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This paper characterizes the dynamics of the positive solutions of ::: a class of sublinear parabolic cooperative systems whose analysis is ::: imperative for ascertaining the dynamics of wider classes of ::: sublinear cooperative and superlinear indefinite Reaction-Diffusion ::: systems, like those introduced by Lopez-Gomez and ::: Molina-Meyer [15].
|
The aim of this work is to ascertain the characterization of the existence of coexistence states for a class of cooperative systems supported by the study of an associated non-local equation through classical variational methods. Thanks to those results, we are able to obtain the blow-up behavior of the solutions in the whole domain for certain values of the main continuation parameter.
|
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
|
eng_Latn
| 797,228 |
de Sitter thermodynamics in the canonical ensemble
|
Kerr-de Sitter spacetime, Penrose process and the generalized area theorem
|
Methodological constraints in the molecular biodiversity study of a thermomineral spring cyanobacterial mat: a case study
|
eng_Latn
| 797,259 |
In this paper we introduce generalised Markov numbers and extend the classical Markov theory for the discrete Markov spectrum to the case of generalised Markov numbers. In particular we show recursive properties for these numbers and find corresponding values in the Markov spectrum. Further we construct a counterexample to the generalised Markov uniqueness conjecture. The proposed generalisation is based on geometry of numbers. It substantively uses lattice trigonometry and geometric theory of continued numbers.
|
We study the Lyapunov exponents $\Lambda(x)$ for Markov dynamics as a function of path determined by $x\in \mathbb RP^1$ on a binary planar tree, describing the Markov triples and their"tropical"version - Euclid triples. We show that the corresponding Lyapunov spectrum is $[0, \ln \varphi]$, where $\varphi$ is the golden ratio, and prove that on the Markov-Hurwitz set $\mathbb{X}$ of the most irrational numbers the corresponding function $\Lambda_\mathbb{X}$ is monotonically increasing and in the Farey parametrization is convex.
|
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
|
eng_Latn
| 797,271 |
Diffuse neurofibroma is an uncommon form of neurofibroma, which occurs principally in children and young adults. This tumor presents most often in the head and neck region. We have seen a young girl with a diffuse neurofibroma on the lower back that was successfully excised.
|
A 22-year-old man presented with a large, soft, compressible swelling in the right occipito-parietal region. Fine needle aspiration cytology revealed blood only. The lesion was excised and histopathology studies revealed it to be a diffuse neurofibroma.
|
We study aspherical manifolds that do not support Anosov diffeomorphisms. Weakening conditions of Gogolev and Lafont, we show that the product of an infranilmanifold with finitely many aspherical manifolds whose fundamental groups have trivial center and finite outer automorphism group does not support Anosov diffeomorphisms. In the course of our study, we obtain a result of independent group theoretic and topological interest on the stability of the Hopf property, namely, that the product of finitely many Hopfian groups with trivial center is Hopfian.
|
eng_Latn
| 797,281 |
In a recent article [10], the authors proved that the non-relativistic Schr\"odinger operator with a generic honeycomb lattice potential has conical (Dirac) points in its dispersion surfaces. These conical points occur for quasi-momenta, which are located at the vertices of the Brillouin zone, a regular hexagon. In this paper, we study the time-evolution of wave-packets, which are spectrally concentrated near such conical points. We prove that the large, but finite, time dynamics is governed by the two-dimensional Dirac equations.
|
We prove a classification result for ground state solutions of the critical Dirac equation on $\mathbb{R}^n$, $n\geq2$. By exploiting its conformal covariance, the equation can be posed on the round sphere $\mathbb{S}^n$ and the non-zero solutions at the ground level are given by Killing spinors, up to conformal diffeomorphisms. Moreover, such ground state solutions of the critical Dirac equation are also related to the Yamabe equation for the sphere, for which we crucially exploit some known classification results.
|
We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.
|
eng_Latn
| 797,291 |
We demonstrate a new type of basin boundary for typical chaotic dynamical systems. For the case of a two dimensional map, this boundary has the character of the graph of a function that is smooth and differentiable except on a set of fractal dimensions less than one. In spite of the basin boundary being smooth {open_quotes}almost everywhere,{close_quotes} its fractal dimension exceeds one (implying degradation of one{close_quote}s ability to predict the attractor an orbit approaches in the presence of small initial condition uncertainty). We call such a boundary {ital sporadically fractal}. {copyright} {ital 1999} {ital The American Physical Society}
|
We study fluctuational transitions in a discrete dynamical system that has two co-existing attractors in phase space, separated by a fractal basin boundary which may be either locally-disconnected or locally-connected. It is shown that, in each case, transitions occur via an accessible point on the boundary. The complicated structure of paths inside the locally-disconnected fractal boundary is determined by a hierarchy of homoclinic original saddles. The most probable escape path from a regular attractor to the fractal boundary is found for the each type of boundary using both statistical analyses of fluctuational trajectories and the Hamiltonian theory of fluctuations.
|
Every function of n inputs can be efficiently computed by a complete network of n processors in such a way that: If no faults occur, no set of size t n /2 of players gets any additional information (other than the function value), Even if Byzantine faults are allowed, no set of size t n /3 can either disrupt the computation or get additional information. Furthermore, the above bounds on t are tight!
