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Results for "Júnior Diniz Toniato"

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Modelo Análogo Acústico ao Buraco Negro de SchwarzschildApr 13 2011Um fluido em movimento pode agir sobre o som da mesma forma que os espa\c{c}o-tempos curvos podem influenciar na trajet\'oria da luz na relatividade geral. Com isso, pode-se descrever a propaga\c{c}\~ao dessas ondas sonoras atrav\'es de uma m\'etrica ... More
The description of gravitational waves in geometric scalar gravityMay 14 2019It is investigated the gravitational waves phenomena in the geometric scalar theory of gravity (GSG), a class of theories such that gravity is described by a single scalar field. The associated physical metric describing the spacetime is constructed from ... More
Gravitational waves in geometric scalar gravityJul 04 2016Oct 18 2016We investigate the gravitational waves phenomena in the geometric scalar theory of gravity (GSG) that belongs to a class of theories such that gravity is described by a single scalar field. The associated physical metric describing the spacetime is constructed ... More
The effect of the domain topology on the number of positive solutions of an elliptic Kirchhoff problemApr 16 2013Using minimax methods and Lusternik-Schnirelmann theory, we study multiple positive solutions for the Schr\"{o}dinger - Kirchhoff equation $$ M\left(\dis\int_{\Omega_{\lambda}}|\nabla u|^{2}dx+\dis\int_{\Omega_{\lambda}}u^{2}dx\right)\left[-\Delta u + ... More
Free structures in division ringsAug 29 2013Makar-Limanov's conjecture states that if a division ring D is finitely generated and infinite dimensional over its center k then D contains a free k-subalgebra of rank 2. In this work, we will investigate the existence of such structures in D, the division ... More
The optimal multilinear Bohnenblust-Hille constants: a computational solution for the real caseDec 08 2017Jun 19 2018The Bohnenblust-Hille inequality for $m$-linear forms was proven in 1931 as a generalization of the famous 4/3-Littlewood inequality. The optimal constants (or at least their asymptotic behavior as $m$ grows) is unknown, but significant for applications. ... More
More about scalar gravityMay 31 2016We discuss a class of models for gravity based on a scalar field. The models include and generalize the old approach by Nordstr\"om which predated and in some way inspired General Relativity. The class include also a model that we have recently introduced ... More
On mono-unary algebras corresponding to n-ary groupoidsMay 02 2017Mar 06 2018In this paper we modify and generalize a construction presented by Novotn\'y: given a groupoid (a set equipped with a binary operation), it is defined a mono-unary algebra corresponding to that specific groupoid. We shall introduce and study a functor ... More
Complex-mass shell renormalization of the higher-derivative electrodynamicsJan 26 2016Aug 25 2016We consider a higher-derivative extension of QED modified by the addition of a gauge-invariant dimension-6 kinetic operator in the U(1) gauge sector. The Feynman diagrams at one-loop level are then computed. The modification in the spin-1 sector leads ... More
An embedded measurement system for electrical characterization of EGFET as pH sensorMar 13 2013Oct 14 2013This work presents the development of an electronic system for the electrical characterization of pH sensors based on the extended gate field effect transistor (EGFET). We designed an electronic circuit with a microcontroller (PIC15F14K50) as the main ... More
Identities and isomorphisms of finite-dimensional graded simple algebrasApr 04 2018Jun 07 2018Let $\mathbb F$ be an algebraically closed field, $G$ be an abelian group, and let $A$ and $B$ be arbitrary finite-dimensional $G$-graded simple algebras over $\mathbb F$. We prove that $A$ and $B$ are isomorphic if, and only if, they satisfy the same ... More
Applications of Jarzynski's relation in lattice gauge theoriesOct 27 2016Jarzynski's equality is a well-known result in statistical mechanics, relating free-energy differences between equilibrium ensembles with fluctuations in the work performed during non-equilibrium transformations from one ensemble to the other. In this ... More
