Results for "Pascal Van Hentenryck"

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The Complexity of DC-Switching ProblemsNov 17 2014This report provides a comprehensive complexity study of line switching in the Linear DC model for the feasibility problem and the optimization problems of maximizing the load that can be served (maximum switching flow, MSF) and minimizing generation ... More
AC-Feasibility on Tree Networks is NP-HardOct 30 2014Recent years have witnessed significant interest in convex relaxations of the power flows, several papers showing that the second-order cone relaxation is tight for tree networks under various conditions on loads or voltages. This paper shows that AC-feasibility, ... More
The Complexity of Switching and FACTS Maximum-Potential-Flow ProblemsJul 17 2015This papers considers the problem of maximizing the load that can be served by a power network. We use the commonly accepted Linear DC power network model and consider wo configuration options: switching lines and using FACTS devices. We present the first ... More
Simulation and Analysis of Container Freight Train Operations at Port BotanyDec 10 2015Dec 22 2015Over two million containers crossed the docks at Sydney's Port Botany in 2011/12; a figure that is forecast increase more than threefold by the end of the next decade. To cope with such large growth in volumes the NSW Government plans to double rail mode ... More
Phase Transitions for Optimality Gaps in Optimal Power Flows A Study on the French Transmission NetworkJul 14 2018This paper investigates phase transitions on the optimality gaps in Optimal Power Flow (OPF) problem on real-world power transmission systems operated in France. The experimental results study optimal power flow solutions for more than 6000 scenarios ... More
Measuring and Optimizing Cultural MarketsAug 07 2014May 25 2015Social influence has been shown to create significant unpredictability in cultural markets, providing one potential explanation why experts routinely fail at predicting commercial success of cultural products. To counteract the difficulty of making accurate ... More
Propagating Regular Counting ConstraintsSep 27 2013Constraints over finite sequences of variables are ubiquitous in sequencing and timetabling. Moreover, the wide variety of such constraints in practical applications led to general modelling techniques and generic propagation algorithms, often based on ... More
Modeling Stated Preference for Mobility-on-Demand Transit: A Comparison of Machine Learning and Logit ModelsNov 04 2018Logit models are usually applied when studying individual travel behavior, i.e., to predict travel mode choice and to gain behavioral insights on traveler preferences. Recently, some studies have applied machine learning to model travel mode choice and ... More
Performance of Social Network Sensors During Hurricane SandyFeb 11 2014Jun 20 2014Information flow during catastrophic events is a critical aspect of disaster management. Modern communication platforms, in particular online social networks, provide an opportunity to study such flow, and a mean to derive early-warning sensors, improving ... More
Graphical Models and Belief Propagation-hierarchy for Optimal Physics-Constrained Network FlowsFeb 07 2017In this manuscript we review new ideas and first results on application of the Graphical Models approach, originated from Statistical Physics, Information Theory, Computer Science and Machine Learning, to optimization problems of network flow type with ... More
A Microkernel Architecture for Constraint ProgrammingJan 21 2014This paper presents a microkernel architecture for constraint programming organized around a number of small number of core functionalities and minimal interfaces. The architecture contrasts with the monolithic nature of many implementations. Experimental ... More
Benders Decomposition for a Class of Mathematical Programs with Constraints on Dual VariablesFeb 12 2019Interdependent systems with mutual feedback are best represented as a multi-level mathematical programming, in which the leader decisions determine the follower operations, which subsequently affect the leader operations. For instance, a recent paper ... More
Unit Commitment With Gas Network AwarenessFeb 08 2019Recent changes in the fuel mix for electricity generation and, in particular, the increase in Gas-Fueled Power Plants (GFPP), have created significant interdependencies between the electrical power and natural gas transmission systems. However, despite ... More
A constraint satisfaction approach to the robust spanning tree problem with interval dataDec 12 2012Robust optimization is one of the fundamental approaches to deal with uncertainty in combinatorial optimization. This paper considers the robust spanning tree problem with interval data, which arises in a variety of telecommunication applications. It ... More
Domain Views for Constraint ProgrammingJan 21 2014Views are a standard abstraction in constraint programming: They make it possible to implement a single version of each constraint, while avoiding to create new variables and constraints that would slow down propagation. Traditional constraint-programming ... More
A Linear-Programming Approximation of AC Power FlowsJun 16 2012Aug 06 2013Linear active-power-only DC power flow approximations are pervasive in the planning and control of power systems. However, these approximations fail to capture reactive power and voltage magnitudes, both of which are necessary in many applications to ... More
