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Sensor-less adaptive optics for Brillouin micro-spectroscopyFeb 08 2018Brillouin spectroscopy is a powerful optical technique for viscoelastic characterization of samples without contact. However, like all optical systems, Brillouin spectroscopy performances are degraded by optical aberrations, and have therefore been limited ... More

A Geometric Construction of Cyclic Cocycles on Twisted Convolution AlgebrasSep 30 2010In this thesis we give a construction of cyclic cocycles on convolution algebras twisted by gerbes over discrete translation groupoids. In his seminal book, Connes constructs a map from the equivariant cohomology of a manifold carrying the action of a ... More

Hierarchical construction of bounded solutions in critical regularity spacesMar 07 2010Sep 15 2014We construct uniformly bounded solutions for the equations $\text{div}\, U=f$ and $\text{curl}\, U=F$ in the critical cases $f \in L^d(T^d,R)$, and respectively, $F \in L^3(T^3,R^3)$. Criticality in this context, manifests itself by the lack of linear ... More

Best subset selection, persistence in high-dimensional statistical learning and optimization under $l_1$ constraintFeb 23 2007Let $(Y,X_1,...,X_m)$ be a random vector. It is desired to predict $Y$ based on $(X_1,...,X_m)$. Examples of prediction methods are regression, classification using logistic regression or separating hyperplanes, and so on. We consider the problem of best ... More

(GL(2n,C),SP(2n,C)) is a Gelfand PairMay 19 2008We prove that (GL_{2n}(C),Sp_{2n}(C)) is a Gelfand pair. More precisely, we show that for an irreducible smooth admissible Frechet representation (\pi,E) of GL_{2n}(C) the space of continuous functionals Hom_{Sp_{2n}(\cc)}(E,C) is at most one dimensional. ... More

On a new scale of regularity spaces with applications to Euler's equationsDec 03 2001We introduce a new ladder of function spaces which is shown to fill in the gap between the weak $L^{p\infty}$ spaces and the larger Morrey spaces, $M^p$. Our motivation for introducing these new spaces, denoted $\V^{pq}$, is to gain a more accurate information ... More

High resolution methods for time dependent problems with piecewise smooth solutionsMay 01 2003A trademark of nonlinear, time-dependent, convection-dominated problems is the spontaneous formation of non-smooth macro-scale features, like shock discontinuities and non-differentiable kinks, which pose a challenge for high-resolution computations. ... More

Cyclic cocycles on twisted convolution algebrasMar 02 2011We give a construction of cyclic cocycles on convolution algebras twisted by gerbes over discrete translation groupoids. For proper \'etale groupoids, Tu and Xu provide a map between the periodic cyclic cohomology of a gerbe-twisted convolution algebra ... More

Rotation Prevents Finite-Time BreakdownFeb 01 2003We consider a two-dimensional convection model augmented with the rotational Coriolis forcing, $U_t + U\cdot\nabla_x U = 2k U^\perp$, with a fixed $2k$ being the inverse Rossby number. We ask whether the action of dispersive rotational forcing alone, ... More

Recovery of edges from spectral data with noise -- a new perspectiveApr 28 2007We consider the problem of detecting edges in piecewise smooth functions from their N-degree spectral content, which is assumed to be corrupted by noise. There are three scales involved: the "smoothness" scale of order 1/N, the noise scale of order $\eta$ ... More

Deconvolution, convex optimization, non-parametric empirical Bayes and treatment of non-responseJun 23 2014Let $(Y_i,\theta_i)$, $i=1,...,n$, be independent random vectors distributed like $(Y,\theta) \sim G^*$, where the marginal distribution of $\theta$ is completely unknown, and the conditional distribution of $Y$ conditional on $\theta$ is known. It is ... More

Descent Construction for Gspin Groups: Main Results and ApplicationsAug 16 2008Dec 08 2008The purpose of this note is to announce an extension of the descent method of Ginzburg, Rallis and Soudry to the setting of essentially self dual representations. This extension of the descent construction provides a complement to recent work of Asgari ... More

Bounds and Constructions of Codes with Multiple LocalitiesJan 12 2016This paper studies bounds and constructions of locally repairable codes (LRCs) with multiple localities so-called multiple-locality LRCs (ML-LRCs). In the simplest case of two localities some code symbols of an ML-LRC have a certain locality while the ... More