|
eng_Latn
| 797,295 |
V-variable fractals and superfractals have recently been introduced by Barnsley [Barnsley Michael, Hutchinson John, Stenflo Orjan. A fractal valued random iteration algorithm and fractal hierarchy. Fractals 2005;13(2):111–46 [MR2151094 (2006b:28014)]] to the world of mathematics and computer graphics. In this paper, we introduce superior iterates to study the role of contractive and non-contractive operators in relation to superfractals. A modified algorithm along with details of computer implementation is also provided to compute V-variable fractals. A brief discussion about the various aspects of the computed figures indicates usefulness of the study.
|
In this paper, we extend Jungck–SP iteration with <inline-formula> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula>–convexity in second sense and define its orbit. We prove the fixed point results for fractal generation via extended iteration and utilize these results to develop algorithms for fractal visualization. Moreover, we present some complex graphs of Julia and Mandelbrot sets in Jungck–SP orbit with <inline-formula> <tex-math notation="LaTeX">$s$ </tex-math></inline-formula>–convexity. We also present some examples to show the variation in images with involved parameters.
|
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
|
eng_Latn
| 797,296 |
A spatial symmetry property of a two-dimensional birth–death process X(t) with constant rates is exploited in order to obtain closed-form expressions for first-passage-time densities through straight-lines x 2 = x 1 + r and for the related taboo transition probabilities. An analogous study is performed on a birth–death process with state-dependent rates that is similar to X(t) in the sense that the ratio of their transition functions is time independent. Examples of applications to double-ended queues and stochastic neuronal modeling are also provided.
|
We consider a bilateral birth-death process having sigmoidal-type rates. A thorough discussion on its transient behaviour is given, which includes studying symmetry properties of the transition probabilities, finding conditions leading to their bimodality, determining mean and variance of the process, and analyzing absorption problems in the presence of 1 or 2 boundaries. In particular, thanks to the symmetry properties we obtain the avoiding transition probabilities in the presence of a pair of absorbing boundaries, expressed as a series.
|
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
|
eng_Latn
| 797,299 |
In this paper, we study locally projectively flat Finsler metrics with constant flag curvature ${\bf K}$. We prove those are totally determined by their behaviors at the origin by solving some nonlinear PDEs. The classifications when ${\bf K}=0$, ${\bf K}=-1$ and ${\bf K} =1$ are given respectively in an algebraic way. Further, we construct a new projectively flat Finsler metric with flag curvature ${\bf K}=1$ determined by a Minkowskian norm with double square roots at the origin. As an application of our main theorems, we give the classification of locally projectively flat spherical symmetric Finsler metrics much easier than before. ----Comments are welcome.
|
Finsler metrics on an open subset in R n with straight geodesics are said to be projective. It is known that the flag curvature of any projective Finsler metric is a scalar function of tangent vectors (the flag curvature must be a constant if it is Riemannian). In this paper, we discuss the classification problem on projective Finsler metrics of constant flag curvature. We express them by a Taylor expansion or an algebraic formula. Many examples constructed in this paper can be used as models in Finsler geometry.
|
Finsler metrics on an open subset in R n with straight geodesics are said to be projective. It is known that the flag curvature of any projective Finsler metric is a scalar function of tangent vectors (the flag curvature must be a constant if it is Riemannian). In this paper, we discuss the classification problem on projective Finsler metrics of constant flag curvature. We express them by a Taylor expansion or an algebraic formula. Many examples constructed in this paper can be used as models in Finsler geometry.
|
eng_Latn
| 797,307 |
In a recent paper [4] a general theory of parameter-invariant integrals in the Calculus of Variations whose Lagrangians involve higher derivatives was developed, and in particular a certain canonical formalism for such problems was discussed. From the point of view of applications it was found that this formalism proved inadequate inas-much as the suggested Hamiltonian function did not depend explicitly on the first derivatives of the positional coordinates. In the present note an alternative Hamiltonian function is defined, which gives rise to a new canonical formalism. The latter is less complicated than the formalism suggested in [4] and is more readily applicable to special problems. A brief discussion of the resulting Hamilton-Jacobi theory is given, and in conclusion the method is illustrated explicitly by means of an example of fairly general character.
|
We study the Hamiltonian formalisms of the second order degenerate Cl\`{e}ment and Sar\i o\u{g}lu-Tekin Lagrangians. The Dirac-Bergmann constraint algorithm is employed while arriving at the total Hamiltonian functions and the Hamilton's equations on the associated momemtum phase spaces whereas the Gotay-Nester-Hinds algorithm is run while investigating the Skinner-Rusk unified formalism on the proper Whitney bundles.
|
In canonical quantization of gravity, the state functional does not seem to depend on time. This hampers the physical interpretation of quantum gravity. I critically examine ten major attempts to circumvent this problem and discuss their shortcomings.
|
eng_Latn
| 797,319 |
We present a method for the numerical computation of invariant manifoids of hyperbolic and pseudohyperbolic fixed points of diffeomorphisms. The derivation of this algorithm is based on well-known properties of (almost) invariant foliations. Numerical results illustrate the performance of our method.
|
1 Generalities.- 2 Filtrations.- 3 Sequences of Filtrations.- 4 Hyperbolic Sets.- 5 Stable Manifolds.- 6 Stable Manifolds for Hyperbolic Sets.- 7 More Consequences of Hyperbolicity.- 8 Stability.- 9 A Potpourri of Stability Results.- 10 Markov Partitions.- List of Notation.
|
We study aspherical manifolds that do not support Anosov diffeomorphisms. Weakening conditions of Gogolev and Lafont, we show that the product of an infranilmanifold with finitely many aspherical manifolds whose fundamental groups have trivial center and finite outer automorphism group does not support Anosov diffeomorphisms. In the course of our study, we obtain a result of independent group theoretic and topological interest on the stability of the Hopf property, namely, that the product of finitely many Hopfian groups with trivial center is Hopfian.
