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Deep Tree Transductions - A Short SurveyFeb 05 2019The paper surveys recent extensions of the Long-Short Term Memory networks to handle tree structures from the perspective of learning non-trivial forms of isomorph structured transductions. It provides a discussion of modern TreeLSTM models, showing the ... More

Text Summarization as Tree Transduction by Top-Down TreeLSTMSep 24 2018Extractive compression is a challenging natural language processing problem. This work contributes by formulating neural extractive compression as a parse tree transduction problem, rather than a sequence transduction task. Motivated by this, we introduce ... More

Informative Bayesian inference for the skew-normal distributionMay 14 2013Motivated by the analysis of the distribution of university grades, which is usually asymmetric, we discuss two informative priors for the shape parameter of the skew-normal distribution, showing that they lead to closed-form full-conditional posterior ... More

Bayesian nonparametric location-scale-shape mixturesNov 29 2013Discrete mixture models are one of the most successful approaches for density estimation. Under a Bayesian nonparametric framework, Dirichlet process location-scale mixture of Gaussian kernels is the golden standard, both having nice theoretical properties ... More

Initial-data contribution to the error budget of gravitational waves from neutron-star binariesMay 23 2016As numerical calculations of inspiralling neutron-star binaries reach values of accuracy that are comparable with those of binary black holes, a fine budgeting of the various sources of error becomes increasingly important. Among such sources, the initial ... More

Crystal growth as an excitable mediumJul 17 2012Crystal growth has been widely studied for many years, and, since the pioneering work of Burton, Cabrera and Frank, spirals and target patterns on the crystal surface have been understood as forms of tangential crystal growth mediated by defects and by ... More

A stigmergy-based analysis of city hotspots to discover trends and anomalies in urban transportation usageApr 16 2018Jan 21 2019A key aspect of a sustainable urban transportation system is the effectiveness of transportation policies. To be effective, a policy has to consider a broad range of elements, such as pollution emission, traffic flow, and human mobility. Due to the complexity ... More

Stigmergy-based modeling to discover urban activity patterns from positioning dataApr 12 2017Jan 21 2019Positioning data offer a remarkable source of information to analyze crowds urban dynamics. However, discovering urban activity patterns from the emergent behavior of crowds involves complex system modeling. An alternative approach is to adopt computational ... More

Detecting Permanent and Intermittent Purchase Hotspots via Computational StigmergyFeb 05 2019The analysis of credit card transactions allows gaining new insights into the spending occurrences and mobility behavior of large numbers of individuals at an unprecedented scale. However, unfolding such spatiotemporal patterns at a community level implies ... More

Understanding and enhancing superconductivity in FeSe/STO by quantum size effectsJun 30 2016Nov 24 2016Superconductivity in one-atom-layer iron selenide (FeSe) on a strontium titanate (STO) substrate is enhanced by almost an order of magnitude with respect to bulk FeSe. There is recent experimental evidence suggesting that this enhancement persists in ... More

Understanding and enhancing superconductivity in FeSe/STO by quantum size effectsJun 30 2016Superconductivity in one-atom-layer iron selenide (FeSe) on a strontium titanate (STO) substrate is enhanced by almost an order of magnitude with respect to bulk FeSe. There is recent experimental evidence suggesting that this enhancement persists in ... More

Local Charge Excesses in Metallic Alloys: a Local Field Coherent Potential Approximation TheoryJun 06 2002Nov 27 2002Electronic structure calculations performed on very large supercells have shown that the local charge excesses in metallic alloys are related through simple linear relations to the local electrostatic field resulting from distribution of charges in the ... More

Marginal and Irrelevant Disorder in Einstein-Maxwell backgroundsDec 01 2015Jan 15 2016We study analytically the effect of a weak random chemical potential of zero average in an Einstein-Maxwell background. For uncorrelated disorder this perturbation is relevant however we show that it can become marginal or even irrelevant by tuning disorder ... More

Modelling the Influence of Cultural Information on Vision-Based Human Home Activity RecognitionMar 21 2018Daily life activities, such as eating and sleeping, are deeply influenced by a person's culture, hence generating differences in the way a same activity is performed by individuals belonging to different cultures. We argue that taking cultural information ... More

Local Charge distributions in Metallic Alloys: a Local Field Coherent Potential Approximation TheoryDec 17 2002Electronic structure calculations performed on very large supercells have shown that the local charge excesses in metallic alloys are related through simple linear relations to the local electrostatic field resulting from distribution of charges in the ... More