Optimal Linear and Cyclic Locally Repairable Codes over Small FieldsFeb 24 2015We consider locally repairable codes over small fields and propose constructions of optimal cyclic and linear codes in terms of the dimension for a given distance and length. Four new constructions of optimal linear codes over small fields with locality ... More

Long time existence of smooth solutions for the rapidly rotating shallow-water and Euler equationsJun 06 2007We study the stabilizing effect of rotational forcing in the nonlinear setting of two-dimensional shallow-water and more general models of compressible Euler equations. In [H. Liu and E. Tadmor, Phys. D 188 (2004), no. 3-4, 262-276] we have shown that ... More

Critical thresholds in flocking hydrodynamics\\with nonlocal alignmentMar 05 2014We study the large-time behavior of Eulerian systems augmented with non-local alignment. Such systems arise as hydrodynamic descriptions of agent-based models for self-organized dynamics, e.g., Cucker-Smale and Motsch-Tadmor models \cite{CS,MT}. We prove ... More

A sharp local blow-up condition for Euler-Poisson equations with attractive forcingFeb 10 2009Feb 14 2009We improve the recent result of Chae & Tadmor in [Comm. Math. Sci. 6(3) (2008) 785-789], proving a one-sided threshold condition which leads to finite-time breakdown of the Euler-Poisson equations in arbitrary dimension n.

On the universality class of the Mott transition in two dimensionsJul 01 2012We use the two-step density-matrix renormalization group method to elucidate the long-standing issue of the universality class of the Mott transition in the Hubbard model in two dimensions. We studied a spatially anisotropic two-dimensional Hubbard model ... More

Flow-level performance of random wireless networksJul 28 2013Aug 22 2013We study the flow-level performance of random wireless networks. The locations of base stations (BSs) follow a Poisson point process. The number and positions of active users are dynamic. We associate a queue to each BS. The performance and stability ... More

Spectral Dynamics of the Velocity Gradient Field in Restricted FlowsDec 03 2001We study the velocity gradients of the fundamental Eulerian equation, $\partial_t u +u\cdot \nabla u=F$, which shows up in different contexts dictated by the different modeling of $F$'s. To this end we utilize a basic description for the spectral dynamics ... More

Deconvolution with application to estimation of sampling probabilities and the Horvitz-Thompson estimatorSep 09 2013Nov 19 2013We elaborate on a deconvolution method, used to estimate the empirical distribution of unknown parameters, as suggested recently by Efron (2013). It is applied to estimating the empirical distribution of the 'sampling probabilities' of m sampled items. ... More

Invariant distributions on non-distinguished nilpotent orbits with application to the Gelfand property of (GL(2n,R),Sp(2n,R))Oct 10 2008We study invariant distributions on the tangent space to a symmetric space. We prove that an invariant distribution with the property that both its support and the support of its Fourier transform are contained in the set of non-distinguished nilpotent ... More

A new model for self-organized dynamics and its flocking behaviorFeb 28 2011Jul 25 2011We introduce a model for self-organized dynamics which, we argue, addresses several drawbacks of the celebrated Cucker-Smale (C-S) model. The proposed model does not only take into account the distance between agents, but instead, the influence between ... More

Dissipation vs. quadratic nonlinearity: from a priori energy bound to higher-order regularizing effectJul 25 2013Dec 30 2013We consider a rather general class of evolutionary PDEs involving dissipation (of possibly fractional order), which competes with quadratic nonlinearities on the regularity of the overall equation. This includes as prototype models, Burgers' equation, ... More

Global Mixed Periods and local Klyachko models for the general linear groupOct 18 2007We show that every irreducible representation in the discrete automorphic spectrum of GL(n) admits a non vanishing mixed (Whittaker-symplectic) period integral. The analog local problem is a study of models first considered by Klyachko over a finite field. ... More

High Dimensional Error-Correcting CodesOct 29 2009Apr 26 2010In this paper we construct multidimensional codes with high dimension. The codes can correct high dimensional errors which have the form of either small clusters, or confined to an area with a small radius. We also consider small number of errors in a ... More

Error-Correction of Multidimensional BurstsDec 26 2007In this paper we present several constructions to generate codes for correcting a multidimensional cluster-error. The goal is to correct a cluster-error whose shape can be a box-error, a Lee sphere error, or an error with an arbitrary shape. Our codes ... More

Heterophilious dynamics enhances consensusJan 16 2013May 08 2014We review a general class of models for self-organized dynamics based on alignment. The dynamics of such systems is governed solely by interactions among individuals or "agents," with the tendency to adjust to their `environmental averages'. This, in ... More

