Results for "Luke Zettlemoyer"

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E3: Entailment-driven Extracting and Editing for Conversational Machine ReadingJun 12 2019Conversational machine reading systems help users answer high-level questions (e.g. determine if they qualify for particular government benefits) when they do not know the exact rules by which the determination is made(e.g. whether they need certain income ... More
Better Character Language Modeling Through MorphologyJun 03 2019We incorporate morphological supervision into character language models (CLMs) via multitasking and show that this addition improves bits-per-character (BPC) performance across 24 languages, even when the morphology data and language modeling data are ... More
Sparse Networks from Scratch: Faster Training without Losing PerformanceJul 10 2019We demonstrate the possibility of what we call sparse learning: accelerated training of deep neural networks that maintain sparse weights throughout training while achieving performance levels competitive with dense networks. We accomplish this by developing ... More
Compositional Questions Do Not Necessitate Multi-hop ReasoningJun 07 2019Multi-hop reading comprehension (RC) questions are challenging because they require reading and reasoning over multiple paragraphs. We argue that it can be difficult to construct large multi-hop RC datasets. For example, even highly compositional questions ... More
Learning to Map Sentences to Logical Form: Structured Classification with Probabilistic Categorial GrammarsJul 04 2012This paper addresses the problem of mapping natural language sentences to lambda-calculus encodings of their meaning. We describe a learning algorithm that takes as input a training set of sentences labeled with expressions in the lambda calculus. The ... More
Global Neural CCG Parsing with Optimality GuaranteesJul 05 2016Sep 24 2016We introduce the first global recursive neural parsing model with optimality guarantees during decoding. To support global features, we give up dynamic programs and instead search directly in the space of all possible subtrees. Although this space is ... More
The Referential Reader: A Recurrent Entity Network for Anaphora ResolutionFeb 05 2019We present a new architecture for storing and accessing entity mentions during online text processing. While reading the text, entity references are identified, and may be stored by either updating or overwriting a cell in a fixed-length memory. The update ... More
Recurrent Additive NetworksMay 21 2017Jun 29 2017We introduce recurrent additive networks (RANs), a new gated RNN which is distinguished by the use of purely additive latent state updates. At every time step, the new state is computed as a gated component-wise sum of the input and the previous state, ... More
Transformers with convolutional context for ASRApr 26 2019The recent success of transformer networks for neural machine translation and other NLP tasks has led to a surge in research work trying to apply it for speech recognition. Recent efforts studied key research questions around ways of combining positional ... More
Higher-order Coreference Resolution with Coarse-to-fine InferenceApr 15 2018We introduce a fully differentiable approximation to higher-order inference for coreference resolution. Our approach uses the antecedent distribution from a span-ranking architecture as an attention mechanism to iteratively refine span representations. ... More
Learning Programmatic Idioms for Scalable Semantic ParsingApr 19 2019Programmers typically organize executable source code using high-level coding patterns or idiomatic structures such as nested loops, exception handlers and recursive blocks, rather than as individual code tokens. In contrast, state of the art semantic ... More
Evaluating Gender Bias in Machine TranslationJun 03 2019We present the first challenge set and evaluation protocol for the analysis of gender bias in machine translation (MT). Our approach uses two recent coreference resolution datasets composed of English sentences which cast participants into non-stereotypical ... More
Deep RNNs Encode Soft Hierarchical SyntaxMay 11 2018We present a set of experiments to demonstrate that deep recurrent neural networks (RNNs) learn internal representations that capture soft hierarchical notions of syntax from highly varied supervision. We consider four syntax tasks at different depths ... More
Extreme Extraction: Only One Hour per RelationJun 21 2015Information Extraction (IE) aims to automatically generate a large knowledge base from natural language text, but progress remains slow. Supervised learning requires copious human annotation, while unsupervised and weakly supervised approaches do not ... More
Adversarial Example Generation with Syntactically Controlled Paraphrase NetworksApr 17 2018We propose syntactically controlled paraphrase networks (SCPNs) and use them to generate adversarial examples. Given a sentence and a target syntactic form (e.g., a constituency parse), SCPNs are trained to produce a paraphrase of the sentence with the ... More
Constant-Time Machine Translation with Conditional Masked Language ModelsApr 19 2019Most machine translation systems generate text autoregressively, by sequentially predicting tokens from left to right. We, instead, use a masked language modeling objective to train a model to predict any subset of the target words, conditioned on both ... More