SU(2) with fundamental fermions and scalarsOct 30 2017We present preliminary results on the lattice simulation of an SU(2) gauge theory with two fermion flavors and one strongly interacting scalar field, all in the fundamental representation of SU(2). The motivation for this study comes from the recent proposal ... More
Jarzynski's theorem for lattice gauge theoryApr 19 2016Aug 12 2016Jarzynski's theorem is a well-known equality in statistical mechanics, which relates fluctuations in the work performed during a non-equilibrium transformation of a system, to the free-energy difference between two equilibrium ensembles. In this article, ... More
Condition number and matricesMar 13 2017It is well known the concept of the condition number $\kappa(A) = \|A\|\|A^{-1}\|$, where $A$ is a $n \times n$ real or complex matrix and the norm used is the spectral norm. Although it is very common to think in $\kappa(A)$ as "the" condition number ... More
About a new family of sequencesJul 20 2016First we define a new kind of function over $\mathbb{N}$. For each $i\in\mathbb{N}$ we have an associated function, which will be called $S_i$ . Then we define a new kind of sequence, to be made from the functions $S_i$ . Finally, we will see that some ... More
Comment on the paper "Random Quantum Circuits are Approximate 2-designs"Jun 22 2010In [A.W. Harrow and R.A. Low, Commun. Math. Phys. 291, 257-302 (2009)], it was shown that a quantum circuit composed of random 2-qubit gates converges to an approximate quantum 2-design in polynomial time. We point out and correct a flaw in one of the ... More
Microscopic origin of subthermal magnons and the spin Seebeck effectJan 08 2016May 12 2016Recent experimental evidence points to low-energy magnons as the primary contributors to the spin Seebeck effect. This spectral dependence is puzzling since it is not observed on other thermocurrents in the same material. Here, we argue that the physical ... More
Will-Nordtvedt PPN formalism applied to renormalization group extensions of general relativityJun 27 2017Aug 29 2017Here we apply the full Will-Nordtvedt version of the Parameterized Post-Newtonian (PPN) formalism to a class of General Relativity extensions that are based on nontrivial renormalization group (RG) effects at large scales. We focus on a class of models ... More
Multiple solutions for a generalized Schrödinger problem with 'concave-convex' nonlinearitiesDec 18 2018A class of generalized Schr\"{o}dinger elliptic problems involving concave-convex and other types of nonlinearities is studied. A reasonable overview about the set of solutions is provided when the parameters involved in the equation assume different ... More
Multiplicity of positive solutions for an equation with degenerate nonlocal diffusionJul 05 2018Even without a variational background, a multiplicity result of positive solutions with ordered $L^{p}(\Omega)$-norms is provided to the following boundary value problem \begin{equation*} \left \{ \begin{array}{ll} -a(\int_{\Omega}u^{p}dx)\Delta u = f(u) ... More
Positive solutions for Kirchhoff problems with vanishing nonlocal termSep 19 2017Apr 27 2018In this paper we study the Kirchhoff problem \begin{equation*} \left \{ \begin{array}{ll} -m(\| u \|^{2})\Delta u = f(u) & \mbox{in $\Omega$,} u=0 & \mbox{on $\partial\Omega$,} \end{array}\right. \end{equation*} in a bounded domain, allowing the function ... More
On a generalized Kirchhoff equation with sublinear nonlinearitiesMar 09 2016In this paper we consider a generalized Kirchhoff? equation in a bounded domain under the effect of a sublinear nonlinearity. Under suitable assumptions on the data of the problem we show that, with a simple change of variable, the equation can be reduced ... More
On a generalized timoshenko-kirchhoff equationMay 09 2017In this paper we consider a generalized fourth order nonlinear Kirchhoff equation in a bounded domain in $\mathbb R^{N}, N\geq2$ under Navier boundary conditions and with sublinear nonlinearity. We employ a change of variable which reduces the problem ... More
A Register Allocation Algorithm in the Presence of Scalar Replacement for Fine-Grain Configurable ArchitecturesOct 25 2007The aggressive application of scalar replacement to array references substantially reduces the number of memory operations at the expense of a possibly very large number of registers. In this paper we describe a register allocation algorithm that assigns ... More