Critical Thresholds in 2D Restricted Euler-Poisson EquationsMar 15 2002Mar 15 2002We provide a complete description of the critical threshold phenomena for the two-dimensional localized Euler-Poisson equations, introduced by the authors in [Liu & Tadmor, Comm. Math Phys., To appear]. Here, the questions of global regularity vs. finite-time ... More

On Unitary Representations of GL2n Distinguished by the Symplectic GroupJun 25 2008We provide a family of representations of GL(2n) over a p-adic field that admit a non-vanishing linear functional invariant under the symplectic group (i.e. representations that are Sp(2n)- distinguished). While our result generalizes a result of M. Heumos ... More

Detection of Edges in Spectral Data II. Nonlinear EnhancementDec 03 2001We discuss a general framework for recovering edges in piecewise smooth functions with finitely many jump discontinuities, where $[f](x):=f(x+)-f(x-) \neq 0$. Our approach is based on two main aspects--localization using appropriate concentration kernels ... More

Implicit-Explicit Variational Integration of Highly Oscillatory ProblemsAug 16 2008Apr 22 2009In this paper, we derive a variational integrator for certain highly oscillatory problems in mechanics. To do this, we take a new approach to the splitting of fast and slow potential forces: rather than splitting these forces at the level of the differential ... More

The Averaging lemma and regularizing effectNov 02 2005We prove new velocity averaging results for second-order multidimensional equations of the general form, $\op(\nabla_x,v)f(x,v)=g(x,v)$ where $\op(\nabla_x,v):=\bba(v)\cdot\nabla_x-\nabla_x^\top\cdot\bbb(v)\nabla_x$. These results quantify the Sobolev ... More

Teaching Logic to Information Systems Students: Challenges and OpportunitiesJul 14 2015In contrast to Computer Science, where the fundamental role of Logic is widely recognized, it plays a practically non-existent role in Information Systems curricula. In this paper we argue that instead of Logic's exclusion from the IS curriculum, a significant ... More

X-ray Absorption of High Redshift QuasarsJul 08 2013Soft X-ray photoelectric absorption of high-z quasars has been known for two decades, but has no unambiguous astro-physical context. We construct the largest sample to date of 58 high redshift quasars (z > 0.45) selected from the XMM-Newton archive based ... More

Detecting Spammers via Aggregated Historical Data SetMay 07 2012The battle between email service providers and senders of mass unsolicited emails (Spam) continues to gain traction. Vast numbers of Spam emails are sent mainly from automatic botnets distributed over the world. One method for mitigating Spam in a computationally ... More

Descent Construction for GSpin GroupsOct 31 2011Oct 16 2012In this paper we provide an extension of the theory of descent of Ginzburg-Rallis- Soudry to the context of essentially self-dual representations, that is representations which are isomorphic to the twist of their own contragredient by some Hecke character. ... More

Uniqueness and disjointness of Klyachko modelsNov 19 2007We show the uniqueness and disjointness of Klyachko models for GL(n,F) over a non-archimedean local field F. This completes, in particular, the study of Klyachko models on the unitary dual. Our local results imply a global rigidity property for the discrete ... More

The SL(2)-type and Base ChangeAug 25 2008The SL(2)-type of any smooth, irreducible and unitarizable representation of GL(n) over a p-adic field was defined by Venkatesh. We provide a natural way to extend the definition to all smooth and irreducible representations. For unitarizable representations ... More

Load Balancing Congestion Games and their Asymptotic BehaviorDec 31 2015A central question in routing games has been to establish conditions for the uniqueness of the equilibrium, either in terms of network topology or in terms of costs. This question is well understood in two classes of routing games. The first is the non-atomic ... More

Adaptive Mollifiers for High Resolution Recovery of Piecewise Smooth Data from its Spectral InformationDec 03 2001We discuss the reconstruction of piecewise smooth data from its (pseudo-) spectral information. Spectral projections enjoy superior resolution provided the data is globally smooth, while the presence of jump discontinuities is responsible for spurious ... More

A variational representation of weak solutions for the pressureless Euler-Poisson equationsFeb 28 2011We derive an explicit formula for global weak solutions of the one dimensional system of pressure-less Euler-Poisson equations. Our variational formulation is an extension of the well-known formula for entropy solutions of the scalar inviscid Burgers' ... More