Ground States for Diffusion Dominated Free Energies with Logarithmic InteractionJan 04 2014Aug 01 2014Replacing linear diffusion by a degenerate diffusion of porous medium type is known to regularize the classical two-dimensional parabolic-elliptic Keller-Segel model. The implications of nonlinear diffusion are that solutions exist globally and are uniformly ... More

A Gain Function for Architectural Decision-Making in Scientific ComputingFeb 01 2016Scientific Computing typically requires large computational needs which have been addressed with High Performance Distributed Computing. It is essential to efficiently deploy a number of complex scientific applications, which have different characteristics, ... More

Rare Kaon Decays in the $1/N_c$-ExpansionSep 14 1992We study the unknown coupling constants that appear at order $p^4$ in the Chiral Perturbation Theory analysis of $K \to \pi \gamma^* \to \pi l^+ l^-$, $K^{+-} \to \pi^{+-} \gamma \gamma$ and $K \to \pi \pi \gamma$ decays. To that end, we compute the chiral ... More

Versatile Hall magnetometer with variable sensitivity assembly for characterization of the magnetic properties of nanoparticlesMay 14 2019A Hall magnetometer with variable sensitivity is constructed to measure the magnetic properties of magnetic nanoparticles manufactured by different methods. This novel magnetometer can also be used to measure bulk materials and samples in liquids. The ... More

High Performance Computing Evaluation A methodology based on Scientific Application RequirementsDec 03 2014High Performance Distributed Computing is essential to boost scientific progress in many areas of science and to efficiently deploy a number of complex scientific applications. These applications have different characteristics that require distinct computational ... More

Extending an Information Extraction tool set to Central and Eastern European languagesSep 12 2006In a highly multilingual and multicultural environment such as in the European Commission with soon over twenty official languages, there is an urgent need for text analysis tools that use minimal linguistic knowledge so that they can be adapted to many ... More

On the cardinality of the $θ$-closed hull of sets IIJun 28 2012Dec 17 2012The research in this paper is a continuation of the investigation of the cardinality of the $\theta$-closed hull of subsets of spaces. This research obtains new upper bounds of the cardinality of the $\theta$-closed hull of subsets using cardinal functions ... More

Transport in a gravity dual with a varying gravitational coupling constantJun 03 2016We study asymptotically AdS Brans-Dicke (BD) backgrounds, where the Ricci tensor R is coupled to a scalar in the radial dimension, as effective models of metals with a varying coupling constant. We show that, for translational invariant backgrounds, the ... More

Regularization of energy-momentum tensor correlators and parity-odd termsMar 11 2015Mar 18 2015We discuss the problem of regularizing correlators in conformal field theories. The only way to do it in coordinate space is to interpret them as distributions. Unfortunately except for the simplest cases we do not have tabulated mathematical results. ... More

On the cardinality of the $θ$-closed hull of setsMar 26 2012The \theta-closed hull of a set A in a topological space is the smallest set C containing A such that, whenever all $closed$ neighborhoods of a point intersect C, this point is in C. We define a new topological cardinal invariant function, the $\theta-bitighness ... More

Maximum a Posteriori State Path Estimation: Discretization Limits and their InterpretationMar 20 2014Continuous-discrete models with dynamics described by stochastic differential equations are used in a wide variety of applications. For these systems, the maximum a posteriori (MAP) state path can be defined as the curves around which lie the infinitesimal ... More

MPTCP Linux Kernel Congestion ControlsDec 07 2018MultiPath TCP (MPTCP) is a promising protocol which brings new light to the TCP/IP protocol stack ossification problem by means of an impactful innovation of the transport layer. A MPTCP connection consists of a set of one or more subflows, where each ... More

Thermal transistor effect in quantum systemsFeb 04 2019We study a quantum system composed of three interacting qubits, each coupled to a different thermal reservoir. We show how to engineer it in order to build a quantum device that is analogous to an electronic bipolar transistor. We outline how the interaction ... More

The Affinity Effects of Parallelized Libraries in Concurrent EnvironmentsJan 28 2015The use of cloud computing grows as it appears to be an additional resource for High-Performance Parallel and Distributed Computing (HPDC), especially with respect to its use in support of scientific applications. Many studies have been devoted to determining ... More