Mass of the Fayet Hypermultiplet Induced by a Central Charge ConstraintAug 06 2001Dec 17 2001We show that the mass of the Fayet hypermultiplet, which represents the matter sector of N=2 supersymmetric Yang-Mills theory, may be induced through a generalization of the central charge constraint usually proposed in the literature. This mass showing ... More
Induced mass in N=2 super Yang-Mills theoriesNov 06 2002The masses of the matter fields of N=2 Super-Yang-Mills theories can be defined as parameters of deformed supersymmetry transformations. The formulation used involves central charges for the matter fields. The explicit form of the deformed supersymmetry ... More
Sparse latent factor models with interactions: Analysis of gene expression dataDec 06 2013Sparse latent multi-factor models have been used in many exploratory and predictive problems with high-dimensional multivariate observations. Because of concerns with identifiability, the latent factors are almost always assumed to be linearly related ... More
Central Polynomials with Involution of $M_{1,1}(E)$Jul 04 2014Jul 16 2014Let $K$ be an infinite field of characteristic $\neq 2$. In this article we study the $*$-space $C(R,*)$ of central polynomials with involution of the $K$-algebra $R= M_{1,1}(E)$, with an involution ($*$) obtanied from a superinvolution on $M_{1,1}(F)$ ... More
Gauss-Bonnet theorem in sub-Riemannian Heisenberg space $H^1$Oct 26 2012We prove a version of Gauss-Bonnet theorem in sub-Riemannian Heisenberg space $H^1$. The sub-Riemannian distance makes $H^1$ a metric space and consenquently with a spherical Hausdorff measure. Using this measure, we define a Gaussian curvature at points ... More
Study of a class of generalized Schrödinger equationsJul 27 2018Oct 23 2018A class of generalized Schr\"{o}dinger problems in bounded domain is studied. A complete overview of the set of solutions is provided, depending on the values assumed by parameters involved in the problem. In order to obtain the results, we combine monotony, ... More
The Exact Foldy-Wouthuysen Transformation for a Dirac Theory RevisitedDec 31 2018Mar 11 2019The Exact Foldy-Wouthuysen transformation (EFWT) method is generalized here. In principle, it is not possible to construct the EFWT to any Hamiltonian. The transformation conditions are the same but the involution operator has a new form. We took a special ... More
Abelian Noncyclic Orbit Codes and Multishot Subspace CodesOct 18 2018In this paper we characterize the orbit codes as geometrically uniform codes. This characterization is based on the description of all isometries over a projective geometry. In addition, the Abelian orbit codes are defined and a new construction of Abelian ... More
The Exact Foldy-Wouthuysen Transformation for a Dirac Theory RevisitedDec 31 2018The Exact Foldy-Wouthuysen transformation (EFWT) method is generalized here. In principle, it is not possible to construct the EFWT to any Hamiltonian. The transformation conditions are the same but the involution operator has a new form. We took a special ... More
To square root the Lagrangian or not: an underlying geometrical analysis on classical and relativistic mechanical modelsMay 02 2019The geodesic has a fundamental role in physics and in mathematics: roughly speaking, it represents the curve that minimizes the arc length between two points on a manifold. We analyze a basic but misinterpreted difference between the Lagrangian that gives ... More
A Semiotics-inspired Domain-Specific Modeling Language for Complex Event Processing RulesAug 17 2017Complex Event Processing (CEP) is one technique used to the handling data flows. It allows pre-establishing conditions through rules and firing events when certain patterns are found in the data flows. Because the rules for defining such patterns are ... More
Lineability of the set of bounded linear non-absolutely summing operatorsNov 01 2008Feb 17 2009In this note we solve, except for extremely pathological cases, a question posed by Puglisi and Seoane-Sepulveda on the lineability of the set of bounded non-absolutely summing linear operators. We also show how the idea of the proof can be adapted to ... More