On the global regularity of sub-critical Euler-Poisson equations with pressureSep 09 2006Nov 05 2006We prove that the one-dimensional Euler-Poisson system driven by the Poisson forcing together with the usual γ-law pressure, γ ≥ 1, admits global solutions for a large class of initial data. Thus, the Poisson forcing regularizes the generic ... More

Stability and spectral convergence of Fourier method for nonlinear problems. On the shortcomings of the 2/3 de-aliasing methodAug 24 2013The high-order accuracy of Fourier method makes it the method of choice in many large scale simulations. We discuss here the stability of Fourier method for nonlinear evolution problems, focusing on the two prototypical cases of the inviscid Burgers' ... More

Mott Transition in Quasi-One-Dimensional SystemsMay 01 2011We report the application of the density-matrix renormalization group method to a spatially anisotropic two-dimensional Hubbard model at half-filling. We find a deconfinement transition induced by the transverse hopping parameter $t_y$ from an insulator ... More

Asymptotic efficiency of simple decisions for the compound decision problemFeb 10 2008We consider the compound decision problem of estimating a vector of $n$ parameters, known up to a permutation, corresponding to $n$ independent observations, and discuss the difference between two symmetric classes of estimators. The first and larger ... More

From particle to kinetic and hydrodynamic descriptions of flockingJun 13 2008We discuss the Cucker-Smale's (C-S) particle model for flocking, deriving precise conditions for flocking to occur when pairwise interactions are sufficiently strong long range. We then derive a Vlasov-type kinetic model for the C-S particle model and ... More

Forward Correction and Fountain codes in Delay Tolerant NetworksAug 27 2008Jan 19 2009Delay tolerant Ad-hoc Networks make use of mobility of relay nodes to compensate for lack of permanent connectivity and thus enable communication between nodes that are out of range of each other. To decrease delivery delay, the information that needs ... More

Codes for Partially Stuck-at Memory CellsMay 13 2015In this work, we study a new model of defect memory cells, called partially stuck-at memory cells, which is motivated by the behavior of multi-level cells in non-volatile memories such as flash memories and phase change memories. If a cell can store the ... More

Impact of Colored Environmental Noise on the Extinction of a Long-Lived Stochastic Population: Role of the Allee EffectOct 24 2012Mar 21 2013We study the combined impact of a colored environmental noise and demographic noise on the extinction risk of a long-lived and well-mixed isolated stochastic population which exhibits the Allee effect. The environmental noise modulates the population ... More

Estimation of the Regularization Parameter in Linear Discrete Ill-Posed Problems Using the Picard parameterJul 04 2016Jul 17 2016We present a new approach for determining the regularization parameter for general-form Tikhonov regularization of linear ill-posed problems. In our approach the regularization parameter is found by approximately minimizing the distance between the unknown ... More

Network Non-Neutrality through Preferential SignalingMar 18 2013One of the central issues in the debate on network neutrality has been whether one should allow or prevent preferential treatment by an internet service provider (ISP) of traffic according to its origin. This raised the question of whether to allow an ... More

Nonparametric empirical Bayes and compound decision approaches to estimation of a high-dimensional vector of normal meansAug 12 2009We consider the classical problem of estimating a vector $\bolds{\mu}=(\mu_1,...,\mu_n)$ based on independent observations $Y_i\sim N(\mu_i,1)$, $i=1,...,n$. Suppose $\mu_i$, $i=1,...,n$ are independent realizations from a completely unknown $G$. We suggest ... More

Codes in the Damerau Distance for DNA StorageJan 26 2016Sep 06 2016Motivated by applications in DNA-based storage, we introduce the new problem of code design in the Damerau metric. The Damerau metric is a generalization of the Levenshtein distance which, in addition to deletions, insertions and substitution errors also ... More

Correcting Grain-Errors in Magnetic MediaJul 26 2013This paper studies new bounds and constructions that are applicable to the combinatorial granular channel model previously introduced by Sharov and Roth. We derive new bounds on the maximum cardinality of a grain-error-correcting code and propose constructions ... More

Self-optimizing load balancing with backhaul-constrained radio access networksJun 10 2015Sep 22 2015Self-Organizing Network (SON) technology aims at autonomously deploying, optimizing and repairing the Radio Access Networks (RAN). SON algorithms typically use Key Performance Indicators (KPIs) from the RAN. It is shown that in certain cases, it is essential ... More