Polynomial SDP Cuts for Optimal Power FlowOct 27 2015The use of convex relaxations has lately gained considerable interest in Power Systems. These relaxations play a major role in providing global optimality guarantees for non-convex optimization problems. For the Optimal Power Flow (OPF) problem, the Semi-Definite ... More
Bargaining Mechanisms for One-Way GamesJul 25 2015We introduce one-way games, a framework motivated by applications in large-scale power restoration, humanitarian logistics, and integrated supply-chains. The distinguishable feature of the games is that the payoff of some player is determined only by ... More
CPBVP: A Constraint-Programming Framework for Bounded Program VerificationJul 15 2008This paper studies how to verify the conformity of a program with its specification and proposes a novel constraint-programming framework for bounded program verification (CPBPV). The CPBPV framework uses constraint stores to represent the specification ... More
Strengthening the SDP Relaxation of AC Power Flows with Convex Envelopes, Bound Tightening, and Lifted Nonlinear CutsDec 15 2015Jan 05 2016This paper considers state-of-the-art convex relaxations for the AC power flow equations and introduces new valid cuts based on convex envelopes and lifted nonlinear constraints. These valid linear inequalities strengthen existing semidefinite and quadratic ... More
Assortment Optimization under the Sequential Multinomial Logit ModelJul 09 2017Aug 30 2018We study the assortment optimization problem under the Sequential Multinomial Logit (SML), a discrete choice model that generalizes the multinomial logit (MNL). Under the SML model, products are partitioned into two levels, to capture differences in attractiveness, ... More
Sonet Network Design ProblemsOct 07 2009This paper presents a new method and a constraint-based objective function to solve two problems related to the design of optical telecommunication networks, namely the Synchronous Optical Network Ring Assignment Problem (SRAP) and the Intra-ring Synchronous ... More
Trial-Offer Markets with ContinuationOct 05 2016Trial-offer markets, where customers can sample a product before deciding whether to buy it, are ubiquitous in the online experience. Their static and dynamic properties are often studied by assuming that consumers follow a multinomial logit model and ... More
Assortment Optimization under the General Luce ModelJun 26 2017This paper studies the assortment optimization problem under the General Luce Model (GLM), a discrete choice introduced by Echenique and Saito (2015) that generalizes the standard multinomial logit model (MNL). The GLM does not satisfy the Independence ... More
Modeling Heterogeneity in Mode-Switching Behavior Under a Mobility-on-Demand Transit System: An Interpretable Machine Learning ApproachFeb 08 2019Recent years have witnessed an increased focus on interpretability and the use of machine learning to inform policy analysis and decision making. This paper applies machine learning to examine travel behavior and, in particular, on modeling changes in ... More
Optimization of Topography-based Flood Mitigation StrategiesMar 01 2018The dynamics of flooding are primarily influenced by the shape and height of the underlying topography. For this reason, mechanisms to mitigate floods frequently employ structures that increase topographic elevation, e.g., levees and sandbags. However, ... More
Benders Decomposition for the Design of a Hub and Shuttle Public Transit SystemDec 30 2015The BusPlus project aims at improving the off-peak hours public transit service in Canberra, Australia. To address the difficulty of covering a large geographic area, BusPlus proposes a hub and shuttle model consisting of a combination of a few high-frequency ... More
A Constraint Programming Approach for Non-Preemptive Evacuation SchedulingMay 11 2015Large-scale controlled evacuations require emergency services to select evacuation routes, decide departure times, and mobilize resources to issue orders, all under strict time constraints. Existing algorithms almost always allow for preemptive evacuation ... More
The Benefits of Segmentation in Trial-Offer Markets with Social Influence and Position BiasNov 03 2015The purchasing behaviour of consumers is often influenced by numerous factors, including the visibility of the products and the influence of other customers through their own purchases or their recommendations. Motivated by trial-offer and freemium markets ... More
Comparison between CPBPV, ESC/Java, CBMC, Blast, EUREKA and Why for Bounded Program VerificationAug 11 2008This report describes experimental results for a set of benchmarks on program verification. It compares the capabilities of CPBVP "Constraint Programming framework for Bounded Program Verification" [4] with the following frameworks: ESC/Java, CBMC, Blast, ... More
The QC Relaxation: Theoretical and Computational Results on Optimal Power FlowFeb 27 2015Jul 29 2015Convex relaxations of the power flow equations and, in particular, the Semi-Definite Programming (SDP) and Second-Order Cone (SOC) relaxations, have attracted significant interest in recent years. The Quadratic Convex (QC) relaxation is a departure from ... More