|
eng_Latn
| 797,327 |
In this paper, applying the Horn's fixed point theorems in Banach spaces we obtain a theorem of existence of positive periodic solutions for periodic Kolmogorov type systems with delays. As the applications of this theorem, we study the existence of positive periodic solutions for some periodic Lotka--VOlterra type systems with delays and establish new and practical distinguishing criteria.
|
In this paper, we study two species time-delayed predator–prey Lotka–Volterra type dispersal systems with periodic coefficients, in which the prey species can disperse among n patches, while the density-independent predator species is confined to one of patches and cannot disperse. Sufficient conditions on the boundedness, permanence and existence of positive periodic solution for this systems are established. The theoretical results are confirmed by a special example and numerical simulations.
|
Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.
|
eng_Latn
| 797,334 |
We study a local system associated with a system ℱ of hypergeometric differential equations in two variables of rank 9 with seven parameters a1,a2,a3 and b1,b2,b3,b4. We modify the fundamental syst...
|
We study a hypergeometric function in two variables and a system of hypergeometric differential equations associated with this function. This is a regular holonomic system of rank $9$. We give a fundamental system of solutions to this system in terms of this hypergeometric series. We give circuit matrices along generators of the fundamental group of the complement of its singular locus with respect to our fundamental system.
|
In this short note we prove that if X is a separably rationally connected variety over an algebraically closed field of positive characteristic, then H^1(X, O_X)=0.
|
eng_Latn
| 797,335 |
The strong halfspace theorem for minimal surfaces
|
D. Hoffman and W.H. Meeks, III Department of Mathematics, University of Massachusetts, Amherst, MA 01003, USA In [6] Jorge and Xavier constructed examples of complete nonplanar minimal surfaces contained between two parallel planes in •3. Recently Rosenberg and Toubiana have found complete minimally immersed annuli that are proper in an open slab 1-12]. On the basis of these and other results, the question has arisen as to whether or not there could exist a properly immersed minimal surface in ~3 that was contained between two parallel planes. The answer is negative, an immediate consequence of the following theorem.
|
We study regularity properties of a positive measure in the euclidean space in terms of two square functions which are the multiplicative analogues of the usual martingale square function and of the Lusin area function of a harmonic function. The size of ...
|
eng_Latn
| 797,343 |
Well-posedness and regularity of hyperbolic boundary control systems on a one-dimensional spatial domain ∗
|
We study a class of hyperbolic partial differential equations on a one dimensional spatial domain with control and observation at the boundary. Using the idea of feedback we show these systems are well-posed in the sense of Weiss and Salamon if and only if the state operator generates a C0-semigroup. Furthermore, we show that the corresponding transfer function is regular, i.e., has a limit for s going to infinity.
|
We consider second-order partial differential operators $H$ in divergence form on $\Ri^d$ with a positive-semidefinite, symmetric, matrix $C$ of real $L_\infty$-coefficients and establish that $H$ is strongly elliptic if and only if the associated semigroup kernel satisfies local lower bounds, or, if and only if the kernel satisfies Gaussian upper and lower bounds.
|
eng_Latn
| 797,347 |
On a new transformation formula for bilateral _6{\psi }_6 series and applications
|
In this paper, we derive a new transformation formula for bilateral \(_6\psi _6\) series using Roger’s \(_6\phi _5\) summation and then use it to deduce the well-known Bailey’s \(_6\psi _6\) summation formula. Also, we deduce some identities involving theta functions and new identities analogous to identities of Ramanujan. Further, we give formulas for finding the number of representations of an integer as sums of squares and sums of triangular numbers.
|
In this paper we study the deformation of right porous cylinders subjected to a prescribed thermal field. We assume that the cylinder is filled by an inhomogeneous anisotropic porous material. In the first part of the paper we study the problem of extension-bending-torsion, when the thermal field is independent of the axial coordinate and then we study the problem of extension-bending-torsion-flexure when the thermal field is considered linear in the axial coordinate. The considered problems are reduced to some generalized plane strain problems in the cross-section of the cylinder. Our analysis shows how the considered thermal fields influence the deformation of the porous cylinders.
|
eng_Latn
| 797,348 |
Stationary cosmological Bianchi II solutions
|
Stationary cosmological solutions for the Bianchi metric II are derived. In the models, use is made of a scalar field with a vacuum-averaged energy-momentum tensor, a cosmological constant, and ideal co-moving or not co-moving liquids as sources of gravitations.
|
The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$.
|
eng_Latn
| 797,349 |
[Persistent Müllerian ducts syndrome].
|
Persistent Müllerian ducts syndrome is a rare form of internal male pseudohermaphroditism, characterized by the presence of the uterus, fallopian tubes and upper vagina in an otherwise normally virilised male with a 46 XY karyotype. It is the result of a deficiency in anti-Müllerian hormone or abnormality of this hormone receptor. Often, the diagnosis is made incidentally during surgical exploration for cryptorchidism or herniorrhaphy, and exceptionally during cancer of ectopic testis. We discuss a rare case of this syndrome revealed by a bilateral intra-abdominal gonadal tumor.