Primeness property for central polynomials of verbally prime P.I. algebrasJul 04 2014Jul 07 2014Let $f$ and $g$ be two noncommutative polynomials in disjoint sets of variables. An algebra $A$ is verbally prime if whenever $f\cdot g$ is an identity for $A$ then either $f$ or $g$ is also an identity. As an analogue of this property Regev proved that ... More
Graded Isomorphisms on Upper Block Triangular Matrix AlgebrasAug 15 2017We describe the graded isomorphisms of rings of endomorphisms of graded flags over graded division algebras. As a consequence describe the isomorphism classes of upper block triangular matrix algebras (over an algebraically closed field of characteristic ... More
Primeness property for graded central polynomials of verbally prime algebrasJul 13 2016Aug 08 2016Let $F$ be an infinite field. The primeness property for central polynomials of $M_n(F)$ was proved by A. Regev, i.e., if the product of two polynomials in distinct variables is central then each factor is also central. In this paper we consider the analogous ... More
Specialized Support Vector Machines for open-set recognitionJun 13 2016Recently, the open-set recognition problem has received more attention by the machine learning community given that most classification problems in practice require an open-set treatment. Thus far, many classifiers were mostly developed for the closed-set ... More
The Exact Foldy-Wouthuysen Transformation for a Dirac Theory with the complete set of CPT-Lorentz violating termsJun 20 2014The exact Foldy-Wouthuysen transformation is performed in order to study the Dirac field interacting with many possible external fields associated with CPT-Lorentz violation. We also derived the calculation of equations of motion as well as the generalized ... More
On the Graded Identities for Elementary Gradings in Matrix Algebras over Infinite FieldsJul 04 2014We find a basis for the $G$-graded identities of the $n\times n$ matrix algebra $M_n(K)$ over an infinite field $K$ of characteristic $p>0$ with an elementary grading such that the neutral component corresponds to the diagonal of $M_n(K)$.
Specht property for the $2$-graded identities of $B_m$Jan 13 2016Let $K$ be a field of characteristic zero and $V$ a vector space of dimension $m>1$ with a nondegenerate symmetric bilinear form $f:V\times V \rightarrow K$. The Jordan algebra $B_m=K\oplus V$ of the form $f$ is a superalgebra with this decomposition. ... More
Identities and central polynomials of real graded division algebrasJan 05 2017Let $A$ be a finite dimensional real algebra with a division grading by a finite abelian group $G$. In this paper we provide finite basis for the $T_G$-ideal of graded identities and for the $T_G$-space of graded central polynomials for $A$.
Spin-orbit coupling and the static polarizability of single-wall carbon nanotubesDec 11 2013We calculate the static longitudinal polarizability of single-wall carbon nanotubes in the long wavelength limit taking into account spin-orbit effects. We use a four-orbital orthogonal tight-binding formalism to describe the electronic states and the ... More
Vortex and disclination structures in a nematic-superconductor stateJun 21 2016The nematic-superconductor state, an example of a quantum liquid crystal that breaks gauge as well as rotation invariance, was conjecture to exist in the pseudogap regime of the cuprates high $T_c$ superconductors. We present a detailed study of the structure ... More
A Bayesian hidden Markov mixture model to detect overexpressed chromosome regionsNov 20 2015Sep 26 2016In this study, we propose a hidden Markov mixture model for the analysis of gene expression measurements mapped to chromosome locations. These expression values represent preprocessed light intensities observed in each probe of Affymetrix oligonucleotide ... More
Comparison between continuous and discrete doses using Escalation With Overdose ControlAug 16 2017Although there is an extensive statistical literature showing the disadvantages of discretizing continuous variables, categorization is a common practice in clinical research which results in substantial loss of information. A large collection of methods ... More
$2$-Graded Identities for the Tensor Square of the Grassmann AlgebraJul 04 2014We consider the algebra $E\otimes E$ over an infinite field equipped with a $\mathbb{Z}_2$-grading where the canonical basis is homogeneous and prove that in various cases the graded identites are just the ordinary ones. If the grading is a non-canonical ... More