Diagonalizations of dense familiesJul 17 2012Jul 29 2012We develop a unified framework for the study of properties involving diagonalizations of dense families in topological spaces. We provide complete classification of these properties. Our classification draws upon a large number of methods and constructions ... More

Coherence effects in disordered geometries with a field-theory dualNov 29 2017Mar 26 2018We investigate the holographic dual of a probe scalar in an asymptotically Anti-de-Sitter (AdS) disordered background which is an exact solution of Einstein's equations in three bulk dimensions. Unlike other approaches to model disorder in holography, ... More

A framework for Culture-aware Robots based on Fuzzy LogicMar 22 2018Cultural adaptation, i.e., the matching of a robot's behaviours to the cultural norms and preferences of its user, is a well known key requirement for the success of any assistive application. However, culture-dependent robot behaviours are often implicitly ... More

Dwarf Elliptical GalaxiesSep 28 1994Dwarf elliptical (dE) galaxies, with blue absolute magnitudes typically fainter than $M_B = -16$, are the most numerous type of galaxy in the nearby universe. Tremendous advances have been made over the past several years in delineating the properties ... More

The invisible power of fairness. How machine learning shapes democracyMar 22 2019Many machine learning systems make extensive use of large amounts of data regarding human behaviors. Several researchers have found various discriminatory practices related to the use of human-related machine learning systems, for example in the field ... More

Effect of Metallicity on the Evolution of the Habitable Zone from the Pre-Main Sequence to the Asymptotic Giant Branch and the Search for LifeApr 04 2013During the course of stellar evolution, the location and width of the habitable zone changes as the luminosity and radius of the star evolves. The duration of habitability for a planet located at a given distance from a star is greatly affected by the ... More

Urban Swarms: A new approach for autonomous waste managementOct 18 2018Mar 01 2019Modern cities are growing ecosystems that face new challenges due to the increasing population demands. One of the many problems they face nowadays is waste management, which has become a pressing issue requiring new solutions. Swarm robotics systems ... More

Short term period variable stars observed at OAUNIApr 03 2019We present the first scientific results of the program on short term period variable stars observed using the OAUNI facility at the peruvian Andes. These results include good quality light curves of delta Scuti stars, rapidly oscillating stars along with ... More

Urban Swarms: A new approach for autonomous waste managementOct 18 2018Modern cities are growing ecosystems that face new challenges due to the increasing population demands. One of the many problems they face nowadays is waste management, which has become a pressing issue requiring new solutions. Swarm robotics systems ... More

Influence of nicotine and alcohol on sleep and implications on insomnia: the reward-attention circuit modelFeb 14 2019Dopamine, a neurotransmitter well known for regulating movement, reward, and learning, is emerging as one of the neuromodulators of wakefulness. Drugs that increase the level of dopamine in the brain (including, but not limited to, nicotine) also increase ... More

Silicon Nitride MOMS Oscillator for Room Temperature Quantum OptomechanicsJun 29 2018Optomechanical SiN nano-oscillators in high-finesse Fabry-Perot cavities can be used to investigate the interaction between mechanical and optical degree of freedom for ultra-sensitive metrology and fundamental quantum mechanical studies. In this work ... More

McMillan-Mayer Theory of Solutions Revisited: Simplifications and ExtensionsJun 05 2014Jun 18 2014McMillan and Mayer (MM) proved two remarkable theorems in their paper on the equilibrium statistical mechanics of liquid solutions. They first showed that the grand canonical partition function for a solution can be reduced to a one with an effectively ... More

Induced extended calculus on the quantum planeJan 28 1994The non-commutative differential calculus on quantum groups can be extended by introducing, in analogy with the classical case, inner product operators and Lie derivatives. For the case of $\GL$ we show how this extended calculus induces by coaction a ... More

SBF Distances to Dwarf Elliptical Galaxies in the Sculptor GroupSep 04 1998As part of an ongoing search for dwarf elliptical galaxies (dE) in the vicinity of the Local Group, we acquired deep B and R-band images for five dE candidates identified in the Sculptor (Scl) group region. We carried out a surface brightness fluctuation ... More

Stiff-spring approximation revisited: inertial effects in non-equilibrium trajectoriesJul 25 2016Use of harmonic guiding potentials is the most common method for implementing steered molecular dynamics (SMD) simulations, performed to obtain potentials of mean force (PMFs) of molecular systems using non-equilibrium work (NEW) theorems. Harmonic guiding ... More