|
We study multiple orthogonal polynomials of Meixner-Pollaczek type with respect to a symmetric system of two orthogonality measures. Our main result is that the limiting distribution of the zeros of these polynomials is one component of the solution to a constrained vector equilibrium problem. We also provide a Rodrigues formula and closed expressions for the recurrence coefficients. The proof of the main result follows from a connection with the eigenvalues of block Toeplitz matrices, for which we provide some general results of independent interest. ::: The motivation for this paper is the study of a model in statistical mechanics, the so-called six-vertex model with domain wall boundary conditions, in a particular regime known as the free fermion line. We show how the multiple Meixner-Pollaczek polynomials arise in an inhomogeneous version of this model.
|
eng_Latn
| 797,358 |
Kolmogorov ε-entropy of attractor for a non-autonomous strongly damped wave equation☆
|
Abstract In this paper, we study the long-time behavior of solutions for a non-autonomous strongly damped wave equation. We first prove the existence of a uniform attractor for the equation with a translation compact driving force and then obtain an upper estimate for the Kolmogorov e -entropy of the uniform attractor. Finally we obtain an upper bound of the fractal dimension of the uniform attractor with quasiperiodic force.
|
The matrix formalism previously introduced for the discussion of polymer dynamics is rendered more tractable by the introduction of an explicit operator representation satisfying boson commutation rules. Techniques are devised by which singular functions of segment coordinates may be expanded in a fluctuation series (containing ordered products of boson operators) around an equilibrium or nonequilibrium average. The techniques are here applied to equilibrium excluded‐volume expansions, and are shown to give good results. The detailed numerical results are presented in the following paper. The Gaussian potential is adopted for polymer chains in a theta solvent, but methods for its improvement are considered.
|
eng_Latn
| 797,359 |
Reduction Arguments for Geometric Inequalities Associated With Asymptotically Hyperboloidal Slices
|
We consider several geometric inequalities in general relativity involving mass, area, charge, and angular momentum for asymptotically hyperboloidal initial data. We show how to reduce each one to the known maximal (or time symmetric) case in the asymptotically flat setting, whenever a geometrically motivated system of elliptic equations admits a solution.
|
In this paper, we study the sharp energy criteria of blow-up and global existence for the nonlinear Klein-Gordon equation by the sharp Gagliardo-Nirebergy-Sobolev inequality.
|
eng_Latn
| 797,362 |
Approaches and Prospects of Provenance Analysis
|
Provenance analysis is the most important aspect in the research of ba sins and orogene and is of great significance in studying the relative position, evolution and the interaction of the basins and orogenes. There have been various ways in provenance analysis. The paper has discussed the ways, rules an d limitations of heavy minerals, clastic rock components, fission track, sedimen tary, geochemistry and isotopic methods. It is showen that geochemistry and iso topic methods have the bright and wide uses in the future. Meanwhile, the influence structure and sedimentation such as structure uplift, erosion, chemical weathering on provenan ce can not be neglected. It is worthy to note that reasonable conclusion sho uld be drawn only through the combination of various ways of provenance analysis .
|
In this paper we study the multivariate ANOVA decomposition for $1$-periodic functions on the torus. In particular we use the integral projection operator that leads to the classical ANOVA decomposition. Relationships between the Fourier coefficients of the function and its ANOVA terms lead to special frequency index sets and give an understanding of the decomposition working in the frequency domain. Moreover, we consider the truncated ANOVA decomposition and provide error bounds for approximation in $\mathrm{L}_\infty$ and $\mathrm{L}_2$. We present an approximation method based on the truncated decomposition with regard to a superposition dimension $d_s$.
|
eng_Latn
| 797,378 |
A Note on Evolution of Quaternionic Curves in the Euclidean Space $\mathbb{R}^{4}$
|
In this paper, we investigate the evolution of quaternionic curve in Euclidean 4-space $\mathbb{R}^{4}$. We obtain evolution equations of the Frenet frame and curvatures. Then we give integrability conditions for the evolutions. Finally we give examples of evolution of curvatures.
|
Abstract In this paper, we study the long-time behavior of solutions for a non-autonomous strongly damped wave equation. We first prove the existence of a uniform attractor for the equation with a translation compact driving force and then obtain an upper estimate for the Kolmogorov e -entropy of the uniform attractor. Finally we obtain an upper bound of the fractal dimension of the uniform attractor with quasiperiodic force.
|
eng_Latn
| 797,380 |
A Calculation of Geodesics in Flat Robertson-Walker Space and its Folding
|
Our aim in the present article is to introduce and study new types of retractions of flat Robertson-Walker space. Types of the deformation retracts of flat Robertson-Walker space are presented. The relations between the folding and the deformation retract of flat Robertson-Walker space are deduced .Types of minimal retractions of flat Robertson-Walker space are also presented. Also, the isometric and topological folding in each case and the relation between the deformation retracts after and before folding have been obtained. The connection between isocurvature folding and tangent spaces are obtained. New types of homotopy maps are deduced
|
In this paper, we consider the density-dependent incompressible Navier–Stokes equations in with linearly growing initial velocity at infinity. We obtain a blow-up criterion and global well-posedness of the two-dimensional system. It generalized the local well-posedness results due to the recent work by the first and third authors to the global well-posedness in . Copyright © 2012 John Wiley & Sons, Ltd.
|
eng_Latn
| 797,398 |
ON CONSTITUTIVE EQUATIONS OF ISOTROPIC NON-LINEAR ELASTIC MEDIUM
|
By means of tensor function,conjugate variables of stress and strain,the different constitutive equations of isotropic non-linear elastic medium and the relations between different equation forms are studied.The constitutive equations of non-linear Green elastic medium in terms of tensor invariables and scalar invariables are deduced.It is proved that the equations are complete and irreducible.Finally the constitutive equations are applied to rubber materials as an illustration of engineering practice.