Helicoidal Fields and Spin Polarized Currents in CNT-DNA HybridsDec 17 2011We report on theoretical studies of electronic transport in the archetypical molecular hybrid formed by DNA wrapped around single-walled carbon nanotubes (CNTs). Using a Green's function formalism in a $\pi$-orbital tight-binding representation, we investigate ... More
Graphene-based spin switch device via modulated Rashba field and strainDec 17 2015Sep 26 2016We investigate the spin-resolved transport in a two-terminal zigzag graphene nanoribbon device with two independent gate induced Rashba spin-orbit coupling regions and in the presence of strain. By employing a recursive Green's function technique to the ... More
Set-Membership Adaptive Algorithms based on Time-Varying Error Bounds for Interference SuppressionJan 01 2013This work presents set-membership adaptive algorithms based on time-varying error bounds for CDMA interference suppression. We introduce a modified family of set-membership adaptive algorithms for parameter estimation with time-varying error bounds. The ... More
Spaceability in Banach and quasi-Banach sequence spacesMay 04 2010Let $X$ be a Banach space. We prove that, for a large class of Banach or quasi-Banach spaces $E$ of $X$-valued sequences, the sets $E-\bigcup _{q\in\Gamma}\ell_{q}(X)$, where $\Gamma$ is any subset of $(0,\infty]$, and $E-c_{0}(X)$ contain closed infinite-dimensional ... More
Specialized Support Vector Machines for open-set recognitionJun 13 2016Nov 01 2016Often, when dealing with real-world recognition problems, we do not need, and often cannot have, knowledge of the entire set of possible classes that might appear during operational testing. Moreover, sometimes some of these classes may be ill-sampled, ... More
Analysis of Maxwell Equations in a Gravitational FieldJun 16 2000In a gravitational field, we analyze the Maxwell equations, the correponding electromagnetic wave and continuity equations. A particular solution for parellel electric and magnetic fields in a gravitational background is presented. These solutions also ... More
Ultrafast QND measurements based on diamond-shape artificial atomFeb 15 2013We propose a Quantum Non Demolition (QND) read-out scheme for a superconducting artificial atom coupled to a resonator in a circuit QED architecture, for which we estimate a very high measurement fidelity without Purcell effect limitations. The device ... More
Positive Polynomials on closed boxesSep 26 2016We present two different proofs that positive polynomials on closed boxes of $\mathbb{R}^2$ can be written as bivariate Bernstein polynomials with strictly positive coefficients. Both strategies can be extended to prove the analogous result for polynomials ... More
Controllable Spin-Charge Transport in Strained Graphene Nanoribbon DevicesMay 11 2014We theoretically investigate the spin-charge transport in two-terminal device of graphene nanoribbons in the presence of an uniform uniaxial strain, spin-orbit coupling, exchange field and smooth staggered potential. We show that the direction of applied ... More
Topological nature of in-gap bound states in disordered large-gap monolayer transition metal dichalcogenidesJan 25 2016We propose a physical model based on disordered (a hole punched inside a material) monolayer transition metal dichalcogenides (TMDs) to demonstrate a large-gap quantum valley Hall insulator. We find an emergence of bound states lying inside the bulk gap ... More
Engineering the Quantum Anomalous Hall Effect in Graphene with Uniaxial StrainsOct 16 2013Nov 13 2013We theoretically investigate the manipulation of the quantum anomalous Hall effect (QAHE) in graphene by means of the uniaxial strain. The values of Chern number and Hall conductance demonstrate that the strained graphene in presence of Rashba spin-orbit ... More
Triple seesaw mechanismFeb 09 2010On fitting the type II seesaw mechanism into the type I seesaw mechanism, we obtain a formula to the neutrino masses which get suppressed by high-scale $M^3$ in its denominator. As a result, light neutrinos are naturally obtained with new physics at TeV ... More
A note on lineabilityMay 16 2009In this note we answer a question concerning lineability of the set of non-absolutely summing operators.
