Results for "Jason J. Bramburger"

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Existence of Rotating Waves on an Infinite Two-Dimensional Lattice of Coupled Phase EquationsMar 08 2016Sep 24 2016Mathematically, rotating wave solutions to evolution equations have been shown to govern many important biological and chemical processes. Much of the rigorous mathematical investigations of rotating waves rely on the model exhibiting a continuous Euclidean ... More
Ultracontractive Properties for Directed Graph Semigroups with Applications to Coupled OscillatorsJul 10 2019It is now well known that ultracontractive properties of semigroups with infinitesimal generator given by an undirected graph Laplacian operator can be obtained through an understanding of the geometry of the underlying infinite weighted graph. The aim ... More
Rotating Wave Solutions to Lattice Dynamical Systems II: Persistence ResultsMay 31 2018This work comes as the second part in a series of investigations into the dynamics of rotating waves as solutions to lattice dynamical systems. Such nonlinear waves as solutions to mathematical equations are of great interest throughout the physical sciences ... More
Rotating Wave Solutions to Lattice Dynamical Systems I: The Anti-Continuum LimitMar 08 2016May 31 2018Rotating waves are a fascinating feature of a wide array of complex systems, particularly those arising in the study of many chemical and biological processes. With many rigorous mathematical investigations of rotating waves relying on the model exhibiting ... More
Stability of Infinite Systems of Coupled Oscillators Via Random Walks on Weighted GraphsMay 06 2018Weakly coupled oscillators are used throughout the physical sciences, particularly in mathematical neuroscience to describe the interaction of neurons in the brain. Systems of weakly coupled oscillators have a well-known decomposition to a canonical phase ... More
Dark Disk Substructure and Superfluid Dark MatterJan 11 2019Apr 17 2019Dark matter substructure has the potential to discriminate between broad classes of dark matter models. With this in mind, we construct novel solutions to the equations of motion governing condensate dark matter candidates, namely axion Bose-Einstein ... More
Novel Substructure and Superfluid Dark MatterJan 11 2019Jan 25 2019The recent observation of the distribution of accreted stars (SDSS-Gaia DR2) suggests that a non-trivial fraction of dark matter is contained within halo substructure. With this in mind, in this letter we construct novel solutions to the equations of ... More
Zero-Hopf bifurcation in the Van der Pol oscillator with delayed position and velocity feedbackFeb 24 2014In this paper, we consider the traditional Van der Pol Oscillator with a forcing dependent on a delay in feedback. The delay is taken to be a nonlinear function of both position and velocity which gives rise to many different types of bifurcations. In ... More
Zariski Cancellation Problem for Noncommutative AlgebrasJan 18 2016A noncommutative analogue of the Zariski cancellation problem asks whether $A[x]\cong B[x]$ implies $A\cong B$ when $A$ and $B$ are noncommutative algebras. We resolve this affirmatively in the case when $A$ is a noncommutative finitely generated domain ... More
The cycle polynomial of a permutation groupJan 24 2017The cycle polynomial of a finite permutation group $G$ is the generating function for the number of elements of $G$ with a given number of cycles: \[F_G(x) = \sum_{g\in G}x^{c(g)},\] where $c(g)$ is the number of cycles of $g$ on $\Omega$. In the first ... More
Asymptotic behavior of a generalized TCP congestion avoidance algorithmAug 19 2006The Transmission Control Protocol (TCP) is a Transport Protocol used in the Internet. Ott has introduced a more general class of candidate Transport Protocols called "protocols in the TCP Paradigm". The long run objective of studying this larger class ... More
Actor-Action Semantic Segmentation with Grouping Process ModelsDec 30 2015Actor-action semantic segmentation made an important step toward advanced video understanding problems: what action is happening; who is performing the action; and where is the action in space-time. Current models for this problem are local, based on ... More
Hamiltonian Streamline Guided Feature Extraction with Applications to Face DetectionAug 17 2011We propose a new feature extraction method based on two dynamical systems induced by intensity landscape: the negative gradient system and the Hamiltonian system. We build features based on the Hamiltonian streamlines. These features contain nice global ... More
