Results for "Timo Nolle"

total 982took 0.34s
Analyzing Business Process Anomalies Using AutoencodersMar 03 2018Businesses are naturally interested in detecting anomalies in their internal processes, because these can be indicators for fraud and inefficiencies. Within the domain of business intelligence, classic anomaly detection is not very frequently researched. ... More
BINet: Multi-perspective Business Process Anomaly ClassificationFeb 08 2019In this paper, we introduce BINet, a neural network architecture for real-time multi-perspective anomaly detection in business process event logs. BINet is designed to handle both the control flow and the data perspective of a business process. Additionally, ... More
RDF Validation Requirements - Evaluation and Logical UnderpinningJan 16 2015Jul 17 2015There are many case studies for which the formulation of RDF constraints and the validation of RDF data conforming to these constraint is very important. As a part of the collaboration with the W3C and the DCMI working groups on RDF validation, we identified ... More
Spaces with $G_m$-action, hyperbolic localization and nearby cyclesNov 05 2016We study families of algebraic spaces with a fiberwise $G_m$-action and prove Braden's theorem on hyperbolic localization for arbitrary base schemes. As an application, we obtain that hyperbolic localization commutes with nearby cycles.
Acoustic Neutrino Detection in Ice: Past, Present, and FutureOct 30 2012Acoustic neutrino detection is a promising technique to instrument the large volumes required to measure the small expected flux of ultra-high energy cosmogenic neutrinos. Using ice as detection medium allows for coincident detection of neutrino interactions ... More
Hydrodynamic profiles for the totally asymmetric exclusion process with a slow bondMar 08 2000We study a totally asymmetric simple exclusion process where jumps happen at rate one, except at the origin where the rate is lower. We prove a hydrodynamic scaling limit to a macroscopic profile described by a variational formula. The limit is valid ... More
Directed random growth models on the planeAug 20 2007This is a brief survey of laws of large numbers, fluctuation results and large deviation principles for asymmetric interacting particle systems that represent moving interfaces on the plane. We discuss the exclusion process, the Hammersley process and ... More
On the Tate-Shafarevich group of Abelian schemes over higher dimensional bases over finite fieldsOct 20 2014May 25 2016We study analogues for the Tate-Shafarevich group for Abelian schemes with everywhere good reduction over higher dimensional bases over finite fields.
Equivalent definitions of very strict $CD(K,N)$ -spacesJun 18 2019We show the equivalence of the definitions of very strict $CD(K,N)$ -condition defined, on one hand, using (only) the entropy functionals, and on the other, the full displacement convexity class $\mathcal{DC}_N$. In particular, we show that assuming the ... More
Improved Berezin-Li-Yau inequalities with a remainder termNov 30 2007We give an improvement of sharp Berezin type bounds on the Riesz means $\sum_k(\Lambda-\lambda_k)_+^\sigma$ of the eigenvalues $\lambda_k$ of the Dirichlet Laplacian in a domain if $\sigma\geq 3/2$. It contains a correction term of the order of the standard ... More
Overly determined agents prevent consensus in a generalized Deffuant model on $\mathbb{Z}$ with dispersed opinionsJan 13 2016During the last decades, quite a number of interacting particle systems have been introduced and studied in the border area of mathematics and statistical physics. Some of these can be seen as simplistic models for opinion formation processes in groups ... More
Galois subfields of inertially split division algebrasSep 09 2011Let D be a valued division algebra, finite-dimensional over its center F. Assume D has an unramified splitting field. The paper shows that if D contains a maximal subfield which is Galois over F (i.e. D is a crossed product) then the residue division ... More
Spaces with $\mathbb{G}_m$-action, hyperbolic localization and nearby cyclesNov 05 2016Aug 21 2018We study families of algebraic spaces with a fiberwise $\mathbb{G}_m$-action and prove Braden's theorem on hyperbolic localization for arbitrary base schemes. As an application, we obtain that hyperbolic localization commutes with nearby cycles.