From Kondo to local singlet state in graphene nanoribbons with magnetic impuritiesOct 04 2017A detailed analysis of the Kondo effect of a magnetic impurity in a zigzag graphene nanoribbon is addressed. An adatom is coupled to the graphene nanoribbon via a hybridization amplitude $\Gamma_{imp}$ in a hollow or top site configuration. In addition, ... More
Comparing probabilistic predictive models applied to footballMay 11 2017We propose two Bayesian multinomial-Dirichlet models to predict the final outcome of football (soccer) matches and compare them to three well-known models regarding their predictive power. All the models predicted the full-time results of 1710 matches ... More
Zero-field and time-reserval-symmetry-broken topological phase transitions in grapheneSep 29 2014Jul 01 2015We propose a quantum electronic device based on strained graphene nanoribbon. Mechanical strain, internal exchange field and spin-orbit couplings (SOCs) have been exploited as principle parameters to tune physical properties of the device. We predict ... More
Quantum cosmology in an anisotropic n-dimensional universeNov 11 2016We investigate quantum cosmological models in an n-dimensional anisotropic universe in the presence of a massless scalar field. Our basic inspiration comes from Chodos and Detweiler's classical model which predicts an interesting behaviour of the extra ... More
A Review of Dynamic NURBS ApproachMar 26 2013Dynamic NURBS, also called D-NURBS, is a known dynamic version of the nonuniform rational B-spline (NURBS) which integrates free-form shape representation and a physically-based model in a unified framework. More recently, computer aided design (CAD) ... More
Specialized Support Vector Machines for Open-set RecognitionJun 13 2016Nov 14 2018Often, when dealing with real-world recognition problems, we do not need, and often cannot have, knowledge of the entire set of possible classes that might appear during operational testing. Sometimes, some of these classes may be ill-sampled, not sampled ... More
Transformation of UML Behavioral Diagrams to Support Software Model CheckingApr 03 2014Unified Modeling Language (UML) is currently accepted as the standard for modeling (object-oriented) software, and its use is increasing in the aerospace industry. Verification and Validation of complex software developed according to UML is not trivial ... More
Multiplicity of solutions for resonant and non-resonant asymptotically linear elliptic problemsAug 10 2017Sep 13 2018Results about existence of a signed ground state solution and multiple solutions (if $f$ is odd with respect to the second variable) are proven for a class of asymptotically linear elliptic problems involving a Carath\'eodory type nonlinearity satisfying ... More
An In-Depth Study on Open-Set Camera Model IdentificationApr 11 2019Camera model identification refers to the problem of linking a picture to the camera model used to shoot it. As this might be an enabling factor in different forensic applications to single out possible suspects (e.g., detecting the author of child abuse ... More
KeV right-handed neutrinos from type II seesaw mechanism in a 3-3-1 modelMar 02 2009We adapt the type II seesaw mechanism to the framework of the 3-3-1 model with right-handed neutrinos. We emphasize that the mechanism is capable of generating small masses for the left-handed and right-handed neutrinos and the structure of the model ... More
Blind Adaptive Interference Suppression Based on Set-Membership Constrained Constant-Modulus Algorithms with Time-Varying BoundsDec 29 2012This work presents blind constrained constant modulus (CCM) adaptive algorithms based on the set-membership filtering (SMF) concept and incorporates dynamic bounds {for interference suppression} applications. We develop stochastic gradient and recursive ... More
RedThreads: An Interface for Application-level Fault Detection/Correction through Adaptive Redundant MultithreadingOct 06 2016In the presence of accelerated fault rates, which are projected to be the norm on future exascale systems, it will become increasingly difficult for high-performance computing (HPC) applications to accomplish useful computation. Due to the fault-oblivious ... More
RedThreads: An Interface for Application-level Fault Detection/Correction through Adaptive Redundant MultithreadingOct 06 2016Jan 17 2017In the presence of accelerated fault rates, which are projected to be the norm on future exascale systems, it will become increasingly difficult for high-performance computing (HPC) applications to accomplish useful computation. Due to the fault-oblivious ... More