|
In this paper, we study the almost periodic solutions for a class of Lasota-Wazewska models with patch structure on time scales. By using a fixed-point theorem and inequality techniques, some sufficient conditions are obtained which guarantee the existence and exponential stability of the almost periodic solutions. The criteria extend and improve some earlier results. Moreover, we give an examples to illustrate our main results.
|
yue_Hant
| 797,400 |
NON-EQUILIBRIUM STATIONARY MODES OF BOUNDARY FRICTION
|
A non-equilibrium thermodynamic model describing the behavior of an ultrathin lubricating material film confined between two atomically-smooth solid surfaces is proposed. As the order parameter the excess volume is chosen whose value increases with melting and subsequent fluidization of lubricant. It is shown that the external pressure, applied perpendicularly to the friction surfaces, influences crucially the lubricant behavior. The total system of kinetic equations is written down in which the relative shear velocity of rubbing surfaces, their temperature, and external normal pressure are the control parameters. Phase diagram with domains of different friction regimes is built.
|
We consider a family of 4-dimensional Hamiltonian time-periodic linear systems depending on three parameters, λ1, λ2 and e such that for e=0 the system becomes autonomous. Using normal form techniques we study stability and bifurcations for e>0 small enough. We pay special attention to the d'Alembert case. The results are applied to the study of the linear stability of homographic solutions of the planar three-body problem, for some homogeneous potential of degree −α, 0
|
yue_Hant
| 797,417 |
On Lagrangian and Eulerian interpretations of the local equilibrium assumption in nonequilibrium convective systems
|
The formulation of nonequilibrium thermodynamics with convective flow under the influence of external potential field is made from the two view points of Lagrangian and Eulerian. Specifying two meanings of the local equilibrium assumption, we define two sets of the thermodynamic forces and fluxes, and derive two evolulion criteria in each picture.
|
A method of solving the eikonal equation, in either flat or curved space–times, with arbitrary Cauchy data, is extended to the case of data given on a characteristic surface. We find a beautiful relationship between the Cauchy and characteristic data for the same solution, namely they are related by a Legendre transformation. From the resulting solutions, we study and describe the wave-front singularities that are associated with their level surfaces (the characteristic surfaces or “big wave fronts”).
|
eng_Latn
| 797,423 |
Global well-posedness for strongly damped viscoelastic wave equation
|
We study the initial boundary value problem for the nonlinear viscoelastic wave equation with strong damping term and dispersive term. By introducing a family of potential wells we not only obtain the invariant sets, but also prove the existence and nonexistence of global weak solution under some conditions with low initial energy. Furthermore, we establish a blow-up result for certain solutions with arbitrary positive initial energy (high energy case)
|
Experimental results are used to validate a 2D phenomenological model of the near wake based on Van Der Pol wake oscillators, which is the first one which describes the 2D motion of a cylinder in its transversal plan. In the case of a single cylinder, experimental and numerical results are in relatively good agreement. Those first results show that the proposed model can be used as a simple computation tool in the prediction of 2D VIV effects.
|
eng_Latn
| 797,425 |
Extended SUSY quantum mechanics: transition amplitudes and path integrals
|
Quantum mechanical models with extended supersymmetry find interesting applications in worldline approaches to relativistic field theories. In this paper we consider one-dimensional nonlinear sigma models with O(N) extended supersymmetry on the worldline, which are used in the study of higher spin fields on curved backgrounds. We calculate the transition amplitude for euclidean times (i.e. the heat kernel) in a perturbative expansion, using both canonical methods and path integrals. The latter are constructed using three different regularization schemes, and the corresponding counterterms that ensure scheme independence are explicitly identified.
|
In this paper the $\omega$-limit behaviour of trajectories of solutions of ordinary differential equations is studied by methods of an axiomatic theory of solution spaces. We prove, under very general assumptions, semi-invariance of $\omega$-limit sets and a Poincar'{e}-Bendixon type theorem.
|
eng_Latn
| 797,436 |
[A case of two-chambered right ventricle associated with severe pulmonary valve regurgitation].
|
A 40-year-old female was admitted to the hospital with the chief complaints of dyspnea on effort. Echocardiography and cardiac catheterization revealed an abnormal muscle bundle in the right ventricle which divided right ventricle into two chambers with the pressure gradient of 86 mmHg between them. And severe regurgitation associated with hypoplastic pulmonary valve and ventricular septal defect were noted. We removed the abnormal muscle bundle through the right atrial and ventricular approach, and pulmonary valve replacement and VSD closure were carried out. We report a case of two-chambered right ventricle with severe pulmonary valve regurgitation because of its rarity.
|
We study boundary regularity of maps from two-dimensional domains into manifolds which are critical with respect to a generic conformally invariant variational functional and which, at the boundary, enter perpendicularly into a support manifold. For example, harmonic maps, or $H$-surfaces, with a partially free boundary condition. In the interior it is known, by the celebrated work of Riviere, that these maps satisfy a system with an antisymmetric potential, from which one can derive regularity of the solution. We show that these maps satisfy along the boundary a system with a nonlocal antisymmetric boundary potential which contains information from the interior potential and the geometric Neumann boundary condition. We then proceed to show boundary regularity for solutions to such systems.
