Results for "Ramon Ferreira de Jesus"

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Submillimeter - sized proximity effect in graphite and bismuthFeb 08 2019In this work, we probe the electrical properties of macroscopic graphite and bismuth in which the electrical current is injected via superconducting electrodes, few millimeters apart from each other. Results reveal the induction of a partial superconducting-like ... More
A Fuzzy Inference System for the IdentificationMay 02 2019Odor identification is an important area in a wide range of industries like cosmetics, food, beverages and medical diagnosis among others. Odor detection could be done through an array of gas sensors conformed as an electronic nose where a data acquisition ... More
A method for the online construction of the set of states of a Markov Decision Process using Answer Set ProgrammingJun 05 2017Non-stationary domains, that change in unpredicted ways, are a challenge for agents searching for optimal policies in sequential decision-making problems. This paper presents a combination of Markov Decision Processes (MDP) with Answer Set Programming ... More
Answer Set Programming for Non-Stationary Markov Decision ProcessesMay 03 2017Non-stationary domains, where unforeseen changes happen, present a challenge for agents to find an optimal policy for a sequential decision making problem. This work investigates a solution to this problem that combines Markov Decision Processes (MDP) ... More
Profinite genus of fundamental groups of Sol and Nil 3-manifoldsNov 17 2018We prove that the profinite genus of the fundamental group $\pi_{1}(M)\cong(\mathbb{Z}\times\mathbb{Z})\rtimes_{A}\mathbb{Z}$ of a Sol 3-manifold $M$ is equal to the order of the class group of the field $\mathbb{Q}(\lambda)$, where $\lambda$ is an eigenvalue ... More
Wimp/Neutralino Direct DetectionFeb 02 2004The most popular candidate for non baryonic dark matter is the neutralino. More than twenty experiments are dedicated to its direct detection. This review describes the most competitive and promising experiments with different detection techniques. The ... More
Self-Driving Cars: A SurveyJan 14 2019We survey research on self-driving cars published in the literature focusing on autonomous cars developed since the DARPA challenges, which are equipped with an autonomy system that can be categorized as SAE level 3 or higher. The architecture of the ... More
Openness for Anosov familiesSep 02 2017Nov 21 2017Anosov families were introduced by A. Fisher and P. Arnoux motivated by generalizing the notion of Anosov diffeomorphism defined on a compact Riemannian manifold. Roughly, an Anosov family is a two-sided sequence of diffeomorphisms (or non-stationary ... More
Local Stable and Unstable Manifolds for Anosov FamiliesSep 02 2017Sep 20 2017Anosov families were introduced by A. Fisher and P. Arnoux motivated by generalizing the notion of Anosov diffeomorphism defined on a compact Riemannian manifold. In addition to presenting several properties and examples of Anosov families, in this paper ... More
On to the continuity of the map square root of nonnegative isomorphisms in Hilbert spacesApr 10 2015Let H be a real (or complex) Hilbert space. Every nonnegative operator $L \in L(H)$ admits a unique nonnegative square root $R \in L(H)$, i.e., a nonnegative operator $R \in L(H)$ such that $R^{2}= L$. Let $GL^{+}_{S}(H)$ be the set of nonnegative isomorphisms ... More
On the Continuity of the Topological Entropy of Non-autonomous Dynamical SystemsSep 03 2017Let $M$ be a compact Riemannian manifold. The set $\text{F}^{r}(M)$ consisting of sequences $(f_{i})_{i\in\mathbb{Z}}$ of $C^{r}$-diffeomorphisms on $M$ can be endowed with the compact topology or with the strong topology. A notion of topological entropy ... More
Structural stability and a characterization of Anosov familiesSep 02 2017Mar 01 2019Anosov families are non-stationary dynamical systems with hyperbolic behavior. Non-trivial examples of Anosov families will be given in this paper. We show the existence of invariant manifolds, the structrural stability and a characterization for a certain ... More
Evolution of Ideas: A Novel Memetic Algorithm Based on Semantic NetworksJan 12 2012Jan 17 2012This paper presents a new type of evolutionary algorithm (EA) based on the concept of "meme", where the individuals forming the population are represented by semantic networks and the fitness measure is defined as a function of the represented knowledge. ... More