Learning a Neural Semantic Parser from User FeedbackApr 27 2017We present an approach to rapidly and easily build natural language interfaces to databases for new domains, whose performance improves over time based on user feedback, and requires minimal intervention. To achieve this, we adapt neural sequence models ... More
Vision-and-Dialog NavigationJul 10 2019Robots navigating in human environments should use language to ask for assistance and be able to understand human responses. To study this challenge, we introduce Cooperative Vision-and-Dialog Navigation, a dataset of over 2k embodied, human-human dialogs ... More
A Theme-Rewriting Approach for Generating Algebra Word ProblemsOct 19 2016Texts present coherent stories that have a particular theme or overall setting, for example science fiction or western. In this paper, we present a text generation method called {\it rewriting} that edits existing human-authored narratives to change their ... More
Zero-Shot Relation Extraction via Reading ComprehensionJun 13 2017We show that relation extraction can be reduced to answering simple reading comprehension questions, by associating one or more natural-language questions with each relation slot. This reduction has several advantages: we can (1) learn relation-extraction ... More
Ultra-Fine Entity TypingJul 13 2018We introduce a new entity typing task: given a sentence with an entity mention, the goal is to predict a set of free-form phrases (e.g. skyscraper, songwriter, or criminal) that describe appropriate types for the target entity. This formulation allows ... More
End-to-end Neural Coreference ResolutionJul 21 2017Dec 15 2017We introduce the first end-to-end coreference resolution model and show that it significantly outperforms all previous work without using a syntactic parser or hand-engineered mention detector. The key idea is to directly consider all spans in a document ... More
Neural AMR: Sequence-to-Sequence Models for Parsing and GenerationApr 26 2017Aug 18 2017Sequence-to-sequence models have shown strong performance across a broad range of applications. However, their application to parsing and generating text usingAbstract Meaning Representation (AMR)has been limited, due to the relatively limited amount ... More
Learning Probabilistic Relational Dynamics for Multiple TasksJun 20 2012The ways in which an agent's actions affect the world can often be modeled compactly using a set of relational probabilistic planning rules. This paper addresses the problem of learning such rule sets for multiple related tasks. We take a hierarchical ... More
Multi-hop Reading Comprehension through Question Decomposition and RescoringJun 07 2019Multi-hop Reading Comprehension (RC) requires reasoning and aggregation across several paragraphs. We propose a system for multi-hop RC that decomposes a compositional question into simpler sub-questions that can be answered by off-the-shelf single-hop ... More
Multi-hop Reading Comprehension through Question Decomposition and RescoringJun 07 2019Jun 30 2019Multi-hop Reading Comprehension (RC) requires reasoning and aggregation across several paragraphs. We propose a system for multi-hop RC that decomposes a compositional question into simpler sub-questions that can be answered by off-the-shelf single-hop ... More
TriviaQA: A Large Scale Distantly Supervised Challenge Dataset for Reading ComprehensionMay 09 2017May 13 2017We present TriviaQA, a challenging reading comprehension dataset containing over 650K question-answer-evidence triples. TriviaQA includes 95K question-answer pairs authored by trivia enthusiasts and independently gathered evidence documents, six per question ... More
NL2Bash: A Corpus and Semantic Parser for Natural Language Interface to the Linux Operating SystemFeb 25 2018Mar 02 2018We present new data and semantic parsing methods for the problem of mapping English sentences to Bash commands (NL2Bash). Our long-term goal is to enable any user to perform operations such as file manipulation, search, and application-specific scripting ... More
Long Short-Term Memory as a Dynamically Computed Element-wise Weighted SumMay 09 2018LSTMs were introduced to combat vanishing gradients in simple RNNs by augmenting them with gated additive recurrent connections. We present an alternative view to explain the success of LSTMs: the gates themselves are versatile recurrent models that provide ... More
Large-Scale QA-SRL ParsingMay 14 2018We present a new large-scale corpus of Question-Answer driven Semantic Role Labeling (QA-SRL) annotations, and the first high-quality QA-SRL parser. Our corpus, QA-SRL Bank 2.0, consists of over 250,000 question-answer pairs for over 64,000 sentences ... More
A Joint Model of Language and Perception for Grounded Attribute LearningJun 27 2012As robots become more ubiquitous and capable, it becomes ever more important to enable untrained users to easily interact with them. Recently, this has led to study of the language grounding problem, where the goal is to extract representations of the ... More
Dissecting Contextual Word Embeddings: Architecture and RepresentationAug 27 2018Sep 27 2018Contextual word representations derived from pre-trained bidirectional language models (biLMs) have recently been shown to provide significant improvements to the state of the art for a wide range of NLP tasks. However, many questions remain as to how ... More
