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DeepMoD: Deep learning for Model Discovery in noisy dataApr 20 2019We introduce DeepMoD, a deep learning based model discovery algorithm which seeks the partial differential equation underlying a spatio-temporal data set. DeepMoD employs sparse regression on a library of basis functions and their corresponding spatial ... More

Crowding induced clustering under confinementJul 17 2015We present Langevin dynamics simulations that study the collective behavior of driven particles embedded in a densely packed background consisting of passive particles. Depending on the driving force, the densities of driven and passive particles, and ... More

A method for molecular dynamics on curved surfacesNov 11 2014Feb 24 2016Dynamics simulations of constrained particles can greatly aid in understanding the temporal and spatial evolution of biological processes such as lateral transport along membranes and self-assembly of viruses. Most theoretical efforts in the field of ... More

Confinement without boundaries: Anisotropic diffusion on the surface of a cylinderJul 14 2014Jul 21 2014Densely packed systems of thermal particles in curved geometries are frequently encountered in biological and microfluidic systems. In 2D systems, at sufficiently high surface coverage, diffusive motion is widely known to be strongly affected by physical ... More

Actin Remodeling and Polymerization Forces Control Dendritic Spine MorphologyOct 29 2015Oct 30 2015Dendritic spines are small membranous structures that protrude from the neuronal dendrite. Each spine contains a synaptic contact site that may connect its parent dendrite to the axons of neighboring neurons. Dendritic spines are markedly distinct in ... More

The Complexity of Simultaneous Geometric Graph EmbeddingFeb 28 2013May 07 2015Given a collection of planar graphs $G_1,\dots,G_k$ on the same set $V$ of $n$ vertices, the simultaneous geometric embedding (with mapping) problem, or simply $k$-SGE, is to find a set $P$ of $n$ points in the plane and a bijection $\phi: V \to P$ such ... More

Kac-Moody groups as discrete groupsFeb 18 2004This survey paper presents the discrete group viewpoint on Kac-Moody groups. Over finite fields, the latter groups are finitely generated; they act on new buildings enjoying remarkable negative curvature properties. The study of these groups is shared ... More

The Fyodorov-Bouchaud formula and Liouville conformal field theoryOct 18 2017Apr 30 2018In a remarkable paper in 2008, Fyodorov and Bouchaud conjectured an exact formula for the density of the total mass of (sub-critical) Gaussian multiplicative chaos (GMC) associated to the Gaussian free field (GFF) on the unit circle. In this paper we ... More

Liouville quantum gravity on the annulusNov 17 2017Jul 06 2018In this work we construct Liouville quantum gravity on an annulus in the complex plane. This construction is aimed at providing a rigorous mathematical framework to the work of theoretical physicists initiated by Polyakov in 1981. It is also a very important ... More

Kac-Moody groups: split and relative theories. LatticesNov 17 2002In this survey article, we recall some facts about split Kac-Moody groups as defined by J. Tits, describe their main properties and then propose an analogue of Borel-Tits theory for a non-split version of them. The main result is a Galois descent theorem, ... More

Forced transport of deformable containers through narrow constrictionsMay 06 2014Nov 19 2014We study, numerically and analytically, the forced transport of deformable containers through a narrow constriction. Our central aim is to quantify the competition between the constriction geometry and the active forcing, regulating whether and at which ... More

Geometric localization in supported elastic strutsJun 11 2019Localized deformation patterns are a common motif in morphogenesis and are increasingly finding widespread applications in materials science, for instance as memory devices. Here we describe the emergence of spatially localized deformations in a minimal ... More

Active elastohydrodynamics of vesicles in narrow, blind constrictionsMay 04 2017Dec 06 2017Fluid-resistance limited transport of vesicles through narrow constrictions is a recurring theme in many biological and engineering applications. Inspired by the motor-driven movement of soft membrane-bound vesicles into closed neuronal dendritic spines, ... More

Perfect and separating Hash families: new bounds via the algorithmic cluster expansion local lemmaJan 20 2016We present new lower bounds for the size of perfect and separating hash families ensuring their existence. Such new bounds are based on the algorithmic Cluster expansion improved version of the Lov\'asz Local Lemma, which also implies that the Moser-Tardos ... More

On the origin of the exponential decay of the Loschmidt echo in integrable systemsDec 11 2013Feb 18 2014We address the time decay of the Loschmidt echo, measuring sensitivity of quantum dynamics to small Hamiltonian perturbations, in one-dimensional integrable systems. Using semiclassical analysis, we show that the Loschmidt echo may exhibit a well-pronounced ... More

