigation is conducted with a 3D hydrodynamic numerical model which has previously been validated for the simulation of storm surges. The results show that even very small changes in the geometry of the estuary can have effects on design levels. This is even the case when they only regard the summer dike crests heights around retention areas and not their volume. Another important finding is that the geometry changes may have their maximum impacts quite far away from the specific river reach in which they are carried out. The results underline that for designing safe and reliable storm surge infrastructure, storm events should be studied in high resolution models which are able to resolve even small scale features such as summer dike lines.
2016-12-21T12:09:00Z
2016-12-21T12:09:00Z
2014
Article
Text
Zorndt, A.C.; Goseberg, N.; Schlurmann, T.: Influence of retention areas on the propagation of storm surges in the Weser estuary. In: Coastal Engineering Proceedings : Proceedings of the International Conference on Coastal Engineering 34 (2014), management.51. DOI: https://doi.org/10.9753/icce.v34.management.51
http://www.repo.uni-hannover.de/handle/123456789/921
http://dx.doi.org/10.15488/897
eng
Proceedings of the Coastal Engineering Conference (2014)
2156-1028
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Reston : American Society of Civil Engineers (ASCE)
oai:www.repo.uni-hannover.de:123456789/9232022-12-02T15:03:41Zcom_123456789_1col_123456789_3doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:510
2016-12-21T12:09:01Z
urn:hdl:123456789/923
The benefit of 3D laser scanning technology in the generation and calibration of FEM models for health assessment of concrete structures
Yang, Hao
Xu, Xiangyang
Neumann, Ingo
Calibration
Concrete
Fem
Point cloud
Surface based
Tls
Computer simulation
Concrete buildings
Concrete construction
Concretes
Laser applications
Scanning
Seebeck effect
Surface analysis
Surveying instruments
3D-laserscanning technology
Finite element method model (FEM)
Finite element simulations
Surface-based
Terrestrial laser scanning
Three-dimensional information
Tls
Finite element method
Terrestrial laser scanning technology (TLS) is a new technique for quickly getting three-dimensional information. In this paper we research the health assessment of concrete structures with a Finite Element Method (FEM) model based on TLS. The goal focuses on the benefits of 3D TLS in the generation and calibration of FEM models, in order to build a convenient, efficient and intelligent model which can be widely used for the detection and assessment of bridges, buildings, subways and other objects. After comparing the finite element simulation with surface-based measurement data from TLS, the FEM model is determined to be acceptable with an error of less than 5%. The benefit of TLS lies mainly in the possibility of a surface-based validation of results predicted by the FEM model.
2016-12-21T12:09:01Z
2016-12-21T12:09:01Z
2014
Article
Text
Yang, H.; Xu, X.; Neumann, I.: The benefit of 3D laser scanning technology in the generation and calibration of FEM models for health assessment of concrete structures. In: Sensors (Switzerland) 14 (2014), Nr. 11, S. 21889-21904. DOI: https://doi.org/10.3390/s141121889
http://www.repo.uni-hannover.de/handle/123456789/923
http://dx.doi.org/10.15488/899
eng
Sensors 14 (2014)
14248220
https://doi.org/10.3390/s141121889
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Basel : MDPI AG
oai:www.repo.uni-hannover.de:123456789/9372022-12-02T15:06:07Zcom_123456789_1col_123456789_6doc-type:Articledoc-type:Textopen_accessddc:330status-type:publishedVersionddc:620ddc:510
2016-12-21T13:00:34Z
urn:hdl:123456789/937
Reliable capacity planning despite uncertain disassembly, regeneration and reassembly workloads by using statistical and mathematical approaches - Validation in subsidiaries of a global MRO company with operations in Asia, Europe and North America
Eickemeyer, Steffen C.
Steinkamp, Simon
Schuster, Bernhardt
Bodenhage, Frank
Nyhuis, Peter
Bayesian networks
Capacity planning
Complex capital goods
Damage library
Data mining
Disassembly
Forecast
Maintenance
Mixed-integer linear programming
MRO
Complex networks
Data mining
Forecasting
Integer programming
Maintenance
Capital goods
Disassembly
Mixed integer linear programming
MRO
Reassembly
Regeneration
Bayesian networks
The MRO industry faces substantial challenges with regard to the capacity planning of disassembly and reassembly work. This is due to the unknown workloads when regenerating complex investment goods and is caused, in particular, by the uncertain degree of disassembly and the complex challenges of reassembly. Forecasting techniques based on Bayesian networks are developed along with mathematical models which optimize capacity utilization, job order and the resulting costs. The approaches are tested and validated in conjunction with an MRO company with global operations. The results show possibilities for enhancing the planning processes and are found to be transferable on an international scale regardless of sociocultural and process differences.
2016-12-21T13:00:34Z
2016-12-21T13:00:34Z
2014
Article
Text
Eickemeyer, S.C.; Steinkamp, S.; Schuster, B.; Bodenhage, F.; Nyhuis, P.: Reliable capacity planning despite uncertain disassembly, regeneration and reassembly workloads by using statistical and mathematical approaches - Validation in subsidiaries of a global MRO company with operations in Asia, Europe and North America. In: Procedia CIRP 23 (2014), Nr. C, S. 252-257. DOI: https://doi.org/10.1016/j.procir.2014.10.097
http://www.repo.uni-hannover.de/handle/123456789/937
http://dx.doi.org/10.15488/913
eng
Procedia CIRP 23 (2014)
22128271
https://doi.org/10.1016/j.procir.2014.10.097
https://creativecommons.org/licenses/by-nc-nd/3.0/
CC BY-NC-ND 3.0 Unported
Amsterdam : Elsevier
oai:www.repo.uni-hannover.de:123456789/9542022-12-02T15:15:01Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2016-12-21T14:07:24Z
urn:hdl:123456789/954
Invariant manifolds with boundary for jump-diffusions
Filipovic, Damir
Tappe, Stefan
Teichmann, Josef
Jump-diffusion
Stochastic invariance
Stochastic partial differential equation
Submanifold with boundary
We provide necessary and sufficient conditions for stochastic invariance of finite dimensional submanifolds with boundary in Hilbert spaces for stochastic partial differential equations driven by Wiener processes and Poisson random measures.
2016-12-21T14:07:24Z
2016-12-21T14:07:24Z
2014
Article
Text
Filipovic, D.; Tappe, S.; Teichmann, J.: Invariant manifolds with boundary for jump-diffusions. In: Electronic Journal of Probability 19 (2014), 51. DOI: https://doi.org/10.1214/EJP.v19-2882
http://www.repo.uni-hannover.de/handle/123456789/954
http://dx.doi.org/10.15488/930
eng
Electronic Journal of Probability 19 (2014)
10836489
https://doi.org/10.1214/EJP.v19-2882
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Washington : University of Washington
oai:www.repo.uni-hannover.de:123456789/9632022-12-02T15:12:31Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:510
2016-12-22T07:22:08Z
urn:hdl:123456789/963
Generalised geometry for string corrections
Coimbra, André
Minasian, Ruben
Triendl, Hagen
Waldram, Daniel
Differential and Algebraic Geometry
Flux compactifications
Supergravity Models
Superstrings and Heterotic Strings
We present a general formalism for incorporating the string corrections in generalised geometry, which necessitates the extension of the generalised tangent bundle. Not only are such extensions obstructed, string symmetries and the existence of a welldefined effective action require a precise choice of the (generalised) connection. The action takes a universal form given by a generalised Lichnerowitz-Bismut theorem. As examples of this construction we discuss the corrections linear in α′ in heterotic strings and the absence of such corrections for type II theories.
2016-12-22T07:22:08Z
2016-12-22T07:22:08Z
2014
Article
Text
Coimbra, A.; Minasian, R.; Triendl, H.; Waldram, D.: Generalised geometry for string corrections. In: Journal of High Energy Physics 2014 (2014), Nr. 11, 160. DOI: https://doi.org/10.1007/JHEP11(2014)160
http://www.repo.uni-hannover.de/handle/123456789/963
http://dx.doi.org/10.15488/939
eng
Journal of High Energy Physics 2014 (2014)
11266708
https://doi.org/10.1007/JHEP11(2014)160
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Berlin : Springer Verlag
oai:www.repo.uni-hannover.de:123456789/9702022-12-02T15:17:14Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:510
2016-12-22T07:22:14Z
urn:hdl:123456789/970
Superlattice structures in twisted bilayers of folded graphene
Schmidt, Hennrik
Rode, Johannes C.
Smirnov, Dmitri
Haug, Rolf J.
graphene
atomic force microscopy
carbon
crystal structure
geometry
numerical model
Article
atomic force microscopy
bilayer membrane
geometry
magnetic field
measurement
scanning probe microscopy
The electronic properties of bilayer graphene strongly depend on relative orientation of the two atomic lattices. Whereas Bernal-stacked graphene is most commonly studied, a rotational mismatch between layers opens up a whole new field of rich physics, especially at small interlayer twist. Here we report on magnetotransport measurements on twisted graphene bilayers, prepared by folding of single layers. These reveal a strong dependence on the twist angle, which can be estimated by means of sample geometry. At small rotation, superlattices with a wavelength in the order of 10 nm arise and are observed by friction atomic force microscopy. Magnetotransport measurements in this small-angle regime show the formation of satellite Landau fans. These are attributed to additional Dirac singularities in the band structure and discussed with respect to the wide range of interlayer coupling models.
2016-12-22T07:22:14Z
2016-12-22T07:22:14Z
2014
Article
Text
Schmidt, H.; Rode, J.C.; Smirnov, D.; Haug, R.J.: Superlattice structures in twisted bilayers of folded graphene. In: Nature Communications 5 (2014), 5742. DOI: https://doi.org/10.1038/ncomms6742
http://www.repo.uni-hannover.de/handle/123456789/970
http://dx.doi.org/10.15488/946
eng
Nature Communications 5 (2014)
20411723
https://doi.org/10.1038/ncomms6742
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
London : Nature Publishing Group
oai:www.repo.uni-hannover.de:123456789/9772022-12-02T15:15:02Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:510
2016-12-22T07:48:52Z
urn:hdl:123456789/977
Hyperkähler manifolds of curves in twistor spaces?
Bielawski, Roger
Hypercomplex structures
Hyperkähler metrics
Projective curves
Twistor methods
We discuss hypercomplex and hyperkähler structures obtained from higher degree curves in complex spaces fibring over P1.
2016-12-22T07:48:52Z
2016-12-22T07:48:52Z
2014
Article
Text
Bielawski, R.: Hyperkähler manifolds of curves in twistor spaces? In: Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 10 (2014), 33. DOI: https://doi.org/10.3842/SIGMA.2014.033
http://www.repo.uni-hannover.de/handle/123456789/977
http://dx.doi.org/10.15488/953
eng
Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 10 (2014)
18150659
https://doi.org/10.3842/SIGMA.2014.033
https://creativecommons.org/licenses/by-sa/4.0/
CC BY-SA 4.0 Unported
Kiev : NAS Institute of Mathematics
oai:www.repo.uni-hannover.de:123456789/9972023-04-17T15:25:14Zcom_123456789_1col_123456789_3doc-type:Articledoc-type:Textopen_accessddc:530status-type:publishedVersionddc:510
2016-12-22T10:06:44Z
urn:hdl:123456789/997
A procedure for semi-automatic orthophoto generation from high resolution satellite imagery
Alrajhi, M.N.
Jacobsen, Karsten
Heipke, Christian
Sunar, F.
Altan, O.
Schindler, K.
Jiang, J.
Li, S.
Automated image matching
HRSI
Orthophotos
Satellite imagery
Aerial photography
Affine transforms
Automation
Image matching
Image processing
Rock mechanics
Satellites
Surveying
Surveys
Affine coordinate transformation
Ground control points
Ground sampling distances
High resolution satellite imagery
Kingdom of Saudi Arabia
Speeded up robust features
Satellite imagery
The General Directorate of Surveying and Mapping (GDSM), under the Ministry of Municipal and Rural Affairs (MOMRA) is responsible for the production and dissemination of accurate geospatial data for all the metropolitan cities, towns and rural settlements in the Kingdom of Saudi Arabia. GDSM maintains digital geospatial databases that support the production of conventional line and orthophoto maps at scales ranging from 1:1,000 to 1:20,000. The current procedures for the acquisition of new aerial imagery cover a long time cycle of three or more years. Consequently, the availability of recently acquired High Resolution Satellite Imagery (HRSI) presents an attractive alternative image data source for rapid response to updated geospatial data needs. The direct sensor orientation of HRSI is not accurate enough requiring ground control points (GCP). A field survey of GCP is time consuming and costly. Seeking an alternative approach, a research study has recently been completed to use existing image and data base information instead of traditional ground control for the orthoprojection of HRSI in order to automate and speed up as much as possible the whole process. Based on a series of practical experiments, the ability for automated matching of aerial and satellite images by using the Speeded-Up Robust Features (SURF) algorithm is demonstrated to be useful for this task. Practical results from matching with SURF validate the ability for multi-scale, multi-sensor and multi-season matching of aerial and satellite images. The matched tie points are then used to transform the satellite orthophoto to the aerial orthophoto through a 2D affine coordinate transformation. GeoEye-1 and IKONOS imagery, when geo-referenced through SURF-based matching and transformed meet the MOMRA Map Accuracy Standards for 1:10,000 and 1:20,000 scale. However, a similarly processed SPOT-5 image does not meet these standards. This research has led to the development of a simple and efficient tool for the geo-referencing of HRSI of 0,5m to 1m ground sampling distance (GSD) that can be used for updating map information. The process completely eliminates the need for any ground control as well as image measurements by human operators.
2016-12-22T10:06:44Z
2016-12-22T10:06:44Z
2013
Article
Text
Alrajhi, M.N.; Jacobsen, K.; Heipke, C.: A procedure for semi-automatic orthophoto generation from high resolution satellite imagery. In: International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives 40 (2013), Nr. 7W2, S. 7-11. DOI: https://doi.org/10.5194/isprsarchives-XL-7-W2-7-2013
http://www.repo.uni-hannover.de/handle/123456789/997
http://dx.doi.org/10.15488/973
eng
ISPRS Conference Serving Society with Geoinformatics (ISPRS2013-SSG) : Antalya, Turkey, 11-17 November 2013
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ; XL-7/W2
2194-9034
978-1-62993-429-7
1682-1750
https://doi.org/10.5194/isprsarchives-XL-7-W2-7-2013
https://doi.org/10.5194/isprsarchives-xl-7-w2-7-2013
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Göttingen : Copernicus GmbH
oai:www.repo.uni-hannover.de:123456789/10322022-12-02T15:09:34Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:620ddc:510
2016-12-22T11:58:58Z
urn:hdl:123456789/1032
First measurement of the Non-instantaneous response Time of a χ(3) nonlinear optical effect
Das, S.K.