Commonly Uncommon: Semantic Sparsity in Situation RecognitionDec 03 2016Semantic sparsity is a common challenge in structured visual classification problems; when the output space is complex, the vast majority of the possible predictions are rarely, if ever, seen in the training set. This paper studies semantic sparsity in ... More
Jointly Predicting Predicates and Arguments in Neural Semantic Role LabelingMay 12 2018Aug 13 2018Recent BIO-tagging-based neural semantic role labeling models are very high performing, but assume gold predicates as part of the input and cannot incorporate span-level features. We propose an end-to-end approach for jointly predicting all predicates, ... More
Crowdsourcing Question-Answer Meaning RepresentationsNov 16 2017We introduce Question-Answer Meaning Representations (QAMRs), which represent the predicate-argument structure of a sentence as a set of question-answer pairs. We also develop a crowdsourcing scheme to show that QAMRs can be labeled with very little training, ... More
Cloze-driven Pretraining of Self-attention NetworksMar 19 2019We present a new approach for pretraining a bi-directional transformer model that provides significant performance gains across a variety of language understanding problems. Our model solves a cloze-style word reconstruction task, where each word is ablated ... More
Neural Metaphor Detection in ContextAug 29 2018We present end-to-end neural models for detecting metaphorical word use in context. We show that relatively standard BiLSTM models which operate on complete sentences work well in this setting, in comparison to previous work that used more restricted ... More
Mapping Language to Code in Programmatic ContextAug 29 2018Source code is rarely written in isolation. It depends significantly on the programmatic context, such as the class that the code would reside in. To study this phenomenon, we introduce the task of generating class member functions given English documentation ... More
Syntactic Scaffolds for Semantic StructuresAug 30 2018We introduce the syntactic scaffold, an approach to incorporating syntactic information into semantic tasks. Syntactic scaffolds avoid expensive syntactic processing at runtime, only making use of a treebank during training, through a multitask objective. ... More
Improving Semantic Parsing for Task Oriented DialogFeb 15 2019Semantic parsing using hierarchical representations has recently been proposed for task oriented dialog with promising results [Gupta et al 2018]. In this paper, we present three different improvements to the model: contextualized embeddings, ensembling, ... More
pair2vec: Compositional Word-Pair Embeddings for Cross-Sentence InferenceOct 20 2018Reasoning about implied relationships (e.g. paraphrastic, common sense, encyclopedic) between pairs of words is crucial for many cross-sentence inference problems. This paper proposes new methods for learning and using embeddings of word pairs that implicitly ... More
Deep contextualized word representationsFeb 15 2018Mar 22 2018We introduce a new type of deep contextualized word representation that models both (1) complex characteristics of word use (e.g., syntax and semantics), and (2) how these uses vary across linguistic contexts (i.e., to model polysemy). Our word vectors ... More
Learning STRIPS Operators from Noisy and Incomplete ObservationsOct 16 2012Agents learning to act autonomously in real-world domains must acquire a model of the dynamics of the domain in which they operate. Learning domain dynamics can be challenging, especially where an agent only has partial access to the world state, and/or ... More
pair2vec: Compositional Word-Pair Embeddings for Cross-Sentence InferenceOct 20 2018Apr 05 2019Reasoning about implied relationships (e.g., paraphrastic, common sense, encyclopedic) between pairs of words is crucial for many cross-sentence inference problems. This paper proposes new methods for learning and using embeddings of word pairs that implicitly ... More
An analytical dynamo solution for large-scale magnetic fields of galaxiesAug 03 2016Sep 01 2016We present an effectively global analytical asymptotic galactic dynamo solution for the regular magnetic field of an axisymmetric thin disc in the saturated state. This solution is constructed by combining two well-known types of local galactic dynamo ... More
A search for GMSB sleptons with lifetime at ALEPHOct 12 2001Mar 22 2002A search for slepton production via the decay of pair-produced neutralinos has been performed under the assumption that the sleptons have observable lifetime in the detector before each decays to a lepton and a gravitino. Sleptons, neutralinos and gravitinos ... More
On Handlebody Structures of Rational BallsJun 06 2014It is known that for coprime integers $p>q\geq 1$, the lens space $L(p^2,pq-1)$ bounds a rational ball, $B_{p,q}$, arising as the 2-fold branched cover of a (smooth) slice disk in $B^4$ bounding the associated 2-bridge knot. Lekilli and Maydanskiy give ... More
Linear-Time and Efficient Distributed Algorithms for List Coloring Graphs on SurfacesApr 07 2019In 1994, Thomassen proved that every planar graph is 5-list-colorable. In 1995, Thomassen proved that every planar graph of girth at least five is 3-list-colorable. His proofs naturally lead to quadratic-time algorithms to find such colorings. Here, we ... More
Polytope Bounds on Multivariate Value SetsOct 10 2013Feb 18 2014We improve upon the upper bounds for the cardinality of the value set of a multivariable polynomial map over a finite field using the polytope of the polynomial. This generalizes earlier bounds only dependent on the degree of a polynomial.