Communication-Constrained Expansion Planning for Resilient Distribution SystemsJan 10 2018Distributed generation and remotely controlled switches have emerged as important technologies to improve the resiliency of distribution grids against extreme weather-related disturbances. Therefore it becomes impor- tant to study how best to place them ... More
DistFlow Extensions for AC Transmission SystemsMay 27 2015Convex relaxations of the power flow equations and, in particular, the Semi-Definite Programming (SDP), Second-Order Cone (SOC), and Convex DistFlow (CDF) relaxations, have attracted significant interest in recent years. Thus far, studies of the CDF model ... More
Differential Privacy for Power Grid ObfuscationJan 21 2019The availability of high-fidelity energy networks brings significant value to academic and commercial research. However, such releases also raise fundamental concerns related to privacy and security as they can reveal sensitive commercial information ... More
Popularity Signals in Trial-Offer MarketsDec 22 2015Dec 23 2015This paper considers trial-offer and freemium markets where consumer preferences are modeled by a multinomial logic model with social influence and position bias. The social signal for a product i is its market share raised to some power r. The paper ... More
Sequence-Based Abstract Interpretation of PrologOct 19 2000Many abstract interpretation frameworks and analyses for Prolog have been proposed, which seek to extract information useful for program optimization. Although motivated by practical considerations, notably making Prolog competitive with imperative languages, ... More
A Local Search Modeling for Constrained Optimum Paths Problems (Extended Abstract)Oct 07 2009Constrained Optimum Path (COP) problems appear in many real-life applications, especially on communication networks. Some of these problems have been considered and solved by specific techniques which are usually difficult to extend. In this paper, we ... More
Modeling Stated Preference for Mobility-on-Demand Transit: A Comparison of Machine Learning and Logit ModelsNov 04 2018Apr 01 2019Logit models are usually applied when studying individual travel behavior, i.e., to predict travel mode choice and to gain behavioral insights on traveler preferences. Recently, some studies have applied machine learning to model travel mode choice and ... More
Crowdsourcing DilemmaApr 12 2013Feb 22 2014Crowdsourcing offers unprecedented potential for solving tasks efficiently by tapping into the skills of large groups of people. A salient feature of crowdsourcing---its openness of entry---makes it vulnerable to malicious behavior. Such behavior took ... More
Optimizing Expected Utility in a Multinomial Logit Model with Position Bias and Social InfluenceNov 02 2014Nov 06 2014Motivated by applications in retail, online advertising, and cultural markets, this paper studies how to find the optimal assortment and positioning of products subject to a capacity constraint. We prove that the optimal assortment and positioning can ... More
Popularity Signals in Trial-Offer Markets with Social Influence and Position BiasDec 22 2015Nov 03 2017This paper considers trial-offer markets where consumer preferences are modeled by a multinomial logit with social influence and position bias. The social signal for a product is given by its current market share raised to power r (or equivalently the ... More
Constraint and Mathematical Programming Models for Integrated Port Container Terminal OperationsDec 14 2017This paper considers the integrated problem of quay crane assignment, quay crane scheduling, yard location assignment, and vehicle dispatching operations at a container terminal. The main objective is to minimize vessel turnover times and maximize the ... More
Network Flow and Copper Plate Relaxations for AC Transmission SystemsJun 17 2015Nov 12 2015Nonlinear convex relaxations of the power flow equations and, in particular, the Semi-Definite Programming (SDP), Convex Quadratic (QC), and Second-Order Cone (SOC) relaxations, have attracted significant interest in recent years. Thus far, little attention ... More
On the Optimality and Predictability of Cultural Markets with Social InfluenceMay 11 2015May 25 2015Social influence is ubiquitous in cultural markets, from book recommendations in Amazon, to song popularities in iTunes and the ranking of newspaper articles in the online edition of the New York Times to mention only a few. Yet social influence is often ... More
Pluricomplex Green and Lempert functions for equally weighted polesJun 20 2002For $\Omega$ a domain in $\mathbb C^n$, the pluricomplex Green function with poles $a_1, ...,a_N \in \Omega$ is defined as $G(z):=\sup \{u(z): u\in PSH_-(\Omega), u(x)\le \log \|x-a_j\|+C_j \text{when} x \to a_j, j=1,...,N \}$. When there is only one ... More
A Conflict-Based Path-Generation Heuristic for Evacuation PlanningSep 10 2013Evacuation planning and scheduling is a critical aspect of disaster management and national security applications. This paper proposes a conflict-based path-generation approach for evacuation planning. Its key idea is to generate evacuation routes lazily ... More
Discontinuity of the Lempert function of the spectral ballNov 19 2008Sep 07 2009We give some further criteria for continuity or discontinuity of the Lempert funtion of the spectral ball $\Omega_n$, with respect to one or both of its arguments, in terms of cyclicity the matrices involved.