Topological simplicity, commensurator super-rigidity and non-linearities of Kac-Moody groupsFeb 10 2003Feb 23 2003We provide new arguments to see topological Kac-Moody groups as generalized semisimple groups over local fields: they are products of topologically simple groups and their Iwahori subgroups are the normalizers of the pro-p Sylow subgroups. We use a dynamical ... More

Frustrated collisions and unconventional pairing on a quantum superlatticeApr 26 2010May 20 2010We solve the problem of scattering and binding of two spin-1/2 fermions on a one-dimensional superlattice with a period of twice the lattice spacing analytically. We find the exact bound states and the scattering states, consisting of a generalized Bethe ... More

Perfect and separating Hash families: new bounds via the algorithmic cluster expansion local lemmaJan 20 2016Dec 09 2016We present new lower bounds for the size of perfect and separating hash families ensuring their existence. Such new bounds are based on the algorithmic Cluster expansion improved version of the Lov\'asz Local Lemma, which also implies that the Moser-Tardos ... More

Topological groups of Kac-Moody type, Fuchsian twinnings and their latticesMay 04 2002This paper deals with a class of totally disconnected groups acting on buildings, among which are certain Kac-Moody groups. The apartments of our buildings are hyperbolic planes tiled by right-angled polygons. We discuss linearity properties for the groups, ... More

Halving Balls in Deterministic Linear TimeMay 08 2014Let $\D$ be a set of $n$ pairwise disjoint unit balls in $\R^d$ and $P$ the set of their center points. A hyperplane $\Hy$ is an \emph{$m$-separator} for $\D$ if each closed halfspace bounded by $\Hy$ contains at least $m$ points from $P$. This generalizes ... More

Quasi-isometric invariance of continuous group $L^p$-cohomology, and first applications to vanishingsMar 25 2018Feb 24 2019We show that the continuous $L^p$-cohomology of locally compact second countable groups is a quasi-isometric invariant. As an application, we prove partial results supporting a positive answer to a question asked by M.~Gromov, suggesting a classical behaviour ... More

High-precision spectroscopy of the forbidden 2 3S1 - 2 1P1 transition in quantum degenerate metastable heliumApr 07 2014We have measured the forbidden 2 3S1 - 2 1P1 transition at 887 nm in a quantum degenerate gas of metastable He-4 atoms confined in an optical dipole trap. The determined transition frequency is 338 133 594.4 (0.5) MHz, from which we obtain an ionization ... More

Quasi-isometric invariance of continuous group $L^p$-cohomology, and first applications to vanishingsMar 25 2018Apr 09 2018We show that the continuous $L^p$-cohomology of locally compact second countable groups is a quasi-isometric invariant. As an application, we prove partial results supporting a positive answer to a question asked by M.~Gromov, suggesting a classical behaviour ... More

Challenges in Community Discovery on Temporal NetworksJul 26 2019Community discovery is one of the most studied problems in network science. In recent years, many works have focused on discovering communities in temporal networks, thus identifying dynamic communities. Interestingly, dynamic communities are not mere ... More

On some pro-p groups from infinite-dimensional Lie theoryFeb 18 2013We initiate the study of some pro-p-groups arising from infinite-dimensional Lie theory. These groups are completions of some subgroups of incomplete Kac-Moody groups over finite fields, with respect to various completions of algebraic or geometric origin. ... More

WKB approach to evaluate series of Mathieu functions in scattering problemsAug 10 2017The scattering of a wave obeying Helmholtz equation by an elliptic obstacle can be described exactly using series of Mathieu functions. This situation is relevant in optics, quantum mechanics and fluid dynamics. We focus on the case when the wavelength ... More

The distribution of Gaussian multiplicative chaos on the unit intervalApr 09 2018Aug 23 2018We consider a sub-critical Gaussian multiplicative chaos (GMC) measure defined on the unit interval [0,1] and prove an exact formula for the fractional moments of the total mass of this measure. Our formula includes the case where log-singularities (also ... More

Commensurators of some non-uniform tree lattices and Moufang twin treesFeb 18 2004Sh. Mozes showed that the commensurator of the lattice ${\rm PSL}_2 \bigl({\bf F}_p[t{}^{-1}] \bigr)$ is dense in the full automorphism group of the Bruhat-Tits tree of valency $p+1$, the latter group being much bigger than ${\rm PSL}_2 \bigl({\bf F}_p((t)) ... More