Top-down induction of clustering treesNov 21 2000An approach to clustering is presented that adapts the basic top-down induction of decision trees method towards clustering. To this aim, it employs the principles of instance based learning. The resulting methodology is implemented in the TIC (Top down ... More
The Minimum Euclidean-Norm Point on a Convex Polytope: Wolfe's Combinatorial Algorithm is ExponentialOct 06 2017Nov 03 2017The complexity of Philip Wolfe's method for the minimum Euclidean-norm point problem over a convex polytope has remained unknown since he proposed the method in 1974. The method is important because it is used as a subroutine for one of the most practical ... More
A study on Stokes-Brinkman dimensionless model for flow in porous mediaJun 27 2019In this work we propose a non-dimensionalization approach for the Stokes-Brinkman model for flow in porous media. We study the effect of the dimensionless number found, which will be denoted by A and named as Anna's number, has on the outflow and transition ... More
Null boundary controllability of a 1-dimensional heat equation with an internal point massJun 26 2015Jul 28 2015We consider a linear hybrid system composed by two rods of equal length connected by a point mass. We show that the system is null controllable with Dirichlet and Neumann controls. The results are based on a careful spectral spectral analysis together ... More
Algebraic Unimodular CountingApr 30 2001We study algebraic algorithms for expressing the number of non-negative integer solutions to a unimodular system of linear equations as a function of the right hand side. Our methods include Todd classes of toric varieties via Gr\"obner bases, and rational ... More
Focal set of curves in the Minkowski space near lightlike pointsJul 28 2015Aug 27 2015We study the geometry of curves in the Minkowski space and in the de Sitter space, specially at points where the tangent direction is lightlike (i.e. has length zero) called lightlike points of the curve. We define the focal sets of these curves and study ... More
Theory of Multipole Solutions to the Sourceless Grad-Shafranov Equation in Plasma PhysicsAug 10 2018The rules to write out any one of the linearly independent functions belonging to the infinite set of those in polynomial form that satisfy the sourceless Grad-Shafranov equation as stated in the toroidal-polar coordinate system are established. It is ... More
Electron and recoil ion momentum imaging with a magneto-optically trapped targetNov 04 2014A reaction microscope (ReMi) has been combined with a magneto-optical trap (MOT) for the kinematically complete investigation of atomic break-up processes. With the novel MOTReMi apparatus, the momentum vectors of the fragments of laser-cooled and state-prepared ... More
On Chubanov's method for Linear ProgrammingApr 10 2012We discuss the method recently proposed by S. Chubanov for the linear feasibility problem. We present new, concise proofs and interpretations of some of his results. We then show how our proofs can be used to find strongly polynomial time algorithms for ... More
Not all simplicial polytopes are weakly vertex-decomposableMar 08 2012In 1980 Provan and Billera defined the notion of weak $k$-decomposability for pure simplicial complexes. They showed the diameter of a weakly $k$-decomposable simplicial complex $\Delta$ is bounded above by a polynomial function of the number of $k$-faces ... More
The generalized Pareto process; with a view towards application and simulationMar 12 2012Oct 16 2014In extreme value statistics, the peaks-over-threshold method is widely used. The method is based on the generalized Pareto distribution characterizing probabilities of exceedances over high thresholds in $\mathbb {R}^d$. We present a generalization of ... More
On the block maxima method in extreme value theory: PWM estimatorsOct 11 2013Dec 30 2014In extreme value theory, there are two fundamental approaches, both widely used: the block maxima (BM) method and the peaks-over-threshold (POT) method. Whereas much theoretical research has gone into the POT method, the BM method has not been studied ... More
Grow-up for a quasilinear heat equation with a localized reaction in higher dimensionsJan 29 2018We study the behaviour of nonnegative solutions to the quasilinear heat equation with a reaction localized in a ball $$ u_t=\Delta u^m+a(x)u^p, $$ for $m>0$, $0<p\le\max\{1,m\}$, $a(x)=\mathds{1}_{B_L}(x)$, $0<L<\infty$ and $N\ge2$. We study when solutions, ... More