Collisional relaxation in the inhomogeneous Hamiltonian-Mean-Field model: diffusion coefficientsOct 21 2016Systems of particles with long range interactions present two important processes: first, the formation of out-of-equilibrium quasi-stationary states (QSS), and the collisional relaxation towards Maxwell-Boltzmann equilibrium in a much longer timescale. ... More

Can Life develop in the expanded habitable zones around Red Giant Stars?Mar 23 2005We present some new ideas about the possibility of life developing around sub-giant and red giant stars. Our study concerns the temporal evolution of the habitable zone. The distance between the star and the habitable zone, as well as its width, increases ... More

Some interesting features of new massive gravityAug 03 2011A proof that new massive gravity - the massive 3D gravity model proposed by Bergshoeff, Hohm and Townsend (BHT) - is the only unitary system at the tree level that can be constructed by augmenting planar gravity through the curvature-squared terms, is ... More

Testing the Surface Brightness Fluctuations Method for Dwarf Elliptical Galaxies in the Centaurus A GroupDec 01 1999We have obtained deep B and R-band CCD photometry for 5 dE galaxies that were previously identified on Schmidt films covering the Cen A group region. From a Fourier analysis of the R-band CCD images we determined the surface brightness fluctuation (SBF) ... More

The minimal model for the Batalin-Vilkovisky operadMay 10 2011Jul 06 2011The purpose of this paper is to explain and to generalize, in a homotopical way, the result of Barannikov-Kontsevich and Manin which states that the underlying homology groups of some Batalin-Vilkovisky algebras carry a Frobenius manifold structure. To ... More

Collisional relaxation in the inhomogeneous Hamiltonian-Mean-Field model: diffusion coefficientsOct 21 2016Feb 06 2017Systems of particles with long range interactions present two important processes: first, the formation of out-of-equilibrium quasi-stationary states (QSS), and the collisional relaxation towards Maxwell-Boltzmann equilibrium in a much longer timescale. ... More

Dixmier traces on noncompact isospectral deformationsJul 21 2005Apr 06 2006We extend the isospectral deformations of Connes, Landi and Dubois-Violette to the case of Riemannian spin manifolds carrying a proper action of the noncompact abelian group $R^l$. Under deformation by a torus action, a standard formula relates Dixmier ... More

Axelrod's Model with Surface TensionDec 12 2012In this work we propose a subtle change in Axelrod's model for the dissemination of culture. The mechanism consists of excluding non-interacting neighbours from the set of neighbours out of which an agent is drawn for potential cultural interactions. ... More

Full Speed Ahead: 3D Spatial Database Acceleration with GPUsAug 28 2018Many industries rely on visual insights to support decision- making processes in their businesses. In mining, the analysis of drills and geological shapes, represented as 3D geometries, is an important tool to assist geologists on the search for new ore ... More

Chaotic-Integrable Transition in the Sachdev-Ye-Kitaev ModelJul 07 2017Jun 18 2018Quantum chaos is one of the distinctive features of the Sachdev-Ye-Kitaev (SYK) model, $N$ Majorana fermions in $0+1$ dimensions with infinite-range two-body interactions, which is attracting a lot of interest as a toy model for holography. Here we show ... More

Proof of concept for an ultrasensitive meta-device to detect and localize nonlinear elastic sourcesDec 25 2016The appearance of nonlinear effects in elastic wave propagation is one of the most reliable and sensitive indicators of the onset of material damage. However, these effects are usually very small and can be detected only using cumbersome digital signal ... More

Everyday the Same Picture: Popularity and Content DiversityJan 28 2015Feb 02 2015Facebook is flooded by diverse and heterogeneous content, from kittens up to music and news, passing through satirical and funny stories. Each piece of that corpus reflects the heterogeneity of the underlying social background. In the Italian Facebook ... More

Joint Maximum a Posteriori State Path and Parameter Estimation in Stochastic Differential EquationsApr 06 2017In this article, we introduce the joint maximum a posteriori state path and parameter estimator (JME) for continuous-time systems described by stochastic differential equations (SDEs). This estimator can be applied to nonlinear systems with discrete-time ... More

Accelerating Algorithms using a Dataflow Graph in a Reconfigurable SystemOct 17 2011In this paper, the acceleration of algorithms using a design of a field programmable gate array (FPGA) as a prototype of a static dataflow architecture is discussed. The static dataflow architecture using operators interconnected by parallel buses was ... More