Bock, M.
Grunwald, R.
Borchers, B.
Hyyti, J.
Steinmeyer, Günter
Ristau, Detlev
Harth, A.
Vockerodt, T.
Nagy, T.
Morgner, Uwe
The third harmonic of a few-cycle pulse, generated at different dielectric surfaces, is investigated using interferometric frequency-resolved optical gating. We present direct experimental evidence for a non-instantaneous nonlinear response in a TiO2 thin film whereas surface third-harmonic generation in a SiO2 sample does not show any indication for non-instanteneity. To the best of our knowledge, this constitutes the first report of a non-instantaneous nonlinear optical response of a dielectric optical material.
2016-12-22T11:58:58Z
2016-12-22T11:58:58Z
2013
Article
Text
Das, S.K.; Bock, M.; Grunwald, R.; Borchers, B.; Hyyti, J. et al.: First measurement of the Non-instantaneous response Time of a χ(3) nonlinear optical effect. In: EPJ Web of Conferences 41 (2013), 12005. DOI: https://doi.org/10.1051/epjconf/20134112005
http://www.repo.uni-hannover.de/handle/123456789/1032
http://dx.doi.org/10.15488/1008
eng
EPJ Web of Conferences 41 (2013)
21016275
https://doi.org/10.1051/epjconf/20134112005
https://creativecommons.org/licenses/by/2.0/
CC BY 2.0 Unported
Les Ulis : EDP Sciences
oai:www.repo.uni-hannover.de:123456789/10562022-12-02T16:17:36Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessddc:330status-type:publishedVersionddc:510
2017-01-12T08:35:30Z
urn:hdl:123456789/1056
Computational optimization of gas compressor stations: MINLP models versus continuous reformulations
Rose, Daniel
Schmidt, Martin
Steinbach, Marc C.
Willert, Bernhard M.
Continuous reformulations
Discrete-continuous nonlinear optimization
Gas compressor stations
Gas networks
Mixed-integer optimization
Compressibility of gases
Compressors
Integer programming
Nonlinear programming
Optimization
Compressor stations
Continuous reformulations
Gas networks
Mixed integer optimization
Non-linear optimization
Gas compressors
When considering cost-optimal operation of gas transport networks, compressor stations play the most important role. Proper modeling of these stations leads to nonconvex mixed-integer nonlinear optimization problems. In this article, we give an isothermal and stationary description of compressor stations, state MINLP and GDP models for operating a single station, and discuss several continuous reformulations of the problem. The applicability and relevance of different model formulations, especially of those without discrete variables, is demonstrated by a computational study on both academic examples and real-world instances. In addition, we provide preliminary computational results for an entire network.
2017-01-12T08:35:30Z
2017-01-12T08:35:30Z
2016
Article
Text
Rose, D.; Schmidt, M.; Steinbach, M.C.; Willert, B.M.: Computational optimization of gas compressor stations: MINLP models versus continuous reformulations. In: Mathematical Methods of Operations Research 83 (2016), Nr. 3, S. 409-444. DOI: http://dx.doi.org/10.1007/s00186-016-0533-5
http://www.repo.uni-hannover.de/handle/123456789/1056
http://dx.doi.org/10.15488/1032
eng
Mathematical Methods of Operations Research 83 (2016), Nr. 3
1432-5217
1432-2994
https://doi.org/10.1007/s00186-016-0533-5
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Heidelberg : Springer Verlag
oai:www.repo.uni-hannover.de:123456789/10722022-12-02T16:17:36Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-01-12T09:06:29Z
urn:hdl:123456789/1072
CPT symmetry and its violation
Lehnert, Ralf
CPT theorem
CPT-symmetry violation
Implications of CPT symmetry
One of the most fundamental symmetries in physics is CPT invariance. This article reviews the conditions under which CPT symmetry holds by recalling two proofs of the CPT theorem: The original Lagrangian-based analysis and the more rigorous one in the context of axiomatic quantum field theory. The presentation of the proofs is followed by a discussion of the major physical implications that arise from CPT symmetry. Motivated by recent theoretical and experimental interest in CPT tests, various approaches to the violation of CPT symmetry are mentioned, and it is briefly discussed how they evade the CPT theorem. An attempt has been made to keep this work self-contained and at a level suitable for a wider readership by excising as many technical aspects as possible. © 2016 by the author.
2017-01-12T09:06:29Z
2017-01-12T09:06:29Z
2016
Article
Text
Lehnert, R.: CPT symmetry and its violation. In: Symmetry 8 (2016), Nr. 11, 114. DOI: http://dx.doi.org/10.3390/sym8110114
http://www.repo.uni-hannover.de/handle/123456789/1072
http://dx.doi.org/10.15488/1048
eng
Symmetry 8 (2016), Nr. 11
2073-8994
https://doi.org/10.3390/sym8110114
https://creativecommons.org/licenses/by-nc-sa/4.0/
CC BY-NC-SA 4.0 Unported
Basel : MDPI AG
oai:www.repo.uni-hannover.de:123456789/10772022-12-02T15:17:15Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-01-27T07:49:19Z
urn:hdl:123456789/1077
The Yamada-Watanabe theorem for mild solutions to stochastic partial differential equations
Tappe, Stefan
Martingale solution
Mild solution
Pathwise uniqueness
Stochastic partial differential equation
We prove the Yamada-Watanabe Theorem for semilinear stochastic partial differential equations with path-dependent coefficients. The so-called 'method of the moving frame' allows us to reduce the proof to the Yamada-Watanabe Theorem for stochastic differential equations in infinite dimensions.
2017-01-27T07:49:19Z
2017-01-27T07:49:19Z
2013
Article
Text
Tappe, Stefan: The Yamada-Watanabe theorem for mild solutions to stochastic partial differential equations. In: Electronic Communications in Probability 18 (2013), 24. DOI: https://doi.org/10.1214/ECP.v18-2392
http://www.repo.uni-hannover.de/handle/123456789/1077
http://dx.doi.org/10.15488/1053
eng
Electronic Communications in Probability 18 (2013)
1083-589X
https://doi.org/10.1214/ECP.v18-2392
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Beachwood, OH : Institute of Mathematical Statistics
oai:www.repo.uni-hannover.de:123456789/10812022-12-02T15:15:01Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-01-27T07:49:21Z
urn:hdl:123456789/1081
Foundations of the theory of semilinear stochastic partial differential equations
Tappe, Stefan
Semilinear stochastic partial differential equations (SPDEs)
Hilbert Spaces
stochastic analysis
The goal of this review article is to provide a survey about the foundations of semilinear stochastic partial differential equations. In particular, we provide a detailed study of the concepts of strong, weak, and mild solutions, establish their connections, and review a standard existence and uniqueness result. The proof of the existence result is based on a slightly extended version of the Banach fixed point theorem.
2017-01-27T07:49:21Z
2017-01-27T07:49:21Z
2013
Article
Text
Tappe, Stefan: Foundations of the theory of semilinear stochastic partial differential equations. In: International Journal of Stochastic Analysis 2013 (2013), 798549. DOI: https://doi.org/10.1155/2013/798549
http://www.repo.uni-hannover.de/handle/123456789/1081
http://dx.doi.org/10.15488/1057
eng
International Journal of Stochastic Analysis 2013 (2013)
2090-3332
https://doi.org/10.1155/2013/798549
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
New York, NY : Hindawi Publishing Corporation
oai:www.repo.uni-hannover.de:123456789/10822022-12-02T15:17:15Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-01-27T07:49:21Z
urn:hdl:123456789/1082
The Itô integral with respect to an infinite dimensional Lévy process: A series approach
Tappe, Stefan
Itô Integral
Lévy Process
Hilbert Spaces
We present an alternative construction of the infinite dimensional Itô integral with respect to a Hilbert space valued Lévy process. This approach is based on the well-known theory of real-valued stochastic integration, and the respective Itô integral is given by a series of Itô integrals with respect to standard Lévy processes. We also prove that this stochastic integral coincides with the Itô integral that has been developed in the literature. © 2013 Stefan Tappe.
2017-01-27T07:49:21Z
2017-01-27T07:49:21Z
2013
Article
Text
Tappe, Stefan: The Itô integral with respect to an infinite dimensional Lévy process: A series approach. In: International Journal of Stochastic Analysis 2013 (2013), 703769. DOI: https://doi.org/10.1155/2013/703769
http://www.repo.uni-hannover.de/handle/123456789/1082
http://dx.doi.org/10.15488/1058
eng
International Journal of Stochastic Analysis 2013 (2013)
2090-3332
https://doi.org/10.1155/2013/703769
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
New York, NY : Hindawi Publishing Corporation
oai:www.repo.uni-hannover.de:123456789/12362022-12-02T16:17:36Zcom_123456789_1col_123456789_2status-type:acceptedVersiondoc-type:Articledoc-type:Textopen_accessddc:510
2017-03-20T13:19:20Z
urn:hdl:123456789/1236
Parametrised complexity of satisfiability in temporal logic
Lück, Martin
Meier, Arne
Schindler, Irena
Computation tree logic
Linear temporal logic
Parametrised complexity
Pathwidth
Post's lattice
Temporal depth
Temporal logic
Treewidth
Boolean functions
Formal logic
Temporal logic
Computation tree logic
Linear temporal logic
Parametrised complexity
Pathwidth
Post's lattice
Temporal depth
Tree-width
Computer circuits
We apply the concept of formula treewidth and pathwidth to computation tree logic, linear temporal logic, and the full branching time logic. Several representations of formulas as graphlike structures are discussed, and corresponding notions of treewidth and pathwidth are introduced. As an application for such structures, we present a classification in terms of parametrised complexity of the satisfiability problem, where we make use of Courcelle's famous theorem for recognition of certain classes of structures. Our classification shows a dichotomy between W[1]-hard and fixed-parameter tractable operator fragments almost independently of the chosen graph representation. The only fragments that are proven to be fixed-parameter tractable (FPT) are those that are restricted to the X operator. By investigating Boolean operator fragments in the sense of Post's lattice, we achieve the same complexity as in the unrestricted case if the set of available Boolean functions can express the function "negation of the implication." Conversely, we show containment in FPT for almost all other clones. © ACM 2017. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in ACM Transactions on Computational Logic 18 (2017), Nr. 1, 1. DOI: https://doi.org/10.1145/3001835.
2017-03-20T13:19:20Z
2017-03-20T13:19:20Z
2017
Article
Text
Luck, M.; Meier, A.; Schindler, I.: Parametrised complexity of satisfiability in temporal logic. In: ACM Transactions on Computational Logic 18 (2017), Nr. 1, 1. DOI: https://doi.org/10.1145/3001835
http://www.repo.uni-hannover.de/handle/123456789/1236
http://dx.doi.org/10.15488/1212
eng
ACM Transactions on Computational Logic 18 (2017), Nr. 1
1529-3785
https://doi.org/10.1145/3001835
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.
Association for Computing Machinery
oai:www.repo.uni-hannover.de:123456789/12372022-12-02T15:15:03Zcom_123456789_1col_123456789_7status-type:acceptedVersiondoc-type:Articledoc-type:Textopen_accessddc:620ddc:510
2018-02-20T23:05:15Z
urn:hdl:123456789/1237
A Flexible PMN-PT Ribbon-Based Piezoelectric-Pyroelectric Hybrid Generator for Human-Activity Energy Harvesting and Monitoring
Chen, Yan
Zhang, Yang
Yuan, Feifei
Ding, Fei
Schmidt, Oliver G.
Flexible electronics
Hybrid generators
Piezoelectrics
PMN-PT ribbons
Pyroelectrics
The rapid advancements of wearable electronics require continued innovation in sustainable power sources and human interactive sensors. An abundance of energy in various forms, such as mechanical, thermal, optical, and sound, are ubiquitous in the environment and human activities. Hybrid generators using piezoelectric polymers with relatively low piezoelectric and pyroelectric constants have been fabricated to simultaneously scavenge mechanical and thermal energies. In this work, micropatterned single-crystal (1-x)Pb(Mg,Nb)O3-xPbTiO3 (PMN-PT) ribbons, which possess excellent piezoelectric and pyroelectric properties, are utilized to build human activities energy harvesting and monitoring systems. The flexible PMN-PT ribbon-based sensor conformally attached on the surface of human skin enables high sensitivity for human body motions and can detect acoustic sounds precisely. The sensor has been used for monitoring temperature-related activities, caused for instance by warm water flow and even light illumination. The multifunctional performance of the PMN-PT ribbon-based hybrid generator shows great potential for self-powered wearable and human activities monitoring devices. This is the peer reviewed version of the following article: Chen, Y. et al.: A Flexible PMN-PT Ribbon-Based Piezoelectric-Pyroelectric Hybrid Generator for Human-Activity Energy Harvesting and Monitoring. In: Advanced Electronic Materials (2017), which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/aelm.201600540/abstract. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
2017-03-20T13:19:20Z
2018-02-20T23:05:15Z
2017
Article
Text
Chen, Y.; Zhang, Y.; Yuan, F.; Ding, F.; Schmidt, O.G.: A Flexible PMN-PT Ribbon-Based Piezoelectric-Pyroelectric Hybrid Generator for Human-Activity Energy Harvesting and Monitoring. In: Advanced Electronic Materials 3 (2017), Nr. 3, 1600540. DOI: https://doi.org/10.1002/aelm.201600540
http://www.repo.uni-hannover.de/handle/123456789/1237
http://dx.doi.org/10.15488/1213
eng
Advanced Electronic Materials 3 (2017), Nr. 3
2199-160X
https://doi.org/10.1002/aelm.201600540
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.