A comparison of adic spaces and Berkovich spacesOct 13 2016This paper reviews the equivalence between the category of taut adic spaces that are locally of finite type and the category of strictly analytic Berkovich spaces. An explicit construction of this functor is provided by using the terminology of valuative ... More
Diffraction intensities of a class of binary Pisot substitutions via exponential sumsJul 26 2016This paper is concerned with the study of diffraction intensities of a relevant class of binary Pisot substitutions via exponential sums. Arithmetic properties of algebraic integers are used to give a new and constructive proof of the fact that there ... More
The Deffuant model on $\mathbb{Z}$ with higher-dimensional opinion spacesFeb 06 2014Aug 20 2014When it comes to the mathematical modelling of social interaction patterns, a number of different models have emerged and been studied over the last decade, in which individuals randomly interact on the basis of an underlying graph structure and share ... More
TaO$^+$, a Candidate Molecular Ion in Search of Physics Beyond the Standard ModelNov 26 2016The TaO$^+$ molecular ion is proposed as a candidate system for detecting signatures of charge parity (${\cal{CP}}$) violating physics beyond the standard model of elementary particles. The electron electric dipole moment (EDM) effective electric field ... More
A variational coupling for a totally asymmetric exclusion process with long jumps but no passingJun 28 1999We prove a weak law of large numbers for a tagged particle in a totally asymmetric exclusion process on the one-dimensional lattice. The particles are allowed to take long jumps but not pass each other. The object of the paper is to illustrate a special ... More
Second-order fluctuations and current across characteristic for a one-dimensional growth model of independent random walksOct 03 2003Apr 06 2005Fluctuations from a hydrodynamic limit of a one-dimensional asymmetric system come at two levels. On the central limit scale n^{1/2} one sees initial fluctuations transported along characteristics and no dynamical noise. The second order of fluctuations ... More
Anomaly Detection in Log Data using Graph Databases and Machine Learning to Defend Advanced Persistent ThreatsFeb 01 2018Advanced Persistent Threats (APTs) are a main impendence in cyber security of computer networks. In 2015, a successful breach remains undetected 146 days on average, reported by [Fi16].With our work we demonstrate a feasible and fast way to analyse real ... More
A growth model in multiple dimensions and the height of a random partial orderNov 04 2002Sep 07 2007We introduce a model of a randomly growing interface in multidimensional Euclidean space. The growth model incorporates a random order model as an ingredient of its graphical construction, in a way that replicates the connection between the planar increasing ... More
Diffusive fluctuations for one-dimensional totally asymmetric interacting random dynamicsAug 24 2001We study central limit theorems for a totally asymmetric, one-dimensional interacting random system. The models we work with are the Aldous-Diaconis-Hammersley process and the related stick model. The A-D-H process represents a particle configuration ... More
Recent results and open problems on the hydrodynamics of disordered asymmetric exclusion and zero-range processesJun 28 1999This paper summarizes results and some open problems about the large-scale and long-time behavior of asymmetric, disordered exclusion and zero-range processes. These processes have randomly chosen jump rates at the sites of the underlying lattice. The ... More
Variational formulas, Busemann functions, and fluctuation exponents for the corner growth model with exponential weightsSep 18 2017Jun 19 2018These lecture notes discuss several related features of the exactly solvable two-dimensional corner growth model with exponentially distributed weights. A key property of this model is the availability of a fairly explicit stationary version that possesses ... More
The isomorphism problem for cyclic algebras and its applicationFeb 23 2007May 04 2007The isomorphism problem means to decide if two given finite-dimensional simple algebras over the same centre are isomorphic and, if so, to construct an isomorphism between them. A solution to this problem has applications in computational aspects of representation ... More
On the conjecture of Birch and Swinnerton-Dyer for Abelian schemes over higher dimensional bases over finite fieldsOct 20 2014We formulate an analogue of the conjecture of Birch and Swinnerton-Dyer for Abelian schemes with everywhere good reduction over higher dimensional bases over finite fields. We prove some conditional results on it, and prove the conjecture for constant ... More
M$^2$VAE - Derivation of a Multi-Modal Variational Autoencoder Objective from the Marginal Joint Log-LikelihoodMar 18 2019This work gives an in-depth derivation of the trainable evidence lower bound obtained from the marginal joint log-Likelihood with the goal of training a Multi-Modal Variational Autoencoder (M$^2$VAE).
Strong law of large numbers for the interface in ballistic depositionJun 28 1999We prove a hydrodynamic limit for ballistic deposition on a multidimensional lattice. In this growth model particles rain down at random and stick to the growing cluster at the first point of contact. The theorem is that if the initial random interface ... More
Affine Grassmannians and Geometric Satake EquivalencesNov 05 2013Jul 07 2015I extend the ramified geometric Satake equivalence of Zhu from tamely ramified groups to include the case of general connected reductive groups. As a prerequisite I prove basic results on the geometry of affine flag varieties.