Linking endogenous and exogenous popularity processes in social mediaFeb 19 2016Jul 20 2016Explaining and predicting the popularity of online multimedia content is an important problem for the practice of information dissemination and consumption. Recent work advances our understanding of popularity, but one important gap remains: to precisely ... More
Convex Relaxations for Gas Expansion PlanningJun 24 2015Expansion of natural gas networks is a critical process involving substantial capital expenditures with complex decision-support requirements. Given the non-convex nature of gas transmission constraints, global optimality and infeasibility guarantees ... More
Efficient Dynamic Compressor Optimization in Natural Gas Transmission SystemsNov 24 2015The growing reliance of electric power systems on gas-fired generation to balance intermittent sources of renewable energy has increased the variation and volume of flows through natural gas transmission pipelines. Adapting pipeline operations to maintain ... More
Mobility-on-demand versus fixed-route transit systems: an evaluation of traveler preferences in low-income communitiesJan 22 2019Emerging transportation technologies, such as ride-hailing and autonomous vehicles, are disrupting the transportation sector and transforming public transit. Some transit observers envision future public transit to be integrated transit systems with fixed-route ... More
Nowcasting Disaster DamageApr 26 2015Could social media data aid in disaster response and damage assessment? Countries face both an increasing frequency and intensity of natural disasters due to climate change. And during such events, citizens are turning to social media platforms for disaster-related ... More
Graphical Models for Optimal Power FlowJun 21 2016Optimal power flow (OPF) is the central optimization problem in electric power grids. Although solved routinely in the course of power grid operations, it is known to be strongly NP-hard in general, and weakly NP-hard over tree networks. In this paper, ... More
Expecting to be HIP: Hawkes Intensity Processes for Social Media PopularityFeb 19 2016Sep 08 2017Modeling and predicting the popularity of online content is a significant problem for the practice of information dissemination, advertising, and consumption. Recent work analyzing massive datasets advances our understanding of popularity, but one major ... More
A quantum magnetic RC circuitJan 22 2014We propose a setup that is the spin analog of the charge-based quantum RC circuit. We define and compute the spin capacitance and the spin resistance of the circuit for both ferromagnetic (FM) and antiferromagnetic (AF) systems. We find that the antiferromagnetic ... More
Activity-Based Search for Black-Box Contraint-Programming SolversMay 31 2011Robust search procedures are a central component in the design of black-box constraint-programming solvers. This paper proposes activity-based search, the idea of using the activity of variables during propagation to guide the search. Activity-based search ... More
Featureless: Bypassing feature extraction in action categorizationMar 19 2018This method introduces an efficient manner of learning action categories without the need of feature estimation. The approach starts from low-level values, in a similar style to the successful CNN methods. However, rather than extracting general image ... More
Novel approaches to spectral properties of correlated electron materials: From generalized Kohn-Sham theory to screened exchange dynamical mean field theoryJul 03 2017The most intriguing properties of emergent materials are typically consequences of highly correlated quantum states of their electronic degrees of freedom. Describing those materials from first principles remains a challenge for modern condensed matter ... More
Gravitational lensing in WDM cosmologies: The cross section for giant arcsApr 07 2014The nature of the dark sector of the Universe remains one of the outstanding problems in modern cosmology, with the search for new observational probes guiding the development of the next generation of observational facilities. Clues come from tension ... More
Preliminary design of the full-Stokes UV and visible spectropolarimeter for UVMag/AragoFeb 03 2015The UVMag consortium proposed the space mission project Arago to ESA at its M4 call. It is dedicated to the study of the dynamic 3D environment of stars and planets. This space mission will be equipped with a high-resolution spectropolarimeter working ... More