On Universal Point Sets for Planar GraphsSep 17 2012Aug 27 2013A set P of points in R^2 is n-universal, if every planar graph on n vertices admits a plane straight-line embedding on P. Answering a question by Kobourov, we show that there is no n-universal point set of size n, for any n>=15. Conversely, we use a computer ... More

Simultaneous Embeddings with Few Bends and CrossingsAug 31 2015A simultaneous embedding with fixed edges (SEFE) of two planar graphs $R$ and $B$ is a pair of plane drawings of $R$ and $B$ that coincide when restricted to the common vertices and edges of $R$ and $B$. We show that whenever $R$ and $B$ admit a SEFE, ... More

Using Genetic Algorithms to Benchmark the CloudAug 27 2015This paper presents a novel application of Genetic Algorithms(GAs) to quantify the performance of Platform as a Service (PaaS), a cloud service model that plays a critical role in both industry and academia. While Cloud benchmarks are not new, in this ... More

OVI, NV and CIV in the Galactic Halo: II. Velocity-Resolved Observations with Hubble and FUSEMar 16 2004We present a survey of NV and OVI (and where available CIV) in the Galactic halo, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Hubble Space Telescope (HST) along 34 sightlines. These ions are usually produced in nonequilibrium ... More

Simplicity of twin tree lattices with non-trivial commutation relationsSep 24 2012We prove a simplicity criterion for certain twin tree lattices. It applies to all rank two Kac-Moody groups over finite fields with non-trivial commutation relations, thereby yielding examples of simple non-uniform lattices in the product of two trees. ... More

Practitioner's guide to social network analysis: Examining physics anxiety in an active-learning settingSep 02 2018The application of social network analysis (SNA) has recently grown prevalent in science, technology, engineering, and mathematics education research. Research on classroom networks has led to greater understandings of student persistence in physics majors, ... More

OVI, NV, and CIV in the Galactic Halo: I. Velocity-Dependent Ionization ModelsMar 16 2004We explore theoretical models of the ionization ratios of the Li-like absorbers NV, OVI, and CIV, in the Galactic halo. These ions are believed to form in nonequilibrium processes such as shocks, evaporative interfaces, or rapidly cooling gas, all of ... More

Characterizing the hyper-parameter space of LSTM language models for mixed context applicationsDec 08 2017Applying state of the art deep learning models to novel real world datasets gives a practical evaluation of the generalizability of these models. Of importance in this process is how sensitive the hyper parameters of such models are to novel datasets ... More

Automorphisms of categories of schemesJun 03 2019Given two schemes $S$ and $S'$, we prove that every equivalence between $\mathbf{Sch}_S$ and $\mathbf{Sch}_{S'}$ comes from a unique isomorphism between $S$ and $S'$. This eliminates all Noetherian and finite type hypotheses from a result of Mochizuki ... More

The equivalence of several conjectures on independence of $\ell$Aug 01 2018Jun 03 2019We consider several conjectures on the independence of $\ell$ of the \'etale cohomology of (singular, open) varieties over $\bar{\mathbf F}_p$. The main result is that independence of $\ell$ of the Betti numbers $h^i_{\text{c}}(X,\mathbf Q_\ell)$ for ... More

Tracking bitcoin users activity using community detection on a network of weak signalsOct 23 2017Bitcoin is a cryptocurrency attracting a lot of interest both from the general public and researchers. There is an ongoing debate on the question of users' anonymity: while the Bitcoin protocol has been designed to ensure that the activity of individual ... More

A variety that cannot be dominated by one that liftsFeb 21 2019We prove a precise version of a theorem of Siu and Beauville on morphisms to higher genus curves, and use it to show that if a variety $X$ in characteristic $p$ lifts to characteristic $0$, then any morphism $X \to C$ to a curve of genus $g \geq 2$ can ... More

The equivalence of several conjectures on independence of $\ell$Aug 01 2018We consider several conjectures on the independence of $\ell$ of the \'etale cohomology of (singular, open) varieties over $\bar{\mathbb F}_p$. The main result is that independence of $\ell$ of the Betti numbers $h^i_{\text{c}}(X,\mathbb Q_\ell)$ for ... More