Hoboken, NJ : Blackwell Publishing Ltd
oai:www.repo.uni-hannover.de:123456789/12382022-12-02T16:17:36Zcom_123456789_1col_123456789_6col_123456789_7status-type:acceptedVersiondoc-type:Articledoc-type:Textopen_accessddc:530ddc:620ddc:510
2018-02-17T23:05:13Z
urn:hdl:123456789/1238
Violaxanthin cycle kinetics analysed in vivo with resonance Raman spectroscopy
Koch, Matthias
Zagermann, Serge
Kniggendorf, Ann-Kathrin
Meinhardt-Wollweber, Merve
Roth, Bernhard
Dunaliellasalina
Kinetics
Resonance Raman
Stress adaptation
Violaxanthin cycle
Measuring the kinetics of the violaxanthin cycle imposes an experimental challenge. Traditionally, carotenoid analysis was carried out laboriously with high-performance liquid chromatography. In this work, we present the first in vivo approach to directly measure the kinetics of the violaxanthin cycle, using resonance Raman spectroscopy in combination with baseline correction and principal component analysis. Applying the new approach allows measuring thousands of data points as opposed to the few possible with chemical analysis over the course of a violaxanthin cycle kinetics experiment. In vivo analysis of the violaxanthin cycle is necessary to fully understand adaptation kinetics to varying light conditions, the knowledge of which is especially important for assessing the stress tolerance of plants in the wake of the increasing climate change. Three experiments on the green alga Dunaliella salina were performed, featuring both the light-to-dark and dark-to-light transitions response of the algae. This is the peer reviewed version of the following article: Koch, M. et al.: Violaxanthin cycle kinetics analysed in vivo with resonance Raman spectroscopy. In: Journal of Raman Spectroscopy (2017), which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/jrs.5102/abstract. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
2017-03-20T13:19:20Z
2018-02-17T23:05:13Z
2017
Article
Text
Koch, M.; Zagermann, S.; Kniggendorf, A.-K.; Meinhardt-Wollweber, M.; Roth, B.: Violaxanthin cycle kinetics analysed in vivo with resonance Raman spectroscopy. In: Journal of Raman Spectroscopy 48 (2017), Nr. 5, S. 686–691. DOI: https://doi.org/10.1002/jrs.5102
http://www.repo.uni-hannover.de/handle/123456789/1238
http://dx.doi.org/10.15488/1214
eng
Journal of Raman Spectroscopy 48 (2017), Nr. 5
0377-0486
https://doi.org/10.1002/jrs.5102
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.
Chichester : John Wiley and Sons Ltd
oai:www.repo.uni-hannover.de:123456789/12392022-12-02T15:04:50Zcom_123456789_1col_123456789_6col_123456789_7status-type:acceptedVersiondoc-type:Articledoc-type:Textopen_accessddc:530ddc:620ddc:510
2017-08-08T22:05:16Z
urn:hdl:123456789/1239
Iterative morphological and mollifier-based baseline correction for Raman spectra
Koch, Matthias
Suhr, Christian
Roth, Bernhard
Meinhardt-Wollweber, Merve
Baseline correction
Fluorescence removal
in vivo
Mollifier
Morphological
In vivo Raman spectroscopy with low signal-to-noise ratio and strong, irregularly shaped fluorescence background imposes a challenge for automatic baseline correction methods. In this work, an approach that enables fast and efficient batch baseline correction has been developed, which is based on a morphological operation in combination with a mollifier algorithm. As this algorithm relies only on three parameters, which are determined by the given experimental conditions, it can be used for automatic and objective processing of many Raman spectra. The applicability of the baseline correction is demonstrated on resonance Raman spectra of beta-carotene mixed with fluorescent red ink as model system, on carotenoids in human skin, and on an excitation–emission map of the green alga Haematococcus pluvialis. In the future, the algorithm opens the potential for wide application in Raman spectra analysis in biological contexts. In particular, it greatly facilitates data processing in cases where special photochemical sample preparation or complex experimental baseline removal was required before. Similarly, processing data of experiments using resonant excitation techniques yielding strong fluorescence background is possible. This is the peer reviewed version of the following article: Koch, M.; Suhr, C.; Roth, B.; Meinhardt-Wollweber, M.: Iterative morphological and mollifier-based baseline correction for Raman spectra. In: Journal of Raman Spectroscopy 48 (2016), Nr. 2, S. 336-342, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/jrs.5010/abstract. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.
2017-03-20T13:19:22Z
2017-08-08T22:05:16Z
2016
Article
Text
Koch, M.; Suhr, C.; Roth, B.; Meinhardt-Wollweber, M.: Iterative morphological and mollifier-based baseline correction for Raman spectra. In: Journal of Raman Spectroscopy 48 (2016), Nr. 2, S. 336-342. DOI: https://doi.org/10.1002/jrs.5010
http://www.repo.uni-hannover.de/handle/123456789/1239
http://dx.doi.org/10.15488/1215
eng
Journal of Raman Spectroscopy 48 (2016), Nr. 2
0377-0486
https://doi.org/10.1002/jrs.5010
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.
Chichester : John Wiley and Sons Ltd
oai:www.repo.uni-hannover.de:123456789/13532022-12-02T15:15:01Zcom_123456789_1col_123456789_7status-type:acceptedVersiondoc-type:Articledoc-type:Textopen_accessddc:510
2019-03-01T23:05:02Z
urn:hdl:123456789/1353
Invariance of closed convex cones for stochastic partial differential equations
Tappe, Stefan
Closed convex cone
Parallel function
Stochastic invariance
Stochastic partial differential equation
The goal of this paper is to clarify when a closed convex cone is invariant for a stochastic partial differential equation (SPDE) driven by a Wiener process and a Poisson random measure, and to provide conditions on the parameters of the SPDE, which are necessary and sufficient.
2017-04-20T08:42:19Z
2019-03-01T23:05:02Z
2017
Article
Text
Tappe, S.: Invariance of closed convex cones for stochastic partial differential equations. In: Journal of Mathematical Analysis and Applications 451 (2017), Nr. 2, S.1077–1122. DOI: https://doi.org/10.1016/j.jmaa.2017.02.044
http://www.repo.uni-hannover.de/handle/123456789/1353
http://dx.doi.org/10.15488/1328
eng
Journal of Mathematical Analysis and Applications 451 (2017), Nr. 2
0022-247X
10.1016/j.jmaa.2017.02.044
https://creativecommons.org/licenses/by-nc-nd/4.0/
CC BY-NC-ND 4.0 Unported
Cambridge, MA : Elsevier Academic Press
oai:www.repo.uni-hannover.de:123456789/13902022-12-02T15:15:02Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-04-21T09:09:56Z
urn:hdl:123456789/1390
Intersecting quantum gravity with noncommutative geometry - A review?
Aastrup, Johannes
Grimstrup, Jesper Moller
Noncommutative geometry
Quantum gravity
Semiclassical analysis
We review applications of noncommutative geometry in canonical quantum gravity. First, we show that the framework of loop quantum gravity includes natural noncommutative structures which have, hitherto, not been explored. Next, we present the construction of a spectral triple over an algebra of holonomy loops. The spectral triple, which encodes the kinematics of quantum gravity, gives rise to a natural class of semiclassical states which entail emerging fermionic degrees of freedom. In the particular semiclassical approximation where all gravitational degrees of freedom are turned off, a free fermionic quantum field theory emerges. We end the paper with an extended outlook section.
2017-04-21T09:09:56Z
2017-04-21T09:09:56Z
2012
Article
Text
Aastrup, J.; Grimstrup, J.M.: Intersecting quantum gravity with noncommutative geometry - A review?. In: Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 8 (2012), 18. DOI: https://doi.org/10.3842/SIGMA.2012.018
http://www.repo.uni-hannover.de/handle/123456789/1390
http://dx.doi.org/10.15488/1365
eng
Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 8 (2012)
1815-0659
https://doi.org/10.3842/SIGMA.2012.018
https://creativecommons.org/licenses/by-sa/4.0/
CC BY-SA 4.0 Unported
Kyiv : Institute of Mathematics of National Academy of Sciences of Ukraine, Department of Applied Research
oai:www.repo.uni-hannover.de:123456789/13942022-12-02T15:17:15Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-04-21T09:47:39Z
urn:hdl:123456789/1394
Some refinements of existence results for SPDEs driven by wiener processes and Poisson random measures
Tappe, Stefan
stochastic
SPDE
SDE
We provide existence and uniqueness of global (and local) mild solutions for a general class of semilinear stochastic partial differential equations driven by Wiener processes and Poisson random measures under local Lipschitz and linear growth (or local boundedness, resp.) conditions. The so-called "method of the moving frame" allows us to reduce the SPDE problems to SDE problems.
2017-04-21T09:47:39Z
2017-04-21T09:47:39Z
2012
Article
Text
Tappe, S.: Some refinements of existence results for SPDEs driven by wiener processes and Poisson random measures. In: International Journal of Stochastic Analysis 2012 (2012), 236327. DOI: https://doi.org/10.1155/2012/236327
http://www.repo.uni-hannover.de/handle/123456789/1394
http://dx.doi.org/10.15488/1369
eng
International Journal of Stochastic Analysis 2012 (2012)
2090-3332
https://doi.org/10.1155/2012/236327
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
New York, NY : Hindawi Publishing Corporation
oai:www.repo.uni-hannover.de:123456789/13992023-09-20T07:04:10Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-04-21T09:47:40Z
urn:hdl:123456789/1399
Trickle-down processes and their boundaries
Evans, Steven N.
Grübel, Rudolf
Wakolbinger, Anton
Binary search tree
Catalan number
Chinese restaurant process
Composition
Digital search tree
Dirichlet random measure
E wens sampling formula
Griffiths-engen-mccloskey distribution
h-transform
Harmonic function
Internal diffusion limited aggregation
Mallows model
Poisson boundary
q-binomial theorem
Quincunx
Random partition
Random recursive tree
Tail σ-field
It is possible to represent each of a number of Markov chains as an evolving sequence of connected subsets of a directed acyclic graph that grow in the following way: initially, all vertices of the graph are unoccupied, particles are fed in one-by-one at a distinguished source vertex, successive particles proceed along directed edges according to an appropriate stochastic mechanism, and each particle comes to rest once it encounters an unoccupied vertex. Examples include the binary and digital search tree processes, the random recursive tree process and generalizations of it arising from nested instances of Pitman's two-parameter Chinese restaurant process, tree-growth models associated with Mallows' φ model of random permutations and with Schützenberger's non-commutative g-binomial theorem, and a construction due to Luczak and Winkler that grows uniform random binary trees in a Markovian manner. We introduce a framework that encompasses such Markov chains, and we characterize their asymptotic behavior by analyzing in detail their Doob-Martin com-pactifications, Poisson boundaries and tail cr-fields.
2017-04-21T09:47:40Z
2017-04-21T09:47:40Z
2012
Article
Text
Evans, S.N.; Grübel, R.; Wakolbinger, A.: Trickle-down processes and their boundaries. In: Electronic Journal of Probability 17 (2012), S. 1-58. DOI: https://doi.org/10.1214/EJP.v17-1698
http://www.repo.uni-hannover.de/handle/123456789/1399
http://dx.doi.org/10.15488/1374
eng
Electronic Journal of Probability 17 (2012)
1083-6489
https://doi.org/10.1214/EJP.v17-1698
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Beachwood, OH : Institute of Mathematical Statistics
oai:www.repo.uni-hannover.de:123456789/14692022-12-02T15:17:15Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-04-28T09:12:00Z
urn:hdl:123456789/1469
The noncommutative ward metric
Lechtenfeld, Olaf
Maceda, Marco
CP1 sigma model
Noncommutative geometry
We analyze the moduli-space metric in the static non-Abelian charge-two sector of the Moyal-deformed CP1 sigma model in 1 + 2 dimensions. After carefully reviewing the commutative results of Ward and Ruback, the noncommutative Kähler potential is expanded in powers of dimensionless moduli. In two special cases we sum the perturbative series to analytic expressions. For any nonzero value of the noncommutativity parameter, the logarithmic singularity of the commutative metric is expelled from the origin of the moduli space and possibly altogether.
2017-04-28T09:12:00Z
2017-04-28T09:12:00Z
2010
Article
Text
Lechtenfeld, O.; Maceda, M.: The noncommutative ward metric. In: Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 6 (2010), 45. DOI: https://doi.org/10.3842/SIGMA.2010.045
http://www.repo.uni-hannover.de/handle/123456789/1469
http://dx.doi.org/10.15488/1444
eng
Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 6 (2010)
1815-0659
https://doi.org/10.3842/SIGMA.2010.045
https://creativecommons.org/licenses/by-sa/4.0/
CC BY-SA 4.0 Unported
Kyiv : Institute of Mathematics of National Academy of Sciences of Ukraine, Department of Applied Research
oai:www.repo.uni-hannover.de:123456789/16092022-12-02T15:12:32Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-05-31T11:16:23Z
urn:hdl:123456789/1609
Measurement Uncertainty for Finite Quantum Observables
Schwonnek, René
Reeb, David
Werner, Reinhard F.
error-disturbance tradeoff
measurement uncertainty
optimal transport
semidefinite programming
uncertainty relations
Measurement uncertainty relations are lower bounds on the errors of any approximate joint measurement of two or more quantum observables. The aim of this paper is to provide methods to compute optimal bounds of this type. The basic method is semidefinite programming, which we apply to arbitrary finite collections of projective observables on a finite dimensional Hilbert space. The quantification of errors is based on an arbitrary cost function, which assigns a penalty to getting result x rather than y, for any pair (x,y) . This induces a notion of optimal transport cost for a pair of probability distributions, and we include an Appendix with a short summary of optimal transport theory as needed in our context. There are then different ways to form an overall figure of merit from the comparison of distributions. We consider three, which are related to different physical testing scenarios. The most thorough test compares the transport distances between the marginals of a joint measurement and the reference observables for every input state. Less demanding is a test just on the states for which a “true value” is known in the sense that the reference observable yields a definite outcome. Finally, we can measure a deviation as a single expectation value by comparing the two observables on the two parts of a maximally-entangled state. All three error quantities have the property that they vanish if and only if the tested observable is equal to the reference. The theory is illustrated with some characteristic examples.
2017-05-31T11:16:23Z
2017-05-31T11:16:23Z
2016
Article
Text
Schwonnek, René; Reeb, David; Werner, Reinhard: Measurement Uncertainty for Finite Quantum Observables. In: Mathematics 4 (2016), Nr. 2, 38. DOI: https://doi.org/10.3390/math4020038
http://www.repo.uni-hannover.de/handle/123456789/1609
http://dx.doi.org/10.15488/1584
eng
Mathematics 4 (2016), Nr. 2
2227-7390
https://doi.org/10.3390/math4020038
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Basel : MDPI AG
oai:www.repo.uni-hannover.de:123456789/16352022-12-02T15:15:02Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-06-14T12:34:50Z
urn:hdl:123456789/1635
Compact Embeddings for Spaces of Forward Rate Curves
Tappe, Stefan
term structure models
existence
The goal of this paper is to prove a compact embedding result for spaces of forward rate curves. As a consequence of this result, we show that any forward rate evolution can be approximated by a sequence of finite dimensional processes in the larger state space.