QuAC : Question Answering in ContextAug 21 2018Aug 28 2018We present QuAC, a dataset for Question Answering in Context that contains 14K information-seeking QA dialogs (100K questions in total). The dialogs involve two crowd workers: (1) a student who poses a sequence of freeform questions to learn as much as ... More
Measuring the electron anti-neutrino beam component in the T2K near detector ND280Apr 27 2015The main irreducible background in the T2K $\nu_e$ appearance analysis is the $\nu_e$ contamination in the $\nu_\mu$ beam. In order to quantify this background, a selection for charged-current $\nu_e$ interactions in the near detector (ND280) tracker ... More
Characterizing 4-Critical Graphs of Ore-Degree at most SevenSep 17 2014Dirac introduced the notion of a k-critical graph, a graph that is not (k-1)-colorable but whose every proper subgraph is (k-1)-colorable. Brook's Theorem states that every graph with maximum degree k is k-colorable unless it contains a subgraph isomorphic ... More
A comparison between the Shooting and Finite-Difference Method in solving a Nonlinear Boundary Value Problem found in the context of light propagationSep 14 2017The shooting and finite-difference method are both numeric methods that approximate the solution of a BVP to a given accuracy. In this report both methods were implemented in Matlab and compared to each other on a BVP found in the context of light propagation ... More
Hyperdeterminants of PolynomialsJul 23 2011May 06 2012The hyperdeterminant of a polynomial (interpreted as a symmetric tensor) factors into several irreducible factors with multiplicities. Using geometric techniques these factors are identified along with their degrees and their multiplicities. The analogous ... More
3 List Coloring Graphs of Girth at least Five on SurfacesOct 18 2017Grotzsch proved that every triangle-free planar graph is 3-colorable. Thomassen proved that every planar graph of girth at least five is 3-choosable. As for other surfaces, Thomassen proved that there are only finitely many 4-critical graphs of girth ... More
Arbitrary Orientations Of Hamilton Cycles In Oriented GraphsJul 20 2009Aug 06 2009We use a randomised embedding method to prove that for all \alpha>0 any sufficiently large oriented graph G with minimum in-degree and out-degree \delta^+(G),\delta^-(G)\geq (3/8+\alpha)|G| contains every possible orientation of a Hamilton cycle. This ... More
Refining Multivariate Value Set BoundsJul 15 2015Jul 23 2015Over finite fields, if the image of a polynomial map is not the entire field, then its cardinality can be bounded above by a significantly smaller value. Earlier results bound the cardinality of the value set using the degree of the polynomial, but more ... More
Examining nuclear effects in neutrino interactions with transverse kinematic imbalanceFeb 22 2016Jun 03 2016We present a Monte Carlo truth study examining nuclear effects in charged-current neutrino interactions using observables constructed in the transverse plane. Three distributions are introduced that show very weak dependence on neutrino flux and its associated ... More
Inferring genotyping error rates from genotyped triosSep 07 2011Genotyping errors are known to influence the power of both family-based and case-control studies in the genetics of complex disease. Estimating genotyping error rate in a given dataset can be complex, but when family information is available error rates ... More
Genus-Zero Mirror Principle For Two Marked PointsJan 01 2010We study a generalization of Lian-Liu-Yau's notion of Euler data in genus zero and show that certain sequences of multiplicative equivariant characteristic classes on Kontsevich's stable map moduli with markings induce data satisfying the generalization. ... More