Grow-up for a quasilinear heat equation with a localized reactionJan 29 2018We study the behaviour of global solutions to the quasilinear heat equation with a reaction localized $$ u_t=(u^m)_{xx}+a(x) u^p, $$ $m, p>0$ and $a(x)$ being the characteristic function of an interval. we prove that there exists $p_0=\max\{1,\frac{m+1}2\}$ ... More
Solution to the Grad-Shafranov Boundary Value Problem for a Thermonuclear Plasma contained in a Toroidal Vase With a Conducting Wall under the Assumption of Constant Sources to the Equilibrium in Flux SpaceSep 05 2018A method is proposed to solve the Grad-Shafranov partial differential equation for the poloidal flux function associated with the equilibrium of a plasma magnetically confined in an axisymmetric torus under the assumption that the sources to the equilibrium ... More
Forecasting day-ahead electricity prices in Europe: the importance of considering market integrationAug 01 2017Dec 07 2017Motivated by the increasing integration among electricity markets, in this paper we propose two different methods to incorporate market integration in electricity price forecasting and to improve the predictive performance. First, we propose a deep neural ... More
Parametric Polyhedra with at least $k$ Lattice Points: Their Semigroup Structure and the k-Frobenius ProblemSep 18 2014Jul 24 2015Given an integral $d \times n$ matrix $A$, the well-studied affine semigroup $\mbox{ Sg} (A)=\{ b : Ax=b, \ x \in {\mathbb Z}^n, x \geq 0\}$ can be stratified by the number of lattice points inside the parametric polyhedra $P_A(b)=\{x: Ax=b, x\geq0\}$. ... More
Pioneer anomaly? Gravitational pull due to the Kuiper beltMar 16 2005Jan 09 2006In this work we study the gravitational influence of the material extending from Uranus orbit to the Kuiper belt and beyond on objects moving within these regions. We conclude that a density distribution given by $\rho(r)=\frac{1}{r}$ (for $r\geq 20 UA$) ... More
Thermalization of particle detectors: The Unruh effect and its reverseJul 18 2016Dec 31 2016We study the Anti-Unruh effect in general stationary scenarios. We find that, for accelerated trajectories, a particle detector coupled to a KMS state of a quantum field can cool down (click less often) as the KMS temperature increases. Remarkably, this ... More
Robust end-to-end deep audiovisual speech recognitionNov 21 2016Speech is one of the most effective ways of communication among humans. Even though audio is the most common way of transmitting speech, very important information can be found in other modalities, such as vision. Vision is particularly useful when the ... More
Dispute Resolution Using Argumentation-Based MediationSep 15 2014Mediation is a process, in which both parties agree to resolve their dispute by negotiating over alternative solutions presented by a mediator. In order to construct such solutions, mediation brings more information and knowledge, and, if possible, resources ... More
A Symbolic Approach to Reasoning with Linguistic QuantifiersMar 13 2013This paper investigates the possibility of performing automated reasoning in probabilistic logic when probabilities are expressed by means of linguistic quantifiers. Each linguistic term is expressed as a prescribed interval of proportions. Then instead ... More
A semantic network-based evolutionary algorithm for computational creativityApr 30 2014Jul 14 2014We introduce a novel evolutionary algorithm (EA) with a semantic network-based representation. For enabling this, we establish new formulations of EA variation operators, crossover and mutation, that we adapt to work on semantic networks. The algorithm ... More
Direct measurement of the two-point function in quantum fieldsJun 29 2018We analyze fast interaction cycles in bipartite quantum systems, showing that the statistics in one of the parties (the detector) can be used to determine the two-point correlator of the observable which mediates the coupling in the other (the target). ... More
Automated Generation of Cross-Domain Analogies via Evolutionary ComputationApr 11 2012Analogy plays an important role in creativity, and is extensively used in science as well as art. In this paper we introduce a technique for the automated generation of cross-domain analogies based on a novel evolutionary algorithm (EA). Unlike existing ... More
The Impact of Redshift on Galaxy Morphometric Classification: case studies for SDSS, DES, LSST and HST with MorfometrykaJul 10 2017Dec 01 2018We have carried a detailed analysis on the impact of cosmological redshift in the non-parametric approach to automated galaxy morphology classification. We artificially redshifted each galaxy from the EFIGI 4458 sample (re-centred at $z \sim 0$) simulating ... More