|
eng_Latn
| 797,442 |
Interactions between a Barotropic Vortex and an Idealized Subtropical Ridge. Part II: Structure Changes
|
Abstract The interactions between a barotropic vortex and an idealized subtropical ridge environment on a beta plane are examined and compared to the well-documented case of a single vortex with no environmental flow. First, the problems and advantages of several potential partitioning methods are discussed and then a three-part partition is chosen. Substantial variations are found from the single vortex case. In particular, the familiar gyres associated with the propagation of a single vortex are markedly distorted and relocated by the environment. A vorticity budget is presented to help isolate the physical mechanisms. This analysis indicates that the major processes are associated with interactions with the gradients of absolute vorticity in the environment. Other nonlinear mechanisms can also be of significance in specific cases.
|
The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$.
|
eng_Latn
| 797,447 |
Forty-five cases of apoplexy treated by electroacupuncture at the points of yin meridians.
|
Forty-five cases of apoplexy were treated by electroacupuncture only at the points of Yin Meridians (i.e. the Hand- and Foot-Taiyin Meridians), and the other 30 cases as the controls were treated only at the points of Yang Meridians (i.e. the Hand- and Foot-Yangming Meridians). The total effective rate was 91.1% in the former and 86.7% in the latter, with no statistically significant difference between the two groups, indicating that acupuncture only at the points of Yin-Meridians is also an effective therapy for apoplexy.
|
We study multiple orthogonal polynomials of Meixner-Pollaczek type with respect to a symmetric system of two orthogonality measures. Our main result is that the limiting distribution of the zeros of these polynomials is one component of the solution to a constrained vector equilibrium problem. We also provide a Rodrigues formula and closed expressions for the recurrence coefficients. The proof of the main result follows from a connection with the eigenvalues of block Toeplitz matrices, for which we provide some general results of independent interest. ::: The motivation for this paper is the study of a model in statistical mechanics, the so-called six-vertex model with domain wall boundary conditions, in a particular regime known as the free fermion line. We show how the multiple Meixner-Pollaczek polynomials arise in an inhomogeneous version of this model.
|
eng_Latn
| 797,453 |
Dynamics and entropy in local algebra
|
We introduce and study a notion of algebraic entropy for self-maps of finite length of Noetherian local rings, and develop its properties. We show that it shares the standard properties of topological entropy. For finite self-maps we explore the connection between the degree of the map and its algebraic entropy, when the ring is a Cohen-Macaulay domain. As an application of algebraic entropy, we give a characteristic-free interpretation of the definition of Hilbert-Kunz multiplicity.
|
We prove existence of solutions for a class of systems of subelliptic PDEs arising from Mean Field Game systems with H\"ormander diffusion. These results are motivated by the feedback synthesis Mean Field Game solutions and the Nash equilibria of a large class of $N$-player differential games.
|
eng_Latn
| 797,460 |
Chaotic flows with a single nonquadratic term
|
Abstract This paper addresses a previously unexplored regime of three-dimensional dissipative chaotic flows in which all but one of the nonlinearities are quadratic. The simplest such systems are determined, and their equilibria and stability are described. These systems often have one or more infinite lines of equilibrium points and sometimes have stable equilibria that coexist with the strange attractors, which are sometimes hidden. Furthermore, the coefficient of the single nonquadratic term provides a simple means for scaling the amplitude and frequency of the system.
|
In this paper, we investigate ${\mathcal F}$-hypercyclicity of linear, not necessarily continuous, operators on Fr\' echet spaces. The notion of lower $(m_{n})$-hypercyclicity seems to be new and not considered elsewhere even for linear continuous operators acting on Fr\' echet spaces. We pay special attention to the study of $q$-frequent hypercyclicity, where $q\geq 1$ is an arbitrary real number. We present several new concepts and results for lower and upper densities in a separate section, providing also a great number of illustrative examples and open problems.
|
eng_Latn
| 797,462 |
Asymptotic structure of the interaction in a laminar axisymmetric wake
|
The method of matched asymptotic expansions is used to investigate the interaction of the axisymmetric wake behind a slender body in an exterior irrotational flow in an incompressible fluid. It is shown that under certain conditions a three-layer scheme applies for the description of the flow, the perturbations of the flow in the leading approximation satisfying the Korteweg-de Vries equation. The well-known solutions of this equation in the form of a solitary wave and a cnoidal wave are considered. Also obtained are the equations of the higher approximations of the asymptotic sequence.
|
Abstract In this paper, we study the long-time behavior of solutions for a non-autonomous strongly damped wave equation. We first prove the existence of a uniform attractor for the equation with a translation compact driving force and then obtain an upper estimate for the Kolmogorov e -entropy of the uniform attractor. Finally we obtain an upper bound of the fractal dimension of the uniform attractor with quasiperiodic force.
|
eng_Latn
| 797,476 |
Toward a Test for Departure of a Trajectory from a Neighborhood of a Chaotic System
|
Many real systems have been identified as potentially chaotic (e.g., trains of heart beats, records of multiple populations in an ecological system, weather and climate data). In such cases, when “healthy” is defined by the measured trajectory being confined to a “strange attractor” in a “phase space,” how can we define and measure degradation? The simplest course is to define degradation as when the attractor changes. The earliest warning of such a change would be when a trajectory leaves an attractor, without an external forcing, but there seems little written on the problem of identifying whether a short trajectory belongs to a given attractor (at least to within a neighborhood defined by stochastic disturbances and uncertainty in the parameters of the defining equations).