The Quadrifocal VarietyJan 06 2015Sep 20 2016Multi-view Geometry is reviewed from an Algebraic Geometry perspective and multi-focal tensors are constructed as equivariant projections of the Grassmannian. A connection to the principal minor assignment problem is made by considering several flatlander ... More
An Improved Lower Bound for Stack SortingDec 04 2012We consider the problem of sorting elements on a series of stacks, introduced by Tarjan and Knuth. We improve the asymptotic lower bound for the number of stacks necessary to sort $n$ elements to $0.561 \log_2 n + O(1)$. This is the first significant ... More
Proof of a Conjecture of Kleinberg-Sawin-SpeyerAug 19 2016In Ellenberg and Gijswijt's groundbreaking work~\cite{EllenbergGijswijt}, the authors show that a subset of $\mathbb{Z}_3^{n}$ with no arithmetic progression of length 3 must be of size at most $2.755^n$ (no prior upper bound was known of $(3-\epsilon)^n)$), ... More
Graph Editing Problems with Extended Regularity ConstraintsOct 12 2015Graph editing problems offer an interesting perspective on sub- and supergraph identification problems for a large variety of target properties. They have also attracted significant attention in recent years, particularly in the area of parameterized ... More
Obstructing Sliceness in a Family of Montesinos KnotsSep 07 2008Using Gauge theoretical techniques employed by Lisca for 2-bridge knots and by Greene-Jabuka for 3-stranded pretzel knots, we show that no member of the family of Montesinos knots M(0;[m_1+1,n_1+2],[m_2+1,n_2+2],q), with certain restrictions on m_i, n_i, ... More
A comparison between the Split Step Fourier and Finite-Difference method in analysing the soliton collision of a type of Nonlinear Schrödinger equation found in the context of optical pulsesSep 14 2017In this report a type of Schr\"odinger Equation which is found in the context of optical pulses is analysed using the $\textit{Split Step}$ and $\textit{Finite Difference}$ method. The investigation shows interesting dynamics regarding certain values ... More
On the iteration of quasimeromorphic mappingsMay 01 2018May 03 2018The Fatou-Julia theory for rational functions has been extended both to transcendental meromorphic functions and more recently to several different types of quasiregular mappings in higher dimensions. We extend the iterative theory to quasimeromorphic ... More
Set-theoretic defining equations of the tangential variety of the Segre varietyNov 27 2009We prove a set-theoretic version of the Landsberg--Weyman Conjecture on the defining equations of the tangential variety of a Segre product of projective spaces. We introduce and study the concept of exclusive rank. For the proof of this conjecture we ... More
AllenNLP: A Deep Semantic Natural Language Processing PlatformMar 20 2018May 31 2018This paper describes AllenNLP, a platform for research on deep learning methods in natural language understanding. AllenNLP is designed to support researchers who want to build novel language understanding models quickly and easily. It is built on top ... More
Remarks on Localizing Futaki-Morita Integrals At Isolated Degenerate ZerosNov 15 2016In this note we study the localization of Futaki-Morita integrals at isolated degenerate zeros by giving a streamlined exposition in the spirit of Bott and implement the localization procedure for a holomorphic vector field on $CP^n$ with a maximally ... More
Applications of the heavy quark expansion: V_{ub} and spectral momentsJul 30 2003The use of inclusive B decays to determine |V_{ub}|, |V_{cb}|, m_b and heavy quark matrix elements via spectral moments is discussed.