Properties of mean dimension and metric mean dimension coming from the topological entropyMay 30 2019Jun 12 2019In the late 1990's, M. Gromov introduced the notion of mean dimension for a continuous map, which is, as well as the topological entropy, an invariant under topological conjugacy. The concept of metric mean dimension for a dynamical system was introduced ... More
Flux moduli stabilisation, Supergravity algebras and no-go theoremsJul 31 2009Jan 20 2010We perform a complete classification of the flux-induced 12d algebras compatible with the set of N=1 type II orientifold models that are T-duality invariant, and allowed by the symmetries of the T^6/(Z_2 x Z_2) isotropic orbifold. The classification is ... More
Complete classification of Minkowski vacua in generalised flux modelsNov 15 2009Nov 18 2009We present a complete and systematic analysis of the Minkowski extrema of the N=1, D=4 Supergravity potential obtained from type II orientifold models that are T-duality invariant, in the presence of generalised fluxes. Based on our previous work on algebras ... More
The cohomology ring of certain families of periodic virtually cyclic groupsMar 04 2016Let G be a virtually cyclic of the form (Z_a x Z_b) x Z or [Z_a x (Z b x Q_{2^i})] x Z. We compute the integral cohomology ring of G, and then obtain the periodicity of the Farell cohomology of these groups.
Curves in a spacelike hypersurface in the Minkowski space-timeJul 03 2019Submanifolds in Lorentz-Minkowski space are investigated from various mathematical viewpoints and are of interest also in relativity theory. We define the hyperbolic surface and the de Sitter surface of a curve in the spacelike hypersurface M in the Minkowski ... More
On maximum likelihood estimation of the extreme value indexJul 05 2004We prove asymptotic normality of the so-called maximum likelihood estimator of the extreme value index.
Audiovisual Analytics Vocabulary and Ontology (AAVO): initial core and example expansionOct 27 2017Visual Analytics might be defined as data mining assisted by interactive visual interfaces. The field has been receiving prominent consideration by researchers, developers and the industry. The literature, however, is complex because it involves multiple ... More
Photospheric Motions and Their Effects on the Corona: a Numerical ApproachAug 28 2009We perform a number of numerical simulations of the solar corona with the aim to understand how it responds to different conditions in the photosphere. By changing parameters which govern the motion of the plasma at the photosphere we study the behavior ... More
Data-driven Algorithm Selection and Parameter Tuning: Two Case studies in Optimization and Signal ProcessingMay 31 2019Machine learning algorithms typically rely on optimization subroutines and are well-known to provide very effective outcomes for many types of problems. Here, we flip the reliance and ask the reverse question: can machine learning algorithms lead to more ... More
A Quantitative Doignon-Bell-Scarf TheoremMay 11 2014Sep 07 2015The famous Doignon-Bell-Scarf Theorem is a Helly-type result about the existence of integer solutions on systems of linear inequalities. The purpose of this paper is to present the following quantitative generalization: Given an integer $k$, we prove ... More
Computation with Polynomial Equations and Inequalities arising in Combinatorial OptimizationSep 04 2009The purpose of this note is to survey a methodology to solve systems of polynomial equations and inequalities. The techniques we discuss use the algebra of multivariate polynomials with coefficients over a field to create large-scale linear algebra or ... More
On Augmentation Algorithms for Linear and Integer-Linear Programming: From Edmonds-Karp to Bland and BeyondAug 15 2014Jan 15 2015Motivated by Bland's linear-programming generalization of the renowned Edmonds-Karp efficient refinement of the Ford-Fulkerson maximum-flow algorithm, we discuss three closely-related natural augmentation rules for linear and integer-linear optimization. ... More
$H_q-$semiclassical orthogonal polynomials via polynomial mappingsDec 18 2017In this work we study orthogonal polynomials via polynomial mappings in the framework of the $H_q-$semiclassical class. We consider two monic orthogonal polynomial sequences $\{p_n (x)\}_{n\geq0}$ and $\{q_n(x)\}_{n\geq0}$ such that $$ p_{kn}(x)=q_n(x^k)\;,\quad ... More
The Gromov Norm of the Product of Two SurfacesJul 12 2004May 09 2008We make an estimation of the value of the Gromov norm of the Cartesian product of two surfaces. Our method uses a connection between these norms and the minimal size of triangulations of the products of two polygons. This allows us to prove that the Gromov ... More