|
We consider a system x(t) = (x 1(t),…, x N (t)) consisting of N Brownian particles with synchronizing interaction between them occurring at random time moments . Under assumption that the free Brownian motions and the sequence are independent we study asymptotic properties of the system when both the dimension N and the time t go to infinity. We find three time scales t = t(N) of qualitatively different behavior of the system.
|
eng_Latn
| 797,479 |
Discrimination nets, production systems and semantic networks: elements of a unified framework
|
A number of formalisms have been used in cognitive science to account for cognition in general and learning in particular. While this variety denotes a healthy state of theoretical development, it somewhat hampers communication between researchers championing different approaches and makes comparison between theories difficult. In addition, it has the consequence that researchers tend to study cognitive phenomena best suited to their favorite formalism. It is therefore desirable to propose frameworks which span traditional formalisms.
|
Abstract In this work, we study the analyticity of Kuramoto–Sivashinsky type equations and related systems by exploring the applicability of the semigroup method, which was developed in Collet et al. [5] . We establish the analyticity, with respect to the spatial variable in a strip around the real axis, for a variety of dissipative–dispersive systems, which possess universal attractors. We also provide lower bounds for the width of the strip of analyticity.
|
eng_Latn
| 797,483 |
Boundary regularity for conformally invariant variational problems with Neumann data
|
We study boundary regularity of maps from two-dimensional domains into manifolds which are critical with respect to a generic conformally invariant variational functional and which, at the boundary, enter perpendicularly into a support manifold. For example, harmonic maps, or $H$-surfaces, with a partially free boundary condition. In the interior it is known, by the celebrated work of Riviere, that these maps satisfy a system with an antisymmetric potential, from which one can derive regularity of the solution. We show that these maps satisfy along the boundary a system with a nonlocal antisymmetric boundary potential which contains information from the interior potential and the geometric Neumann boundary condition. We then proceed to show boundary regularity for solutions to such systems.
|
The Moyal *-deformed noncommutative version of Burgers' equation is considered. Using the *-analog of the Cole-Hopf transformation, the linearization of the model in terms of the linear heat equation is found. Noncommutative q-deformations of shock soliton solutions and their interaction are described
|
eng_Latn
| 797,484 |
Relative chaos in gravitating systems with massive centre
|
Abstract A geometric method, namely the Ricci curvature criterion, is used to study the relative instability of evolving N-body gravitating systems with massive centres. The performed numerical experiments show that the Ricci curvature decreases with the increase in central concentration, thus indicating an increasing instability for systems with massive centre — either in the form of a point mass or a core formed during the evolution of single and multimass systems. Simulations of such systems do indeed suggest that they have faster gravothermal evolution than less concentrated ones.
|
O. Introduction This lecture will unfortunately not be a systematic review of the subject of rigorous results in non-equilibrium statistical mechanics. A preliminary attempt to outline such a review led me quickly to the conclusion that the field is too diverse to be summarized in a single lecture. I have therefore decided instead to discuss a few related.works in depth. The works I have chosen are: 1. The paper of J. Fritz and R. L. Dobrushin[5] on two-dimensional dynamics. 2. The paper of W. Braun and K. Hepp[3] on classical mechanics in the Vlasov limit. 3. A recent preprint by H. van Beijeren, J. L. Lebowitz, H. Spohn, and myself[2] on autocorrelations and fluctuations in the dilute equilibrium hard-sphere gas.
|
eng_Latn
| 797,487 |
Periodic Systems Dependent on Parameters
|
This paper is concerned with a periodic system dependent on parameter. We study differentiability with respect to parameters of the periodic solution of the system. Applying a fixed point theorem and the results regarding parameters for Open image in new window -semigroups, we obtained some convenient conditions for determining differentiability with parameters of the periodic solution. The paper is concluded with an application of the obtained results to a periodic boundary value problem.
|
Introduction Periods of automorphic forms Locally split extensions of flat vector bundles bis. Automorphic forms attached to the symmetric powers of a second order differential equation and their periods Descent Differential equations associated to automorphic forms Examples.
|
eng_Latn
| 797,496 |
A REDUCTION OF THE BOLTZMANN-PEIERLS EQUATION
|
This paper deals with the solutions of initial value problems of the Boltzmann-Peierls equation (BPE). This integro-differential equation describes the evolution of heat in crystalline solids at very low temperatures. The BPE describes the evolution of the phase density of a phonon gas. The corresponding entropy density is given by the entropy density of a Bose-gas. We derive a reduced three-dimensional kinetic equation which has a much simpler structure than the original BPE. By using special coordinates in the one-dimensional case, we can perform a further reduction of the kinetic equation. By assuming one-dimensionality on the initial phase density one can show that this property is preserved for all later times. We derive kinetic schemes for the kinetic equation as well as for the derived moment systems. Several numerical test cases are presented to validate the theory.
|
We study boundary regularity of maps from two-dimensional domains into manifolds which are critical with respect to a generic conformally invariant variational functional and which, at the boundary, enter perpendicularly into a support manifold. For example, harmonic maps, or $H$-surfaces, with a partially free boundary condition. In the interior it is known, by the celebrated work of Riviere, that these maps satisfy a system with an antisymmetric potential, from which one can derive regularity of the solution. We show that these maps satisfy along the boundary a system with a nonlocal antisymmetric boundary potential which contains information from the interior potential and the geometric Neumann boundary condition. We then proceed to show boundary regularity for solutions to such systems.