2017-06-14T12:34:50Z
2017-06-14T12:34:50Z
2013
Article
Text
Tappe, Stefan: Compact Embeddings for Spaces of Forward Rate Curves. In: Abstract and Applied Analysis 2013 (2013), 709505. DOI: https://doi.org/10.1155/2013/709505
http://www.repo.uni-hannover.de/handle/123456789/1635
http://dx.doi.org/10.15488/1610
eng
Abstract and Applied Analysis 2013 (2013)
1085-3375
https://doi.org/10.1155/2013/709505
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
New York, NY : Hindawi Publishing Corporation
oai:www.repo.uni-hannover.de:123456789/16942022-12-02T15:12:32Zcom_123456789_1col_123456789_7status-type:acceptedVersiondoc-type:Articledoc-type:Textopen_accessddc:510
2018-02-07T23:05:15Z
urn:hdl:123456789/1694
Critical vertices in k-connected digraphs
Mader, W.
Connectivity-critical vertices
k-connected digraphs
Survey on k-critical graphs
It is proved that every non-complete, finite digraph of connectivity number k has a fragment F containing at most k critical vertices. The following result is a direct consequence: every k-connected, finite digraph D of minimum out- and indegree at least 2k+m−1 for positive integers k, m has a subdigraph H of minimum outdegree or minimum indegree at least m−1 such that D−x is k-connected for all x∈V(H). For m=1, this implies immediately the existence of a vertex of indegree or outdegree less than 2k in a k-critical, finite digraph, which was proved in Mader (J Comb Theory (B) 53:260–272, 1991). The final publication is available at Springer via https://doi.org/10.1007/s12188-016-0173-y.
2017-07-04T10:06:03Z
2018-02-07T23:05:15Z
2017
Article
Text
Mader, W.: Critical vertices in k-connected digraphs. In: Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg 87 (2017), S. 409–419. DOI: https://doi.org/10.1007/s12188-016-0173-y
http://www.repo.uni-hannover.de/handle/123456789/1694
http://dx.doi.org/10.15488/1669
eng
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg (2017)
0025-5858
https://doi.org/10.1007/s12188-016-0173-y
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.
Heidelberg : Springer Verlag
oai:www.repo.uni-hannover.de:123456789/16962022-12-02T15:03:41Zcom_123456789_1col_123456789_4doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-07-04T10:06:04Z
urn:hdl:123456789/1696
Generalized associahedra via brick polytopes
Pilaud, Vincent
Stump, Christian
Cambrian fans
Cambrian lattices
Cluster complexes
Coxeter-Catalan combinatorics
Generalized associahedra
Subword complexes
Cambrians
Cluster complexes
Combinatorics
Generalized associahedra
Sub words
Brick
Topology
Combinatorial mathematics
We generalize the brick polytope of V. Pilaud and F. Santos to spherical subword complexes for finite Coxeter groups. This construction provides polytopal realizations for a certain class of subword complexes containing all cluster complexes of finite types. For the latter, the brick polytopes turn out to coincide with the known realizations of generalized associahedra, thus opening new perspectives on these constructions. This new approach yields in particular the vertex description and a relevant Minkowski sum decomposition of generalized associahedra.
2017-07-04T10:06:04Z
2017-07-04T10:06:04Z
2012
Article
Text
Pilaud, V.; Stump, C.: Generalized associahedra via brick polytopes. In: Discrete Mathematics and Theoretical Computer Science (2012), S. 73-84.
http://www.repo.uni-hannover.de/handle/123456789/1696
http://dx.doi.org/10.15488/1671
eng
Discrete Mathematics and Theoretical Computer Science (2012)
1462-7264
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Nancy : French Association for Discrete Mathematics & Theoretical Computer Science
oai:www.repo.uni-hannover.de:123456789/16972022-12-02T15:03:41Zcom_123456789_1col_123456789_4doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-07-04T10:06:04Z
urn:hdl:123456789/1697
Multi-cluster complexes
Ceballos, Cesar
Labbé, Jean-Philippe
Stump, Christian
Cluster complexes
Coxeter-Catalan combinatorics
Generalized associahedra
Multi-triangulations
Sorting words
Subword complexes
Cluster complexes
Combinatorics
Generalized associahedra
Multi-triangulations
Sub words
Computer science
Combinatorial mathematics
We present a family of simplicial complexes called multi-cluster complexes. These complexes generalize the concept of cluster complexes, and extend the notion of multi-associahedra of types A and B to general finite Coxeter groups. We study combinatorial and geometric properties of these objects and, in particular, provide a simple combinatorial description of the compatibility relation among the set of almost positive roots in the cluster complex.
2017-07-04T10:06:04Z
2017-07-04T10:06:04Z
2012
Article
Text
Ceballos, C.; Labbé, J.-P.; Stump, C.: Multi-cluster complexes. In: Discrete Mathematics and Theoretical Computer Science (2012), S. 1-8.
http://www.repo.uni-hannover.de/handle/123456789/1697
http://dx.doi.org/10.15488/1672
eng
Discrete Mathematics and Theoretical Computer Science (2012)
1462-7264
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Nancy : French Association for Discrete Mathematics & Theoretical Computer Science
oai:www.repo.uni-hannover.de:123456789/16982022-12-02T16:11:40Zcom_123456789_1col_123456789_8doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-07-04T10:06:05Z
urn:hdl:123456789/1698
Rank-based multiple test procedures and simultaneous confidence intervals
Konietschke, Frank
Hothorn, Ludwig A.
Brunner, Edgar
Multiple comparisons
Nonparametric Behrens-Fisher problem
Rank statistics
We study simultaneous rank procedures for unbalanced designs with independent observations. The hypotheses are formulated in terms of purely nonparametric treatment effects. In this context, we derive rank-based multiple contrast test procedures and simultaneous confidence intervals which take the correlation between the test statistics into account. Hereby, the individual test decisions and the simultaneous confidence intervals are compatible. This means, whenever an individual hypothesis has been rejected by the multiple contrast test, the corresponding simultaneous confidence interval does not include the null, i.e. the hypothetical value of no treatment effect. The procedures allow for testing arbitrary purely nonparametric multiple linear hypotheses (e.g. many-to-one, all-pairs, changepoint, or even average comparisons). We do not assume homogeneous variances of the data; in particular, the distributions can have different shapes even under the null hypothesis. Thus, a solution to the multiple nonparametric Behrens-Fisher problem is presented in this unified framework.
2017-07-04T10:06:05Z
2017-07-04T10:06:05Z
2012
Article
Text
Konietschke, F.; Hothorn, L.A.; Brunner, E.: Rank-based multiple test procedures and simultaneous confidence intervals. In: Electronic Journal of Statistics 6 (2012), S. 738-759. DOI: https://doi.org/10.1214/12-EJS691
http://www.repo.uni-hannover.de/handle/123456789/1698
http://dx.doi.org/10.15488/1673
eng
Electronic Journal of Statistics 6 (2012)
1935-7524
https://doi.org/10.1214/12-EJS691
https://creativecommons.org/licenses/by/4.0/
CC BY 4.0 Unported
Bethesda, MD : Institute of Mathematical Statistics (IMS)
oai:www.repo.uni-hannover.de:123456789/17002022-12-02T15:15:02Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-07-04T10:06:07Z
urn:hdl:123456789/1700
Euler equations on a semi-direct product of the diffeomorphisms group by itself
Escher, Joachim
Ivanov, Rossen
Kolev, Boris
Dieomorphism group of the circle
Euler equation
Integrable systems
Peakons
The geodesic equations of a class of right invariant metrics on the semi-direct product Diff(S 1)sDiff(S 1) are studied. The equations are explicitly described, they have the form of a system of coupled equations of Camassa-Holm type and possess singular (peakon) solutions. Their integrability is further investigated, however no compatible bi-Hamiltonian structures on the corresponding dual Lie algebra (Vect(S 1) sVect(S 1))* are found.
2017-07-04T10:06:07Z
2017-07-04T10:06:07Z
2011
Article
Text
Escher, J.; Ivanov, R.; Kolev, B.: Euler equations on a semi-direct product of the diffeomorphisms group by itself. In: Journal of Geometric Mechanics 3 (2011), Nr. 3, S. 313-322. DOI: https://doi.org/10.3934/jgm.2011.3.313
http://www.repo.uni-hannover.de/handle/123456789/1700
http://dx.doi.org/10.15488/1675
eng
Journal of Geometric Mechanics 3 (2011), Nr. 3
1941-4889
https://doi.org/10.3934/jgm.2011.3.313
https://creativecommons.org/licenses/by-nc-sa/3.0/
CC BY-NC-SA 3.0 Unported
Springfield, MO : American Institute of Mathematical Sciences
oai:www.repo.uni-hannover.de:123456789/18972022-12-02T15:12:30Zcom_123456789_1col_123456789_7status-type:acceptedVersiondoc-type:Articledoc-type:Textopen_accessddc:510
2018-01-07T23:05:13Z
urn:hdl:123456789/1897
A-free rigidity and applications to the compressible Euler system
Chiodaroli, Elisabetta
Feireisl, Eduard
Kreml, Ondrej
Wiedemann, Emil
$$\mathcal {A}$$A-free condition
Compressible Euler equations
Measure-valued solutions
Rigidity
Can every measure-valued solution to the compressible Euler equations be approximated by a sequence of weak solutions? We prove that the answer is negative: generalizing a well-known rigidity result of Ball and James to a more general situation, we construct an explicit measure-valued solution for the compressible Euler equations which cannot be generated by a sequence of distributional solutions. We also give an abstract necessary condition for measure-valued solutions to be generated by weak solutions, relying on work of Fonseca and Müller. While a priori it is not unexpected that not every measure-valued solution arises from a sequence of weak solutions, it is noteworthy that this observation in the compressible case is in contrast to the incompressible situation, where every measure-valued solution can be approximated by weak solutions, as shown by Székelyhidi and Wiedemann. The final publication is available at Springer via http://dx.doi.org/10.1007/s10231-016-0629-9.
2017-09-08T08:47:23Z
2018-01-07T23:05:13Z
2017
Article
Text
Chiodaroli, E.; Feireisl, E.; Kreml, O.; Wiedemann, E.: A-free rigidity and applications to the compressible Euler system. In: Annali di Matematica Pura ed Applicata 196 (2017), Nr. 4, S. 1557-1572. DOI: https://doi.org/10.1007/s10231-016-0629-9
http://www.repo.uni-hannover.de/handle/123456789/1897
http://dx.doi.org/10.15488/1872
eng
Annali di Matematica Pura ed Applicata (2017)
03733114
https://doi.org/10.1007/s10231-016-0629-9
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.
Heidelberg : Springer Verlag
oai:www.repo.uni-hannover.de:123456789/19502022-12-02T15:04:49Zcom_123456789_1col_123456789_4ddc:004doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-09-14T14:08:59Z
urn:hdl:123456789/1950
Time Constrained Verification of Analog Circuits using Model-Checking Algorithms
Grabowski, Darius
Platte, Daniel
Hedrich, Lars
Barke, Erich
Constraint theory
Integrated circuits
Mathematical models
Specifications
Analog Circuits
CTL
Model Checking
Time Constraints
Analog computers
In this contribution we present algorithms for model checking of analog circuits enabling the specification of time constraints. Furthermore, a methodology for defining time-based specifications is introduced. An already known method for model checking of integrated analog circuits has been extended to take into account time constraints. The method will be presented using three industrial circuits. The results of model checking will be compared to verification by simulation.
2017-09-14T14:08:59Z
2017-09-14T14:08:59Z
2006
Article
Text
Grabowski, D.; Platte, D.; Hedrich, L.; Barke, E.: Time Constrained Verification of Analog Circuits using Model-Checking Algorithms. In: Electronic Notes in Theoretical Computer Science 153 (2006), Nr. 3, S. 37-52. DOI: https://doi.org/10.1016/j.entcs.2006.01.026
http://www.repo.uni-hannover.de/handle/123456789/1950
http://dx.doi.org/10.15488/1925
eng
Electronic Notes in Theoretical Computer Science 153 (2006), Nr. 3
15710661
https://doi.org/10.1016/j.entcs.2006.01.026
https://creativecommons.org/licenses/by-nc-nd/3.0
CC BY-NC-ND 3.0 Unported
Amsterdam : Elsevier BV
oai:www.repo.uni-hannover.de:123456789/19612022-12-02T15:03:40Zcom_123456789_1col_123456789_3doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-09-22T11:47:54Z
urn:hdl:123456789/1961
Sensitivity or Bayesian model updating: a comparison of techniques using the DLR AIRMOD test data
Patelli, Eduardo
Govers, Yves
Broggi, Matteo
Gomes, Herbert Martins
Link, Michael
Mottershead, John E.
Bayesian networks
Finite element method
Statistical tests
Stochastic systems
Testing
Bayesian
Covariance
Deterministic
Model updating
Stochastic
Stochastic models
Bayesian
Covariance
Deterministic
Model updating
Deterministic model updating is now a mature technology widely applied to large-scale industrial structures. It is concerned with the calibration of the parameters of a single model based on one set of test data. It is, of course, well known that different analysts produce different finite element models, make different physics-based assumptions, and parameterize their models differently. Also, tests carried out on the same structure, by different operatives, at different times, under different ambient conditions produce different results. There is no unique model and no unique data. Therefore, model updating needs to take account of modeling and test-data variability. Much emphasis is now placed on what has become known as stochastic model updating where data are available from multiple nominally identical test structures. In this paper two currently prominent stochastic model updating techniques (sensitivity-based updating and Bayesian model updating) are described and applied to the DLR AIRMOD structure.
