510 Mathematik
Refine
Year of publication
Document Type
- Article (187)
- Doctoral Thesis (129)
- Preprint (44)
- diplomthesis (38)
- Report (21)
- Book (17)
- Contribution to a Periodical (12)
- Master's Thesis (12)
- Conference Proceeding (11)
- Diploma Thesis (10)
Has Fulltext
- yes (498)
Is part of the Bibliography
- no (498)
Keywords
- Kongress (6)
- Kryptologie (5)
- Mathematik (5)
- Stochastik (5)
- Online-Publikation (4)
- Statistik (4)
- point process (4)
- Brownian motion (3)
- Finanzmathematik (3)
- LLL-reduction (3)
Institute
- Mathematik (320)
- Informatik und Mathematik (93)
- Informatik (54)
- Präsidium (13)
- Frankfurt Institute for Advanced Studies (FIAS) (9)
- Physik (9)
- Medizin (4)
- Goethe-Zentrum für Wissenschaftliches Rechnen (G-CSC) (3)
- Wirtschaftswissenschaften (3)
- Biochemie und Chemie (2)
Der Artikel stellt aktuelle stilometrische Studien im Delta-Kontext vor. Diskutiert wird, warum die Verwendung des Kosinus-Abstands zu einer Verbesserung der Erfolgsquote führt; durch Experimente zur Vektornormalisierung gelingt es, die Funktionsweise von Delta besser zu verstehen. Anhand von mittelhochdeutschen Texten wird gezeigt, dass auch metrische Eigenschaften zur Autorschaftsattribution eingesetzt werden können. Zudem wird untersucht, inwieweit die mittelalterliche, nicht-normierte Schreibung die Erfolgsquote von Delta beeinflusst. Am Beispiel von arabisch-lateinischen Übersetzungen wird geprüft, inwieweit eine selektive Merkmalseliminierung dazu beitragen kann, das Übersetzersignal vom Genresignal zu isolieren.
[Nachruf] Wolfgang Schwarz
(2013)
Based on the quadratic residuosity assumption we present a non-interactive crypto-computing protocol for the greater-than function, i.e., a non-interactive procedure between two parties such that only the relation of the parties' inputs is revealed. In comparison to previous solutions our protocol reduces the number of modular multiplications significantly. We also discuss applications to conditional oblivious transfer, private bidding and the millionaires' problem.
Derived from a biophysical model for the motion of a crawling cell, the evolution system(⋆){ut=Δu−∇⋅(u∇v),0=Δv−kv+u, is investigated in a finite domain Ω⊂Rn, n≥2, with k≥0. Whereas a comprehensive literature is available for cases in which (⋆) describes chemotaxis-driven population dynamics and hence is accompanied by homogeneous Neumann-type boundary conditions for both components, the presently considered modeling context, besides yet requiring the flux ∂νu−u∂νv to vanish on ∂Ω, inherently involves homogeneous Dirichlet boundary conditions for the attractant v, which in the current setting corresponds to the cell's cytoskeleton being free of pressure at the boundary. This modification in the boundary setting is shown to go along with a substantial change with respect to the potential to support the emergence of singular structures: It is, inter alia, revealed that in contexts of radial solutions in balls there exist two critical mass levels, distinct from each other whenever k>0 or n≥3, that separate ranges within which (i) all solutions are global in time and remain bounded, (ii) both global bounded and exploding solutions exist, or (iii) all nontrivial solutions blow up. While critical mass phenomena distinguishing between regimes of type (i) and (ii) belong to the well-understood characteristics of (⋆) when posed under classical no-flux boundary conditions in planar domains, the discovery of a distinct secondary critical mass level related to the occurrence of (iii) seems to have no nearby precedent. In the planar case with the domain being a disk, the analytical results are supplemented with some numerical illustrations, and it is discussed how the findings can be interpreted biophysically for the situation of a cell on a flat substrate.
We propose a fast variant of the Gaussian algorithm for the reduction of two dimensional lattices for the l1-, l2- and l-infinite- norm. The algorithm runs in at most O(nM(B) logB) bit operations for the l-infinite- norm and in O(n log n M(B) logB) bit operations for the l1 and l2 norm on input vectors a, b 2 ZZn with norm at most 2B where M(B) is a time bound for B-bit integer multiplication. This generalizes Schönhages monotone Algorithm [Sch91] to the centered case and to various norms.
We derive a shape derivative formula for the family of principal Dirichlet eigenvalues λs(Ω) of the fractional Laplacian (−Δ)s associated with bounded open sets Ω⊂RN of class C1,1. This extends, with a help of a new approach, a result in Dalibard and Gérard-Varet (Calc. Var. 19(4):976–1013, 2013) which was restricted to the case s=12. As an application, we consider the maximization problem for λs(Ω) among annular-shaped domains of fixed volume of the type B∖B¯¯¯¯′, where B is a fixed ball and B′ is ball whose position is varied within B. We prove that λs(B∖B¯¯¯¯′) is maximal when the two balls are concentric. Our approach also allows to derive similar results for the fractional torsional rigidity. More generally, we will characterize one-sided shape derivatives for best constants of a family of subcritical fractional Sobolev embeddings.
We consider versions of the FIND algorithm where the pivot element used is the median of a subset chosen uniformly at random from the data. For the median selection we assume that subsamples of size asymptotic to c⋅nα are chosen, where 0<α≤12, c>0 and n is the size of the data set to be split. We consider the complexity of FIND as a process in the rank to be selected and measured by the number of key comparisons required. After normalization we show weak convergence of the complexity to a centered Gaussian process as n→∞, which depends on α. The proof relies on a contraction argument for probability distributions on càdlàg functions. We also identify the covariance function of the Gaussian limit process and discuss path and tail properties.