Simplicity and superrigidity of twin building latticesJul 26 2006Sep 26 2006Kac-Moody groups over finite fields are finitely generated groups. Most of them can naturally be viewed as irreducible lattices in products of two closed automorphism groups of non-positively curved twinned buildings: those are the most important (but ... More

FIR extended emission from cold gas and dust in Blue Compact Dwarf Galaxies: the anomalous cases of POX 186 and UM 461Aug 04 2016FIR observation of BCD galaxies with Herschel has revealed a wealth of new insights in these objects which are thought to resemble high-redshift forming galaxies. Dust and cold gas showed to be colder, in more or less quantities than expected and of uncertain ... More

On the distortion of twin building latticesAug 23 2009We show that twin building lattices are undistorted in their ambient group; equivalently, the orbit map of the lattice to the product of the associated twin buildings is a quasi-isometric embedding. As a consequence, we provide an estimate of the quasi-flat ... More

Goodness-of-Fit tests with Dependent ObservationsJun 15 2011Aug 03 2011We revisit the Kolmogorov-Smirnov and Cram\'er-von Mises goodness-of-fit (GoF) tests and propose a generalisation to identically distributed, but dependent univariate random variables. We show that the dependence leads to a reduction of the "effective" ... More

X-CSIT: a toolkit for simulating 2D pixel detectorsFeb 05 2015A new, modular toolkit for creating simulations of 2D X-ray pixel detectors, X-CSIT (X-ray Camera SImulation Toolkit), is being developed. The toolkit uses three sequential simulations of detector processes which model photon interactions, electron charge ... More

An Optimal Algorithm for Reconstructing Point Set Order Types from Radial OrderingsJul 29 2015Aug 12 2016Let $P$ be a set of $n$ labeled points in the plane. The radial system of $P$ describes, for each $p\in P$, the order in which a ray that rotates around $p$ encounters the points in $P \setminus \{p\}$. This notion is related to the order type of $P$, ... More

Detector Development for the European XFEL: Requirements and StatusOct 05 2012Oct 29 2012The variety of applications and especially the unique European XFEL time structure will require adequate instrumentation to be developed to exploit the full potential of the light source. Two-dimensional integrating X-ray detectors with ultra-fast read ... More

Using multiple-criteria methods to evaluate community partitionsFeb 18 2015Community detection is one of the most studied problems on complex networks. Although hundreds of methods have been proposed so far, there is still no universally accepted formal definition of what is a good community. As a consequence, the problem of ... More

A local lemma via entropy compressionSep 15 2015In the framework of the probabilistic method in combinatorics we present a new local lemma which can efficiently replace the Lov\'asz local lemma in a restricted setting where the underlying probability space of the bad events is generated by a finite ... More

Nonlinear System Identification of Soft Robot Dynamics Using Koopman Operator TheoryOct 15 2018Soft robots are challenging to model due to their nonlinear behavior. However, their soft bodies make it possible to safely observe their behavior under random control inputs, making them amenable to large-scale data collection and system identification. ... More

A proposition of a robust system for historical document images indexationAug 28 2013Characterizing noisy or ancient documents is a challenging problem up to now. Many techniques have been done in order to effectuate feature extraction and image indexation for such documents. Global approaches are in general less robust and exact than ... More

Sign tests for weak principal directionsDec 21 2018Aug 29 2019We consider inference on the first principal direction of a $p$-variate elliptical distribution. We do so in challenging double asymptotic scenarios for which this direction eventually fails to be identifiable. In order to achieve robustness not only ... More

Agglomeration in a preferential attachment random graph with edge-stepsJan 08 2019In this paper we investigate geometric properties of graphs generated by a preferential attachment random graph model with edge-steps. More precisely, at each time $t\in\mathbb{N}$, with probability $p$ a new vertex is added to the graph (a vertex-step ... More

Preferential Attachment Random Graphs with Edge-Step FunctionsApr 26 2017Jan 08 2019We propose a random graph model with preferential attachment rule and \emph{edge-step functions} that govern the growth rate of the vertex set. We study the effect of these functions on the empirical degree distribution of these random graphs. More specifically, ... More

Topological properties of P.A. random graphs with edge-step functionsFeb 26 2019In this work we investigate a preferential attachment model whose parameter is a function $f:\mathbb{N}\to[0,1]$ that drives the asymptotic proportion between the numbers of vertices and edges of the graph. We investigate topological features of the graphs, ... More