User-Network Association in a WLAN-UMTS Hybrid Cell: Global & Individual OptimalityAug 04 2006We study optimal user-network association in an integrated 802.11 WLAN and 3G-UMTS hybrid cell. Assuming saturated resource allocation on the downlink of WLAN and UMTS networks and a single QoS class of mobiles arriving at an average location in the hybrid ... More

(O(V+F), O(V)) is a Gelfand pair for any quadratic space V over a local field FNov 09 2007May 17 2009Let V be a quadratic space with a form q over an arbitrary local field F of characteristic different from 2. Let $W=V \oplus Fe$ with the form Q extending q with Q(e)=1. Consider the standard embedding of O(V) into O(W) and the two-sided action of $O(V)\times ... More

Altruism in groups: an evolutionary games approachSep 25 2014Sep 26 2014We revisit in this paper the relation between evolution of species and the mathematical tool of evolutionary games, which has been used to model and predict it. We indicate known shortcoming of this model that restricts the capacity of evolutionary games ... More

Application Neutrality and a Paradox of Side PaymentsAug 13 2010Oct 21 2010The ongoing debate over net neutrality covers a broad set of issues related to the regulation of public networks. In two ways, we extend an idealized usage-priced game-theoretic framework based on a common linear demand-response model. First, we study ... More

Towards a Human-Centred Approach in Modelling and Testing of Cyber-Physical SystemsJan 23 2016The ability to capture different levels of abstraction in a system model is especially important for remote integration, testing/verification, and manufacturing of cyber-physical systems (CPSs). However, the complexity of modelling and testing of CPSs ... More

Multilevel Pricing Schemes in a Deregulated Wireless Network MarketJan 07 2014Typically the cost of a product, a good or a service has many components. Those components come from different complex steps in the supply chain of the product from sourcing to distribution. This economic point of view also takes place in the determination ... More

Crossover from adiabatic to antiadiabatic phonon-assisted tunneling in single-molecule transistorsMar 28 2013The crossover between two customary limits of phonon-assisted tunneling, the adiabatic and antiadiabatic regimes, is studied systematically in the framework of a minimal model for molecular devices: a resonant level coupled by displacement to a localized ... More

Critical Thresholds in Euler-Poisson EquationsDec 03 2001We present a preliminary study of a new phenomena associated with the Euler-Poisson equations -- the so called critical threshold phenomena, where the answer to questions of global smoothness vs. finite time breakdown depends on whether the initial configuration ... More

Coding for Locality in Reconstructing PermutationsJan 18 2016May 04 2016The problem of storing permutations in a distributed manner arises in several common scenarios, such as efficient updates of a large, encrypted, or compressed data set. This problem may be addressed in either a combinatorial or a coding approach. The ... More

Green Broadcast Transmission in Cellular Networks: A Game Theoretic ApproachAug 03 2014This paper addresses the mobile assignment problem in a multi-cell broadcast transmission seeking minimal total power consumption by considering both transmission and operational powers. While the large scale nature of the problem entails to find distributed ... More

On the Nash Stability in the Hedonic Coalition Formation GamesMay 14 2014This paper studies the Nash stability in hedonic coalition formation games. We address the following issue: for a general problem formulation, is there any utility allocation method ensuring a Nash-stable partition? We propose the definition of the Nash-stable ... More

PIR with Low Storage Overhead: Coding instead of ReplicationMay 22 2015Private information retrieval (PIR) protocols allow a user to retrieve a data item from a database without revealing any information about the identity of the item being retrieved. Specifically, in information-theoretic $k$-server PIR, the database is ... More

Generalized Harish-Chandra descent, Gelfand pairs and an Archimedean analog of Jacquet-Rallis' TheoremDec 30 2008Mar 26 2015In the first part of the paper we generalize a descent technique due to Harish-Chandra to the case of a reductive group acting on a smooth affine variety both defined over an arbitrary local field F of characteristic zero. Our main tool is the Luna Slice ... More

Long-time relaxation in pilot-wave theoryOct 07 2013Aug 06 2014We initiate the study of relaxation to quantum equilibrium over long timescales in pilot-wave theory. We simulate the time evolution of the coarse-grained H-function Hbar(t) for a two-dimensional harmonic oscillator. For a (periodic) wave function that ... More

