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Results for "Simona Boboila"

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On Designing Machine Learning Models for Malicious Network Traffic ClassificationJul 10 2019Machine learning (ML) started to become widely deployed in cyber security settings for shortening the detection cycle of cyber attacks. To date, most ML-based systems are either proprietary or make specific choices of feature representations and machine ... More
Weakly globular Tamsamani N-categories and their rigidificationJul 17 2016Sep 14 2016We introduce a new class of higher categorical structures called weakly globular Tamsamani n-categories. These generalize the Tamsamani-Simpson model of higher categories by using the new paradigm of weak globularity to weaken higher categorical structures. ... More
Chimera states in coupled Kuramoto oscillators with inertiaDec 14 2015The dynamics of two symmetrically coupled populations of rotators is studied for different values of the inertia. The system is characterized by different types of solutions, which all coexist with the fully synchronized state. At small inertia the system ... More
A stability-like theorem for cohomology of pure braid groups of the series A, B and DJul 10 2003Oct 15 2003Consider the ring $R:=\Q[\tau,\tau^{-1}]$ of Laurent polynomials in the variable $\tau$. The Artin's Pure Braid Groups (or Generalized Pure Braid Groups) act over $R,$ where the action of every standard generator is the multiplication by $\tau$. In this ... More
Applications of Asymptotic Riesz Representation TheoremAug 27 2012We review the relation between compact asymptotic spectral measures and certain positive asymptotic morphism on locally compact spaces via asymptotic Riesz representation theorem, as introduced by Martinez and Trout [3]. Applications to this theorem will ... More
The development of a fuzzy regulator with an entry and an output in FislabMar 25 2009The present article is a sequel of the article "Fislab the Fuzzy Inference Tool-Box for Scilab" and it represents the practical application of:"The development of the Fuzzy regulator with an input and an output in Fislab". The article contains, besides ... More
Pseudo-functors modelling higher structuresMay 22 2016We introduce a new higher categorical structure called a weakly globular n-fold category. This structure is based on iterated internal categories and on the notion of weak globularity. We identify a suitable class of pseudo-functors whose strictification ... More
Role of calcium and noise in the persistent activity of an isolated neuronJun 03 2004The activity of an isolated and auto-connected neuron is studied using Hodgkin--Huxley and Integrate-and-Fire frameworks. Main ingredients of the modeling are the auto-stimulating autaptic current observed in experiments, with a spontaneous synaptic liberation ... More
Local spectrum of a family of operatorsJul 13 2012Starting from the classic definitions of local resolvent set and spectrum of a linear bounded operator on a Banach space, we introduce the local resolvent set and spectrum, the local space and the single-valued extention property of a family of linear ... More
FISLAB - the Fuzzy Inference Tool-box for SCILABMar 25 2009The present study represents "The Fislab package of programs meant to develop the fuzzy regulators in the Scilab environment" in which we present some general issues, usage requirements and the working mode of the Fislab environment. In the second part ... More
Homotopically discrete higher categorical structuresMay 17 2016We introduce the notion of homotopically discrete n-fold category as an n-fold generalization of a groupoid with no non-trivial loops. We give two equivalent descriptions of this structure: in terms of a Segal-type model and in terms of iterated internal ... More
On the non-balanced property of the category of crossed modules in groupsSep 24 2003An algebraic category $\mathcal{C}$ is called balanced if the cotriple cohomology of any object of $\mathcal{C}$ vanishes in positive dimensions on injective coefficient modules. Important examples of balanced and of non-balanced categories occur in the ... More