More Reduced Obstruction TheoriesSep 20 2012This short note first develops a general formalism for globally removing a factor from an obstruction theory. This formalism is then applied to give a construction of a reduced obstruction theory on the moduli of maps from a curve to a surface satisfying ... More
Deriving Deligne-Mumford Stacks with Perfect Obstruction TheoriesMay 21 2010Sep 03 2014We give conditions for a n-connective quasicoherent obstruction theory on a Deligne-Mumford stack to come from the structure of a connective spectral Deligne-Mumford stack on the underlying topos.
Lectures on F-theory compactifications and model buildingSep 17 2010Oct 12 2010These lecture notes are devoted to formal and phenomenological aspects of F-theory. We begin with a pedagogical introduction to the general concepts of F-theory, covering classic topics such as the connection to Type IIB orientifolds, the geometry of ... More
${\cal{(P,T)}}$-Odd Tensor-Pseudotensor Interactions in atomic {$^{199}$Hg} and {$^{225}$Ra}Nov 05 2018Highly correlated pure {\it{ab initio}} relativistic configuration interaction theory is in the present paper applied to the calculation of the tensor-pseudotensor ${\cal{(P,T)}}$-violating nucleon-electron interaction constant in the electronic ground ... More
Experimental and simulation study of irradiated silicon pad detectors for the CMS High Granularity CalorimeterNov 14 2017The foreseen upgrade of the LHC to its high luminosity phase (HL-LHC), will maximize the physics potential of the facility. The upgrade is expected to increase the instantaneous luminosity by a factor of 5 and deliver an integrated luminosity of 3000 ... More
Electrostatic interaction between non-identical charged particles at an electrolyte interfaceOct 15 2017In this thesis we study the lateral electrostatic interaction between a pair of non-identical, moderately charged colloidal particles trapped at an electrolyte interface in the limit of short inter-particle separations. Using a simplified model system ... More
Simulation of radiation-induced defectsSep 29 2015Mainly due to their outstanding performance the position sensitive silicon detectors are widely used in the tracking systems of High Energy Physics experiments such as the ALICE, ATLAS, CMS and LHCb at LHC, the world's largest particle physics accelerator ... More
Existence of optimal transport maps in very strict $CD(K,\infty)$ -spacesDec 11 2017We introduce a more restrictive version of the strict $CD(K,\infty)$ -condition, the so-called very strict $CD(K,\infty)$ -condition, and show the existence of optimal maps in very strict $CD(K,\infty)$ -spaces despite the possible lack of uniqueness ... More
Scaling for a one-dimensional directed polymer with boundary conditionsNov 12 2009Aug 26 2015We study a (1+1)-dimensional directed polymer in a random environment on the integer lattice with log-gamma distributed weights. Among directed polymers, this model is special in the same way as the last-passage percolation model with exponential or geometric ... More
On the Structure of the Graph of Unique Symmetric Base Exchanges of Bispanning GraphsJan 14 2016May 11 2016Bispanning graphs are undirected graphs with an edge set that can be decomposed into two disjoint spanning trees. The operation of symmetrically swapping two edges between the trees, such that the result is a different pair of disjoint spanning trees, ... More
On an analogue of the conjecture of Birch and Swinnerton-Dyer for Abelian schemes over higher dimensional bases over finite fieldsOct 20 2014Apr 07 2019We formulate an analogue of the conjecture of Birch and Swinnerton-Dyer for Abelian schemes with everywhere good reduction over higher dimensional bases over finite fields of characteristic $p$. We prove the prime-to-$p$ part conditionally on the finiteness ... More
A twisted Laurent series ring that is a noncrossed productMar 01 2007May 04 2007The striking results on noncrossed products were their existence (Amitsur) and the determination of Q(t) and Q((t)) as their smallest possible centres (Brussel). This paper gives the first fully explicit noncrossed product example over Q((t)). As a consequence, ... More
On absolute Galois splitting fields of central simple algebrasFeb 23 2007A splitting field of a central simple algebra is said to be absolute Galois if it is Galois over some fixed subfield of the centre of the algebra. The paper provides an existence theorem for such fields over global fields with enough roots of unity. As ... More