On simple Lie 2-algebra of toral rank 3Feb 28 2019Simple Lie algebras of finite dimension over an algebraically closed field of characteristic 0 or $p> 3$ were recently classified. However, the problem over an algebraically closed field of characteristics 2 or 3 there exist only partial results. The ... More
Random numerical semigroups and a simplicial complex of irreducible semigroupsOct 03 2017Oct 24 2017We examine properties of random numerical semigroups under a probabilistic model inspired by the Erdos-Renyi model for random graphs. We provide a threshold function for cofiniteness, and bound the expected embedding dimension, genus, and Frobenius number ... More
Estimate of the validity interval for the Antimaximum Principle and application to a non-cooperative systemJan 11 2019We are concerned with the sign of the solutions of non-cooperative systems when the parameter varies near a principal eigenvalue of the system. With this aim we give precise estimates of the validity interval for the Antimaximum Principle for an equation ... More
A Generating Function for all Semi-Magic Squares and the Volume of the Birkhoff PolytopeJan 30 2007Oct 09 2008We present a multivariate generating function for all n x n nonnegative integral matrices with all row and column sums equal to a positive integer t, the so called semi-magic squares. As a consequence we obtain formulas for all coefficients of the Ehrhart ... More
Properties of mean dimension and metric mean dimension coming from the topological entropyMay 30 2019Jun 15 2019In the late 1990's, M. Gromov introduced the notion of mean dimension for a continuous map, which is, as well as the topological entropy, an invariant under topological conjugacy. The concept of metric mean dimension for a dynamical system was introduced ... More
Identification of redundant and synergetic circuits in triplets of electrophysiological dataApr 27 2014Sep 10 2015Neural systems are comprised of interacting units, and relevant information regarding their function or malfunction can be inferred by analyzing the statistical dependencies between the activity of each unit. Whilst correlations and mutual information ... More
Classification via an Embedded ApproachMay 15 2019This paper presents the results of an automated volatile organic compound (VOC) classification process implemented by embedding a machine learning algorithm into an Arduino Uno board. An electronic nose prototype is constructed to detect VOCs from three ... More
Role of Sterile Neutrino Warm Dark Matter in Rhenium and Tritium Beta DecaysSep 15 2011Sep 24 2012Sterile neutrinos with mass in the range of one to a few keV are important as extensions of the Standard Model of particle physics and are serious dark matter (DM) candidates. This DM mass scale (warm DM) is in agreement with both cosmological and galactic ... More
Coherent blue emission induced by a combination of diode and femtosecond lasersMay 01 2016We report the investigation of a collimated blue light generated in rubidium vapor due to the combined action of an ultrashort pulse train and a cw diode laser. Each step of the two-photon transition 5S - 5P$_{3/2}$ - 5D is excited by one of the lasers, ... More
Weak values in collision theoryMar 19 2018Weak measurements have an increasing number of applications in contemporary quantum mechanics. They were originally described as a weak interaction that slightly entangled the translational degrees of freedom of a particle to its spin, yielding surprising ... More
Elliptical orbits in the phase-space quantizationMay 25 2016Jul 14 2016The energy levels of hydrogen-like atoms are obtained from the phase-space quantization, one of the pillars of the old quantum theory, by three different methods - (i) direct integration, (ii) Sommerfeld's original method, and (iii) complex integration. ... More
Plasma Diagnostic and Performance of a Permanent Magnet Hall ThrusterOct 20 2004Electric propulsion is now a sucessfull method for primary propulsion of deep space long duration missions and for geosyncronous satellite attitude control. Closed Drift Plasma Thruster, so called Hall Thruster or SPT (stationary plasma thruster) were ... More
The Exact Value for European Options on a Stock Paying a Discrete DividendSep 07 2006In the context of a Black-Scholes economy and with a no-arbitrage argument, we derive arbitrarily accurate lower and upper bounds for the value of European options on a stock paying a discrete dividend. Setting the option price error below the smallest ... More