Interdependent Scheduling GamesMay 31 2016We propose a model of interdependent scheduling games in which each player controls a set of services that they schedule independently. A player is free to schedule his own services at any time; however, each of these services only begins to accrue reward ... More
Coupling in the queue with impatience: case of several serversNov 08 2017Nov 17 2017We present the explicit construction of a stable queue with several servers and impatient customers, under stationary ergodic assumptions. Using a stochastic comparison of the (multivariate) workload sequence with two monotonic stochastic recursions, ... More
On the stability of a class of non-monotonic systems of parallel queuesDec 14 2015We investigate, under general stationary ergodic assumptions, the stability of systems of $S$ parallel queues in which any incoming customer joins the queue of the server having the $p+1$-th shortest workload ($p < S$), or a free server if any. This change ... More
La cohomologie des espaces de Lubin-Tate est libreSep 08 2013Aug 31 2018This article is the entire version, that is with coefficients in the ring of integers of a local field, of my last paper at inventiones. The principal result is the freeness of the cohomology groups of the Lubin-Tate tower. The strategy is to study the ... More
Filtrations de stratification de quelques variétés de Shimura simplesSep 08 2013Dec 22 2014We define and study new filtrations called of stratification of a perverse sheaf on a scheme; beside the cases of the weight or monodromy filtrations, these filtrations are available whatever are the ring of coefficients. We illustrate these constructions ... More
Faisceaux pervers des cycles évanescents des variétés de Drinfeld et groupes de cohomologie du modèle de Deligne-CarayolFeb 06 2006In the first half of the paper, we translate in the geometric situation of Drinfeld varieties, the principal results of the Harris and Taylor's book. We give in particular the restriction to the open strata of the vanishing cycles sheaves in terms of ... More
Une grammaire formelle du créole martiniquais pour la génération automatiqueOct 07 2008In this article, some first elements of a computational modelling of the grammar of the Martiniquese French Creole dialect are presented. The sources of inspiration for the modelling is the functional description given by Damoiseau (1984), and Pinalie's ... More
The attractor structure of logarithmic iterations in the complex planeDec 29 2010We use the methods of empirical mathematics to show that iterative logarithmic operations will result in an attractor point on the complex plane. Moreover, we demonstrate that different bases converge onto different attractors. Finally, we elicit the ... More
On the $\bar{\mathbb F}_l$-cohomology of a simple unitary Shimura varietyDec 07 2015Apr 06 2016We study the torsion cohomology classes of Shimura varieties of type Kottwitz-Harris-Taylor and we show that " up to an arbitrary place " one can raise them to an automorphic representation. In application, to any mod $l$ system of Hecke eigenvalues appearing ... More
A Semantics-based Communication System for Dysphasic SubjectsMar 12 1997Dysphasic subjects do not have complete linguistic abilities and only produce a weakly structured, topicalized language. They are offered artificial symbolic languages to help them communicate in a way more adapted to their linguistic abilities. After ... More
The q-deformed analogue of the Onsager algebra: Beyond the Bethe ansatz approachApr 17 2006Sep 18 2006The spectral properties of operators formed from generators of the q-Onsager non-Abelian infinite dimensional algebra are investigated. Using a suitable functional representation, all eigenfunctions are shown to obey a second-order q-difference equation ... More
Sur les extensions intermédiaires des systèmes locaux d'Harris-TaylorSep 23 2013Mar 29 2016In the geometric situation of some simple unitary Shimura varieties studied by Harris and Taylor, I have built two filtrations of the perverse sheaf of vanishing cycles. The graduate of the first are the $p$-intermediate extension of some local Harris-Taylor's ... More
La $\mathrm{Z}_l$-cohomologie du modèle de Deligne-Carayol est sans torsionJul 30 2007Sep 17 2017This article is the $\mathrm{Z}_l$-version of my paper "Monodromie du faisceau pervers des cycles \'evanescents de quelques vari\'et\'es de Shimura simples" in Invent. Math. 2009 vol 177 pp. 239-280, where we study the vanishing cycles of some unitary ... More