On biconservative surfacesApr 15 2017We study in a uniform manner the properties of biconservative surfaces in arbitrary Riemannian manifolds. Biconservative surfaces being characterized by the vanishing of the divergence of a symmetric tensor field $S_2$ of type $(1,1)$, their properties ... More
Diffuse radio sources in colliding galaxy clusters - Low frequency follow up of the GMRT Radio Halo SurveyFeb 09 2011The knowledge of the origin and statistical properties of diffuse radio emission in galaxy clusters has appreciably improved thanks to the GMRT Radio Halo Survey, a project based on 610 MHz observations of clusters belonging to a statistically complete ... More
Cohomology of Pure Braid Groups of exceptional casesMay 26 2005May 10 2006Consider the ring R:=\Q[\tau,\tau^{-1}] of Laurent polynomials in the variable \tau. The Artin's Pure Braid Groups (or Generalized Pure Braid Groups) act over R, where the action of every standard generator is the multiplication by \tau. In this paper ... More
Semistrict Tamsamani n-groupoids and connected n-typesJan 23 2007Oct 03 2007Tamsamani's weak n-groupoids are known to model n-types. In this paper we show that every Tamsamani weak n-groupoid representing a connected n-type is equivalent in a suitable way to a semistrict one. We obtain this result by comparing Tasmamani's weak ... More
Semistrict models of connected 3-types and Tamsamani's weak 3-groupoidsJul 14 2006Homotopy 3-types can be modelled algebraically by Tamsamani's weak 3-groupoids as well as, in the path-connected case, by cat^2-groups. This paper gives a comparison between the two models in the path-connected case. This leads to two different semistrict ... More
Weakly globular N-fold categories as a model of weak N-categoriesSep 13 2016We study a new type of higher categorical structure, called weakly globular n-fold category, previously introduced by the author. We show that this structure is a model of weak n-categories by proving that it is suitably equivalent to the Tamsamani-Simpson ... More
Complete biconservative surfaces in $\mathbb{R}^3$ and $\mathbb{S}^3$May 27 2016In this paper we consider the complete biconservative surfaces in Euclidean space $\mathbb{R}^3$ and in the unit Euclidean sphere $\mathbb{S}^3$. Biconservative surfaces in 3-dimensional space forms are characterized by the fact that the gradient of their ... More
Blocking Sets in the complement of hyperplane arrangements in projective spaceFeb 14 2008It is well know that the theory of minimal blocking sets is studied by several author. Another theory which is also studied by a large number of researchers is the theory of hyperplane arrangements. We can remark that the affine space $AG(n,q)$ is the ... More
The integer cohomology of toric Weyl arrangementsAug 03 2010Dec 16 2011A referee found an error in the proof of the Theorem 2 that we could not fix. More precisely, the proof of Lemma 2.1 is incorrect. Hence the fact that integer cohomology of complement of toric Weyl arrangements is torsion free is still a conjecture. ----- ... More
(Co)homology of crossed modules with coefficients in a $π_1$-moduleJun 04 2003Jul 24 2003We define a cotriple (co)homology of crossed modules with coefficients in a $\pi_1$-module. We prove its general properties, including the connection with the existing cotriple theories on crossed modules. We establish the relationship with the (co)homology ... More
Spectrum of a family of operatorsJul 10 2012Having as start point the classic definitions of resolvent set and spectrum of a linear bounded operator on a Banach space, we introduce the resolvent set and spectrum of a family of linear bounded operators on a Banach space. In addition, we present ... More
The distribution of cycles in breakpoint graphs of signed permutationsApr 17 2011Aug 05 2012Breakpoint graphs are ubiquitous structures in the field of genome rearrangements. Their cycle decomposition has proved useful in computing and bounding many measures of (dis)similarity between genomes, and studying the distribution of those cycles is ... More
Heuristic average-case analysis of the backtrack resolution of random 3-Satisfiability instancesJan 14 2004An analysis of the average-case complexity of solving random 3-Satisfiability (SAT) instances with backtrack algorithms is presented. We first interpret previous rigorous works in a unifying framework based on the statistical physics notions of dynamical ... More