Time-Space Constrained Codes for Phase-Change MemoriesJul 19 2012Phase-change memory (PCM) is a promising non-volatile solid-state memory technology. A PCM cell stores data by using its amorphous and crystalline states. The cell changes between these two states using high temperature. However, since the cells are sensitive ... More

ENO reconstruction and ENO interpolation are stableDec 06 2011We prove stability estimates for the ENO reconstruction and ENO interpolation procedures. In particular, we show that the jump of the reconstructed ENO pointvalues at each cell interface has the same sign as the jump of the underlying cell averages across ... More

Quantum phase transitions, frustration, and the Fermi surface in the Kondo lattice modelFeb 13 2011The quantum phase transition from a spin-Peierls phase with a small Fermi surface to a paramagnetic Luttinger-liquid phase with a large Fermi surface is studied in the framework of a one-dimensional Kondo-Heisenberg model that consists of an electron ... More

Stochastic Geometry based Medium Access Games in Mobile Ad hoc NetworksDec 16 2011Jan 04 2012This paper studies the performance of Mobile Ad hoc Networks (MANETs) when the nodes, that form a Poisson point process, selfishly choose their Medium Access Probability (MAP). We consider goodput and delay as the performance metric that each node is ... More

Generalized Sphere Packing BoundJan 25 2014Kulkarni and Kiyavash recently introduced a new method to establish upper bounds on the size of deletion-correcting codes. This method is based upon tools from hypergraph theory. The deletion channel is represented by a hypergraph whose edges are the ... More

Location Aware Opportunistic Bandwidth Sharing between Static and Mobile Users with Stochastic Learning in Cellular NetworksAug 15 2016We consider location-dependent opportunistic bandwidth sharing between static and mobile downlink users in a cellular network. Each cell has some fixed number of static users. Mobile users enter the cell, move inside the cell for some time and then leave ... More

Multilevel beamforming for high data rate communication in 5G networksApr 01 2015Oct 05 2015Large antenna arrays can be used to generate highly focused beams that support very high data rates and reduced energy consumption. However, optimal beam focusing requires large amount of feedback from the users in order to choose the best beam, especially ... More

Generalized Harish-Chandra descent and applications to Gelfand pairsMar 24 2008May 17 2009In the first part of the paper we generalize a descent technique due to Harish-Chandra to the case of a reductive group acting on a smooth affine variety both defined over arbitrary local field F of characteristic zero. Our main tool is Luna slice theorem. ... More

Interpolation of compact Lipschitz operatorsJul 21 2009Let (A_0,A_1) and (B_0,B_1) be Banach couples such that A_0 is contained in A_1 and (B_0,B_1) satisfies Arne Persson's approximation condition (H). Let T:A_1 --> B_1 be a possibly nonlinear Lipschitz mapping which also maps A_0 into B_0 and satisfies ... More

Analytic continuation of equivariant distributionsAug 11 2016We establish a method for constructing equivariant distributions on smooth real algebraic varieties from equivariant distributions on Zariski open subsets. This is based on Bernstein's theory of analytic continuation of holonomic distributions. We use ... More

Invariant Functionals on the Speh representationMay 12 2014Oct 04 2015We study Sp(2n,R)-invariant functionals on the spaces of smooth vectors in Speh representations of GL(2n,R). For even n we give expressions for such invariant functionals using an explicit realization of the space of smooth vectors in the Speh representations. ... More

Invariant measures on homogeneous spaces, with applications to function spaces and lattice countingApr 12 2010Jun 20 2011Let G be a real reductive group and G/H a unimodular homogeneous G space with a closed connected subgroup H. We establish estimates for the invariant measure on G/H. Using these, we prove that all smooth vectors in the Banach representation L^p(G/H) of ... More

Vanishing at infinity on homogeneous spaces of reductive typeNov 12 2012Dec 10 2014Let G be a real reductive group and Z=G/H a unimodular homogeneous G-space. The space Z is said to satisfy VAI if all smooth vectors in the Banach representations L^{p}(Z) vanish at infinity, 1 <=p. For H connected we show that Z satisfies VAI if and ... More

Optimal Control in Two-Hop Relay RoutingNov 17 2009We study the optimal control of propagation of packets in delay tolerant mobile ad-hoc networks. We consider a two-hop forwarding policy under which the expected number of nodes carrying copies of the packets obeys a linear dynamics. We exploit this property ... More

Coding for Caches in the PlaneSep 03 2013We consider wireless caches located in the plane according to general point process and specialize the results for the homogeneous Poisson process. A large data file is stored at the caches, which have limited storage capabilities. Hence, they can only ... More