Orbital pseudospin-momentum locking in two-dimensional chiral boropheneJul 09 2019Aug 07 2019Recently, orbital-textures have been found in Rashba and topological insulator (TI) surface states as a result of the spin-orbit coupling (SOC). Here, we predict a $p_x/p_y$ orbital texture, in linear dispersive Dirac bands, arising at the K/K' points ... More
Topological flat band, Dirac fermions and quantum spin Hall phase in 2D Archimedean latticesAug 14 2019Materials with designed properties arises in a synergy between theoretical and experimental approaches. In this study we explore the set of Archimedean lattices forming a guidance to its electronic properties and topological phases. Within these lattices, ... More
Probing QCD Corrections to QED Effects Through Optical Experiments in VacuumSep 29 2006Jul 03 2007A numerical estimative error of the magnitude of the vacuum polarization effect due to electron-positron by a factor of $10^3$ in [PRL97(2006)100403; 269901(E)] invalidates the study carried in this work in its present context.
Reconstructing the invisible with matrix elementsDec 08 2017Nov 01 2018We propose a fully flexible method to perform an hypothesis test between signal and background based on the Matrix Element Method in the presence of multiple invisible particles. The proposed method performs a mapping of the measured final state onto ... More
Fast and Extensible Online Multivariate Kernel Density EstimationJun 08 2016We present xokde++, a state-of-the-art online kernel density estimation approach that maintains Gaussian mixture models input data streams. The approach follows state-of-the-art work on online density estimation, but was redesigned with computational ... More
Molecule survival in magnetized protostellar disk winds. II. Predicted H2O line profiles versus Herschel/HIFI observationsNov 12 2015We investigate whether the broad wings of H2O emission identified with Herschel towards low-mass Class 0 and Class 1 protostars may be consistent with an origin in a dusty MHD disk wind, and the constraints it would set on the underlying disk properties. ... More
Orbital pseudospin-momentum locking in two-dimensional chiral boropheneJul 09 2019Recently, orbital-textures have been found in Rashba and topological insulator (TI) surface states as a result of the spin-orbit coupling (SOC). Here, we predict a $p_x/p_y$ orbital texture, in linear dispersive Dirac bands, arising at the K/K' points ... More
Electrostatic analogy of the Jackiw-Rebbi zero energy stateDec 04 2017We present an analogy between the one dimensional Poisson equation in inhomogeneous media and the Dirac equation in one space dimension with a Lorentz scalar potential for zero energy. We illustrate how the zero energy state in the Jackiw-Rebbi model ... More
Non-thermal radiation from a pulsar wind interacting with an inhomogeneous stellar windNov 11 2016Binaries hosting a massive star and a non-accreting pulsar are powerful non-thermal emitters due to the interaction of the pulsar and the stellar wind. The winds of massive stars are thought to be inhomogeneous, which could have an impact on the non-thermal ... More
CBR with Commonsense Reasoning and Structure Mapping: An Application to MediationJul 30 2011Oct 12 2011Mediation is an important method in dispute resolution. We implement a case based reasoning approach to mediation integrating analogical and commonsense reasoning components that allow an artificial mediation agent to satisfy requirements expected from ... More
Zero-bias anomaly in a nanowire quantum dot coupled to superconductorsJul 05 2012Oct 16 2012We studied the low-energy states of spin-1/2 quantum dots defined in InAs/InP nanowires and coupled to aluminium superconducting leads. By varying the superconducting gap, \Delta, with a magnetic field, B, we investigated the transition from strong coupling, ... More
Random Monomial IdealsJan 25 2017Jan 05 2018Inspired by the study of random graphs and simplicial complexes, and motivated by the need to understand average behavior of ideals, we propose and study probabilistic models of random monomial ideals. We prove theorems about the probability distributions, ... More
Automatic continuity and weighted composition operators between spaces of vector-valued differentiable functionsDec 20 2000Jan 19 2001It is proved that every linear biseparating map between spaces of vector-valued differentiable functions is a weighted composition map. As a consequence, such a map is always continuous.