Contraction groups in complete Kac-Moody groupsJun 19 2007Let $G$ be an abstract Kac-Moody group over a finite field and $\bar{G}$ be the closure of the image of $G$ in the automorphism group of its positive building. We show that if the Dynkin diagram associated to $G$ is irreducible and neither of spherical ... More

Geometric Approach to Digital Quantum InformationDec 24 2003Nov 17 2004We present geometric methods for uniformly discretizing the continuous N-qubit Hilbert space. When considered as the vertices of a geometrical figure, the resulting states form the equivalent of a Platonic solid. The discretization technique inherently ... More

Bruhat-Tits theory from Berkovich's point of view. II. Satake compactificationsJul 19 2009In our previous paper "Bruhat-Tits theory from Berkovich's point of view. I ? Realizations and compactifications of buildings", we investigated realizations of the Bruhat-Tits building B(G,k) of a connected and reductive linear algebraic group G over ... More

Existence of Gibbsian point processes with geometry-dependent interactionsMar 15 2010We establish the existence of stationary Gibbsian point processes for interactions that act on hyperedges between the points. For example, such interactions can depend on Delaunay edges or triangles, cliques of Voronoi cells or clusters of $k$-nearest ... More

Reshaping the use of digital tools to fight malariaMay 06 2018In this extended abstract we present our approach to marshal digital tools in the fight against malaria. We describe our scalable infrastructure which leverages abstractions to support effective deployment of existing computational models and their associated ... More

Flat rank of automorphism groups of buildingsOct 14 2005Jan 26 2006The flat rank of a totally disconnected locally compact group G, denoted flat-rk(G), is an invariant of the topological group structure of G. It is defined thanks to a natural distance on the space of compact open subgroups of G. For a topological Kac-Moody ... More

Sign tests for weak principal directionsDec 21 2018We consider inference on the first principal direction of a $p$-variate elliptical distribution. We do so in challenging double asymptotic scenarios for which this direction eventually fails to be identifiable. In order to achieve robustness not only ... More

Fidelity of the near resonant quantum kicked rotorApr 14 2011Jun 21 2011We present a perturbative result for the temporal evolution of the fidelity of the quantum kicked rotor, i.e. the overlap of the same initial state evolved with two slightly different kicking strengths, for kicking periods close to a principal quantum ... More

High altitude wind velocity at Sierra Negra and San Pedro MártirDec 20 2004It has been proposed that the global circulation of the atmosphere winds at 200 mb can be used as a criteria to establish the suitability of a site for the development of adaptive optics techniques such as slow wavefront corrugation correction. By using ... More

Testing for Principal Component Directions under Weak IdentifiabilityOct 15 2017Dec 30 2018We consider the problem of testing, on the basis of a $p$-variate Gaussian random sample, the null hypothesis ${\cal H}_0: {\pmb \theta}_1= {\pmb \theta}_1^0$ against the alternative ${\cal H}_1: {\pmb \theta}_1 \neq {\pmb \theta}_1^0$, where ${\pmb \theta}_1$ ... More

A local lemma via entropy compressionSep 15 2015Jan 31 2017In the framework of the probabilistic method in combinatorics we present a new local lemma based on an entropy compression random algorithm and we show through examples that it can efficiently replace the Moser-Tardos algorithmic version of the Lov\'asz ... More

On Termination, Confluence and Consistent CHR-based Type InferenceMay 14 2014We consider the application of Constraint Handling Rules (CHR) for the specification of type inference systems, such as that used by Haskell. Confluence of CHR guarantees that the answer provided by type inference is correct and consistent. The standard ... More

Categorizing ancient documentsAug 28 2013The analysis of historical documents is still a topical issue given the importance of information that can be extracted and also the importance given by the institutions to preserve their heritage. The main idea in order to characterize the content of ... More

The resonant nonlinear scattering theory with bound states in the radiation continuum and the second harmonic generationJul 03 2011Mar 09 2012A nonlinear electromagnetic scattering problem is studied in the presence of bound states in the radiation continuum. It is shown that the solution is not analytic in the nonlinear susceptibility and the conventional perturbation theory fails. A non-perturbative ... More

Aperiodic Quantum Random WalksJun 11 2004We generalize the quantum random walk protocol for a particle in a one-dimensional chain, by using several types of biased quantum coins, arranged in aperiodic sequences, in a manner that leads to a rich variety of possible wave function evolutions. Quasiperiodic ... More