LIBSVX: A Supervoxel Library and Benchmark for Early Video ProcessingDec 30 2015Supervoxel segmentation has strong potential to be incorporated into early video analysis as superpixel segmentation has in image analysis. However, there are many plausible supervoxel methods and little understanding as to when and where each is most ... More
Zariski Cancellation Problem for Noncommutative AlgebrasJan 18 2016Feb 21 2017A noncommutative analogue of the Zariski cancellation problem asks whether $A[x]\cong B[x]$ implies $A\cong B$ when $A$ and $B$ are noncommutative algebras. We resolve this affirmatively in the case when $A$ is a noncommutative finitely generated domain ... More
Spell Once, Summon Anywhere: A Two-Level Open-Vocabulary Language ModelApr 23 2018Nov 23 2018We show how the spellings of known words can help us deal with unknown words in open-vocabulary NLP tasks. The method we propose can be used to extend any closed-vocabulary generative model, but in this paper we specifically consider the case of neural ... More
An isomorphism lemma for graded ringsSep 29 2015Let $A$ and $B$ be two connected graded algebras finitely generated in degree one. If $A$ is isomorphic to $B$ as ungraded algebras, then they are also isomorphic to each other as graded algebras.
Evolving Spectra of Pop III Stars: Consequences for Cosmological ReionizationJun 21 2002Oct 24 2002We examine the significance of the first metal-free stars (Pop III) for the cosmological reionization of HI and HeII. These stars have unusually hard spectra, with the integrated ionizing photon rates from a Pop III stellar cluster for HI and HeII being ... More
Active Clustering with Model-Based Uncertainty ReductionFeb 07 2014Feb 14 2014Semi-supervised clustering seeks to augment traditional clustering methods by incorporating side information provided via human expertise in order to increase the semantic meaningfulness of the resulting clusters. However, most current methods are \emph{passive} ... More
The dynamical Mordell-Lang problem for etale mapsAug 24 2008We prove a dynamical version of the Mordell-Lang conjecture for etale endomorphisms of quasiprojective varieties. We use p-adic methods inspired by the work of Skolem, Mahler, and Lech, combined with methods from algebraic geometry. As special cases of ... More
Very twisting families of pointed lines on GrassmanniansFeb 28 2006There exist very twisting families of lines on Grassmannians and isotropic Grassmannians. This is a key step in proving existence of a rational section of a family of isotropic Grassmannians over a surface with vanishing Brauer obstruction.
Divisor classes and the virtual canonical bundle for genus 0 mapsFeb 28 2006Some divisor class relations are proved and used to compute the Cartier divisor class of the virtual canonical bundle for genus 0 maps to a smooth target.
Higher Fano manifolds and rational surfacesFeb 28 2006For a Fano manifold of pseudo-index at least 3 and $c_1^2-2c_2$ nef, we show irreducibility of certain spaces of curves on the Fano manifold implies the manifold is a union of rational surfaces.
The structure of hypersonic shock waves using Navier-Stokes equations modified to include mass diffusionJun 01 2007Howard Brenner has recently proposed modifications to the Navier-Stokes equations that relate to a diffusion of fluid volume that would be significant for flows with high density gradients. In a previous paper (Greenshields & Reese, 2007), we found these ... More
Adviser Networks: Learning What Question to Ask for Human-In-The-Loop Viewpoint EstimationFeb 05 2018Oct 25 2018Humans have an unparalleled visual intelligence and can overcome visual ambiguities that machines currently cannot. Recent works have shown that incorporating guidance from humans during inference for monocular viewpoint-estimation can help overcome difficult ... More
Mark-Recapture with Multiple Non-invasive MarksAug 21 2012Mar 08 2013Non-invasive marks, including pigmentation patterns, acquired scars,and genetic mark- ers, are often used to identify individuals in mark-recapture experiments. If animals in a population can be identified from multiple, non-invasive marks then some individuals ... More
The mod 2 homology of infinite loopspacesSep 16 2011Jun 25 2013We study the spectral sequence that one obtains by applying mod 2 homology to the Goodwillie tower which sends a spectrum X to the suspension spectrum of its 0th space X_0. This converges strongly to H_*(X_0) when X is 0-connected. The E^1 term is the ... More
A note on Fano manifolds whose second Chern character is positiveFeb 28 2006This note outlines some first steps in the classification of Fano manifolds for which $c_1^2-2c_2$ is positive or nef.