Homology graph of real arrangements and monodromy of Milnor FiberJun 11 2016We study the first homology group of the Milnor fiber of sharp arrangements in the real projective plane. Our work relies on the minimal Salvetti complex of the deconing arrangement and its boundary map. We describe an algorithm which computes possible ... More
Modifications of the Dielectric Properties of Biological Membranes by HeatingApr 28 2004Biological cell suspensions are known to show dielectric dispersions due to the Maxwell-Wagner mechanism. Many examples are summarized in a number of papers by Schwan [7, 9, 10]. By the application of an appropriate analysis to the dielectric dispersion, ... More
Stochastic Dynamics of the Multi-State Voter Model over a Network based on Interacting Cliques and Zealot CandidatesSep 02 2013May 09 2014The stochastic dynamics of the multi-state voter model is investigated on a class of complex networks made of non-overlapping cliques, each hosting a political candidate and interacting with the others via Erd\H{o}s-R\'enyi links. Numerical simulations ... More
Combinatorial polar orderings and recursively orderable arrangementsNov 09 2007Oct 25 2012Polar orderings arose in recent work of Salvetti and the second author on minimal CW-complexes for complexified hyperplane arrangements. We study the combinatorics of these orderings in the classical framework of oriented matroids, and reach thereby a ... More
The $\textbf{nbc}$ minimal complex of supersolvable arrangementsMar 19 2015In this paper we give a very natural description of the bijections between the minimal CW-complex homotopy equivalent to the complement of a supersolvable arrangement $\mathcal{A}$, the $\textbf{nbc}$ basis of the Orlik-Solomon algebra associated to $\mathcal{A}$ ... More
The homotopy type of toric arrangementsSep 19 2010Oct 27 2010A toric arrangement is a finite set of hypersurfaces in a complex torus, every hypersurface being the kernel of a character. In the present paper we build a CW-complex homotopy equivalent to the arrangement complement, with a combinatorial description ... More
Comonad Cohomology of Track CategoriesJan 15 2018Apr 14 2019We define a comonad cohomology of track categories and we show it is linked by a long exact sequence to its Dwyer-Kan-Smith cohomology . Under mild hypothesis on the track category, we show that its comonad cohomology coincides, up to dimension shift, ... More
Natural Diagonal Riemannian Almost Product and Para-Hermitian Cotangent BundlesApr 14 2011We obtain the natural diagonal almost product and locally product structures on the total space of the cotangent bundle of a Riemannian manifold. We find the Riemannian almost product (locally product) and the (almost) para-Hermitian cotangent bundles ... More
Other Classes of Tangent Bundles with General Natural Almost Anti-Hermitian StructuresFeb 17 2010We continue the study of the anti-Hermitian structures of general natural lift type on the tangent bundles. We get the conditions under which these structures are in the eight classes obtained by Ganchev and Borisov. We complete the characterization of ... More
Global properties of biconservative surfaces in $\mathbb{R}^3$ and $\mathbb{S}^3$Jan 26 2017Apr 14 2017We survey some recent results on biconservative surfaces in $3$-dimensional space forms $N^3(c)$ with a special emphasis on the $c=0$ and $c=1$ cases. We study the local and global properties of such surfaces, from extrinsic and intrinsic point of view. ... More
Two-track categoriesFeb 17 2010We describe a 2-dimensional analogue of track categories, called two-track categories, and show that it can be used to model categories enriched in 2-type mapping spaces. We also define a Baues-Wirsching type cohomology theory for track categories, and ... More
Topological aspects of the multi-language phases of the Naming Game on community-based networksOct 27 2016The Naming Game is an agent-based model where individuals communicate to name an initially unnamed object. On a large class of networks continual pairwise interactions lead the system to an ultimate consensus state, in which agents converge on a globally ... More