Coordinate free integrals in Geometric CalculusSep 28 2015Sep 14 2016We introduce a method for evaluating integrals in geometric calculus without introducing coordinates, based on using the fundamental theorem of calculus repeatedly and cutting the resulting manifolds so as to create a boundary and allow for the existence ... More
Integer matrices that are not copositive have certificates of less than quadratic complexityJun 17 2013A real symmetric n times n matrix is called copositive if the corresponding quadratic form is non-negative on the closed first orthant. If the matrix fails to be copositive there exists some non-negative certificate for which the quadratic form is negative. ... More
On the Calogero-Moser solution by root-type Lax pairNov 30 2011The `root type Lax pair' for the rational Calogero-Moser system for any simply-laced root system yields not a solution for the path q(t), but for the values of the inner products (\alpha,q(t)), where \alpha\ ranges over all roots of the root system. It ... More
Transition-Based Generation from Abstract Meaning RepresentationsJul 24 2017This work addresses the task of generating English sentences from Abstract Meaning Representation (AMR) graphs. To cope with this task, we transform each input AMR graph into a structure similar to a dependency tree and annotate it with syntactic information ... More
${\cal{P,T}}$-Odd and Magnetic Hyperfine Interaction Constants and Excited-State Lifetime for HfF$^+$Jun 09 2017Parity- and time-reversal-symmetry violating interaction constants required for the interpretation of a recent measurement (arXiv:1704.07928 [physics.atom-ph]) of corresponding symmetry violations in the $\Omega=1$ (${^3\Delta}_1$) science state of the ... More
Schubert varieties in twisted affine flag varieties and local modelsNov 24 2010Our concern in this paper is the dimension and inclusion relations of Schubert varieties in twisted partial affine flag varieties. In the end we apply our results to some local models of certain Schubert varieties.
Theorie des longitudinalen Atomstrahl-Spinechos und paritaetsverletzende Berry-Phasen in AtomenMay 17 2007May 18 2007We present a nonrelativistic theory for the quantum mechanical description of longitudinal atomic beam spin echo experiments, where a beam of neutral atoms is subjected to static electric and magnetic fields. The atomic wave function is the solution of ... More
An upper bound on the fluctuations of a second class particleMay 15 2002This note proves an upper bound for the fluctuations of a second-class particle in the totally asymmetric simple exclusion process. The proof needs a lower tail estimate for the last-passage growth model associated with the exclusion process. A stronger ... More
Second class particles as microscopic characteristics in totally asymmetric nearest-neighbor K-exclusion processesSep 04 2000We study aspects of the hydrodynamics of one-dimensional totally asymmetric K-exclusion, building on the hydrodynamic limit of Seppalainen (1999). We prove that the weak solution chosen by the particle system is the unique one with maximal current past ... More
Perturbation of the equilibrium for a totally asymmetric stick process in one dimensionSep 02 1999We study the evolution of a small perturbation of the equilibrium of a totally asymmetric one-dimensional interacting system. The model we take as example is Hammersley's process as seen from a tagged particle, which can be viewed as a process of interacting ... More
Existence, uniqueness and coalescence of directed planar geodesics: proof via the increment-stationary growth processDec 06 2018Jan 01 2019We present a proof of the almost sure existence, uniqueness and coalescence of directed semi-infinite geodesics in planar growth models that is based on properties of an increment-stationary version of the growth process. The argument is developed in ... More
Silicon Sensors for Trackers at High-Luminosity EnvironmentNov 26 2014Mar 12 2015The planned upgrade of the LHC accelerator at CERN, namely the high luminosity (HL) phase of the LHC (HL-LHC foreseen for 2023), will result in a more intense radiation environment than the present tracking system was designed for. The required upgrade ... More
A new approach to the geometric Satake equivalenceJul 23 2012Sep 24 2012I give another proof of the geometric Satake equivalence from Mirkovic-Vilonen over a separably closed field. Using Galois descent, I obtain a canonical construction of the Galois form of the full $L$-group.