Video Object Segmentation-based Visual Servo Control and Object Depth Estimation on a Mobile Robot PlatformMar 20 2019To be useful in everyday environments, robots must be able to identify and locate unstructured, real-world objects. In recent years, video object segmentation has made significant progress on densely separating such objects from background in real and ... More
Nucleosynthesis, Reionization, and the Mass Function of the First StarsJan 19 2004May 27 2004We critique the hypothesis that the first stars were very massive stars (VMS; M > 140 Msun). We review the two major lines of evidence for the existence of VMS: (1) that the relative metal abundances of extremely metal-poor Galactic halo stars show evidence ... More
Cosmological Effects of the First Stars: Evolving Spectra of Population IIIJun 21 2002Oct 24 2002The first stars hold intrinsic interest for their uniqueness and for their potential importance to galaxy formation, chemical enrichment, and feedback on the intergalactic medium (IGM). The metal-free composition of the first stars restricts the stellar ... More
The discovery and legacy of Kepler's multi-transiting planetary systemsMay 12 2019We revisit the discovery and implications of the first candidate systems to contain multiple transiting exoplanets. These systems were discovered using data from the Kepler space telescope. The initial paper, presenting five systems (Steffen et al. 2010), ... More
Action Understanding with Multiple Classes of ActorsApr 27 2017Despite the rapid progress, existing works on action understanding focus strictly on one type of action agent, which we call actor---a human adult, ignoring the diversity of actions performed by other actors. To overcome this narrow viewpoint, our paper ... More
The structure of shock waves as a test of Brenner's modifications to the Navier-Stokes equationsNov 28 2006Brenner has recently proposed modifications to the Navier-Stokes equations that are based on theoretical arguments but supported only by experiments having a fairly limited range. These modifications relate to a diffusion of fluid volume that would be ... More
Towards Automatic Learning of Procedures from Web Instructional VideosMar 28 2017Nov 21 2017The potential for agents, whether embodied or software, to learn by observing other agents performing procedures involving objects and actions is rich. Current research on automatic procedure learning heavily relies on action labels or video subtitles, ... More
Dual-Mixed Finite Element Methods for the Navier-Stokes EquationsMar 30 2016A mixed finite element method for the Navier-Stokes equations is introduced in which the stress is a primary variable. The variational formulation retains the mathematical structure of the Navier-Stokes equations and the classical theory extends naturally ... More
Vortex Pairs in the Discrete Nonlinear Schr{ö}dinger EquationJan 03 2019The aim of the present work is to examine the role of discreteness in the interaction of both co-winding and counter-winding vortices in the context of the nonlinear Schr{\"o}dinger equation. Contrary to the well-known rotation of same charge vortices, ... More
The remapped particle-mesh advection schemeJul 26 2006We describe the remapped particle-mesh method, a new mass-conserving method for solving the density equation which is suitable for combining with semi-Lagrangian methods for compressible flow applied to numerical weather prediction. In addition to the ... More
Induced Saturation NumberDec 08 2011Jun 14 2012In this paper, we discuss a generalization of the notion of saturation in graphs in order to deal with induced structures. In particular, we define ${\rm indsat}(n,H)$, which is the fewest number of gray edges in a trigraph so that no realization of that ... More
Transport fluctuations in integrable models out of equilibriumDec 05 2018Jun 27 2019We present exact results for the full counting statistics, or the scaled cumulant generating function, pertaining to the transfer of arbitrary conserved quantities across an interface in homogeneous integrable models out of equilibrium. We do this by ... More
Custom Chipset and Compact Module Design for a 75-110 GHz Laboratory Signal SourceJul 19 2016We report on the development and characterization of a compact, full-waveguide bandwidth (WR-10) signal source for general-purpose testing of mm-wave components. The MMIC-based multichip module is designed for compactness and ease-of-use, especially in ... More