First-principles simulations of glass-formersApr 27 2016In this article we review results of computer simulation of glasses carried out using first principles approaches, notably density functional theory. We start with a brief introduction to this method and compare the pros and cons of this approach with ... More
Reconstructing a Random Potential from its Random WalksApr 19 2007The problem of how many trajectories of a random walker in a potential are needed to reconstruct the values of this potential is studied. We show that this problem can be solved by calculating the probability of survival of an abstract random walker in ... More
The impact of baryonic physics on the subhalo mass function and implications for gravitational lensingAug 24 2016We investigate the impact of baryonic physics on the subhalo population by analyzing the results of two recent hydrodynamical simulations (EAGLE and Illustris), which have very similar configuration, but a different model of baryonic physics. We concentrate ... More
Combinatorial Morse theory and minimality of hyperplane arrangementsMay 21 2007We find an explicit combinatorial gradient vector field on the well known complex S (Salvetti complex) which models the complement to an arrangement of complexified hyperplanes. The argument uses a total ordering on the facets of the stratification of ... More
Covering cubic graphs with matchings of large sizeOct 15 2012Let m be a positive integer and let G be a cubic graph of order 2n. We consider the problem of covering the edge-set of G with the minimum number of matchings of size m. This number is called excessive [m]-index of G in literature. The case m=n, that ... More
Octahedral, dicyclic and special linear solutions of some unsolved Hamilton-Waterloo problemsFeb 29 2016We give a sharply-vertex-transitive solution of each of the nine Hamilton-Waterloo problems left open by Danziger, Quattrocchi and Stevens.
Bicategories and Weakly Globular Double CategoriesOct 15 2012Mar 27 2013This paper introduces the notion of weakly globular double categories, a particular class of strict double categories, as a way to model weak 2-categories; it explores its use in defining a double category of fractions, and shows that the sub-2-category ... More
The Weakly Globular Double Category of Fractions of a CategoryJun 18 2014This paper introduces the construction of a weakly globular double category of fractions for a category and studies its universal properties. It shows that this double category is locally small and considers a couple of concrete examples.
Adaptive cluster expansion for the inverse Ising problem: convergence, algorithm and testsOct 25 2011We present a procedure to solve the inverse Ising problem, that is to find the interactions between a set of binary variables from the measure of their equilibrium correlations. The method consists in constructing and selecting specific clusters of variables, ... More
Fast Inference of Interactions in Assemblies of Stochastic Integrate-and-Fire Neurons from Spike RecordingsFeb 25 2011We present two Bayesian procedures to infer the interactions and external currents in an assembly of stochastic integrate-and-fire neurons from the recording of their spiking activity. The first procedure is based on the exact calculation of the most ... More
Adaptive Cluster Expansion for Inferring Boltzmann Machines with Noisy DataFeb 16 2011We introduce a procedure to infer the interactions among a set of binary variables, based on their sampled frequencies and pairwise correlations. The algorithm builds the clusters of variables contributing most to the entropy of the inferred Ising model, ... More
Protein-Mediated DNA Loops: Effects of Protein Bridge Size and KinksAug 11 2005Nov 16 2005This paper focuses on the probability that a portion of DNA closes on itself through thermal fluctuations. We investigate the dependence of this probability upon the size r of a protein bridge and/or the presence of a kink at half DNA length. The DNA ... More