On the idempotency of some composite functorsDec 22 2009In this note we present examples of localization functors (in the category of spaces) whose composition with certain cellularization functors is not idempotent, and vice versa.
Magnon delocalization in ferromagnetic chains with long-range correlated disorderDec 14 2001We study one-magnon excitations in a random ferromagnetic Heisenberg chain with long-range correlations in the coupling constant distribution. By employing an exact diagonalization procedure, we compute the localization length of all one-magnon states ... More
The Support of Integer Optimal SolutionsDec 24 2017The support of a vector is the number of nonzero-components. We show that given an integral $m\times n$ matrix $A$, the integer linear optimization problem $\max\left\{\boldsymbol{c}^T\boldsymbol{x} : A\boldsymbol{x} = \boldsymbol{b}, \, \boldsymbol{x}\ge\boldsymbol{0}, ... More
Vibrations on pulse tube based Dry Dilution Refrigerators for low noise measurementsMar 27 2017Mar 30 2017Dry Dilution Refrigerators (DDR) based on pulse tube cryo-coolers have started to replace Wet Dilution Refrigerators (WDR) due to the ease and low cost of operation. However these advantages come at the cost of increased vibrations, induced by the pulse ... More
Crystal structure and physical properties of EuPtIn$_{4}$ intermetallic antiferromagnetApr 07 2014We report the synthesis of EuPtIn$_{4}$ single crystalline platelets by the In-flux technique. This compound crystallizes in the orthorhombic Cmcm structure with lattice parameters $a=4.542(1)$ \AA, $b=16.955(2)$ \AA$\,$ and $c=7.389(1)$ \AA. Measurements ... More
On the Index of Constant Mean Curvature HypersurfacesJan 28 2009In 1968, Simons introduced the concept of index for hypersurfaces immersed into the Euclidean sphere S^{n+1}. Intuitively, the index measures the number of independent directions in which a given hypersurface fails to minimize area. The earliest results ... More
Application of p-adic analysis to time seriesDec 13 2013Time series defined by a p-adic pseudo-differential equation is investigated using the expansion of the time series over p-adic wavelets. Quadratic correlation function is computed. This correlation function shows a degree--like behavior and is locally ... More
Sparse solutions of linear Diophantine equationsJan 31 2016Jan 06 2017We present structural results on solutions to the Diophantine system $A{\boldsymbol y} = {\boldsymbol b}$, ${\boldsymbol y} \in \mathbb Z^t_{\ge 0}$ with the smallest number of non-zero entries. Our tools are algebraic and number theoretic in nature and ... More
Short Rational Functions for Toric Algebra and ApplicationsJul 26 2003We encode the binomials belonging to the toric ideal $I_A$ associated with an integral $d \times n$ matrix $A$ using a short sum of rational functions as introduced by Barvinok \cite{bar,newbar}. Under the assumption that $d,n$ are fixed, this representation ... More
Control of fluorescence in quantum emitter and metallic nanoshell hybrids for medical applicationsJun 29 2017We study the light emission from quantum emitter and double metallic nanoshell hybrid systems. Quantum emitters act as local sources which transmit their light efficiently due to a double nanoshell near field. The double nanoshell consists a dielectric ... More
Thesaurus as a complex networkDec 22 2003A thesaurus is one, out of many, possible representations of term (or word) connectivity. The terms of a thesaurus are seen as the nodes and their relationship as the links of a directed graph. The directionality of the links retains all the thesaurus ... More