Observing quantum chaos with noisy measurements and highly mixed statesSep 23 2016A fundamental requirement for the emergence of classical behavior from an underlying quantum description is that certain observed quantum systems make a transition to chaotic dynamics as their action is increased relative to $\hbar$. While experiments ... More
A FUSE Survey of Interstellar Molecular Hydrogen toward High-Latitude AGNJul 25 2005We report results from a FUSE survey of interstellar molecular hydrogen (H2) along 45 sight lines to AGN at high Galactic latitudes (|b| > 20 degrees). Most (39 of 45) of the sight lines show detectable Galactic H2 absorption from Lyman and Werner bands ... More
Applications of p-adic analysis for bounding periods of subvarieties under etale mapsOct 22 2013Nov 11 2013Using methods of p-adic analysis we give a different proof of Burnside's problem for automorphisms of quasiprojective varieties X defined over a field of characteristic 0. More precisely, we show that any finitely generated torsion subgroup of Aut(X) ... More
Model-Based Estimation of Vortex Shedding in Unsteady Cylinder WakesApr 30 2019This paper considers single-sensor estimation of vortex shedding in cylinder wakes at $Re=100$ in simulations and at $Re=1036$ in experiments. A model based on harmonic decomposition is developed to capture the periodic dynamics of vortex shedding. Two ... More
Computer Assisted Proofs of Contracting Invariant Tori for ODEsMay 20 2019This work studies existence and regularity questions for attracting invariant tori in three dimensional dissipative systems of ordinary differential equations. Our main result is a constructive method of computer assisted proof which applies to explicit ... More
Approximating electronically excited states with equation-of-motion linear coupled-cluster theoryJul 07 2015A new perturbative approach to canonical equation-of-motion coupled-cluster theory is presented using coupled-cluster perturbation theory. A second-order M{\o}ller-Plesset partitioning of the Hamiltonian is used to obtain the well known equation-of-motion ... More
Epidemic fronts in complex networks with metapopulation structureApr 16 2013Apr 20 2013Infection dynamics have been studied extensively on complex networks, yielding insight into the effects of heterogeneity in contact patterns on disease spread. Somewhat separately, metapopulations have provided a paradigm for modeling systems with spatially ... More
Pulsed versus continuous wave operation of a ring Stark deceleratorDec 19 2017Stark deceleration is a technique that uses time-varying inhomogeneous electric fields to decelerate polar molecules for various molecular beam and trapping experiments. New ring-geometry Stark decelerators with continuously varying voltages offer a method ... More
Competitive Exclusion in a DAE Model for Microbial Electrolysis CellsJun 05 2019Microbial electrolysis cells (MECs) are devices that employ electroactive bacteria to perform extracellular electron transfer, enabling hydrogen generation from biodegradable substrates. Previously we analyzed a regular, semi-explicit, index 1 differential-algebraic ... More
Joint Surgical Gesture and Task Classification with Multi-Task and Multimodal LearningMay 02 2018We propose a novel multi-modal and multi-task architecture for simultaneous low level gesture and surgical task classification in Robot Assisted Surgery (RAS) videos.Our end-to-end architecture is based on the principles of a long short-term memory network ... More
A High Power Density, High Efficiency Hydrogen-Chlorine Regenerative Fuel Cell with a Low Precious Metal Content CatalystJun 13 2012We report the performance of a hydrogen-chlorine electrochemical cell with a chlorine electrode employing a low precious metal content alloy oxide electrocatalyst for the chlorine electrode: (Ru_0.09Co_0.91)_3O_4. The cell employs a commercial hydrogen ... More
Biases in Expansion Distances of Novae Arising from the Prolate Geometry of Nova ShellsMar 21 2000(abridged) Expansion distances (or expansion parallaxes) for classical novae are based on comparing a measurement of the shell expansion velocity, multiplied by the time since outburst, with some measure of the angular size of the shell. We review and ... More