A complex network approach to cloud computingApr 10 2015Cloud computing has become an important means to speed up computing. One problem influencing heavily the performance of such systems is the choice of nodes as servers responsible for executing the users' tasks. In this article we report how complex networks ... More

Apps, Places and People: strategies, limitations and trade-offs in the physical and digital worldsApr 19 2019Cognition has been found to constrain several aspects of human behaviour, such as the number of friends and the number of favourite places a person keeps stable over time. This limitation has been empirically defined in the physical and social spaces. ... More

The scaling properties of exchange and correlation holes of the valence shell of second row atomsNov 30 2011Feb 01 2012We study the exchange and correlation hole of the valence shell of second row atoms using variational Monte Carlo techniques, especially correlated estimates, and norm-conserving pseudopotentials. The well-known scaling of the valence shell provides a ... More

The FGK formalism for black p-branes in d dimensionsMar 01 2012Mar 14 2012We present a generalization to an arbitrary number of spacetime (d) and worldvolume (p+1) dimensions of the formalism proposed by Ferrara, Gibbons and Kallosh to study black holes (p=0) in d=4 dimensions. We include the special cases in which there can ... More

Linear maps between C*-algebras preserving extreme points and strongly linear preserversJul 21 2015We study new classes of linear preservers between C$^*$-algebras and JB$^*$-triples. Let $E$ and $F$ be JB$^*$-triples with $\partial_{e} (E_1)$. We prove that every linear map $T:E\to F$ strongly preserving Brown-Pedersen quasi-invertible elements is ... More

Is the chiral phase transition induced by a metal-insulator transition?Nov 18 2007We investigate the QCD Dirac operator with gauge configurations given by a liquid of instantons in the region of temperatures about the chiral phase transition. Both the quenched and unquenched cases are examined in detail. We present evidence of a localization ... More

The QCD vacuum as a disordered medium: A simplified model for the QCD Dirac operatorDec 12 2003We model the QCD Dirac operator as a power-law random banded matrix (RBM) with the appropriate chiral symmetry. Our motivation is the form of the Dirac operator in a basis of instantonic zero modes with a corresponding gauge background of instantons. ... More

L-functions of symmetric powers of the generalized Airy family of exponential sums: ell-adic and p-adic methodsAug 09 2009Aug 02 2010For \psi a nontrivial additive character on the finite field F_q, the map t \mapsto \sum_{x \in F_q} \psi(f(x)+tx) is the Fourier transform of the map t \mapsto \psi(f(t))$. As is well-known, this has a cohomological interpretation, producing a continuous ... More

Search of Complex Binary Cellular Automata Using Behavioral MetricsDec 06 2014Jan 16 2015We propose the characterization of binary cellular automata using a set of behavioral metrics that are applied to the minimal Boolean form of a cellular automaton's transition function. These behavioral metrics are formulated to satisfy heuristic criteria ... More

A model for periodic blazarsOct 15 2016We describe a scenario to explain blazar periodicities with timescales of $\sim$ few years. The scenario is based on a binary super-massive black hole (SMBH) system in which one of the two SMBH carries a jet. We discuss the various mechanisms that can ... More

Laplacian-based generalized gradient approximations for the exchange energyAug 17 2013It is well known that in the gradient expansion approximation to density functional theory (DFT) the gradient and Laplacian of the density make interchangeable contributions to the exchange correlation (XC) energy. This is an arbitrary "gauge" freedom ... More

An infinite family of magnetized Morgan-Morgan relativistic thin disksNov 13 2010Dec 02 2011Applying the Horsk\'y-Mitskievitch conjecture to the empty space solutions of Morgan and Morgan due to the gravitational field of a finite disk, we have obtained the corresponding solutions of the Einstein-Maxwell equations. The resulting expressions ... More

L-functions of symmetric powers of the generalized Airy family of exponential sumsAug 02 2010This paper looks at the L-function of the k-th symmetric power of the ell-adic sheaf over the affine line associated to the generalized Airy family of exponential sums. We compute the degree of this rational function and the local factors at infinity. ... More

Model-based clustering via linear cluster-weighted modelsJun 18 2012Mar 09 2015A novel family of twelve mixture models with random covariates, nested in the linear $t$ cluster-weighted model (CWM), is introduced for model-based clustering. The linear $t$ CWM was recently presented as a robust alternative to the better known linear ... More