The WILDTRACK Multi-Camera Person DatasetJul 28 2017People detection methods are highly sensitive to the perpetual occlusions among the targets. As multi-camera set-ups become more frequently encountered, joint exploitation of the across views information would allow for improved detection performances. ... More
Evolution of the Magnetic Field Distribution of Active RegionsSep 13 2016Aims. Although the temporal evolution of active regions (ARs) is relatively well understood, the processes involved continue to be the subject of investigation. We study how the magnetic field of a series of ARs evolves with time to better characterise ... More
Modelling the Effect of Mass-Draining on Prominence EruptionsJan 30 2019Quiescent solar prominences are observed to exist within the solar atmosphere for up to several solar rotations. Their eruption is commonly preceded by a slow increase in height that can last from hours to days. This increase in the prominence height ... More
Quarkonium measurements in nucleus--nucleus collisions with ALICEJul 20 2018Quarkonia, i.e. bound states of $b\bar{b}$ and $c\bar{c}$ quarks, are powerful observables to study the properties of nuclear matter under extreme conditions. The formation of a Quark-Gluon Plasma (QGP), which is predicted by lattice QCD calculations ... More
Kondo screening cloud in a double-quantum dot systemFeb 16 2005We analyze the transport properties of two artificial magnetic impurities coupled togethervia a tunable RKKY interaction mediated by conduction electrons of a finite size one dimensional wire. We show that the sign of the RKKY interaction can be controlled ... More
On quantum shuffle and quantum affine algebrasJul 24 2001A construction of the quantum affine algebra $U_q(g)$ is given in two steps. We explain how to obtain the algebra from its positive Borel subalgebra $U_q(b^+)$, using a construction similar to Drinfeld's quantum double. Then we show how the positive Borel ... More
Construction of a stationary FIFO queue with impatient customersFeb 18 2008In this paper, we study the stability of queues with impatient customers. Under general stationary ergodic assumptions, we first provide some conditions for such a queue to be regenerative (i.e. to empty a.s. an infinite number of times). In the particular ... More
Speed and fluctuations of N-particle branching Brownian motion with spatial selectionApr 02 2013Jun 19 2018We consider branching Brownian motion on the real line with the following selection mechanism: Every time the number of particles exceeds a (large) given number $N$, only the $N$ right-most particles are kept and the others killed. After rescaling time ... More
A family of tridiagonal pairs and related symmetric functionsApr 17 2006Mar 11 2007A family of tridiagonal pairs which appear in the context of quantum integrable systems is studied in details. The corresponding eigenvalue sequences, eigenspaces and the block tridiagonal structure of their matrix realizations with respect the dual eigenbasis ... More
Comprehensive Feature-Based Landscape Analysis of Continuous and Constrained Optimization Problems Using the R-Package flaccoAug 17 2017Choosing the best-performing optimizer(s) out of a portfolio of optimization algorithms is usually a difficult and complex task. It gets even worse, if the underlying functions are unknown, i.e., so-called Black-Box problems, and function evaluations ... More
Construction of torsion cohomology classes for KHT Shimura varietiesMar 26 2019Let $Sh_K(G,\mu)$ be a Shimura variety of KHT type, as introduced in Harris-Taylor book, associated to some similitude group $G/\mathbb Q$ and a open compact subgroup $K$ of $G(\mathbb A)$. For any irreducible algebraic $\overline{\mathbb Q}_l$-representation ... More
About Galois reducibility of torsion cohomology classes for KHT Shimura varietiesMar 26 2019We pursue the original strategy of my paper at JIMJ and we give a new criterion so that the localization of the cohomology of KHT Shimura variety is free. Precisely let $G$ be a similitude group with signatures $(1,d-1),(0,d),\cdots,(0,d)$ and $V_{\xi,\overline{\mathbb ... More
On the irreductibility of some Igusa varietiesFeb 12 2007We describe the connected components of Igusa's varieties of second species defined par Harris and Taylor in their book. There are in bijection with the characters of the inversible group of the maximal order of the division algebra attached to them.