A Structured Variational Autoencoder for Contextual Morphological InflectionJun 10 2018Statistical morphological inflectors are typically trained on fully supervised, type-level data. One remaining open research question is the following: How can we effectively exploit raw, token-level data to improve their performance? To this end, we ... More
Predicting Future Lane Changes of Other Highway Vehicles using RNN-based Deep ModelsJan 12 2018May 16 2019In the event of sensor failure, autonomous vehicles need to safely execute emergency maneuvers while avoiding other vehicles on the road. To accomplish this, the sensor-failed vehicle must predict the future semantic behaviors of other drivers, such as ... More
A System for the Generation of Synthetic Wide Area Aerial Surveillance ImageryMar 13 2018The development, benchmarking and validation of aerial Persistent Surveillance (PS) algorithms requires access to specialist Wide Area Aerial Surveillance (WAAS) datasets. Such datasets are difficult to obtain and are often extremely large both in spatial ... More
The Dynamical Mordell-Lang problemJan 26 2014Let X be a Noetherian space, let f be a continuous self-map on X, let Y be a closed subset of X, and let x be a point on X. We show that the set S consisting of all nonnegative integers n such that f^n(x) is in Y is a union of at most finitely many arithmetic ... More
BSM Hadronic Matrix Elements for $ε'/ε$ and $K\toππ$ Decays in the Dual QCD ApproachJul 04 2018Jan 27 2019We calculate for the first time all four-quark hadronic matrix elements of local operators possibly contributing to $K\to\pi\pi$ decays and in particular to the ratio $\epsilon'/\epsilon$ beyond the Standard Model (BSM). To this end we use the Dual QCD ... More
Watch What You Just Said: Image Captioning with Text-Conditional AttentionJun 15 2016Nov 24 2016Attention mechanisms have attracted considerable interest in image captioning due to its powerful performance. However, existing methods use only visual content as attention and whether textual context can improve attention in image captioning remains ... More
A microfluidic chip and its use in characterising the particle-scale behaviour of Microbial-Induced Carbonate Precipitation (MICP)Apr 09 2018Jan 17 2019Microbial-Induced Carbonate Precipitation (MICP) is an innovative ground improvement technique which can enhance the strength and stiffness of soils, and can also control their hydraulic conductivity. These engineering properties of MICP-treated soils ... More
FEMSIM+HRMC: Simulation of and Structural Refinement using Fluctuation Electron Microscopy for Amorphous MaterialsJul 14 2016FEMSIM, a Fortran code, has been developed to simulate the fluctuation electron microscopy signal, the variance, V(k), from a model atomic structure. FEMSIM has been incorporated into a hybrid-reverse Monte Carlo code that combines an embedded atom or ... More
Unsupervised Disambiguation of Syncretism in Inflected LexiconsJun 10 2018Lexical ambiguity makes it difficult to compute various useful statistics of a corpus. A given word form might represent any of several morphological feature bundles. One can, however, use unsupervised learning (as in EM) to fit a model that probabilistically ... More
Floyd-Warshall Reinforcement Learning: Learning from Past Experiences to Reach New GoalsSep 25 2018Jan 04 2019Consider mutli-goal tasks that involve static environments and dynamic goals. Examples of such tasks, such as goal-directed navigation and pick-and-place in robotics, abound. Two types of Reinforcement Learning (RL) algorithms are used for such tasks: ... More
Stochastic Variational Inference for Hidden Markov ModelsNov 06 2014Variational inference algorithms have proven successful for Bayesian analysis in large data settings, with recent advances using stochastic variational inference (SVI). However, such methods have largely been studied in independent or exchangeable data ... More
Bounding periods of subvarieties of (P^1)^nDec 08 2017Using methods of p-adic analysis, along with the powerful result of Medvedev-Scanlon (Annals of Mathematics, 2014) for the classification of periodic subvarieties of (P^1)^n, we bound the length of the orbit of a periodic subvariety Y of (P^1)^n under ... More
Optically Thin Core Accretion: How Planets Get Their Gas in Nearly Gas-Free DisksOct 06 2017Feb 07 2018Models of core accretion assume that in the radiative zones of accreting gas envelopes, radiation diffuses. But super-Earths/sub-Neptunes (1-4$R_\oplus$, 2-20$M_\oplus$) point to formation conditions that are optically thin: their modest gas masses are ... More