Visualizing the large-$Z$ scaling of the kinetic energy density of atomsMay 25 2016The scaling of neutral atoms to large $Z$, combining periodicity with a gradual trend to homogeneity, is a fundamental probe of density functional theory, one that has driven recent advances in understanding both the kinetic and exchange-correlation energies. ... More

Newman-Janis Ansatz in conformastatic spacetimesJul 15 2016The Newman-Janis Ansatz was used first to obtain the stationary Kerr metric from the static Schwarzschild metric. Many works have been devoted to investigate the physical significance of this Ansatz, but no definite answer has been given so far. We show ... More

Chiral phase transition and Anderson localization in the Instanton Liquid Model for QCDDec 20 2005We study the spectrum and eigenmodes of the QCD Dirac operator in a gauge background given by an Instanton Liquid Model (ILM) at temperatures around the chiral phase transition. Generically we find the Dirac eigenvectors become more localized as the temperature ... More

Relativistic static magnetized finite thin disk: An infinite family of exact solutionsJun 10 2010Dec 02 2011An infinite family of relativistic finite thin disk model with magnetic field is presented. The model is obtained for solving the Einstein-Maxwell equations for static spacetimes by means of the Horsk\'y-Mitskievitch generating conjecture. The vacuum ... More

$C^3$ matching for asymptotically flat spacetimesJan 05 2019We propose a criterion for finding the minimum distance at which an interior solution of Einstein's equations can be matched with an exterior asymptotically flat solution. It is based upon the analysis of the eigenvalues of the Riemann curvature tensor ... More

Chiral phase transition as an Anderson transition in the Instanton Liquid Model for QCDSep 24 2005We study the spectrum and eigenmodes of the QCD Dirac operator in a gauge background given by an Instanton Liquid Model (ILM) at temperatures around the chiral phase transition. For two massless quark flavors we observe that at the chiral phase transition, ... More

Essential spectrum of a class of Riemannian manifoldsMay 24 2012Jul 30 2012In this paper we consider a family of Riemannian manifolds, not necessarily complete, with curvature conditions in a neighborhood of a ray. Under these conditions we obtain that the essential spectrum of the Laplacian contains an interval. The results ... More

Global dynamics of a family of 3D Lotka-Volterra SystemsMar 19 2015In this paper we analyze the flow of a family of three dimensional Lotka-Volterra systems restricted to an invariant and bounded region. The behaviour of the flow in the interior of this region is simple: either every orbit is a periodic orbit or they ... More

Chiral phase transition in lattice QCD as a metal-insulator transitionNov 17 2006Mar 09 2007We investigate the lattice QCD Dirac operator with staggered fermions at temperatures around the chiral phase transition. We present evidence of a metal-insulator transition in the low lying modes of the Dirac operator around the same temperature as the ... More

Counterrotating Dust Disk Around a Schwarzschild Black Hole: New Fully Integrated Explicit Exact SolutionNov 18 2008The first fully integrated explicit exact solution of the Einstein field equations corresponding to the superposition of a counterrotating dust disk with a central black hole is presented. The obtained solution represents an infinite annular thin disk ... More

Beyond the local approximation to exchange and correlation: the role of the Laplacian of the density in the energy density of SiJun 18 2005We model the exchange-correlation (XC) energy density of the Si crystal and atom as calculated by variational Monte Carlo (VMC) methods with a gradient analysis beyond the local density approximation (LDA). We find the Laplacian of the density to be an ... More

Master Equation for a Particle Coupled to a Two-Level ReservoirSep 16 1994We study the quantum dissipative dynamics of a particle coupled linearly to a set of two-level systems (the heat bath) via the master equation method which we extract from the path integral formalism independently from the form of the bath spectral density. ... More

Itinerant Nature of Atom-Magnetization Excitation by Tunneling ElectronsOct 06 2010Nov 04 2010We have performed single-atom magnetization curve (SAMC) measurements and inelastic scanning tunneling spectroscopy (ISTS) on individual Fe atoms on a Cu(111) surface. The SAMCs show a broad distribution of magnetic moments with $\unit[3.5]{\mu_{\rm B}}$ ... More