Scalable String and Suffix Sorting: Algorithms, Techniques, and ToolsAug 02 2018This dissertation focuses on two fundamental sorting problems: string sorting and suffix sorting. The first part considers parallel string sorting on shared-memory multi-core machines, the second part external memory suffix sorting using the induced sorting ... More
Heterotic Vacua from general (non-) Abelian BundlesDec 15 2005Dec 22 2005We report on the construction of four-dimensional string vacua by considering general abelian and non-abelian bundles on an internal Calabi-Yau for both heterotic theories. The structure of the resulting gauge sector is extremely rich and gives rise to ... More
Detection of ultra high energy neutrinos with an underwater very large volume array of acoustic sensors: A simulation studyAug 15 2006This thesis investigates the detection of ultra high energy (E > 1 EeV) cosmic neutrinos using acoustic sensors immersed in water. The method is based on the thermoacoustic model describing the production of microsecond bipolar acoustic pulses by neutrino-induced ... More
A Direct Approach to Noncrossed Product Division AlgebrasSep 07 2011A valuation theoretic approach is presented that directly leads to division algebras that are noncrossed products (instead of, e.g., describing Brauer classes of noncrossed products in an abstract manner). While this feature is shared by Amitsur's original ... More
Current fluctuations for stochastic particle systems with drift in one spatial dimensionApr 13 2010This review article discusses limit distributions and variance bounds for particle current in several dynamical stochastic systems of particles on the one-dimensional integer lattice: independent particles, independent particles in a random environment, ... More
Existence, uniqueness and coalescence of directed planar geodesics: proof via the increment-stationary growth processDec 06 2018Jul 13 2019We present a proof of the almost sure existence, uniqueness and coalescence of directed semi-infinite geodesics in planar growth models that is based on properties of an increment-stationary version of the growth process. The argument is developed in ... More
Attentive Mimicking: Better Word Embeddings by Attending to Informative ContextsApr 02 2019Learning high-quality embeddings for rare words is a hard problem because of sparse context information. Mimicking (Pinter et al., 2017) has been proposed as a solution: given embeddings learned by a standard algorithm, a model is first trained to reproduce ... More
On the Emotion of Users in App ReviewsMar 07 2017App store analysis has become an important discipline in recent software engineering research. It empirically studies apps using information mined from their distribution platforms. Information provided by users, such as app reviews, are of high interest ... More
G4-Flux and Standard Model Vacua in F-theoryApr 14 2016Sep 16 2016We study the geometry of gauge fluxes in four-dimensional F-theory vacua with gauge group SU(3)xSU(2)xU(1)xU(1) and its implications for phenomenology. The models are defined by a previously introduced class of elliptic fibrations whose fibre is given ... More
Optimal transport maps on Alexandrov spaces revisitedMar 27 2018Apr 03 2018We give an alternative proof for the fact that in $n$-dimensional Alexandrov spaces with curvature bounded below there exists a unique optimal transport plan from any purely $(n-1)$-unrectifiable starting measure, and that this plan is induced by an optimal ... More
Robust semi-Dirac points and unconventional topological phase transitions in doped superconducting Sr2IrO4 tunnel coupled to t2g electron systemsMay 08 2017Jan 11 2018Semi-Dirac fermions are known to exist at the critical points of topological phase transitions requiring fine-tuning of the parameters. We show that robust semi-Dirac points can appear in a heterostructure consisting of superconducting Sr2IrO4 and a t2g ... More
The Pareto Frontier for Random MechanismsFeb 20 2015Jan 10 2017We study the trade-offs between strategyproofness and other desiderata, such as efficiency or fairness, that often arise in the design of random ordinal mechanisms. We use approximate strategyproofness to define manipulability, a measure to quantify the ... More
Partial Strategyproofness: Relaxing Strategyproofness for the Random Assignment ProblemJan 15 2014Jul 10 2017We present partial strategyproofness, a new, relaxed notion of strategyproofness for studying the incentive properties of non-strategyproof assignment mechanisms. Informally, a mechanism is partially strategyproof if it makes truthful reporting a dominant ... More
Noncrossed products in Witt's TheoremMay 16 2009May 21 2009Since Amitsur's discovery of noncrossed product division algebras more than 35 years ago, their existence over more familiar fields has been an object of investigation. Brussel's work was a culmination of this effort, exhibiting noncrossed products over ... More
Solar Line Asymmetries: Modelling the Effect of Granulation on the Solar SpectrumAug 21 2017A parametric model of granulation employing a small number of parameters was developed. Synthetic spectra calculated using this model closely match observed spectra and, in particular, reproduce the asymmetries observed in spectral lines. Both the microturbulent ... More
Temporal Ensembling for Semi-Supervised LearningOct 07 2016In this paper, we present a simple and efficient method for training deep neural networks in a semi-supervised setting where only a small portion of training data is labeled. We introduce temporal ensembling, where we form a consensus prediction of the ... More