Graded identities of simple real graded division algebrasOct 09 2015Feb 26 2016Let A and B be finite dimensional simple real algebras with division gradings by an abelian group G. In this paper we give necessary and sufficient conditions for the coincidence of the graded identities of A and B. We also prove that every finite dimensional ... More
Feeding Versus Feedback in AGNs from Near-Infrared IFU Observations: The Case of Mrk 766Aug 25 2014We have mapped the emission-line flux distributions and ratios as well as the gaseous kinematics of the inner 450 pc radius of the Seyfert 1 galaxy Mrk 766 using integral field near-IR J- and Kl-band spectra obtained with the Gemini nifs at a spatial ... More
Quantum cosmology in an anisotropic n-dimensional universeNov 11 2016Jan 31 2018We investigate quantum cosmological models in an n-dimensional anisotropic universe in the presence of a massless scalar field. Our basic inspiration comes from Chodos and Detweiler's classical model which predicts an interesting behaviour of the extra ... More
Specialized Support Vector Machines for Open-set RecognitionJun 13 2016May 02 2019Often, when dealing with real-world recognition problems, we do not need, and often cannot have, knowledge of the entire set of possible classes that might appear during operational testing. Sometimes, some of these classes may be ill-sampled, not sampled ... More
Application-Specific System Processor for the SHA-1 Hash AlgorithmDec 10 2018This work proposes an Application-Specific System Processor (ASSP) hardware for the Secure Hash Algorithm 1 (SHA-1) algorithm. The proposed hardware was implemented in a Field Programmable Gate Array (FPGA) Xilinx Virtex 6 xc6vlx240t-1ff1156. The throughput ... More
Electromagnetic waves, gravitational coupling and duality analysisOct 27 2005In this letter we introduce a particular solution for parallel electric and magnetic fields, in a gravitational background, which satisfy free-wave equations and the phenomenology suggested by astrophysical plasma physics. These free-wave equations are ... More
The Likelihood Ratio Test and Full Bayesian Significance Test under small sample sizes for contingency tablesNov 27 2016Aug 10 2017Hypothesis testing in contingency tables is usually based on asymptotic results, thereby restricting its proper use to large samples. To study these tests in small samples, we consider the likelihood ratio test and define an accurate index, the P-value, ... More
Effect of a Dissipative Term in the Drift Waves Hamiltonian SystemMay 07 2015This paper analyses the Hamiltonian model of drift waves which describes the chaotic transport of particles in the plasma confinement. With one drift wave the system is integrable and it presents stable orbits. When one wave is added the system may or ... More
An Adaptable Maturity Strategy for Information SecurityJul 17 2018The lack of security in information systems has caused numerous financial and moral losses to several organizations. The organizations have a series of information security measures recommended by literature and international standards. However, the implementation ... More
Role-separating ordering in social dilemmas controlled by topological frustrationFeb 27 2017"Three is a crowd" is an old proverb that applies as much to social interactions, as it does to frustrated configurations in statistical physics models. Accordingly, social relations within a triangle deserve special attention. With this motivation, we ... More
Identification of Dynamic Systems with Interval ArithmeticAug 08 2017This paper aims to identify three electrical systems: a series RLC circuit, a motor/generator coupled system, and the Duffing-Ueda oscillator. In order to obtain the system's models was used the error reduction ratio and the Akaike information criterion. ... More
Time-Reversal Symmetry Breaking and Decoherence in Chaotic Dirac BilliardsSep 21 2016In this work, we perform a statistical study on Dirac Billiards in the extreme quantum limit (a single open channel on the leads). Our numerical analysis uses a large ensemble of random matrices and demonstrates the preponderant role of dephasing mechanisms ... More