Border Ranks of MonomialsAug 08 2016Sep 16 2016Young flattenings, introduced by Landsberg and Ottaviani, give determinantal equations for secant varieties and provide lower bounds for border ranks of tensors. We find special monomial-optimal Young flattenings that provide the best possible lower bound ... More
Set Reconstruction on the HypercubeJul 19 2016Given an action of a group $G$ on a set $S$, the $k$-deck of a subset $T$ of $S$ is the multiset of all subsets of $T$ of size $k$, each given up to translation by $G$. For a given subset $T$, the {\em reconstruction number} of $T$ is the minimum $k$ ... More
Graph Operations and Upper Bounds on Graph Homomorphism CountsOct 07 2015Jun 21 2016We construct a family of countexamples to a conjecture of Galvin [5], which stated that for any $n$-vertex, $d$-regular graph $G$ and any graph $H$ (possibly with loops), \[\hom(G,H) \leq \max\left\lbrace\hom(K_{d,d}, H)^{\frac{n}{2d}}, \hom(K_{d+1},H)^{\frac{n}{d+1}}\right\rbrace,\] ... More
Simple commutative algebras in Deligne's categories Rep($S_t$)Jun 24 2015Dec 31 2015We show that in the Deligne categories $\mathrm{Rep}(S_t)$ for $t$ a transcendental number, the only simple algebra objects are images of simple algebras in the category of representations of a symmetric group under a canonical induction functor. They ... More
PAWL-Forced Simulated TemperingMay 22 2013In this short note, we show how the parallel adaptive Wang-Landau (PAWL) algorithm of Bornn et al. (2013) can be used to automate and improve simulated tempering algorithms. While Wang-Landau and other stochastic approximation methods have frequently ... More
A Proof Checking View of Parameterized ComplexityJun 12 2012Jul 27 2012The PCP Theorem is one of the most stunning results in computational complexity theory, a culmination of a series of results regarding proof checking it exposes some deep structure of computational problems. As a surprising side-effect, it also gives ... More
On the Minimum Number of Edges in Triangle-Free 5-Critical GraphsFeb 09 2016Kostochka and Yancey proved that every 5-critical graph G satisfies: |E(G)|>= (9/4)|V(G)| - 5/4. A construction of Ore gives an infinite family of graphs meeting this bound. We prove that there exists e,d > 0 such that if G is a 5-critical graph, then ... More
Bergman theory of certain generalized Hartogs trianglesApr 29 2015Feb 20 2016The Bergman theory of domains $\{ |{z_{1} |^{\gamma}} < |{z_{2}} | < 1 \}$ in $\mathbb{C}^2$ is studied for certain values of $\gamma$, including all positive integers. For such $\gamma$, we obtain a closed form expression for the Bergman kernel, $\mathbb{B}_{\gamma}$. ... More
Minimally intersecting filling pairs on the punctured surface of genus twoJul 19 2018In this short note, we construct a minimally intersecting pair of simple closed curves that fill a genus 2 surface with an odd, greater than 3, number of punctures. This finishes the determination of minimally intersecting filling pairs for all surfaces ... More
On the Minimum Number of Edges in Triangle-Free 5-Critical GraphsFeb 09 2016Aug 07 2017Kostochka and Yancey proved that every 5-critical graph G satisfies: |E(G)|>= (9/4)|V(G)| - 5/4. A construction of Ore gives an infinite family of graphs meeting this bound. We prove that there exists e,d > 0 such that if G is a 5-critical graph, then ... More
Are all Secant Varieties of Segre Products Arithmetically Cohen-Macaulay?Mar 29 2016Apr 06 2016When present, the Cohen-Macaulay property can be useful for finding the minimal defining equations of an algebraic variety. It is conjectured that all secant varieties of Segre products of projective spaces are arithmetically Cohen-Macaulay. A summary ... More
Single-cylinder square-tiled surfaces and the ubiquity of ratio-optimising pseudo-AnosovsJun 05 2019In every connected component of every stratum of Abelian differentials, we construct square-tiled surfaces with one vertical and one horizontal cylinder. We show that for all but the hyperelliptic components this can be achieved in the minimum number ... More
Constructing a quasiregular analogue of $z \exp(z)$ in dimension 3Jul 10 2019We construct a quasiregular analogue of the function $z\exp(z)$ in dimension 3, which gives the first explicit example of a quasiregular mapping of transcendental type that has exactly one zero. We then modify the construction to create a family of such ... More
Exponentially Many 4-List-Colorings of Triangle-Free Graphs on SurfacesFeb 15 2016Thomassen proved that every planar graph $G$ on $n$ vertices has at least $2^{n/9}$ distinct $L$-colorings if $L$ is a 5-list-assignment for $G$ and at least $2^{n/10000}$ distinct $L$-colorings if $L$ is a 3-list-assignment for $G$ and $G$ has girth ... More
Adjusting chaotic indicators to curved spacetimesNov 25 2013Feb 07 2014In this work, chaotic indicators, which have been established in the framework of classical mechanics, are reformulated in the framework of general relativity in such a way that they are invariant under coordinate transformation. For achieving this, the ... More