Theoretical study of collective modes in DNA at ambient temperatureNov 02 1999The instantaneous normal modes corresponding to base pair vibrations (radial modes) and twist angle fluctuations (angular modes) of a DNA molecule model at ambient temperature are theoretically investigated. Due to thermal disorder, normal modes are not ... More
Statistical Mechanics of Torque Induced Denaturation of DNAApr 20 1999Sep 24 1999A unifying theory of the denaturation transition of DNA, driven by temperature T or induced by an external mechanical torque Gamma is presented. Our model couples the hydrogen-bond opening and the untwisting of the helicoidal molecular structure. We show ... More
Indecomposable $1$-factorizations of the complete multigraph $λ K_{2n}$ for every $λ\leq 2n$Nov 10 2016A $1$-factorization of the complete multigraph $\lambda K_{2n}$ is said to be indecomposable if it cannot be represented as the union of $1$-factorizations of $\lambda_0 K_{2n}$ and $(\lambda-\lambda_0) K_{2n}$, where $\lambda_0<\lambda$. It is said to ... More
2-nerves for bicategoriesJul 11 2006We describe a Cat-valued nerve of bicategories, which associates to every bicategory a simplicial object in Cat, called the 2-nerve. We define a 2-category NHom whose objects are bicategories and whose 1-cells are normal homomorphisms of bicategories, ... More
Segal-type algebraic models of n-typesApr 23 2012Jun 17 2014For each n\geq 1 we introduce two new Segal-type models of n-types of topological spaces: weakly globular n-fold groupoids, and a lax version of these. We show that any n-type can be represented up to homotopy by such models via an explicit algebraic ... More
Optimal control problems for stress tensor in plastic plane mediumApr 22 2015This paper joins some concepts from Mechanics, Partial Differential Equations and Control Theory in order to solve bi-time optimization problems related to stress tensor in plastic deformations. The main goal is to analyze some optimal control problems ... More
Trajectories in phase diagrams, growth processes and computational complexity: how search algorithms solve the 3-Satisfiability problemSep 26 2000Most decision and optimization problems encountered in practice fall into one of two categories with respect to any particular solving method or algorithm: either the problem is solved quickly (easy) or else demands an impractically long computational ... More
Dynamics of fully coupled rotators with unimodal and bimodal frequency distributionAug 04 2015We analyze the synchronization transition of a globally coupled network of N phase oscillators with inertia (rotators) whose natural frequencies are unimodally or bimodally distributed. In the unimodal case, the system exhibits a discontinuous hysteretic ... More
Parametric Connectives in Disjunctive Logic ProgrammingNov 07 2003Disjunctive Logic Programming (\DLP) is an advanced formalism for Knowledge Representation and Reasoning (KRR). \DLP is very expressive in a precise mathematical sense: it allows to express every property of finite structures that is decidable in the ... More
Do radio core-halos and cold fronts in non major merging clusters originate from the same gas sloshing?Jan 12 2008We show an interesting correlation between the surface brightness and temperature structure of the relaxed clusters RXJ1720.1+2638 and MS1455.0+2232, hosting a pair of cold fronts, and their central core--halo radio source. We discuss the possibility ... More
Homology graph of real arrangements and monodromy of Milnor FiberJun 11 2016Mar 30 2017We study the first homology group of the Milnor fiber of sharp arrangements in the real projective plane. Our work relies on the minimal Salvetti complex of the deconing arrangement and its boundary map. We describe an algorithm which computes possible ... More
On the uniqueness of complete biconservative surfaces in $\mathbb{R}^3$Nov 20 2017We study the uniqueness of complete biconservative surfaces in the Euclidean space $\mathbb{R}^3$, and prove that the only complete biconservative regular surfaces in $\mathbb{R}^3$ are either $CMC$ or certain surfaces of revolution. In particular, any ... More
Braid groups in complex GrassmanniansNov 22 2013We describe the fundamental group and second homotopy group of ordered $k-$point sets in $Gr(k,n)$ generating a subspace of fixed dimension.