A Chart-Parsing Algorithm for Efficient Semantic AnalysisSep 02 2002In some contexts, well-formed natural language cannot be expected as input to information or communication systems. In these contexts, the use of grammar-independent input (sequences of uninflected semantic units like e.g. language-independent icons) ... More
Modelling Semantic Association and Conceptual Inheritance for Semantic AnalysisSep 15 2001Allowing users to interact through language borders is an interesting challenge for information technology. For the purpose of a computer assisted language learning system, we have chosen icons for representing meaning on the input interface, since icons ... More
A Layered Grammar Model: Using Tree-Adjoining Grammars to Build a Common Syntactic Kernel for Related DialectsOct 07 2008This article describes the design of a common syntactic description for the core grammar of a group of related dialects. The common description does not rely on an abstract sub-linguistic structure like a metagrammar: it consists in a single FS-LTAG where ... More
Default reasoning over domains and concept hierarchiesSep 01 2004W.C. Rounds and G.-Q. Zhang (2001) have proposed to study a form of disjunctive logic programming generalized to algebraic domains. This system allows reasoning with information which is hierarchically structured and forms a (suitable) domain. We extend ... More
Change of angle in tent spacesJan 20 2011We prove sharp bounds for the equivalence of norms in tent spaces with respect to changes of angles. Some applications are given.
A factorisation theorem for curve with vanishing self-intersectionMay 14 2014Jun 20 2014Let C be a curve in a compact Kahler surface Y. Assume that the self-intersection of C is vanishing, and the image of the fundamental group of C in Y is of infinite index in the fundamental group of Y. Does it follow that C is a fiber of a holomorphic ... More
SuperpfaffianFeb 04 2004Let V=V_0+V_1 be a real finite dimensional supervector space provided with a non-degenerate antisymmetric even bilinear form B. Let spo(V) be the Lie superalgebra of endomorphisms of V which preserve B. We consider spo(V) as a supermanifold. We show that ... More
The theory of Liouville functionsMar 12 2002A Liouville function is a complex analytic function H with a Taylor series \sum_{n=1}^{\infty} x^n/a_n such the a_n's form a ``very fast growing'' sequence of integers. In this paper we exhibit the complete first-order theory of the complex field expanded ... More
Using the Incompressibility Method to obtain Local Lemma results for Ramsey-type ProblemsApr 04 2008We reveal a connection between the incompressibility method and the Lovasz local lemma in the context of Ramsey theory. We obtain bounds by repeatedly encoding objects of interest and thereby compressing strings. The method is demonstrated on the example ... More
The $λ$-invariant measures of subcritical Bienaymé--Galton--Watson processesAug 04 2015Jun 13 2016A $\lambda$-invariant measure of a sub-Markov chain is a left eigenvector of its transition matrix of eigenvalue $\lambda$. In this article, we give an explicit integral representation of the $\lambda$-invariant measures of subcritical Bienaym\'e--Galton--Watson ... More
On Zero Divisors with Small Support in Group Rings of Torsion-Free GroupsFeb 29 2012Kaplanski's Zero Divisor Conjecture envisions that for a torsion-free group G and an integral domain R, the group ring R[G] does not contain non-trivial zero divisors. We define the length of an element a in R[G] as the minimal non-negative integer k ... More
Géométrie, points entiers et courbes entièresSep 21 2007Let $X$ be a projective variety over a number field $K$ (resp. over $\mathbb{C}$). Let $H$ be the sum of ``sufficiently many positive divisors'' on $X$. We show that any set of quasi-integral points (resp. any integral curve) in $X-H$ is not Zariski dense. ... More
Géométrie des surfaces algébriques et points entiersJun 08 2006Let $X$ be a projective normal surface over a number field $K$. Let $H$ be the sum of four properly intersecting ample effective divisors on $X$. We show that any set of $S$-integral points in $X-H$ is not Zariski dense.
On the Calderón-Zygmund lemma for Sobolev functionsOct 28 2008We correct an inaccuracy in the original proof