Segregating Markov chainsOct 13 2015Dealing with finite Markov chains in discrete time, the focus often lies on convergence behavior and one tries to make different copies of the chain meet as fast as possible and then stick together. There is, however, a very peculiar kind of discrete ... More
The Efficient Frontier in Randomized Social ChoiceFeb 20 2015Mar 02 2015Since the celebrated Gibbard-Satterthwaite impossibility results and Gibbard's 1977 extension for randomized rules, it is known that strategyproofness imposes severe restrictions on the design of social choice rules. In this paper, we employ approximate ... More
The Naive versus the Adaptive Boston MechanismJun 12 2014The Boston mechanism is often criticized for its manipulability and the resulting negative implications for welfare and fairness. Nonetheless, it is one of the most popular school choice mechanisms used in practice. In this paper, we first study the traditional ... More
Spectral asymptotics for the Dirichlet Laplacian with a Neumann window via a Birman-Schwinger analysis of the Dirichlet-to-Neumann operatorNov 17 2015In the present article we will give a new proof of the ground state asymptotics of the Dirichlet Laplacian with a Neumann window acting on functions which are defined on a two-dimensional infinite strip or a three-dimensional infinite layer. The proof ... More
Further results on consensus formation in the Deffuant modelNov 13 2013Jan 17 2014The so-called Deffuant model describes a pattern for social interaction, in which two neighboring individuals randomly meet and share their opinions on a certain topic, if their discrepancy is not beyond a given threshold $\theta$. The major focus of ... More
Homomorphic Payment Addresses and the Pay-to-Contract ProtocolDec 13 2012We propose an electronic payment protocol for typical customer-merchant relations which does not require a trusted (signed) payment descriptor to be sent from the merchant to the customer. Instead, the destination "account" number for the payment is solely ... More
Decomposition mechanisms in metal borohydrides and their ammoniatesApr 25 2017Ammoniation in metal borohydrides (MBs) with the form $\mathcal{M}$(BH$_4$)$_x$ has been shown to lower their decomposition temperatures with $\mathcal{M}$ of low electronegativity ($\chi_p \lesssim 1.6$), but raise it for high-$\chi_p$ MBs ($\chi_p \gtrsim ... More
Retrofitting and the mu ProblemJun 02 2009One of the challenges of supersymmetry (SUSY) breaking and mediation is generating a mu term consistent with the requirements of electro-weak symmetry breaking. The most common approach to the problem is to generate the mu term through a SUSY breaking ... More
Deterministic Secure Direct Communication Using EntanglementSep 05 2002Oct 13 2002A novel secure communication protocol is presented, based on an entangled pair of qubits and allowing asymptotically secure key distribution and quasi-secure direct communication. Since the information is transferred in a deterministic manner, no qubits ... More
Towards an implementable dependency grammarSep 01 1998Sep 02 1998The aim of this paper is to define a dependency grammar framework which is both linguistically motivated and computationally parsable. See the demo at
Rare Words: A Major Problem for Contextualized Embeddings And How to Fix it by Attentive MimickingApr 14 2019Pretraining deep neural network architectures with a language modeling objective has brought large improvements for many natural language processing tasks. Exemplified by BERT, a recently proposed such architecture, we demonstrate that despite being trained ... More
The SDA Method for Numerical Solution of Lur'e EquationsJan 06 2011We introduce a numerical method for the numerical solution of the so-called Lur'e matrix equations that arise in balancing-related model reduction and linear-quadratic infinite time horizon optimal control. Based on the fact that the set of solutions ... More
Regression Based Expected Shortfall BacktestingJan 12 2018In this article, we introduce a regression based backtest for the risk measure Expected Shortfall (ES) which is based on a joint regression framework for the quantile and the ES. We also introduce a second variant of this ES backtest which allows for ... More
Quasi-adiabatic path integral approach for quantum systems under the influence of multiple non-commuting fluctuationsAug 10 2018Quantum systems are typically subject to various environmental noise sources. Treating these environmental disturbances with a system-bath approach beyond weak coupling one must refer to numerical methods as, for example, the numerically exact quasi-adiabatic ... More
Testing for Causality in Continuous Time Bayesian Network Models of High-Frequency DataJan 25 2016Continuous time Bayesian networks are investigated with a special focus on their ability to express causality. A framework is presented for doing inference in these networks. The central contributions are a representation of the intensity matrices for ... More
On the Discrete Spectrum of a Pseudo-Relativistic Two-Body Pair OperatorNov 22 2001We prove Cwikel-Lieb-Rosenbljum and Lieb-Thirring type bounds on the discrete spectrum of a two-body pair operator and calculate spectral asymptotics for the eigenvalue moments and the local spectral density in the pseudo-relativistic limit.