R-local Delaunay inhibition modelApr 11 2006Let us consider the local specification system of Gibbs point process with inhib ition pairwise interaction acting on some Delaunay subgraph specifically not con taining the edges of Delaunay triangles with circumscribed circle of radius grea ter than ... More

Nonlinear System Identification of Soft Robot Dynamics Using Koopman Operator TheoryOct 15 2018May 02 2019Soft robots are challenging to model due in large part to the nonlinear properties of soft materials. Fortunately, this softness makes it possible to safely observe their behavior under random control inputs, making them amenable to large-scale data collection ... More

Wonderful compactifications of Bruhat-Tits buildingsFeb 10 2017Dec 11 2017Given a split semisimple group over a local field, we consider the maximal Satake-Berkovich compactification of the corresponding Euclidean building. We prove that it can be equivariantly identified with the compactification which we get by embedding ... More

Bruhat-Tits buildings and analytic geometryOct 06 2011Mar 24 2015This paper provides an overview of the theory of Bruhat-Tits buildings. Besides, we explain how Bruhat-Tits buildings can be realized inside Berkovich spaces. In this way, Berkovich analytic geometry canbe used to compactify buildings. We discuss in detail ... More

Australia Telescope Compact Array Survey of Candidate Ultra-Compact and Buried HII Regions in the Magellanic CloudsJul 23 2004We present a systematic survey for ultracompact HII (UCHII) regions in the Magellanic Clouds. Understanding the physics of massive star formation (MSF) is a critical astrophysical problem. The study of MSF began in our galaxy with surveys of UCHII regions, ... More

Bohmian trajectories for the half-line barrierJul 19 2017Dec 08 2017Bohmian trajectories are considered for a particle that is free (i.e. the potential energy is zero), except for a half-line barrier. On the barrier, both Dirichlet and Neumann boundary conditions are considered. The half-line barrier yields one of the ... More

Diffusive-Ballistic Transition in Random Walks with Long-Range Self-RepulsionDec 04 2007Dec 06 2007We prove that a class of random walks on $\Z^2$ with long-range self-repulsive interactions have a diffusive-ballistic phase transition.

Large Communities in a scale-free networkSep 15 2015Oct 11 2016We prove the existence of a large complete subgraph w.h.p. in a preferential attachment random graph process with an edge-step. That is, we prove that the random graph $G_{t}$ produced by the so-called GLP model at time $t$ contains a complete subgraph ... More

The X-ray Telescope of the CAST ExperimentNov 14 2005The CERN Axion Solar Telescope (CAST) searches for solar axions employing a 9 Tesla superconducting dipole magnet equipped with 3 independent detection systems for X-rays from axion-photon conversions inside the 10 m long magnetic field. Results of the ... More

The Planar Tree Packing TheoremMar 24 2016Packing graphs is a combinatorial problem where several given graphs are being mapped into a common host graph such that every edge is used at most once. In the planar tree packing problem we are given two trees T1 and T2 on n vertices and have to find ... More

First functionality tests of a 64 x 64 pixel DSSC sensor module connected to the complete ladder readoutJan 13 2017The European X-ray Free Electron Laser (XFEL.EU) will provide every 0.1 s a train of 2700 spatially coherent ultrashort X-ray pulses at 4.5 MHz repetition rate. The Small Quantum Systems (SQS) instrument and the Spectroscopy and Coherent Scattering instrument ... More

Validation of Compton Scattering Monte Carlo Simulation ModelsJan 08 2014Several models for the Monte Carlo simulation of Compton scattering on electrons are quantitatively evaluated with respect to a large collection of experimental data retrieved from the literature. Some of these models are currently implemented in general ... More

Status of detector development for the European XFELApr 24 2013The European X-ray Free Electron Laser (XFEL.EU) will provide as-yet-unrivaled peak brilliance and ultra-short pulses of spatially coherent X-rays with a pulse length of less than 100 fs in the energy range between 0.25 and 25 keV. The high radiation ... More

Performance of the LBNL FastCCD for the European XFELDec 12 2016The European X-ray Free Electron Laser (XFEL.EU) is currently being commissioned in Schenefeld, Germany. From 2017 onwards it will provide spatially coherent X-rays of energies between 0.25\,keV and 25\,keV with a unique timing structure. One of the detectors ... More

Arc diagrams, flip distances, and Hamiltonian triangulationsNov 08 2016Nov 11 2016We show that every triangulation (maximal planar graph) on $n\ge 6$ vertices can be flipped into a Hamiltonian triangulation using a sequence of less than $n/2$ combinatorial edge flips. The previously best upper bound uses $4$-connectivity as a means ... More