Simulation of Dynamical Systems with Interval Analysis: A case study of RLC Circuit (Simulação de Sistemas Dinâmicos com Análise Intervalar: Um Estudo De Caso Com O Circuito RLC)Dec 07 2016Differences between computer simulation of dynamical systems and laboratory experiments are common in teaching and research in engineering. Normally, numerical inaccuracy and the non-ideal behaviour of the devices involved in the experiment are the most ... More
Depth-Sensing Indentation on REBa2Cu3O(7-δ) Single Crystals obtained from Xenotime MineralMay 30 2012A natural mixture of heavy rare earths oxides extracted from xenotime mineral have been used to prepare large single crystals of high-temperature REBa2Cu3O(7-\delta) superconductor grown using the CuO-BaO self-flux method. Its mechanical properties along ... More
Improving the management of cost and scope in software projects using agile practicesMar 08 2013While organizations want to develop software products with reduced cost and flexible scope, stories about the applicability of agile practices to improve project development and performance in the software industry are scarce and focused on specific methodologies ... More
Bistability, softening, and quenching of magnetic moments in Ni-filled carbon nanotubesSep 03 2010The authors apply first-principles calculations to investigate the interplay between structural, electronic, and magnetic properties of nanostructures composed of narrow nanotubes filled with metallic nanowires. The focus is on the structural and magnetic ... More
Web of Science: showing a bug today that can mislead scientific research output's predictionNov 04 2016As it happened in all domains of human activities, economic issues and the increase of people working in scientific research have altered the way scientific production is evaluated so as the objectives of performing the evaluation. Introduced in 2005 ... More
The asymptotic growth of the constants in the Bohnenblust-Hille inequality is optimalAug 07 2011Aug 14 2011We provide (for both the real and complex settings) a family of constants, $% (C_{m})_{m\in \mathbb{N}}$, enjoying the Bohnenblust--Hille inequality and such that $\displaystyle\lim_{m\rightarrow \infty}\frac{C_{m}}{C_{m-1}}=1$, i.e., their asymptotic ... More
A Learning Approach to Enhance Assurances for Real-Time Self-Adaptive SystemsApr 03 2018The assurance of real-time properties is prone to context variability. Providing such assurance at design time would require to check all the possible context and system variations or to predict which one will be actually used. Both cases are not viable ... More
First variation of the Hausdorff measure of non-horizontal submanifolds in stratified Lie groupsApr 05 2014Dec 23 2015We determine necessary conditions for a non-horizontal submanifold of a sub-Riemannian stratified Lie group to be of minimal measure. We calculate the first variation of the measure for a non-horizontal submanifold and find that the minimality condition ... More
Using the youngest asteroid clusters to constrain the Space Weathering and Gardening rate on S-complex asteroidsApr 22 2010We have extended our earlier work on space weathering of the youngest S-complex asteroid families to include results from asteroid clusters with ages <10^6 years and to newly identified asteroid pairs with ages <5x10^5 years. We have identified three ... More
First principles modeling of defects in the Al_2O_3/In_0.53Ga_0.47As systemSep 24 2016Density functional theory paired with a first order many-body perturbation theory correction is applied to determine formation energies and charge transition energies for point defects in bulk In_0.53Ga_0.47As and for models of the In_0.53Ga_0.47As/Al_2O_3 ... More
The seesaw mechanism at TeV scale in the 3-3-1 model with right-handed neutrinosJun 18 2008We implement the seesaw mechanism in the 3-3-1 model with right-handed neutrinos. This is accomplished by the introduction of a scalar sextet into the model and the spontaneous violation of the lepton number. We identify the Majoron as a singlet under ... More
Lower bounds for the constants in the Bohnenblust-Hille inequality: the case of real scalarsNov 14 2011Nov 18 2011The Bohnenblust-Hille inequality was obtained in 1931 and (in the case of real scalars) asserts that for every positive integer $N$ and every $m$-linear mapping $T:\ell_{\infty}^{N}\times...\times\ell_{\infty}^{N}\rightarrow \mathbb{R}$ one has (\sum\limits_{i_{1},...,i_{m}=1}^{N}|T(e_{i_{^{1}}},...,e_{i_{m}})|^{\frac{2m}{m+1}})^{\frac{m+1}{2m}}\leq ... More