Low energy neutron propagation in MCNPX and GEANT4Jan 17 2006Simulations of neutron background from rock for underground experiments are presented. Neutron propagation through two types of rock, lead and hydrocarbon material is discussed. The results show a reasonably good agreement between GEANT4, MCNPX and GEANT3 ... More
Fundamental ingredients for the emergence of discontinuous phase transitions in the majority vote modelFeb 14 2018Discontinuous transitions have received considerable interest due to the uncovering that many phenomena such as catastrophic changes, epidemic outbreaks and synchronization present a behavior signed by abrupt (macroscopic) changes (instead of smooth ones) ... More
A Matrix form of Ramanujan-type series for $1/π$Jul 09 2009In this paper we prove theorems related to the Ramanujan-type series for $1/\pi$ (type $_3F_2$) and to the Ramanujan-like series, discovered by the author, for $1/\pi^2$ (type $_5F_4$). Our developments for the cases $_3 F_2$ and $_5 F_4$ connect with ... More
On WZ-pairs which prove Ramanujan seriesApr 02 2009Jul 03 2019The known WZ-proofs for Ramanujan-type series related to $1/\pi$ gave us the insight to develop a new proof strategy based on the WZ-method. Using this approach we are able to find more generalizations and discover first WZ-proofs for certain series of ... More
Expansion of hydrogen-poor knots in the born-again planetary nebulae A30 and A78Oct 14 2014We analyze the expansion of hydrogen-poor knots and filaments in the born-again planetary nebulae A30 and A78 based on Hubble Space Telescope (HST) images obtained almost 20 yr apart. The proper motion of these features generally increases with distance ... More
Polynomial Chaos-Based Adaptive Control for Nonlinear SystemsAug 24 2018In this work we present a nonlinear adaptive suboptimal control strategy for uncertain nonlinear systems. Stochastic parametric uncertainty is dealt with by employing spectral decomposition of the random variables by means of the generalized polynomial ... More
Strict Very Fast Decision Tree: a memory conservative algorithm for data stream miningMay 16 2018May 17 2018Dealing with memory and time constraints are current challenges when learning from data streams with a massive amount of data. Many algorithms have been proposed to handle these difficulties, among them, the Very Fast Decision Tree (VFDT) algorithm. Although ... More
On wavelets to select the parametric form of a regression modelSep 28 2018Let Y be a response variable related with a set of explanatory variables and let f1, f2, ..., fk be a set of the parametric forms representing a set of candidate's model. Let f* be the true model among the set of k plausible models. We discuss in this ... More
Symmetric topological complexity as the first obstruction in Goodwillie's Euclidean embedding tower for real projective spacesNov 05 2009Aug 27 2010As a first goal, it is explained why Goodwillie-Weiss calculus of embeddings offers new information about the Euclidean embedding dimension of P^m only for m < 16. Concrete scenarios are described in these low-dimensional cases, pinpointing where to look ... More
Multiplicative bijections of semigroups of interval-valued continuous functionsOct 23 2007Dec 13 2007We characterize all compact and Hausdorff spaces $X$ which satisfy that for every multiplicative bijection $\phi$ on $C(X, I)$, there exist a homeomorphism $\mu : X \to X$ and a continuous map $p: X \to (0, +\infty)$ such that $$\phi (f) (x) = f(\mu (x))^{p(x)}$$ ... More