A Dataset To Evaluate The Representations Learned By Video Prediction ModelsFeb 25 2018Mar 22 2018We present a parameterized synthetic dataset called Moving Symbols to support the objective study of video prediction networks. Using several instantiations of the dataset in which variation is explicitly controlled, we highlight issues in an existing ... More
On a Dynamical Mordell-Lang Conjecture for Coherent SheavesNov 17 2016May 05 2017We introduce a dynamical Mordell-Lang-type conjecture for coherent sheaves. When the sheaves are structure sheaves of closed subschemes, our conjecture becomes a statement about unlikely intersections. We prove an analogue of this conjecture for affinoid ... More
Nanoscale electrical measurements in liquids using AFM - progress and outlookJan 23 2017Fundamental mechanisms of energy storage, corrosion, sensing, and multiple biological functionalities are directly coupled to electrical processes and ionic dynamics at solid-liquid interfaces. In many cases, these processes are spatially inhomogeneous ... More
The topological basis of function in flow networksJan 03 2019Feb 05 2019The ability to reroute and control flow is vital to the function of many biological transport networks. By tuning the conductance of edges, many flow networks robustly control the propagation of inputs in order to achieve a wide variety of specific tasks. ... More
Measurements of trap dynamics of cold OH molecules using resonance enhanced multiphoton ionizationMay 17 2017Trapping cold, chemically important molecules with electromagnetic fields is a useful technique to study small molecules and their interactions. Traps provide long interaction times that are needed to precisely examine these low density molecular samples. ... More
A Simple Method for Computing Singular or Nearly Singular Integrals on Closed SurfacesAug 02 2015Jul 26 2016We present a simple, accurate method for computing singular or nearly singular integrals on a smooth, closed surface, such as layer potentials for harmonic functions evaluated at points on or near the surface. The integral is computed with a regularized ... More
A new cohomological formula for helicity in $\R^{2k+1}$ reveals the effect of a diffeomorphism on helicityMar 08 2009Oct 26 2012The helicity of a vector field is a measure of the average linking of pairs of integral curves of the field. Computed by a six-dimensional integral, it is widely useful in the physics of fluids. For a divergence-free field tangent to the boundary of a ... More
Families of rationally simply connected varieties over surfaces and torsors for semisimple groupsSep 30 2008Under suitable hypotheses, we prove that a form of a projective homogeneous variety $G/P$ defined over the function field of a surface over an algebraically closed field has a rational point. The method uses an algebro-geometric analogue of simple connectedness ... More
Random Forests for Metric Learning with Implicit Pairwise Position DependenceJan 03 2012Metric learning makes it plausible to learn distances for complex distributions of data from labeled data. However, to date, most metric learning methods are based on a single Mahalanobis metric, which cannot handle heterogeneous data well. Those that ... More
Semi-Supervised Nonlinear Distance Metric Learning via Forests of Max-Margin Cluster HierarchiesFeb 23 2014Metric learning is a key problem for many data mining and machine learning applications, and has long been dominated by Mahalanobis methods. Recent advances in nonlinear metric learning have demonstrated the potential power of non-Mahalanobis distance ... More
Anatomy of $\varepsilon'/\varepsilon$ beyond the Standard ModelAug 01 2018Mar 18 2019We present for the first time a model-independent anatomy of the ratio $\varepsilon'/\varepsilon$ in the context of the $\Delta S = 1$ effective theory with operators invariant under QCD and QED and in the context of the Standard Model Effective Field ... More
Berkeley Supernova Ia Program II: Initial Analysis of Spectra Obtained Near Maximum BrightnessFeb 09 2012May 04 2012In this second paper in a series we present measurements of spectral features of 432 low-redshift (z < 0.1) optical spectra of 261 Type Ia supernovae (SNe Ia) within 20 d of maximum brightness. The data were obtained from 1989 through the end of 2008 ... More