Drilling deep in South Pole IceOct 20 2014To detect the tiny flux of ultra-high energy neutrinos from active galactic nuclei or from interactions of highest energy cosmic rays with the microwave background photons needs target masses of the order of several hundred cubic kilometers. Clear Antarctic ... More
Ring Migration Topology Helps Bypassing Local OptimaJun 04 2018Running several evolutionary algorithms in parallel and occasionally exchanging good solutions is referred to as island models. The idea is that the independence of the different islands leads to diversity, thus possibly exploring the search space better. ... More
Normalized Features for Improving the Generalization of DNN Based Speech EnhancementSep 07 2017Jan 15 2018Enhancing noisy speech is an important task to restore its quality and to improve its intelligibility. In traditional non-machine-learning (ML) based approaches the parameters required for noise reduction are estimated blindly from the noisy observation ... More
On the Importance of Super-Gaussian Speech Priors for Machine-Learning Based Speech EnhancementMar 15 2017Jan 16 2018For enhancing noisy signals, machine-learning based single-channel speech enhancement schemes exploit prior knowledge about typical speech spectral structures. To ensure a good generalization and to meet requirements in terms of computational complexity ... More
Parallel solution, adaptivity, computational convergence, and open-source code of 2d and 3d pressurized phase-field fracture problemsJun 26 2018We present a scalable, parallel implementation of a solver for the solution of a phase-field model for quasi-static brittle fracture. The code is available as open source. Numerical solutions in 2d and 3d with adaptive mesh refinement show optimal scaling ... More
Segregating Markov chainsOct 13 2015Feb 14 2017Dealing with finite Markov chains in discrete time, the focus often lies on convergence behavior and one tries to make different copies of the chain meet as fast as possible and then stick together. There is, however, a very peculiar kind of discrete ... More
A note on measures vanishing at infinityOct 11 2016In this paper, we review the basic properties of measures vanishing at infinity and prove a version of the Riemann--Lebesgue lemma for Fourier transformable measures.
Ergodic frequency measures for random substitutionsOct 25 2018We construct a family of ergodic measures on random substitution subshifts (RS-subshifts) associated to a primitive random substitution. In particular, the word frequencies of every finite legal word exist for almost every element of the random substitution ... More
Dynamical systems arising from random substitutionsJul 31 2017Random substitutions are a natural generalisation of their classical `deterministic' counterpart, whereby at every step of iterating the substitution, instead of replacing a letter with a predetermined word, every letter is independently replaced by a ... More
Training Object Detectors on Synthetic Images Containing Reflecting MaterialsMar 29 2019One of the grand challenges of deep learning is the requirement to obtain large labeled training data sets. While synthesized data sets can be used to overcome this challenge, it is important that these data sets close the reality gap, i.e., a model trained ... More
Two weight inequality for vector-valued positive dyadic operators by parallel stopping cubesApr 28 2014Mar 05 2015We study the vector-valued positive dyadic operator \[T_\lambda(f\sigma):=\sum_{Q\in\mathcal{D}} \lambda_Q \int_Q f \mathrm{d}\sigma 1_Q,\] where the coefficients $\{\lambda_Q:C\to D\}_{Q\in\mathcal{D}}$ are positive operators from a Banach lattice $C$ ... More
Attentive Mimicking: Better Word Embeddings by Attending to Informative ContextsApr 02 2019Apr 05 2019Learning high-quality embeddings for rare words is a hard problem because of sparse context information. Mimicking (Pinter et al., 2017) has been proposed as a solution: given embeddings learned by a standard algorithm, a model is first trained to reproduce ... More