Dynamic control of Coding in Delay Tolerant NetworksJul 30 2009Aug 07 2009Delay tolerant Networks (DTNs) leverage the mobility of relay nodes to compensate for lack of permanent connectivity and thus enable communication between nodes that are out of range of each other. To decrease message delivery delay, the information to ... More

Self Organizing strategies for enhanced ICIC (eICIC)Jan 10 2014Small cells have been identified as an effective solution for coping with the important traffic increase that is expected in the coming years. But this solution is accompanied by additional interference that needs to be mitigated. The enhanced Inter Cell ... More

Network Non-neutrality Debate: An Economic AnalysisDec 29 2010Feb 16 2011This paper studies the economic utilities and the quality of service (QoS) in a two-sided non-neutral market where Internet service providers (ISPs) charge content providers (CPs) for the content delivery. We propose new models on a two-sided market which ... More

Finite Word Length Effects on Transmission Rate in Zero Forcing Linear Precoding for Multichannel DSLOct 09 2008Crosstalk interference is the limiting factor in transmission over copper lines. Crosstalk cancelation techniques show great potential for enabling the next leap in DSL transmission rates. An important issue when implementing crosstalk cancelation techniques ... More

Dense Error-Correcting Codes in the Lee MetricApr 02 2010Several new applications and a number of new mathematical techniques have increased the research on error-correcting codes in the Lee metric in the last decade. In this work we consider several coding problems and constructions of error-correcting codes ... More

Coding for the Lee and Manhattan Metrics with Weighing MatricesOct 21 2012Dec 11 2012This paper has two goals. The first one is to discuss good codes for packing problems in the Lee and Manhattan metrics. The second one is to consider weighing matrices for some of these coding problems. Weighing matrices were considered as building blocks ... More

Optimal Routing and Power Control for a Single Cell, Dense, Ad Hoc Wireless NetworkJul 21 2009We consider a dense, ad hoc wireless network, confined to a small region. The wireless network is operated as a single cell, i.e., only one successful transmission is supported at a time. Data packets are sent between sourcedestination pairs by multihop ... More

Differential Games of Competition in Online Content DiffusionDec 02 2013Access to online contents represents a large share of the Internet traffic. Most such contents are multimedia items which are user-generated, i.e., posted online by the contents' owners. In this paper we focus on how those who provide contents can leverage ... More

Pricing Agreement between Service and Content Providers: A Net Neutrality IssueMay 13 2015The Net Neutrality issue has been at the center of debate worldwide lately. Some countries have established laws so that principles of Net Neutrality are respected, the Netherlands being the latest country in Europe. Among the questions that have been ... More

Competitive Selection of Ephemeral Relays in Wireless NetworksJun 20 2015We consider a setting in which two nodes (referred to as forwarders) compete to choose a relay node from a set of relays, as they ephemerally become available (e.g., wake up from a sleep state). Each relay, when it arrives, offers a (possibly different) ... More

Performance of Multilevel Flash Memories with Different Binary Labelings: A Multi-User PerspectiveMay 03 2016In this work, we study the performance of different decoding schemes for multilevel flash memories where each page in every block is encoded independently. We focus on the multi-level cell (MLC) flash memory, which is modeled as a two-user multiple access ... More

Global Regularity of the 4D Restricted Euler EquationsOct 10 2008We are concerned with the critical threshold phenomena in the Restricted Euler (RE) equations. Using the spectral and trace dynamics we identify the critical thresholds for 3D and the 4D restricted Euler equations. It is well known that the 3D RE solutions ... More

Closed form solutions for symmetric water filling gamesJul 26 2007Jul 30 2007We study power control in optimization and game frameworks. In the optimization framework there is a single decision maker who assigns network resources and in the game framework users share the network resources according to Nash equilibrium. The solution ... More

Cell planning for mobility management in heterogeneous cellular networksMay 24 2016In small cell networks, high mobility of users results in frequent handoff and thus severely restricts the data rate for mobile users. To alleviate this problem, we propose to use heterogeneous, two-tier network structure where static users are served ... More

Coordination of autonomic functionalities in communications networksSep 06 2012Future communication networks are expected to feature autonomic (or self-organizing) mechanisms to ease deployment (self-configuration), tune parameters automatically (self-optimization) and repair the network (self-healing). Self-organizing mechanisms ... More