Are All Languages Equally Hard to Language-Model?Jun 10 2018For general modeling methods applied to diverse languages, a natural question is: how well should we expect our models to work on languages with differing typological profiles? In this work, we develop an evaluation framework for fair cross-linguistic ... More
Ferromagnetism in Mn-doped Sb2TeDec 23 2013We report that Sb2Te, a natural superlattice phase consisting of two elemental Sb2 layers interleaved with single Sb2Te3 layers, becomes ferromagnetic at low temperatures on doping with small percentages of Mn. Ferromagnetism appears for Mn concentrations ... More
Superconducting Properties of the K$_{x}$WO$_{3}$ Tetragonal Tungsten Bronze and the Superconducting Phase Diagram of the Tungsten Bronze FamilyFeb 18 2014We report the superconducting properties of the K$_{x}$WO$_{3}$ tetragonal tungsten bronze. The highest superconducting transition temperature ($T_{c}=2.1$K) was obtained for K$_{0.38}$WO$_{3}$. $T_{c}$ decreases linearly with increasing K content. Using ... More
Superconductor-semiconductor hybrid cavity quantum electrodynamicsMay 03 2019Light-matter interactions at the single particle level have generally been explored in the context of atomic, molecular, and optical physics. Recent advances motivated by quantum information science have made it possible to explore coherent interactions ... More
Using Agent to Coordinate Web ServicesJun 20 2009Traditionally, agent and web service are two separate research areas. We figure that, through agent communication, agent is suitable to coordinate web services. However, there exist agent communication problems due to the lack of uniform, cross-platform ... More
Bayesian nonparametric generative models for causal inference with missing at random covariatesFeb 27 2017We propose a general Bayesian nonparametric (BNP) approach to causal inference in the point treatment setting. The joint distribution of the observed data (outcome, treatment, and confounders) is modeled using an enriched Dirichlet process. The combination ... More
Spatially Heterogeneous Biofilm Simulations using an Immersed Boundary Method with Lagrangian Nodes Defined by Bacterial LocationsFeb 15 2013In this work we consider how surface-adherent bacterial biofilm communities respond in flowing systems. We simulate the fluid-structure interaction and separation process using the immersed boundary method. In these simulations we model and simulate different ... More
The Effect of Particle Strength on the Ballistic Resistance of Shear Thickening FluidsJul 04 2012Apr 01 2013The response of shear thickening fluids (STFs) under ballistic impact has received considerable attention due to its field-responsive nature. While efforts have primarily focused on the response of traditional ballistic fabrics impregnated with fluids, ... More
A Minimal Subsystem of the Kari-Culik TilingsOct 06 2014Sep 29 2015The Kari-Culik tilings are formed from a set of 13 Wang tiles that tile the plane only aperiodically. They are the smallest known set of Wang tiles to do so and are not as well understood as other examples of aperiodic Wang tiles. We show that the $\mathbb{Z}^2$ ... More
The combinatorics of biased riffle shufflesDec 09 1997This paper studies biased riffle shuffles, first defined by Diaconis, Fill, and Pitman. These shuffles generalize the well-studied Gilbert-Shannon-Reeds shuffle and convolve nicely. An upper bound is given for the time for these shuffles to converge to ... More
A $2$-compact group as a spetsJun 03 2019Jun 12 2019In 1998 Malle introduced spetses which are mysterious objects with non-real Weyl groups. In algebraic topology, a $p$-compact group $\mathbf{X}$ is a space which is a homotopy-theoretic $p$-local analogue of a compact Lie group. A connected $p$-compact ... More
Free Diffusions and Property AOJul 07 2009We consider von Neumann algebras generated by the stationary laws of free stochastic differential equations of the form $dX_t = dS_t -1/2 DV(X_t)$ for a suitably convex multivariate noncommutative polynomial $V$. Using techniques of Guionnet and Shlyakhtenko, ... More
Totally geodesic surfaces and homologyJan 23 2006Apr 23 2009We construct examples of hyperbolic rational homology spheres and hyperbolic knot complements in rational homology spheres containing closed embedded totally geodesic surfaces.