2017-09-22T11:47:54Z
2017-09-22T11:47:54Z
2017
Article
Text
Patelli, E.; Govers, Y.; Broggi, M.; Gomes, H.M.; Link, M.; Mottershead, J.E.: Sensitivity or Bayesian model updating: a comparison of techniques using the DLR AIRMOD test data. In: Archive of Applied Mechanics 87 (2017), Nr. 5, S. 905-925. DOI: https://doi.org/10.1007/s00419-017-1233-1
http://www.repo.uni-hannover.de/handle/123456789/1961
http://dx.doi.org/10.15488/1936
eng
Archive of Applied Mechanics 87 (2017), Nr. 5
09391533
https://doi.org/10.1007/s00419-017-1233-1
https://creativecommons.org/licenses/by/4.0
CC BY 4.0 Unported
Heidelberg : Springer Verlag
oai:www.repo.uni-hannover.de:123456789/19712022-12-02T15:06:08Zcom_123456789_1col_123456789_6doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:620ddc:510
2017-09-22T12:52:56Z
urn:hdl:123456789/1971
High order sensitivity analysis of a mistuned blisk including intentional mistuning
Pohle, Linus
Tatzko, Sebastian
Panning-von Scheidt, Lars
Wallaschek, Jörg
Mistuning
Sensitivity analysis
Turbine blades
Finite element method
Frequency response
Intelligent systems
Normal distribution
Probability distributions
Sensitivity analysis
Turbine components
Turbines
Turbomachine blades
Frequency response functions
Intentional mistuning
Manufacturing tolerances
Material inhomogeneities
Mistuning
Taylor series approximation
Turbine blade
Vibration amplitude
Monte Carlo methods
Small deviations between turbine blades exist due to manufacturing tolerances or material inhomogeneities. This effect is called mistuning and usually causes increased vibration amplitudes and also a lower service life expectancy of bladed disks or so called blisks (bladed integrated disk). The major resulting problem is to estimate the maximum amplitude with respect to these deviations. Due to the probability distribution of these deviations, statistical methods are used to predict the maximum amplitude. State of the art is the Monte-Carlo simulation which is based on a high number of randomly re-arranged input parameters. The aim of this paper is to introduce a useful method to calculate the probability distribution of the maximum amplitude of a mistuned blisk with respect to the random input parameters. First, the applied reduction method is presented to initiate the sensitivity analysis. This reduction method enables the calculation of the frequency response function (FRF) of a Finite Element Model (FEM) in a reasonable calculation time. Based on the Taylor series approximation, the sensitivity of the vibration amplitude depending on normally distributed input parameters is calculated and therewith, it is possible to estimate the maximum amplitude. Calculating only a single frequency response function shows a good agreement with the results of over 1000 Monte-Carlo simulations.
2017-09-22T12:52:56Z
2017-09-22T12:52:56Z
2017
Article
Text
Pohle, L.; Tatzko, S.; von Scheidt, L.P.; Wallaschek, J.: High order sensitivity analysis of a mistuned blisk including intentional mistuning. In: Journal of Theoretical and Applied Mechanics (Poland) 55 (2017), Nr. 1, S. 353-368. DOI: https://doi.org/10.15632/jtam-pl.55.1.353
http://www.repo.uni-hannover.de/handle/123456789/1971
http://dx.doi.org/10.15488/1946
eng
Journal of Theoretical and Applied Mechanics (Poland) 55 (2017), Nr. 1
14292955
https://doi.org/10.15632/jtam-pl.55.1.353
https://creativecommons.org/licenses/by-nc/3.0
CC BY-NC 3.0 Unported
Warsaw : Polish Society of Theoretical and Allied Mechanics
oai:www.repo.uni-hannover.de:123456789/19722022-12-02T15:03:41Zcom_123456789_1col_123456789_4ddc:004doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-09-22T12:52:56Z
urn:hdl:123456789/1972
On the implicit graph conjecture
Chandoo, Maurice
Adjacency labeling scheme
Complexity classes
Diagonalization
Logic
Computational complexity
Computer circuits
Decoding
Formal logic
Polynomial approximation
Adjacency labeling
Algorithmic problems
Complexity class
Diagonalizations
Directed acyclic graph (DAG)
First order logic
Logic
Recursive languages
Directed graphs
The implicit graph conjecture states that every sufficiently small, hereditary graph class has a labeling scheme with a polynomial-time computable label decoder. We approach this conjecture by investigating classes of label decoders defined in terms of complexity classes such as P and EXP. For instance, GP denotes the class of graph classes that have a labeling scheme with a polynomial-time computable label decoder. Until now it was not even known whether GP is a strict subset of GR where R is the class of recursive languages. We show that this is indeed the case and reveal a strict hierarchy akin to classical complexity. We also show that classes such as GP can be characterized in terms of graph parameters. This could mean that certain algorithmic problems are feasible on every graph class in GP. Lastly, we define a more restrictive class of label decoders using first-order logic that already contains many natural graph classes such as forests and interval graphs. We give an alternative characterization of this class in terms of directed acyclic graphs. By showing that some small, hereditary graph class cannot be expressed with such label decoders a weaker form of the implicit graph conjecture could be disproven.
2017-09-22T12:52:56Z
2017-09-22T12:52:56Z
2016
Article
Text
Chandoo, M.: On the implicit graph conjecture. In: Leibniz International Proceedings in Informatics, LIPIcs 58 (2016), No. 23. DOI: https://doi.org/10.4230/LIPIcs.MFCS.2016.23
http://www.repo.uni-hannover.de/handle/123456789/1972
http://dx.doi.org/10.15488/1947
eng
Leibniz International Proceedings in Informatics, LIPIcs 58 (2016)
18688969
https://doi.org/10.4230/LIPIcs.MFCS.2016.23
https://creativecommons.org/licenses/by/3.0
CC BY 3.0 Unported
Saarbrücken : Dagstuhl Publishing
oai:www.repo.uni-hannover.de:123456789/19732022-12-02T15:04:50Zcom_123456789_1col_123456789_4ddc:004doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-09-22T12:52:57Z
urn:hdl:123456789/1973
Descriptive complexity of #AC0 functions
Durand, Arnaud
Haak, Anselm
Kontinen, Juha
Vollmer, Heribert
Arithmetic circuits
Counting classes
Fagin's theorem
Finite model theory
Skolem function
Computational complexity
Logic circuits
Arithmetic circuit
Arithmetic computations
Counting class
Descriptive complexity
Fagin's theorem
Finite model theory
Function variables
Inclusion structure
Computer circuits
We introduce a new framework for a descriptive complexity approach to arithmetic computations. We define a hierarchy of classes based on the idea of counting assignments to free function variables in first-order formulae. We completely determine the inclusion structure and show that #P and #AC0 appear as classes of this hierarchy. In this way, we unconditionally place #AC0 properly in a strict hierarchy of arithmetic classes within #P. We compare our classes with a hierarchy within #P defined in a model-theoretic way by Saluja et al. We argue that our approach is better suited to study arithmetic circuit classes such as #AC0 which can be descriptively characterized as a class in our framework.
2017-09-22T12:52:57Z
2017-09-22T12:52:57Z
2016
Article
Text
Durand, A.; Haak, A.; Kontinen, J.; Vollmer, H.: Descriptive complexity of #AC0 functions. In: Leibniz International Proceedings in Informatics, LIPIcs 62 (2016). DOI: https://doi.org/10.4230/LIPIcs.CSL.2016.20
http://www.repo.uni-hannover.de/handle/123456789/1973
http://dx.doi.org/10.15488/1948
eng
Leibniz International Proceedings in Informatics, LIPIcs 62 (2016)
18688969
https://doi.org/10.4230/LIPIcs.CSL.2016.20
https://creativecommons.org/licenses/by/3.0
CC BY 3.0 Unported
Saarbrücken : Dagstuhl Publishing
oai:www.repo.uni-hannover.de:123456789/19742022-12-02T15:04:49Zcom_123456789_1col_123456789_4ddc:004doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-09-22T12:52:57Z
urn:hdl:123456789/1974
Decidability of predicate logics with team semantics
Kontinen, Juha
Kuusisto, Antti
Virtema, Jonni
Complexity
Dependence logic
Team semantics
Two-variable logic
Formal logic
Problem solving
Semantics
Complexity
Dependence logic
Predicate logic
Satisfiability problems
Two-variable logic
Computer circuits
We study the complexity of predicate logics based on team semantics. We show that the satisfiability problems of two-variable independence logic and inclusion logic are both NEXPTIMEcomplete. Furthermore, we show that the validity problem of two-variable dependence logic is undecidable, thereby solving an open problem from the team semantics literature. We also briefly analyse the complexity of the Bernays-Schönfinkel-Ramsey prefix classes of dependence logic.
2017-09-22T12:52:57Z
2017-09-22T12:52:57Z
2016
Article
Text
Kontinen, J.; Kuusisto, A.; Virtema, J.: Decidability of predicate logics with team semantics. In: Leibniz International Proceedings in Informatics, LIPIcs 58 (2016), No. 60. DOI: https://doi.org/10.4230/LIPIcs.MFCS.2016.60
http://www.repo.uni-hannover.de/handle/123456789/1974
http://dx.doi.org/10.15488/1949
eng
Leibniz International Proceedings in Informatics, LIPIcs 58 (2016)
18688969
https://doi.org/10.4230/LIPIcs.MFCS.2016.60
https://creativecommons.org/licenses/by/3.0
CC BY 3.0 Unported
Saarbrücken : Dagstuhl Publishing
oai:www.repo.uni-hannover.de:123456789/19752022-12-02T15:12:32Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-09-22T12:52:58Z
urn:hdl:123456789/1975
Discrete derived categories I: Homomorphisms, autoequivalences and t-structures
Broomhead, Nathan
Pauksztello, David
Ploog, David
Auslander-Reiten quiver
Discrete derived category
Hom-hammock
Silting object
String algebra
t-Structure
Twist functor
Discrete derived categories were studied initially by Vossieck (J Algebra 243:168–176, 2001) and later by Bobiński et al. (Cent Eur J Math 2:19–49, 2004). In this article, we describe the homomorphism hammocks and autoequivalences on these categories. We classify silting objects and bounded t-structures.
2017-09-22T12:52:58Z
2017-09-22T12:52:58Z
2017
Article
Text
Broomhead, N.; Pauksztello, D.; Ploog, D.: Discrete derived categories I: Homomorphisms, autoequivalences and t-structures. In: Mathematische Zeitschrift 285 (2017), Nr. 42767, S. 39-89. DOI: https://doi.org/10.1007/s00209-016-1690-1
http://www.repo.uni-hannover.de/handle/123456789/1975
http://dx.doi.org/10.15488/1950
eng
Mathematische Zeitschrift 285 (2017), Nr. 42767
00255874
https://doi.org/10.1007/s00209-016-1690-1
https://creativecommons.org/licenses/by/4.0
CC BY 4.0 Unported
Heidelberg : Springer Verlag
oai:www.repo.uni-hannover.de:123456789/19812022-12-02T15:12:32Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-09-22T12:53:00Z
urn:hdl:123456789/1981
Nef divisors for moduli spaces of complexes with compact support
Bayer, Arend
Craw, Alastair
Zhang, Ziyu
Bridgeland stability conditions
Derived categories
Moduli spaces of sheaves and complexes
Nef divisors
t-structures
In Bayer and Macrì (J Am Math Soc 27(3):707–752, 2014), the first author and Macrì constructed a family of nef divisors on any moduli space of Bridgeland-stable objects on a smooth projective variety X. In this article, we extend this construction to the setting of any separated scheme Y of finite type over a field, where we consider moduli spaces of Bridgeland-stable objects on Y with compact support. We also show that the nef divisor is compatible with the polarising ample line bundle coming from the GIT construction of the moduli space in the special case when Y admits a tilting bundle and the stability condition arises from a θ-stability condition for the endomorphism algebra. Our main tool generalises the work of Abramovich–Polishchuk (J Reine Angew Math 590:89–130, 2006) and Polishchuk (Mosc Math J 7(1):109–134, 2007): given a t-structure on the derived category Dc(Y) on Y of objects with compact support and a base scheme S, we construct a constant family of t-structures on a category of objects on Y×S with compact support relative to S.
2017-09-22T12:53:00Z
2017-09-22T12:53:00Z
2017
Article
Text
Bayer, A.; Craw, A.; Zhang, Z.: Nef divisors for moduli spaces of complexes with compact support. In: Selecta Mathematica, New Series 23 (2017), Nr. 2, S. 1507-1561. DOI: https://doi.org/10.1007/s00029-016-0298-y
http://www.repo.uni-hannover.de/handle/123456789/1981
http://dx.doi.org/10.15488/1956
eng
Selecta Mathematica, 23 (2017), Nr. 2
10221824
https://doi.org/10.1007/s00029-016-0298-y
https://creativecommons.org/licenses/by/4.0
CC BY 4.0 Unported
Heidelberg : Springer Verlag
oai:www.repo.uni-hannover.de:123456789/20202022-12-02T15:15:01Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-10-10T07:51:07Z
urn:hdl:123456789/2020
Flatness of invariant manifolds for stochastic partial differential equations driven by Levy processes
Tappe, Stefan
stochastic partial differential equation
flatness of a submanifold
stochastic invariance
levy process with small jumps
term structure models
higher rank
existence
curvature
The purpose of this note is to prove that the flatness of an invariant manifold for a semilinear stochastic partial differential equation driven by Levy processes is at least equal to the number of driving sources with small jumps. We illustrate our findings by means of an example.
2017-10-10T07:51:07Z
2017-10-10T07:51:07Z
2015
Article
Text
Tappe, Stefan: Flatness of invariant manifolds for stochastic partial differential equations driven by Levy processes. In: Electronic Communications in Probability 20 (2015), S. 1-11. DOI: https://doi.org/10.1214/ECP.v20-3943
http://www.repo.uni-hannover.de/handle/123456789/2020
http://dx.doi.org/10.15488/1995
eng
Electronic Communications in Probability 20 (2015)
1083-589X
https://doi.org/10.1214/ECP.v20-3943
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Seattle : University Washington, Dept. Mathematics
oai:www.repo.uni-hannover.de:123456789/20382022-12-02T15:15:01Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-10-10T08:16:59Z
urn:hdl:123456789/2038
Random recursive trees: a boundary theory approach
Gruebel, Rudolf
Michailow, Igor
doob-martin compactification
markov chains
path length
random trees
harris trees
wiener index
search-trees
limit-theorems
quicksort
index
We show that an algorithmic construction of sequences of recursive trees leads to a direct proof of the convergence of random recursive trees in an associated Doob-Martin compactification; it also gives a representation of the limit in terms of the input sequence of the algorithm. We further show that this approach can be used to obtain strong limit theorems for various tree functionals, such as path length or the Wiener index.