On the Configuration Spaces of Grassmannian ManifoldsNov 22 2013Let $\mathcal{F}_h^i(k,n)$ be the $i$th ordered configuration space of all distinct points $H_1,\ldots,H_h$ in the Grassmannian $Gr(k,n)$ of $k$-dimensional subspaces of $\mc^n$, whose sum is a subspace of dimension $i$. We prove that $\mathcal{F}_h^i(k,n)$ ... More
Asymptotic normality and combinatorial aspects of the prefix exchange distance distributionApr 16 2016The prefix exchange distance of a permutation is the minimum number of exchanges involving the leftmost element that sorts the permutation. We give new combinatorial proofs of known results on the distribution of the prefix exchange distance for a random ... More
Improvements on the distribution of maximal segmental scores in a Markovian sequenceMar 07 2018Let $(A_i)_{i \geq 0}$ be a finite state irreducible aperiodic Markov chain and $f$ a lattice score function such that the average score is negative and positive scores are possible. Define $S_0:=0$ and $S_k:=\sum_{i=1}^k f(A_i)$ the successive partial ... More
On the density profile of dark matter substructure in gravitational lens galaxiesJun 04 2014Jul 02 2014We consider three extensions of the Navarro, Frenk and White (NFW) profile and investigate the intrinsic degeneracies among the density profile parameters on the gravitational lensing effect of satellite galaxies on highly magnified Einstein rings. In ... More
Chimera states in pulse coupled neural networks: the influence of dilution and noiseJun 28 2016We analyse the possible dynamical states emerging for two symmetrically pulse coupled populations of leaky integrate-and-fire neurons. In particular, we observe broken symmetry states in this set-up: namely, breathing chimeras, where one population is ... More
Analysis of the computational complexity of solving random satisfiability problems using branch and bound search algorithmsDec 11 2000The computational complexity of solving random 3-Satisfiability (3-SAT) problems is investigated. 3-SAT is a representative example of hard computational tasks; it consists in knowing whether a set of alpha N randomly drawn logical constraints involving ... More
Comonad Cohomology of Track CategoriesJan 15 2018Apr 03 2018We define a comonad cohomology of track categories and we show it is linked by a long exact sequence to its Dwyer-Kan-Smith cohomology . Under mild hypothesis on the track category, we show that its comonad cohomology coincides, up to dimension shift, ... More
On the Power-Law Tails of Vote Distributions in Proportional ElectionsJan 25 2016In proportional elections with open lists the excess of preferences received by candidates with respect to the list average is known to follow a universal lognormal distribution. We show that lognormality is broken provided preferences are conditioned ... More
Modularity and Optimality in Social ChoiceApr 20 2010Marengo and the second author have developed in the last years a geometric model of social choice when this takes place among bundles of interdependent elements, showing that by bundling and unbundling the same set of constituent elements an authority ... More
Modification of the Lifshitz-Kosevich formula for anomalous quantum oscillations in inverted insulatorsApr 21 2017It is generally believed that quantum oscillations are a hallmark of a Fermi surface and the oscillations constitute the ringing of it. Recently, it was understood that in order to have well defined quantum oscillations you do not only not need well defined ... More
Multi-valued boundary value problems involving Leray-Lions operators and discontinuous nonlinearitiesFeb 13 2003We prove an existence result for a class of Dirichlet boundary value problems with discontinuous nonlinearity and involving a Leray-Lions operator. The proof combines monotonicity methods for elliptic problems, variational inequality techniques and basic ... More
A novel characterization of cubic Hamiltonian graphs via the associated quartic graphsAug 08 2015We give a necessary and sufficient condition for a cubic graph to be Hamiltonian by analyzing Eulerian tours in certain spanning subgraphs of the quartic graph associated with the cubic graph by 1-factor contraction. This correspondence is most useful ... More
Large time behavior for a viscous Hamilton-Jacobi equation with Neumann boudary conditionSep 08 2006Sep 20 2006We prove the existence and the uniqueness of strong solutions for the viscous Hamilton-Jacobi Equation with Neumann boundary condition and initial data a continious function. Then, we study the large time behavior of the solutions.