The Use of Epistemic Distancing to Create a Safe Space to Sensemake in Introductory Physics TutorialsAug 07 2015In active engagement physics classrooms, students get opportunities to make sense of physics together through discussion. They do not always take up these opportunities, in part because of the risk of sharing their ideas and having them rejected by their ... More
Spallative Nucleosynthesis in Supernova Remnants. II. Time-dependent numerical resultsMar 23 1999We calculate the spallative production of light elements associated with the explosion of an isolated supernova in the interstellar medium, using a time-dependent model taking into account the dilution of the ejected enriched material and the adiabatic ... More
Local Music Event Recommendation with Long Tail ArtistsSep 07 2018In this paper, we explore the task of local music event recommendation. Many local artists tend to be obscure long-tail artists with a small digital footprint. That is, it can be hard to find social tag and artist similarity information for many of the ... More
Randomization Tests that Condition on Non-Categorical Covariate BalanceFeb 03 2018Oct 04 2018A benefit of randomized experiments is that covariate distributions of treatment and control groups are balanced on average, resulting in simple unbiased estimators for treatment effects. However, it is possible that a particular randomization yields ... More
Comparing Covariate Prioritization via Matching to Machine Learning Methods for Causal Inference using Five Empirical ApplicationsMay 09 2018Jan 08 2019When investigators seek to estimate causal effects, they often assume that selection into treatment is based only on observed covariates. Under this identification strategy, analysts must adjust for observed confounders. While basic regression models ... More
A Parallel Trajectory Swapping Wang - Landau Study Of The HP Protein ModelJul 12 2016The HP model of protein folding, where the chain exists in a free medium, is investigated using a parallel Monte Carlo scheme based upon Wang-Landau sampling. Expanding on the work of Wust and Landau by introducing a lesser known replica -exchange scheme ... More
Hyperbolic families and coloring graphs on surfacesSep 21 2016May 06 2018Let $G$ be a graph embedded in a fixed surface $\Sigma$ of genus $g$ and let $L=(L(v):v\in V(G))$ be a collection of lists such that either each list has size at least five, or each list has size at least four and $G$ is triangle-free, or each list has ... More
Five-list-coloring graphs on surfaces III. One list of size one and one list of size twoAug 19 2016Let $G$ be a plane graph with outer cycle $C$ and let $(L(v):v\in V(G))$ be a family of non-empty sets. By an $L$-coloring of $G$ we mean a (proper) coloring $\phi$ of $G$ such that $\phi(v)\in L(v)$ for every vertex $v$ of $G$. Thomassen proved that ... More
Five-list-coloring graphs on surfaces II. A linear bound for critical graphs in a diskMay 22 2015Let $G$ be a plane graph with outer cycle $C$ and let $(L(v):v\in V(G))$ be a family of sets such that $|L(v)|\ge 5$ for every $v\in V(G)$. By an $L$-coloring of a subgraph $J$ of $G$ we mean a (proper) coloring $\phi$ of $J$ such that $\phi(v)\in L(v)$ ... More
Tangential varieties of Segre-Veronese varietiesNov 26 2011Feb 01 2013We determine the minimal generators of the ideal of the tangential variety of a Segre-Veronese variety, as well as the decomposition into irreducible GL-representations of its homogeneous coordinate ring. In the special case of a Segre variety, our results ... More
Eigenvectors of tensors and algorithms for Waring decompositionMar 01 2011Nov 06 2012A Waring decomposition of a (homogeneous) polynomial f is a minimal sum of powers of linear forms expressing f. Under certain conditions, such a decomposition is unique. We discuss some algorithms to compute the Waring decomposition, which are linked ... More
Fractional coloring with local demandsNov 28 2018We investigate fractional colorings of graphs in which the amount of color given to a vertex depends on local parameters, such as its degree or the clique number of its neighborhood; in a \textit{fractional $f$-coloring}, vertices are given color from ... More
A note on sensitivity of principal component subspaces and the efficient detection of influential observations in high dimensionsMar 04 2008Jun 26 2008In this paper we introduce an influence measure based on second order expansion of the RV and GCD measures for the comparison between unperturbed and perturbed eigenvectors of a symmetric matrix estimator. Example estimators are considered to highlight ... More
Closed, Palindromic, Rich, Privileged, Trapezoidal, and Balanced Words in Automatic SequencesAug 09 2015Nov 30 2015We prove that the property of being closed (resp., palindromic, rich, privileged trapezoidal, balanced) is expressible in first-order logic for automatic (and some related) sequences. It therefore follows that the characteristic function of those n for ... More