2017-10-10T08:16:59Z
2017-10-10T08:16:59Z
2015
Article
Text
Gruebel, Rudolf; Michailow, Igor: Random recursive trees: a boundary theory approach. In: Electronic Journal of Probability 20 (2015), UNSP 37. DOI: https://doi.org/10.1214/EJP.v20-3832
http://www.repo.uni-hannover.de/handle/123456789/2038
http://dx.doi.org/10.15488/2013
eng
Electronic Journal of Probability 20 (2015)
1083-6489
https://doi.org/10.1214/EJP.v20-3832
https://creativecommons.org/licenses/by/3.0/
CC BY 3.0 Unported
Seattle : University Washington, Dept. Mathematics
oai:www.repo.uni-hannover.de:123456789/20622022-12-02T15:15:02Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-10-12T10:54:34Z
urn:hdl:123456789/2062
On the automorphisms of a rank one Deligne-Hitchin moduli space
Biswas, Indranil
Heller, Sebastian
Deligne-Hitchin moduli space
Hodge moduli space
Moishezon twistor space
λ-connections
Let X be a compact connected Riemann surface of genus g ≥ 2, and let MDHbe the rank one Deligne-Hitchin moduli space associated to X. It is known that MDHis the twistor space for the hyper-Kähler structure on the moduli space of rank one holomorphic connections on X. We investigate the group Aut(MDH) of all holomorphic automorphisms of MDH. The connected component of Aut (MDH) containing the identity automorphism is computed. There is a natural element of H2(MDH;ℤ). We also compute the subgroup of Aut(MDH) that fixes this second cohomology class. Since MDHadmits an ample rational curve, the notion of algebraic dimension extends to it by a theorem of Verbitsky. We prove that MDH is Moishezon. © 2017, Institute of Mathematics. All rights reserved.
2017-10-12T10:54:34Z
2017-10-12T10:54:34Z
2017
Article
Text
Biswas, I.; Heller, S.: On the automorphisms of a rank one Deligne-Hitchin moduli space. In: Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 13 (2017), 72. DOI: https://doi.org/10.3842/SIGMA.2017.072
http://www.repo.uni-hannover.de/handle/123456789/2062
http://dx.doi.org/10.15488/2037
eng
Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 13 (2017)
1815-0659
https://doi.org/10.3842/SIGMA.2017.072
https://creativecommons.org/licenses/by-sa/4.0/
CC BY-SA 4.0 Unported
Kiev : Institute of Mathematics of National Academy of Sciences of Ukraine
oai:www.repo.uni-hannover.de:123456789/20652022-12-02T15:17:14Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-10-12T10:54:35Z
urn:hdl:123456789/2065
Restriction of odd degree characters of Sn
Bessenrodt, Christine
Giannelli, Eugenio
Olsson, Jorn B.
Characters of symmetric groups
Hooks in partitions
Let n and k be natural numbers such that 2k < n. We study the restriction to Sn−2k of odd-degree irreducible characters of the symmetric group Sn. This analysis completes the study begun in [Ayyer A., Prasad A., Spallone S., Sém. Lothar. Combin. 75 (2015), Art. B75g, 13 pages] and recently developed in [Isaacs I.M., Navarro G., Olsson J.B., Tiep P.H., J. Algebra 478 (2017), 271-282].
2017-10-12T10:54:35Z
2017-10-12T10:54:35Z
2017
Article
Text
Bessenrodt, C.; Giannelli, E.; Olsson, J.B.: Restriction of odd degree characters of Sn. In: Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 13 (2017), 70. DOI: https://doi.org/10.3842/SIGMA.2017.070
http://www.repo.uni-hannover.de/handle/123456789/2065
http://dx.doi.org/10.15488/2040
eng
Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 13 (2017)
1815-0659
https://doi.org/10.3842/SIGMA.2017.070
https://creativecommons.org/licenses/by-sa/4.0/
CC BY-SA 4.0 Unported
Kiev : Institute of Mathematics of National Academy of Sciences of Ukraine
oai:www.repo.uni-hannover.de:123456789/23122022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T08:10:19Z
urn:hdl:123456789/2312
A moving boundary problem for the Stokes equations involving osmosis: Variational modelling and short-time well-posedness
Lippoth, Friedrich
Peletier, Mark A.
Prokert, Georg
maximal continuous regularity
moving boundary problem
osmosis
Stokes equations
variational modelling
Navier Stokes equations
Classical solutions
maximal continuous regularity
Moving boundary problems
Semi-permeable membranes
Stokes equations
Variational modelling
Viscous liquids
Wellposedness
Osmosis
Within the framework of variational modelling we derive a one-phase moving boundary problem describing the motion of a semipermeable membrane enclosing a viscous liquid, driven by osmotic pressure and surface tension of the membrane. For this problem we prove the existence of classical solutions for a short-time. © 2015 Cambridge University Press.
2017-11-17T08:10:19Z
2017-11-17T08:10:19Z
2016
Article
Text
Lippoth, F.; Peletier, M.A.; Prokert, G.: A moving boundary problem for the Stokes equations involving osmosis: Variational modelling and short-time well-posedness. In: European Journal of Applied Mathematics 27 (2016), Nr. 4, S. 647-666. DOI: https://doi.org/10.1017/S0956792515000595
http://www.repo.uni-hannover.de/handle/123456789/2312
http://dx.doi.org/10.15488/2286
eng
European Journal of Applied Mathematics 27 (2016), Nr. 4
0956-7925
https://doi.org/10.1017/S0956792515000595
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23142022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T08:10:20Z
urn:hdl:123456789/2314
Analysis of a two-phase model describing the growth of solid tumors
Escher, Joachim
Matioc, Anca-Voichita
Classical solution
Radially symmetric stationary solution
Stability
Taxis
Tumor growth
Biophysical parameters
Cell apoptosis
Classical solutions
Far field
Healthy tissues
Mathematical formulation
Nutrient concentrations
Radially symmetric
Solid tumors
Stability properties
Stationary solutions
Steady state solution
Taxis
Tumor cells
Tumor growth
Two-phase model
Well-posed problems
Cell adhesion
Cell death
Cell proliferation
Convergence of numerical methods
Nutrients
Stability
Tumors
In this paper we consider a two-phase model describing the growth of avascular solid tumors when taking into account the effects of cell-to-cell adhesion and taxis due to nutrient. The tumor is surrounded by healthy tissue which is the source of nutrient for tumor cells. In a three-dimensional context, we prove that the mathematical formulation corresponds to a well-posed problem, and find radially symmetric steady-state solutions of the problem. They appear in the regime where the rate of cell apoptosis to cell proliferation is less than the far field nutrient concentration. Furthermore, we study the stability properties of those radially symmetric equilibria and find, depending on the biophysical parameters involved in the problem, both stable and unstable regimes for tumor growth. Copyright © Cambridge University Press 2012.
2017-11-17T08:10:20Z
2017-11-17T08:10:20Z
2013
Article
Text
Escher, J.; Matioc, A.V.: Analysis of a two-phase model describing the growth of solid tumors. In: European Journal of Applied Mathematics 24 (2013), Nr. 1, S. 25-48. DOI: https://doi.org/10.1017/S0956792512000290
http://www.repo.uni-hannover.de/handle/123456789/2314
http://dx.doi.org/10.15488/2288
eng
European Journal of Applied Mathematics 24 (2013), Nr. 1
0956-7925
https://doi.org/10.1017/S0956792512000290
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23202022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T08:10:22Z
urn:hdl:123456789/2320
Brill-Noether loci in codimension two
Tarasca, N.
Brill-Noether theory
moduli of curves
Let us consider the locus in the moduli space of curves of genus 2k defined by curves with a pencil of degree k. Since the Brill-Noether number is equal to - 2, such a locus has codimension two. Using the method of test surfaces, we compute the class of its closure in the moduli space of stable curves.
2017-11-17T08:10:22Z
2017-11-17T08:10:22Z
2013
Article
Text
Tarasca, N.: Brill-Noether loci in codimension two. In: Compositio Mathematica 149 (2013), Nr. 9, S. 1535-1568. DOI: https://doi.org/10.1112/S0010437X13007215
http://www.repo.uni-hannover.de/handle/123456789/2320
http://dx.doi.org/10.15488/2294
eng
Compositio Mathematica 149 (2013), Nr. 9
0010-437X
https://doi.org/10.1112/S0010437X13007215
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23232022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T08:34:55Z
urn:hdl:123456789/2323
Counting imaginary quadratic points via universal torsors
Derenthal, U.
Frei, C.
Del pezzo surfaces
Imaginary quadratic fields
Manin's conjecture
Universal torsors
A conjecture of Manin predicts the distribution of rational points on Fano varieties. We provide a framework for proofs of Manin's conjecture for del Pezzo surfaces over imaginary quadratic fields, using universal torsors. Some of our tools are formulated over arbitrary number fields. As an application, we prove Manin's conjecture over imaginary quadratic fields K for the quartic del Pezzo surface S of singularity type A3 with five lines given in double-struck PK4 by the equations x0x1 - x2x3 = x0x3 + x1x3 + x2x4 = 0. © Foundation Compositio Mathematica 2014.
2017-11-17T08:34:55Z
2017-11-17T08:34:55Z
2014
Article
Text
Derenthal, U.; Frei, C.: Counting imaginary quadratic points via universal torsors. In: Compositio Mathematica 150 (2014), Nr. 10, S. 1631-1678. DOI: https://doi.org/10.1112/S0010437X13007902
http://www.repo.uni-hannover.de/handle/123456789/2323
http://dx.doi.org/10.15488/2297
eng
Compositio Mathematica 150 (2014), Nr. 10
0010-437X
https://doi.org/10.1112/S0010437X13007902
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23252022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2018-03-20T23:05:15Z
urn:hdl:123456789/2325
Degree cones and monomial bases of lie algebras and quantum groups
Backhaus, Teodor
Fang, Xin
Fourier, Ghislain
degree cones
monomial bases
lie algebras
quantum groups
We provide ℕ-filtrations on the negative part Uq(−) of the quantum group associated to a finite-dimensional simple Lie algebra , such that the associated graded algebra is a skew-polynomial algebra on −. The filtration is obtained by assigning degrees to Lusztig's quantum PBW root vectors. The possible degrees can be described as lattice points in certain polyhedral cones. In the classical limit, such a degree induces an ℕ-filtration on any finite-dimensional simple -module. We prove for type An, Cn, B3, D4 and G2 that a degree can be chosen such that the associated graded modules are defined by monomial ideals, and conjecture that this is true for any g.
2017-11-17T08:34:56Z
2018-03-20T23:05:15Z
2017
Article
Text
Backhaus, T.; Fang, X.; Fourier, G.: Degree cones and monomial bases of lie algebras and quantum groups. In: Glasgow Mathematical Journal 59 (2017), Nr. 3, S. 595-621. DOI: https://doi.org/10.1017/S0017089516000422
http://www.repo.uni-hannover.de/handle/123456789/2325
http://dx.doi.org/10.15488/2299
eng
Glasgow Mathematical Journal 59 (2017), Nr. 3
0017-0895
https://doi.org/10.1017/S0017089516000422
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23272022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T08:34:57Z
urn:hdl:123456789/2327
Dynamics on supersingular K3 surfaces
Schütt, M.
Automorphism
Elliptic fibration
K3 surface
Lift-ability
Salem number
Supersingular
For any odd characteristic p ≡ 2 mod 3, we exhibit an explicit automorphism on the supersingular K3 surface of Artin invariant one which does not lift to any characteristic zero model. Our construction builds on elliptic fibrations to produce a closed formula for the automorphism's characteristic polynomial on second cohomology, which turns out to be an irreducible Salem polynomial of degree 22 with coefficients varying with p. © Swiss Mathematical Society.
2017-11-17T08:34:57Z
2017-11-17T08:34:57Z
2016
Article
Text
Schütt, M.: Dynamics on supersingular K3 surfaces. In: Commentarii Mathematici Helvetici 91 (2016), Nr. 4, S. 705-719. DOI: https://doi.org/10.4171/CMH/400
http://www.repo.uni-hannover.de/handle/123456789/2327
http://dx.doi.org/10.15488/2301
eng
Commentarii Mathematici Helvetici 91 (2016), Nr. 4
0010-2571
https://doi.org/10.4171/CMH/400
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23312022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T08:34:58Z
urn:hdl:123456789/2331
Equivariant Compactifications of Two-Dimensional Algebraic Groups
Derenthal, Ulrich
Loughran, Daniel
algebraic groups
del Pezzo surfaces
equivariant compactifications
Manin's conjectures
We classify generically transitive actions of semi-direct products Ga ⋊ Gm on ℙ2. Motivated by the program to study the distribution of rational points on del Pezzo surfaces (Manin's conjecture), we determine all (possibly singular) del Pezzo surfaces that are equivariant compactifications of homogeneous spaces for semi-direct products Ga ⋊ Gm. © 2014 The Edinburgh Mathematical Society.
2017-11-17T08:34:58Z
2017-11-17T08:34:58Z
2014
Article
Text
Derenthal, U.; Loughran, D.: Equivariant Compactifications of Two-Dimensional Algebraic Groups. In: Proceedings of the Edinburgh Mathematical Society 58 (2014), Nr. 1, S. 149-168. DOI: https://doi.org/10.1017/S001309151400042X
http://www.repo.uni-hannover.de/handle/123456789/2331
http://dx.doi.org/10.15488/2305
eng
Proceedings of the Edinburgh Mathematical Society 58 (2014), Nr. 1
0013-0915
https://doi.org/10.1017/S001309151400042X
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23342022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T08:34:59Z
urn:hdl:123456789/2334
Existence of affine realizations for Lévy term structure models
Tappe, S.
Affine realization
Invariant foliation
Lévy term structure model
Short-rate realization
Affine realization
Invariant foliation
Short-rate realization
Term structure
Industrial engineering
Engineering
We investigate the existence of affine realizations for term structure models driven by Lévy processes. It turns out that we obtain more severe restrictions on the volatility than in the classical diffusion case without jumps. As special cases, we study constant direction volatilities and the existence of short-rate realizations. © 2012 The Royal Society.
2017-11-17T08:34:59Z
2017-11-17T08:34:59Z
2012
Article
Text
Tappe, S.: Existence of affine realizations for Lévy term structure models. In: Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468 (2012), Nr. 2147, S. 3685-3704. DOI: https://doi.org/10.1098/rspa.2012.0089
http://www.repo.uni-hannover.de/handle/123456789/2334
http://dx.doi.org/10.15488/2308
eng
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468 (2012), Nr. 2147
1364-5021
https://doi.org/10.1098/rspa.2012.0089
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
London : Royal Society of London
oai:www.repo.uni-hannover.de:123456789/23352022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T09:26:03Z
urn:hdl:123456789/2335
Existence of affine realizations for stochastic partial differential equations driven by Lévy processes
Tappe, S.