Generalized equivariant homology on simplicial complexesMar 08 2011A careful account is given of generalized equivariant homology theories on the category of topological pairs acted on by a group. In particular, upon restriction to the category of equivariant simplicial complexes, the equivalence of equivariant simplicial ... More
Construction of Regular Non-Atomic Strictly-Positive Measures in Second-Countable Locally Compact Non-Atomic Hausdorff SpacesJul 14 2018Feb 21 2019This paper presents a constructive proof of the existence of a regular non-atomic strictly-positive measure on any second-countable locally compact non-atomic Hausdorff space. This construction involves a sequence of finitely-additive set functions defined ... More
Descent algebras, hyperplane arrangements, and shuffling cardsJan 20 1998Jul 15 1999Two notions of riffle shuffling on finite Coxeter groups are given: one using Solomon's descent algebra and another using random walk on chambers of hyperplane arrangements. These coincide for types $A$,$B$,$C$, $H_3$, and rank two groups. Both notions ... More
The Kodaira dimension of spaces of rational curves on low degree hypersurfacesMay 29 2003For a hypersurface in complex projective space $X\subset \PP^n$, we investigate the singularities and Kodaira dimension of the Kontsevich moduli spaces $\Kbm{0,0}{X,e}$ parametrizing rational curves of degree $e$ on $X$. If $d+e \leq n$ and $X$ is a general ... More
Asymmetric Dark MatterAug 21 2013Sep 17 2013We review the theoretical framework underlying models of asymmetric dark matter, describe astrophysical constraints which arise from observations of neutron stars, and discuss the prospects for detecting asymmetric dark matter.
WIMPless Dark Matter: Models and SignaturesDec 01 2010We consider experimental signatures of WIMPless dark matter. We focus on models where the WIMPless dark matter candidate is a Majorana fermion, and dark matter scattering is predominantly spin-dependent. These models can be probed by IceCube/DeepCore, ... More
A note on the Brown--Erdős--Sós conjecture in groupsFeb 20 2019Apr 09 2019We show that a dense subset of a sufficiently large group multiplication table contains either a large part of the addition table of the integers modulo some $k$, or the entire multiplication table of a certain large abelian group, as a subgrid. As a ... More
Stein's Method and Non-Reversible Markov ChainsDec 09 1997Aug 17 2004Let W be either the number of descents or inversions of a permutation. Stein's method is applied to show that W satisfies a central limit theorem with error rate n^(-1/2). The construction of an exchangeable pair (W,W') used in Stein's method is non-trivial ... More
On the maximal graded shifts of ideals and modulesJan 24 2018We generalize a result of Eisenbud-Huneke-Ulrich on the maximal graded shifts of a module with prescribed annihilator and prove a linear regularity bound for ideals in a polynomial ring depending only on the first $p - c$ steps in the resolution, where ... More