Approaching Maximum Embedding Efficiency on Small Covers Using Staircase-Generator CodesAug 10 2015We introduce a new family of binary linear codes suitable for steganographic matrix embedding. The main characteristic of the codes is the staircase random block structure of the generator matrix. We propose an efficient list decoding algorithm for the ... More
Uniqueness and non-degeneracy for a nuclear nonlinear Schrödinger equationMay 06 2014We prove the uniqueness and non-degeneracy of positive solutions to a cubic nonlinear Schr\"odinger (NLS) type equation that describes nucleons. The main difficulty stems from the fact that the mass depends on the solution itself. As an application, we ... More
A Thomason Model Structure on the Category of Small n-fold CategoriesAug 29 2008Apr 01 2010We construct a cofibrantly generated Quillen model structure on the category of small n-fold categories and prove that it is Quillen equivalent to the standard model structure on the category of simplicial sets. An n-fold functor is a weak equivalence ... More
Equidistribution of jellium energy for Coulomb and Riesz InteractionsSep 13 2016For general dimension $d$ we prove the equidistribution of energy at the micro-scale in $\mathbb R^d$, for the optimal point configurations appearing in Coulomb gases at zero temperature. At the microscopic scale, i.e. after blow-up at the scale corresponding ... More
Renormalized energy equidistribution and local charge balance in 2D Coulomb systemsJul 12 2013Feb 12 2014We consider two related problems: the first is the minimization of the "Coulomb renormalized energy" of Sandier-Serfaty, which corresponds to the total Coulomb interaction of point charges in a uniform neutralizing background (or rather variants of it). ... More
Maximum Likelihood Estimation of Gaussian Cluster Weighted Models and Relationships with Mixtures of RegressionJul 12 2012Aug 08 2013Cluster-weighted modeling (CWM) is a mixture approach for modeling the joint probability of a response variable and a set of explanatory variables. The parameters are estimated by means of the expectation-maximization algorithm according to the maximum ... More
First principles study of a sodium borosilicate glass-former II: The glass stateAug 21 2014We use ab initio simulations to investigate the properties of a sodium borosilicate glass of composition 3Na_2O-B_2O_3-6SiO_2. We find that the broadening of the first peak in the radial distribution functions g_BO(r) and g_BNa(r) is due to the presence ... More
The merging galaxy cluster A520 --- a broken-up cool core, a dark subcluster, and an X-ray channelMar 16 2016Mar 17 2016We present results from a deep Chandra X-ray observation of a merging galaxy cluster A520. A high-resolution gas temperature map, after the subtraction of the cluster-scale emission, reveals a long trail of dense, cool clumps --- apparently the fragments ... More
Local statistical modeling by cluster-weightedNov 13 2009Jun 15 2011We investigate statistical properties of Cluster-Weighted Modeling, which is a framework for supervised learning originally developed in order to recreate a digital violin with traditional inputs and realistic sound. The analysis is carried out in comparison ... More
Parallel Instantiation of ASP Programs: Techniques and ExperimentsOct 05 2011Oct 13 2011Answer Set Programming (ASP) is a powerful logic-based programming language, which is enjoying increasing interest within the scientific community and (very recently) in industry. The evaluation of ASP programs is traditionally carried out in two steps. ... More
Growth problems of stellar black holes in early galaxiesJul 16 2018The nature of the seeds of the observed high-z super-massive black holes (SMBH) is unknown. Although different options have been proposed, involving e.g. intermediate mass direct collapse black holes, BH remnants of massive stars remain the most natural ... More
Elliptic operators with unbounded diffusion coefficients perturbed by inverse square potentials in $L^p$-spacesMar 09 2016Oct 01 2016In this paper we give sufficient conditions on $\alpha \geq 0$ and $c\in \mathbb{R}$ ensuring that the space of test functions $C_c^\infty(\mathbb{R}^N)$ is a core for the operator $$L_0u=(1+|x|^\alpha )\Delta u+\frac{c}{|x|^2}u=:Lu+\frac{c}{|x|^2}u,$$ ... More