Affine realization
Invariant foliation
Quasi-exponential volatility
Stochastic partial differential equation
Differential equations
Stochastic programming
Stochastic systems
Affine realizations
Invariant foliations
Quasi-exponential volatility
Semilinear
Stochastic partial differential equation
Partial differential equations
The goal of this paper is to clarify when a semilinear stochastic partial differential equation driven by Lévy processes admits an affine realization. Our results are accompanied by several examples arising in natural sciences and economics. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
2017-11-17T09:26:03Z
2017-11-17T09:26:03Z
2015
Article
Text
Tappe, S.: Existence of affine realizations for stochastic partial differential equations driven by Lévy processes. In: Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 471 (2015), Nr. 2178, 20150104. DOI: https://doi.org/10.1098/rspa.2015.0104
http://www.repo.uni-hannover.de/handle/123456789/2335
http://dx.doi.org/10.15488/2309
eng
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 471 (2015), Nr. 2178
1364-5021
https://doi.org/10.1098/rspa.2015.0104
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
London : Royal Society of London
oai:www.repo.uni-hannover.de:123456789/23382022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T09:26:04Z
urn:hdl:123456789/2338
Extending the Prym map to toroidal compactifications of the moduli space of abelian varieties (with an appendix by Mathieu Dutour Sikiric)
Casalaina-Martin, Sebastian
Grushevsky, Samuel
Hulek, Klaus
Laza, Radu
Dutour Sikiric, M.
Abelian varieties
Moduli
Period maps
Prym varieties
The main purpose of this paper is to present a conceptual approach to understanding the extension of the Prym map from the space of admissible double covers of stable curves to different toroidal compactifications of the moduli space of principally polarized abelian varieties. By separating the combinatorial problems from the geometric aspects we can reduce this to the computation of certain monodromy cones. In this way we not only shed new light on the extension results of Alexeev, Birkenhake, Hulek, and Vologodsky for the second Voronoi toroidal compactification, but we also apply this to other toroidal compactifications, in particular the perfect cone compactification, for which we obtain a combinatorial characterization of the indeterminacy locus, as well as a geometric description up to codimension six, and an explicit toroidal resolution of the Prym map up to codimension four. © 2017 European Mathematical Society.
2017-11-17T09:26:04Z
2017-11-17T09:26:04Z
2017
Article
Text
Casalaina-Martin, S.; Grushevsky, S.; Hulek, K.; Laza, R.; Dutour Sikiric, M.: Extending the Prym map to toroidal compactifications of the moduli space of abelian varieties (with an appendix by Mathieu Dutour Sikiric). In: Journal of the European Mathematical Society 19 (2017), Nr. 3, S. 659-723. DOI: https://doi.org/10.4171/JEMS/678
http://www.repo.uni-hannover.de/handle/123456789/2338
http://dx.doi.org/10.15488/2312
eng
Journal of the European Mathematical Society 19 (2017), Nr. 3
1435-9855
https://doi.org/10.4171/JEMS/678
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23402022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2019-07-05T22:05:02Z
urn:hdl:123456789/2340
Finite speed of propagation and waiting time for a thin-film Muskat problem
Laurençot, Philippe
Matioc, Bogdan-Vasile
degenerate parabolic system
finite propagation speed
waiting time
Propagation at a finite speed is established for non-negative weak solutions to a thin-film approximation of the two-phase Muskat problem. The expansion rate of the support matches the scale invariance of the system. Moreover, we determine sufficient conditions on the initial data for the occurrence of waiting time phenomena. Copyright © Royal Society of Edinburgh 2017
2017-11-17T09:26:05Z
2019-07-05T22:05:02Z
2017
Article
Text
Laurençot, P.; Matioc, B.-V.: Finite speed of propagation and waiting time for a thin-film Muskat problem. In: Proceedings of the Royal Society of Edinburgh Section A: Mathematics 147 (2017), Nr. 4, S. 813-830. DOI: https://doi.org/10.1017/S030821051600038X
http://www.repo.uni-hannover.de/handle/123456789/2340
http://dx.doi.org/10.15488/2314
eng
Proceedings of the Royal Society of Edinburgh Section A: Mathematics 147 (2017), Nr. 4
0308-2105
https://doi.org/10.1017/S030821051600038X
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23432022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T09:26:06Z
urn:hdl:123456789/2343
Generalized friezes and a modified Caldero-Chapoton map depending on a rigid object
Holm, Thorsten
Jørgensen, Peter
Primary 05E10
Secondary 13F60
16G70
18E30
The (usual) Caldero-Chapoton map is a map from the set of objects of a category to a Laurent polynomial ring over the integers. In the case of a cluster category, it maps reachable indecomposable objects to the corresponding cluster variables in a cluster algebra. This formalizes the idea that the cluster category is a categorification of the cluster algebra. The definition of the Caldero-Chapoton map requires the category to be 2-Calabi-Yau, and the map depends on a cluster-tilting object in the category. We study a modified version of the Caldero-Chapoton map which requires only that the category have a Serre functor and depends only on a rigid object in the category. It is well known that the usual Caldero-Chapoton map gives rise to so-called friezes, for instance, Conway-Coxeter friezes. We show that the modified Caldero-Chapoton map gives rise to what we call generalized friezes and that, for cluster categories of Dynkin type A, it recovers the generalized friezes introduced by combinatorial means in recent work by the authors and Bessenrodt. © 2015 by The Editorial Board of the Nagoya Mathematical Journal.
2017-11-17T09:26:06Z
2017-11-17T09:26:06Z
2015
Article
Text
Holm, T.; Jørgensen, P.: Generalized friezes and a modified Caldero-Chapoton map depending on a rigid object. In: Nagoya Mathematical Journal 218 (2015), Nr. 1, S. 101-124. DOI: https://doi.org/10.1215/00277630-2891495
http://www.repo.uni-hannover.de/handle/123456789/2343
http://dx.doi.org/10.15488/2317
eng
Nagoya Mathematical Journal 218 (2015), Nr. 1
0027-7630
https://doi.org/10.1215/00277630-2891495
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23452022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T09:26:06Z
urn:hdl:123456789/2345
Hele-Shaw flow in thin threads: A rigorous limit result
Matioc, Bogdan-Vasile
Prokert, Georg
Degenerate parabolic equation
Hele-Shaw flow
Surface tension
Thin Film equation
We rigorously prove the convergence of appropriately scaled solutions of the 2D Hele-Shaw moving boundary problem with surface tension in the limit of thin threads to the solution of the formally corresponding Thin Film equation. The proof is based on scaled parabolic estimates for the nonlocal, nonlinear evolution equations that arise from these problems. © European Mathematical Society 2012.
2017-11-17T09:26:06Z
2017-11-17T09:26:06Z
2012
Article
Text
Matioc, B.-V.; Prokert, G.: Hele-Shaw flow in thin threads: A rigorous limit result. In: Interfaces and Free Boundaries 14 (2012), Nr. 2, S. 205-230. DOI: https://doi.org/10.4171/IFB/280
http://www.repo.uni-hannover.de/handle/123456789/2345
http://dx.doi.org/10.15488/2319
eng
Interfaces and Free Boundaries 14 (2012), Nr. 2
1463-9963
https://doi.org/10.4171/IFB/280
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23492022-12-13T15:12:26Zcom_123456789_1col_123456789_10doc-type:Articledoc-type:Textopen_accessddc:330status-type:publishedVersionddc:510
2017-11-17T09:49:34Z
urn:hdl:123456789/2349
Information criteria for nonlinear time series models
Rinke, S.
Sibbertsen, P.
information criteria
Monte Carlo
nonlinear time series
threshold models
In this paper the performance of different information criteria for simultaneous model class and lag order selection is evaluated using simulation studies. We focus on the ability of the criteria to distinguish linear and nonlinear models. In the simulation studies, we consider three different versions of the commonly known criteria AIC, SIC and AICc. In addition, we also assess the performance of WIC and evaluate the impact of the error term variance estimator. Our results confirm the findings of different authors that AIC and AICc favor nonlinear over linear models, whereas weighted versions of WIC and all versions of SIC are able to successfully distinguish linear and nonlinear models. However, the discrimination between different nonlinear model classes is more difficult. Nevertheless, the lag order selection is reliable. In general, information criteria involving the unbiased error term variance estimator overfit less and should be preferred to using the usual ML estimator of the error term variance. © 2016 by De Gruyter.
2017-11-17T09:49:34Z
2017-11-17T09:49:34Z
2016
Article
Text
Rinke, S.; Sibbertsen, P.: Information criteria for nonlinear time series models. In: Studies in Nonlinear Dynamics and Econometrics 20 (2016), Nr. 3, S. 325-341. DOI: https://doi.org/10.1515/snde-2015-0026
http://www.repo.uni-hannover.de/handle/123456789/2349
http://dx.doi.org/10.15488/2323
eng
Studies in Nonlinear Dynamics and Econometrics 20 (2016), Nr. 3
1081-1826
https://doi.org/10.1515/snde-2015-0026
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Berlin : Walter de Gruyter
oai:www.repo.uni-hannover.de:123456789/23572022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T09:49:38Z
urn:hdl:123456789/2357
Non-negative global weak solutions for a degenerate parabolic system modelling thin films driven by capillarity
Matioc, Bogdan-Vasile
thin films
Galerkin approximations
parabolic system
We prove the global existence of non-negative weak solutions for a strongly coupled, fourth-order degenerate parabolic system governing the motion of two thin fluid layers in a porous medium when capillarity is the sole driving mechanism. © 2012 Royal Society of Edinburgh.
2017-11-17T09:49:38Z
2017-11-17T09:49:38Z
2012
Article
Text
Matioc, B.-V.: Non-negative global weak solutions for a degenerate parabolic system modelling thin films driven by capillarity. In: Proceedings of the Royal Society of Edinburgh Section A: Mathematics 142 (2012), Nr. 5, S. 1071-1085. DOI: https://doi.org/10.1017/S0308210511000680
http://www.repo.uni-hannover.de/handle/123456789/2357
http://dx.doi.org/10.15488/2331
eng
Proceedings of the Royal Society of Edinburgh Section A: Mathematics 142 (2012), Nr. 5
0308-2105
https://doi.org/10.1017/S0308210511000680
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23592022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T09:49:38Z
urn:hdl:123456789/2359
On a three-dimensional free boundary problem modeling electrostatic MEMS
Laurençot, P.
Walker, C.
Free boundary problem
MEMS
Stationary solutions
We consider the dynamics of an electrostatically actuated thin elastic plate being clamped at its boundary above a rigid plate. While the existing literature focuses so far on a two-dimensional geometry, the present model considers a three-dimensional device where the harmonic electrostatic potential varies in the three-dimensional time-dependent region between the plates. The elastic plate deflection evolves according to a fourth-order semilinear parabolic equation which is coupled to the square of the gradient trace of the electrostatic potential on this plate. The strength of the coupling is tuned by a parameter λ proportional to the square of the applied voltage. We prove that this free boundary problem is locally well-posed in time and that for small values of λ solutions exist globally in time. We also derive the existence of a branch of asymptotically stable stationary solutions for small values of λ and non-existence of stationary solutions for large values thereof, the latter being restricted to a disc-shaped plate. © European Mathematical Society 2016.
2017-11-17T09:49:38Z
2017-11-17T09:49:38Z
2016
Article
Text
Laurençot, P.; Walker, C.: On a three-dimensional free boundary problem modeling electrostatic MEMS. In: Interfaces and Free Boundaries 18 (2016), Nr. 3, S. 393-411. DOI: https://doi.org/10.4171/IFB/368
http://www.repo.uni-hannover.de/handle/123456789/2359
http://dx.doi.org/10.15488/2333
eng
Interfaces and Free Boundaries 18 (2016), Nr. 3
1463-9963
https://doi.org/10.4171/IFB/368
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23602022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T09:49:39Z
urn:hdl:123456789/2360
On the blow-up mechanism of moving boundary problems
Lippoth, Friedrich-Matthias
Blow-up
Moving boundary problem
We introduce the notion of maximal solutions of a class of moving boundary problems in the sense that we characterize what inhibits global existence of solutions. The technique is demonstrated on a model describing the growth of an avascular tumor. Further applications of the main result will be given elsewhere. © European Mathematical Society 2011.
2017-11-17T09:49:39Z
2017-11-17T09:49:39Z
2011
Article
Text
Lippoth, F.-M.: On the blow-up mechanism of moving boundary problems. In: Interfaces and Free Boundaries 13 (2011), Nr. 3, S. 423-435. DOI: https://doi.org/10.4171/IFB/266
http://www.repo.uni-hannover.de/handle/123456789/2360
http://dx.doi.org/10.15488/2334
eng
Interfaces and Free Boundaries 13 (2011), Nr. 3
1463-9963
https://doi.org/10.4171/IFB/266
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23632022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T10:07:35Z
urn:hdl:123456789/2363
On the justification of the quasistationary approximation of several parabolic moving boundary problems - Part II
Lippoth, Friedrich
Maximal regularity
Moving boundary problem
Quasistationary approximation
Singular limit
We rigorously justify the quasistationary approximations of two moving boundary problems. We work out a systematic procedure to derive a priori estimates that allow to pass to the singular limit. The problems under our consideration are a one-phase osmosis model and the one-phase Stefan problem with Gibbs-Thomson correction and kinetic undercooling. © European Mathematical Society 2016.
2017-11-17T10:07:35Z
2017-11-17T10:07:35Z
2016
Article
Text
Lippoth, F.: On the justification of the quasistationary approximation of several parabolic moving boundary problems - Part II. In: Interfaces and Free Boundaries 18 (2016), Nr. 3, S. 413-439. DOI: https://doi.org/10.4171/IFB/369
http://www.repo.uni-hannover.de/handle/123456789/2363
http://dx.doi.org/10.15488/2337
eng
Interfaces and Free Boundaries 18 (2016), Nr. 3
1463-9963
https://doi.org/10.4171/IFB/369
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23652022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T10:07:36Z
urn:hdl:123456789/2365
On the parabolicity of the Muskat problem: Well-posedness, fingering, and stability results
Escher, Joachim
Matioc, Bogdan-Vasile
Classical solution
Stability
Steady-state solutions
We study the Muskat problem in a periodic geometry and incorporate capillary as well as gravity effects in the modelling. The problem is rewritten as an abstract evolution equation. By analysing this evolution equation we prove wellposedness of the problem and we establish exponential stability of some flat equilibrium. Using bifurcation theory we also find finger shaped steady-states which are all unstable. © European Mathematical Society.