Arc diagrams, flip distances, and Hamiltonian triangulationsNov 08 2016We show that every triangulation (maximal planar graph) on $n\ge 6$ vertices can be flipped into a Hamiltonian triangulation using a sequence of less than $n/2$ combinatorial edge flips. The previously best upper bound uses $4$-connectivity as a means ... More

What's in an Attribute? Consequences for the Least Common SubsumerJun 01 2011Functional relationships between objects, called `attributes', are of considerable importance in knowledge representation languages, including Description Logics (DLs). A study of the literature indicates that papers have made, often implicitly, different ... More

Students' network integration as a predictor of persistence in introductory physics coursesNov 02 2016Increasing student retention (successfully finishing a particular course) and persistence (continuing through the major area of study) is currently a major challenge for universities. While students' academic and social integration into an institution ... More

Modeling and Control of Soft Robots Using the Koopman Operator and Model Predictive ControlFeb 07 2019Controlling soft robots with precision is a challenge due in large part to the difficulty of constructing models that are amenable to model-based control design techniques. Koopman Operator Theory offers a way to construct explicit linear dynamical models ... More

The importance of Wolf-Rayet ionization and feedback on super star cluster evolutionAug 03 2015The feedback from massive stars is important to super star cluster (SSC) evolution and the timescales on which it occurs. SSCs form embedded in thick material, and eventually, the cluster is cleared out and revealed at optical wavelengths -- however, ... More

The Prevalence and Impact of Wolf-Rayet Stars in Emerging Massive Star ClustersMay 25 2016We investigate Wolf-Rayet (WR) stars as a source of feedback contributing to the removal of natal material in the early evolution of massive star clusters. Despite previous work suggesting that massive star clusters clear out their natal material before ... More

Decay Properties of the Connectivity for Mixed Long Range Percolation Models on $\Z^d$May 15 2006Sep 10 2007In this short note we consider mixed short-long range independent bond percolation models on $\Z^{k+d}$. Let $p_{uv}$ be the probability that the edge $(u,v)$ will be open. Allowing a $x,y$-dependent length scale and using a multi-scale analysis due to ... More

Some results on the Weiss-Weinstein bound for conditional and unconditional signal models in array processingNov 28 2012In this paper, the Weiss-Weinstein bound is analyzed in the context of sources localization with a planar array of sensors. Both conditional and unconditional source signal models are studied. First, some results are given in the multiple sources context ... More

Comparison and Experimental Validation of Predictive Models for Soft, Fiber-Reinforced ActuatorsJan 31 2019Successful soft robot modeling approaches appearing in recent literature have been based on a variety of distinct theories, including traditional robotic theory, continuum mechanics, and machine learning. Though specific modeling techniques have been ... More

Contact Process under heavy-tailed renewals on finite graphsJun 29 2019We investigate a non-Markovian analogue of the Harris contact process in a finite connected graph G=(V,E): an individual is attached to each site x in V, and it can be infected or healthy; the infection propagates to healthy neighbors just as in the usual ... More

On the practical interest of discrete Inverse Polya and Weibull-1 models in industrial reliability studiesNov 03 2014Engineers often cope with the problem of assessing the lifetime of industrial components, under the basis of observed industrial feedback data. Usually, lifetime is modelled as a continuous random variable, for instance exponentially or Weibull distributed. ... More

Engagement, integration, involvement: supporting academic performance and developing a classroom social networkJun 13 2017Theories developed by Tinto and Nora identify academic performance, learning gains, and involvement in learning communities as important facets of student engagement that support student persistence. Collaborative learning environments, such as those ... More

2-D Models of Protostars: III. Effects of Stellar TemperatureSep 28 2004We model how the mid-infrared colors of Young Stellar Objects (YSOs) vary with stellar temperature. The spectral energy distribution (SED) of each object has contributions from thermal emission of circumstellar dust, from direct stellar photospheric emission, ... More

Liouville quantum gravity with central charge in $(1,25)$: a probabilistic approachMar 21 2019There is a substantial literature concerning Liouville quantum gravity (LQG) with coupling constant $\gamma \in (0,2]$. In this setting, the central charge of the corresponding matter field satisfies $\mathbf c = 25 - 6(2/\gamma+\gamma/2)^2 \in (-\infty,1]$. ... More