Clustering of Modal Valued Symbolic DataJul 23 2015Symbolic Data Analysis is based on special descriptions of data - symbolic objects (SO). Such descriptions preserve more detailed information about units and their clusters than the usual representations with mean values. A special kind of symbolic object ... More
Trip Table Estimation and Prediction for Dynamic Traffic Assignment ApplicationsJun 11 2019The study focuses on estimating and predicting time-varying origin to destination (OD) trip tables for a dynamic traffic assignment (DTA) model. A bi-level optimisation problem is formulated and solved to estimate OD flows from pre-existent demand matrix ... More
Helicoidal model for DNA openingApr 19 1999We present a new dynamical model of DNA. This model has two degrees of freedom per base-pair: one radial variable related to the opening of the hydrogen bonds and an angular one related to the twisting of each base-pair responsible for the helicoidal ... More
Ground States for a Stationary Mean-Field Model for a NucleonAug 12 2012In this paper we consider a variational problem related to a model for a nucleon interacting with the $\omega$ and $\sigma$ mesons in the atomic nucleus. The model is relativistic, and we study it in a nuclear physics nonrelativistic limit, which is of ... More
Symmetric Excited States for a Mean-Field Model for a NucleonNov 22 2012In this paper, we consider a stationary model for a nucleon interacting with the $\omega$ and $\sigma$ mesons in the atomic nucleus. The model is relativistic, and we study it in a nuclear physics nonrelativistic limit. By a shooting method, we prove ... More
Geodesicity and Isoclinity Properties for the Tangent Bundle of the Heisenberg Manifold with Sasaki MetricFeb 17 2010We prove that the horizontal and vertical distributions of the tangent bundle with the Sasaki metric are isocline, the distributions given by the kernels of the horizontal and vertical lifts of the contact form $\omega$ from the Heisenberg manifold $(H_3,g)$ ... More
Double Parton Scatterings in High-Energy Proton-Nucleus Collisions and Partonic CorrelationsSep 24 2013Dec 13 2013The joint study of Double Parton Scatterings, in high energy proton-proton and proton-nucleus collisions, can provide a lot of information on multi-parton correlations. The multi-parton structure is in fact probed in a different way by DPS, in $p$-$p$ ... More
Cold fronts in galaxy clustersMar 04 2010Cold fronts have been observed in a large number of galaxy clusters. Understanding their nature and origin is of primary importance for the investigation of the internal dynamics of clusters. To gain insight on the nature of these features, we carry out ... More
Signatures of reionization on Lyman alpha emittersJul 18 2008Jul 23 2008We use a semi-analytic model of Lyman alpha emitters (LAEs) to constrain the reionization history. By considering two physically motivated scenarios in which reionization ends either early (ERM, z_i ~ 7) or late (LRM, z_i ~ 6), we fix the global value ... More
Metal jumps across sloshing cold fronts: the case of A496Jun 05 2013Cold-fronts in cool-core clusters are thought to be induced by minor mergers and to develop through a sloshing mechanism. While temperature and surface-brightness jumps have been detected and measured in many systems, a detailed characterization of the ... More
Seeing the Wood for the Trees: Reliable Localization in Urban and Natural EnvironmentsSep 08 2018Sep 14 2018In this work we introduce Natural Segmentation and Matching (NSM), an algorithm for reliable localization, using laser, in both urban and natural environments. Current state-of-the-art global approaches do not generalize well to structure-poor vegetated ... More
Enhancing power grid synchronization and stability through time delayed feedback controlJan 16 2019We study the synchronization and stability of power grids within the Kuramoto phase oscillator model with inertia with a bimodal frequency distribution representing the generators and the loads. We identify critical nodes through solitary frequency deviations ... More
Lambda Calculus and Probabilistic ComputationJan 09 2019Jan 30 2019We introduce two extensions of the $\lambda$-calculus with a probabilistic choice operator, $\Lambda_\oplus^{cbv}$ and $\Lambda_\oplus^{cbn}$, modeling respectively call-by-value and call-by-name probabilistic computation. We prove that both enjoys confluence ... More