2017-11-17T10:07:36Z
2017-11-17T10:07:36Z
2011
Article
Text
Escher, J.; Matioc, B.-V.: On the parabolicity of the Muskat problem: Well-posedness, fingering, and stability results. In: Zeitschrift für Analysis und ihre Anwendung 30 (2011), Nr. 2, S. 193-218. DOI: https://doi.org/10.4171/ZAA/1431
http://www.repo.uni-hannover.de/handle/123456789/2365
http://dx.doi.org/10.15488/2339
eng
Zeitschrift für Analysis und ihre Anwendung 30 (2011), Nr. 2
0232-2064
https://doi.org/10.4171/ZAA/1431
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23672022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2019-05-24T22:05:03Z
urn:hdl:123456789/2367
Orbifold Zeta Functions for Dual Invertible Polynomials
Ebeling, W.
Gusein-Zade, S.M.
group action
invertible polynomial
monodromy
orbifold zeta function
An invertible polynomial in n variables is a quasi-homogeneous polynomial consisting of n monomials so that the weights of the variables and the quasi-degree are well defined. In the framework of the construction of mirror symmetric orbifold Landau–Ginzburg models, Berglund, Hübsch and Henningson considered a pair (f,G) consisting of an invertible polynomial f and an abelian group G of its symmetries together with a dual pair (Figure presented.). Here we study the reduced orbifold zeta functions of dual pairs (f,G) and (Figure presented.) and show that they either coincide or are inverse to each other depending on the number n of variables. Copyright © Edinburgh Mathematical Society 2016
2017-11-17T10:07:36Z
2019-05-24T22:05:03Z
2016
Article
Text
Ebeling, W.; Gusein-Zade, S.M.: Orbifold Zeta Functions for Dual Invertible Polynomials. In: Proceedings of the Edinburgh Mathematical Society 60 (2016), Nr. 1, S. 99-106. DOI: https://doi.org/10.1017/S0013091516000043
http://www.repo.uni-hannover.de/handle/123456789/2367
http://dx.doi.org/10.15488/2341
eng
Proceedings of the Edinburgh Mathematical Society 60 (2016), Nr. 1
0013-0915
https://doi.org/10.1017/S0013091516000043
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23682022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T10:07:37Z
urn:hdl:123456789/2368
Partially ample line bundles on toric varieties
Broomhead, N.
Ottem, J.C.
Prendergast-Smith, A.
Kodaira-type vanishing theorem
toric varieties
q-ample line bundles
In this note we study properties of partially ample line bundles on simplicial projective toric varieties. We prove that the cone of q-ample line bundles is a union of rational polyhedral cones, and calculate these cones in examples. We prove a restriction theorem for big q-ample line bundles, and deduce that q-ampleness of the anticanonical bundle is not invariant under flips. Finally we prove a Kodaira-type vanishing theorem for q-ample line bundles. © Glasgow Mathematical Journal Trust 2015.
2017-11-17T10:07:37Z
2017-11-17T10:07:37Z
2016
Article
Text
Broomhead, N.; Ottem, J.C.; Prendergast-Smith, A.: Partially ample line bundles on toric varieties. In: Glasgow Mathematical Journal 58 (2016), Nr. 3, S. 587-598. DOI: https://doi.org/10.1017/S001708951500035X
http://www.repo.uni-hannover.de/handle/123456789/2368
http://dx.doi.org/10.15488/2342
eng
Glasgow Mathematical Journal 58 (2016), Nr. 3
0017-0895
https://doi.org/10.1017/S001708951500035X
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23702022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T10:07:37Z
urn:hdl:123456789/2370
Pruned discrete random samples
Grübel, Rudolf
Hitczenko, Pawel
Chinese restaurant process
Digital search trees
Geometric distribution
Maxima
Tail behaviour
Let Xi, i N, be independent and identically distributed random variables with values in N0. We transform ('prune') the sequence {X1, ⋯ , Xn}, n N, of discrete random samples into a sequence {0, 1, 2, ⋯ , Yn}, n ? N, of contiguous random sets by replacing Xn+1 with Yn+1 if Xn+1 > Yn. We consider the asymptotic behaviour of Yn as n. Applications include path growth in digital search trees and the number of tables in Pitman's Chinese restaurant process if the latter is conditioned on its limit value. © 2013 Applied Probability Trust.
2017-11-17T10:07:37Z
2017-11-17T10:07:37Z
2013
Article
Text
Grübel, R.; Hitczenko, P.: Pruned discrete random samples. In: Journal of Applied Probability 50 (2013), Nr. 2, S. 542-556. DOI: https://doi.org/10.1017/S0021900200013553
http://www.repo.uni-hannover.de/handle/123456789/2370
http://dx.doi.org/10.15488/2344
eng
Journal of Applied Probability 50 (2013), Nr. 2
0021-9002
https://doi.org/10.1017/S0021900200013553
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23752022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2018-11-09T23:05:05Z
urn:hdl:123456789/2375
Shift–tail equivalence and an unbounded representative of the Cuntz–Pimsner extension
Goffeng, Magnus
Mesland, Bram
Rennie, Adam
Cuntz–Pimsner extension
non-commutative geometry
Cuntz–Krieger algebra
We show how the fine structure in shift–tail equivalence, appearing in the non-commutative geometry of Cuntz–Krieger algebras developed by the first two listed authors, has an analogue in a wide range of other Cuntz–Pimsner algebras. To illustrate this structure, and where it appears, we produce an unbounded representative of the defining extension of the Cuntz–Pimsner algebra constructed from a finitely generated projective bi-Hilbertian module, extending work by the third listed author with Robertson and Sims. As an application, our construction yields new spectral triples for Cuntz and Cuntz–Krieger algebras and for Cuntz–Pimsner algebras associated to vector bundles twisted by an equicontinuous -automorphism.
2017-11-17T12:10:51Z
2018-11-09T23:05:05Z
2016
Article
Text
Goffeng, M.; Mesland, B.; Rennie, A.: Shift–tail equivalence and an unbounded representative of the Cuntz–Pimsner extension. In: Ergodic Theory and Dynamical Systems 2016 (2016), S. 1-33. DOI: https://doi.org/10.1017/etds.2016.75
http://www.repo.uni-hannover.de/handle/123456789/2375
http://dx.doi.org/10.15488/2349
eng
Ergodic Theory and Dynamical Systems 2016 (2016)
0143-3857
https://doi.org/10.1017/etds.2016.75
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23772022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T12:10:52Z
urn:hdl:123456789/2377
Short-time asymptotic expansions of semilinear evolution equations
Fahrenwaldt, M.A.
asymptotic analysis
backward stochastic differential equations
Banach algebras
semilinear equations
We develop an algebraic approach to constructing short-time asymptotic expansions of solutions of a class of abstract semilinear evolution equations. The expansions are typically valid for both the solution of the equation and its gradient. We apply a perturbation approach based on the symbolic calculus of pseudo-differential operators and heat kernel methods. The construction is explicit and can be done to arbitrary order. All results are rigorously formulated in terms of Banach algebras. As an application we obtain a novel approach to finding approximate solutions of Markovian backward stochastic differential equations. © 2016 Royal Society of Edinburgh.
2017-11-17T12:10:52Z
2017-11-17T12:10:52Z
2016
Article
Text
Fahrenwaldt, M.A.: Short-time asymptotic expansions of semilinear evolution equations. In: Proceedings of the Royal Society of Edinburgh Section A: Mathematics 146 (2016), Nr. 1, S. 141-167. DOI: https://doi.org/10.1017/S0308210515000372
http://www.repo.uni-hannover.de/handle/123456789/2377
http://dx.doi.org/10.15488/2351
eng
Proceedings of the Royal Society of Edinburgh Section A: Mathematics 146 (2016), Nr. 1
0308-2105
https://doi.org/10.1017/S0308210515000372
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23812022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T12:10:53Z
urn:hdl:123456789/2381
Stability of equilibria of a two-phase Stokes-osmosis problem
Lippoth, Friedrich
Prokert, Georg
Maximal Lp-regularity
Moving boundary problem
Osmosis
Two-phase Stokes equations
Variational modelling
Within the framework of variational modelling we derive a two-phase moving boundary problem that describes the motion of a semipermeable membrane separating two viscous liquids in a fixed container. The model includes the effects of osmotic pressure and surface tension of the membrane. For this problem we prove that the manifold of steady states is locally exponentially attractive. © European Mathematical Society 2016.
2017-11-17T12:10:53Z
2017-11-17T12:10:53Z
2016
Article
Text
Lippoth, F.; Prokert, G.: Stability of equilibria of a two-phase Stokes-osmosis problem. In: Interfaces and Free Boundaries 18 (2016), Nr. 2, S. 161-179. DOI: https://doi.org/10.4171/IFB/361
http://www.repo.uni-hannover.de/handle/123456789/2381
http://dx.doi.org/10.15488/2355
eng
Interfaces and Free Boundaries 18 (2016), Nr. 2
1463-9963
https://doi.org/10.4171/IFB/361
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23822022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2019-06-21T22:05:03Z
urn:hdl:123456789/2382
Sub-Riemannian Ricci curvatures and universal diameter bounds for 3-Sasakian manifolds
Rizzi, L.
Silveira, P.
3-Sasakian
53-XX differential geometry
curvature
sub-Riemannian geometry
For a fat sub-Riemannian structure, we introduce three canonical Ricci curvatures in the sense of Agrachev–Zelenko–Li. Under appropriate bounds we prove comparison theorems for conjugate lengths, Bonnet–Myers type results and Laplacian comparison theorems for the intrinsic sub-Laplacian. As an application, we consider the sub-Riemannian structure of 3-Sasakian manifolds, for which we provide explicit curvature formulas. We prove that any complete 3-Sasakian structure of dimension 4d+3, with d>1, has sub-Riemannian diameter bounded by π. When d=1, a similar statement holds under additional Ricci bounds. These results are sharp for the natural sub-Riemannian structure on S4d+3
of the quaternionic Hopf fibrations:
S3↪S4d+3→HPd,
whose exact sub-Riemannian diameter is π, for all d⩾1
.
2017-11-17T12:10:53Z
2019-06-21T22:05:03Z
2017
Article
Text
Rizzi, L.; Silveira, P.: Sub-Riemannian Ricci curvatures and universal diameter bounds for 3-Sasakian manifolds. In: Journal of the Institute of Mathematics of Jussieu 2017 (2017), S. 1-45. DOI: https://doi.org/10.1017/S1474748017000226
http://www.repo.uni-hannover.de/handle/123456789/2382
http://dx.doi.org/10.15488/2356
eng
Journal of the Institute of Mathematics of Jussieu 2017 (2017)
1474-7480
https://doi.org/10.1017/S1474748017000226
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
oai:www.repo.uni-hannover.de:123456789/23842022-12-13T15:14:00Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T12:10:54Z
urn:hdl:123456789/2384
The freeness of ideal subarrangements of Weyl arrangements
Abe, Takuro
Barakat, Mohamed
Cuntz, Michael
Hoge, Torsten
Terao, Hiroaki
Arrangement of hyperplanes
Dual partition theorem
Free arrangement
Ideals
Root system
Weyl arrangement
A Weyl arrangement is the arrangement defined by the root system of a finite Weyl group. When a set of positive roots is an ideal in the root poset, we call the corresponding arrangement an ideal subarrangement. Our main theorem asserts that any ideal subarrangement is a free arrangement and that its exponents are given by the dual partition of the height distribution, which was conjectured by Sommers-Tymoczko. In particular, when an ideal subarrangement is equal to the entire Weyl arrangement, our main theorem yields the celebrated formula by Shapiro, Steinberg, Kostant, and Macdonald. The proof of the main theorem is classification-free. It heavily depends on the theory of free arrangements and thus greatly differs from the earlier proofs of the formula. © European Mathematical Society 2016.
2017-11-17T12:10:54Z
2017-11-17T12:10:54Z
2016
Article
Text
Abe, T.; Barakat, M.; Cuntz, M.; Hoge, T.; Terao, H.: The freeness of ideal subarrangements of Weyl arrangements. In: Journal of the European Mathematical Society 18 (2016), Nr. 6, S. 1339-1348. DOI: https://doi.org/10.4171/JEMS/615
http://www.repo.uni-hannover.de/handle/123456789/2384
http://dx.doi.org/10.15488/2358
eng
Journal of the European Mathematical Society 18 (2016), Nr. 6
1435-9855
https://doi.org/10.4171/JEMS/615
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Zürich : European Mathematical Society Publishing House
oai:www.repo.uni-hannover.de:123456789/23852022-12-13T15:12:27Zcom_123456789_1col_123456789_7doc-type:Articledoc-type:Textopen_accessstatus-type:publishedVersionddc:510
2017-11-17T12:10:55Z
urn:hdl:123456789/2385
The Hasse principle for lines on diagonal surfaces
Jahnel, Jörg
Loughran, Daniel
Hasse principle
mathematik
Given a number field k and a positive integer d, in this paper we consider the following question: does there exist a smooth diagonal surface of degree d in 3 over k which contains a line over every completion of k, yet no line over k? We answer the problem using Galois cohomology, and count the number of counter-examples using a result of Erdős.
2017-11-17T12:10:55Z
2017-11-17T12:10:55Z
2016
Article
Text
Jahnel, J.; Loughran, D.: The Hasse principle for lines on diagonal surfaces. In: Mathematical Proceedings of the Cambridge Philosophical Society 160 (2016), Nr. 1, S. 107-119. DOI: https://doi.org/10.1017/S0305004115000596
http://www.repo.uni-hannover.de/handle/123456789/2385
http://dx.doi.org/10.15488/2359
eng
Mathematical Proceedings of the Cambridge Philosophical Society 160 (2016), Nr. 1
0305-0041
https://doi.org/10.1017/S0305004115000596
Es gilt deutsches Urheberrecht. Das Dokument darf zum eigenen Gebrauch kostenfrei genutzt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
Cambridge : Cambridge University Press
didl///ddc:510/100