A frequency-preserving and time-invariant metamaterial-based nonlinear acoustic diodeOct 24 2018We present the realization of an acoustic diode or rectifier, exploiting symmetry-breaking nonlinear effects like harmonic generation and wave mixing and the filtering capabilities of metamaterials. The essential difference and advantage compared with ... More

Adatoms in GrapheneDec 11 2008We review the problem of adatoms in graphene under two complementary points of view, scattering theory and strong correlations. We show that in both cases impurity atoms on the graphene surface present effects that are absent in the physics of impurities ... More

Dynamic texture analysis with diffusion in networksJun 27 2018Dynamic texture is a field of research that has gained considerable interest from computer vision community due to the explosive growth of multimedia databases. In addition, dynamic texture is present in a wide range of videos, which makes it very important ... More

Inspiralling, Non-Precessing, Spinning Black Hole Binary Spacetime via Asymptotic MatchingDec 17 2015Mar 23 2016We construct a new global, fully analytic, approximate spacetime which accurately describes the dynamics of non-precessing, spinning black hole binaries during the inspiral phase of the relativistic merger process. This approximate solution of the vacuum ... More

Harmonic maps into the orthogonal group and null curvesDec 13 2017Nov 05 2018We find algebraic parametrizations of extended solutions of harmonic maps of finite uniton number from a surface to the orthogonal group O(n) in terms of free holomorphic data which lead to formulae for all such harmonic maps. Our work reveals an interesting ... More

Low-cost Autonomous Navigation System Based on Optical Flow ClassificationMar 11 2018This work presents a low-cost robot, controlled by a Raspberry Pi, whose navigation system is based on vision. The strategy used consisted of identifying obstacles via optical flow pattern recognition. Its estimation was done using the Lucas-Kanade algorithm, ... More

Quasi-particle dephasing time in disordered d-wave superconductorsJan 20 2005Sep 26 2005We evaluate the low-temperature cutoff for quantum interference 1/tf induced in a d-wave superconductor by the diffusion enhanced quasiparticle interactions in the presence of disorder. We carry out our analysis in the framework of the non-linear sigma-model ... More

Implementation of a two-qubit controlled-U gate based on unconventional geometric phase with a constant gating timeMay 18 2011We propose an alternative scheme to implement a two-qubits Controlled-U gate in the hybrid system atom-$CCA$ (coupled cavities array). Our scheme results in a constant gating time and, with an adjustable qubit-bus coupling (atom-resonator), one can specify ... More

A Compression-Inspired Framework for Macro DiscoveryNov 24 2017Feb 03 2019In this paper we consider the problem of how a reinforcement learning agent tasked with solving a set of related Markov decision processes can use knowledge acquired early in its lifetime to improve its ability to more rapidly solve novel, but related, ... More

A Compression-Inspired Framework for Macro DiscoveryNov 24 2017Feb 22 2019In this paper we consider the problem of how a reinforcement learning agent tasked with solving a set of related Markov decision processes can use knowledge acquired early in its lifetime to improve its ability to more rapidly solve novel, but related, ... More

Berry phase of magnons in textured ferromagnetsMar 01 2005We study the energy spectrum of magnons in a ferromagnet with topologically nontrivial magnetization profile. In the case of inhomogeneous magnetization corresponding to a metastable state of ferromagnet, the spin-wave equation of motion acquires a gauge ... More

Unstable and elusive superconductorsMay 28 2015We briefly review earlier and report original experimental results in the context of metastable or possible superconducting materials. We show that applied electric field induces conducting state in Copper Chloride (CuCl) whose characteristics resemble ... More

All harmonic 2-spheres in the unitary group, completely explicitlyNov 07 2008Sep 01 2009We give a completely explicit formula for all harmonic maps of finite uniton number from a Riemann surface to the unitary group U(n) in any dimension, and so all harmonic maps from the 2-sphere, in terms of freely chosen meromorphic functions on the surface ... More

Separating Use and Reuse to Improve BothFeb 01 2019Context: Trait composition has inspired new research in the area of code reuse for object oriented (OO) languages. One of the main advantages of this kind of composition is that it makes possible to separate subtyping from subclassing; which is good for ... More

Full Optical Fiber Link Characterization with the BSS-LassoJun 08 2018Dec 29 2018Manipulation of the detected backscattered Rayleigh signal inside the bandwidth of a frequency-swept optical sub-carrier propagating into an optical fiber permits an efficient localization of faults through a Fourier operator. When the bandwidth is restricted, ... More