|
yue_Hant
| 797,501 |
The Hardy inequality and the heat flow in curved wedges
|
We show that the polynomial decay rate of the heat semigroup of the Dirichlet Laplacian in curved planar wedges equals the sum of the usual dimensional decay rate and a multiple of the reciprocal value of the opening angle. To prove the result, we develop the method of self-similar variables for the associated heat equation and study the asymptotic behaviour of the transformed non-autonomous parabolic problem for large times. We also establish an improved Hardy inequality for the Dirichlet Laplacian in non-trivially curved wedges and state a conjecture about an improved decay rate in this case.
|
We study a random walk in a N dimensional hypercube.To each site of the hypercube we associate a random value according to a Bernoulli distribution.These values together with the temperature define the law of waiting times of the walk at each site.We exhibit a transition between the high and low temperatures regime by studying the distance between two trajectories starting from different initial conditions and subjected to the same noise.
|
eng_Latn
| 797,506 |
Completeness properties of group topologies for R
|
We study the completeness properties of several different group topologies for the additive group of real numbers, and we also compute the corresponding dual groups. We first present two metrizable connected group topologies on R with topologically isomorphic dual groups, one of which is noncomplete and arcwise connected and the other one is compact (therefore complete), but not arcwise connected. Using a theorem about T -sequences and adapting a result about weakened analytic groups, we then describe a method for obtaining Hausdorff group topologies R that are strictly weaker than the usual topology and are complete. They are not Baire, and consequently not metrizable.
|
We consider second-order partial differential operators $H$ in divergence form on $\Ri^d$ with a positive-semidefinite, symmetric, matrix $C$ of real $L_\infty$-coefficients and establish that $H$ is strongly elliptic if and only if the associated semigroup kernel satisfies local lower bounds, or, if and only if the kernel satisfies Gaussian upper and lower bounds.
|
eng_Latn
| 797,510 |
Flosolver Mk1B - An eight processor parallel machine
|
The Flosolver MklB has two nodes, each having four processing elements based on intel's 8086/8087 chips. In each node one of the processor acts as the host. The internade communication is done through the parallel ports available on the hosts. Within a node the cynchronisation and inter processor communication is done through the global memory. As a sample case the flow part NACA 0012 aerofoil at zero incident using transonic small perturbation equation is computed and an efficiency of 90 percent is obtained.
|
We study multiple orthogonal polynomials of Meixner-Pollaczek type with respect to a symmetric system of two orthogonality measures. Our main result is that the limiting distribution of the zeros of these polynomials is one component of the solution to a constrained vector equilibrium problem. We also provide a Rodrigues formula and closed expressions for the recurrence coefficients. The proof of the main result follows from a connection with the eigenvalues of block Toeplitz matrices, for which we provide some general results of independent interest. ::: The motivation for this paper is the study of a model in statistical mechanics, the so-called six-vertex model with domain wall boundary conditions, in a particular regime known as the free fermion line. We show how the multiple Meixner-Pollaczek polynomials arise in an inhomogeneous version of this model.
|
eng_Latn
| 797,537 |
Localization of a random copolymer at an interface: an untethered self-avoiding walk model
|
We consider two related n-step self-avoiding walk models of a copolymer at an interface between two bulk phases. In one case the walk is confined to start in the interface while in the other this condition is relaxed. We prove that both models have the same limiting free energy (in the n → ∞ limit) and hence that their phase diagrams are identical. We also show that the limits n → ∞ and certain energy parameters going to plus or minus infinity can be interchanged. These latter results are interesting from the viewpoint of numerical studies.
|
Abstract In this paper, we study the long-time behavior of solutions for a non-autonomous strongly damped wave equation. We first prove the existence of a uniform attractor for the equation with a translation compact driving force and then obtain an upper estimate for the Kolmogorov e -entropy of the uniform attractor. Finally we obtain an upper bound of the fractal dimension of the uniform attractor with quasiperiodic force.
|
eng_Latn
| 797,547 |
Applications of Harmonic Principal Functions to Fluid Dynamics and Thermodynamics.
|
Abstract : In this work the author systematically applies the theory of principal functions to fluid dynamics and thermodynamics. (Author)
|
We study a rational matroid invariant, obtained as the tropicalization of the Feynman period integral. It equals the volume of the polar of the matroid polytope and we give efficient formulas for its computation. This invariant is proven to respect all known identities of Feynman integrals for graphs. We observe a strong correlation between the tropical and transcendental integrals, which yields a method to approximate unknown Feynman periods.
|
eng_Latn
| 797,549 |
Peristaltic motion of a power-law fluid in an asymmetric channel
|
The flow of a power-law fluid is investigated in an asymmetric channel caused by the movement of peristaltic waves with the same speed but with different amplitudes and phases on the flexible walls of the channel. The differential equation governing the flow is non-linear and can admit non-unique solutions. There exist two different physically meaningful solutions one satisfying the boundary conditions at the upper wall and the other at the lower wall. The effects of the power-law nature of the fluid on the pumping characteristics and axial velocity are studied in detail.
|
Abstract In this paper, we study the long-time behavior of solutions for a non-autonomous strongly damped wave equation. We first prove the existence of a uniform attractor for the equation with a translation compact driving force and then obtain an upper estimate for the Kolmogorov e -entropy of the uniform attractor. Finally we obtain an upper bound of the fractal dimension of the uniform attractor with quasiperiodic force.
|
eng_Latn
| 797,557 |
Phase-space approach to dynamical density functional theory
|
We consider a system of interacting particles subjected to Langevin inertial dynamics and derive the governing time-dependent equation for the one-body density. We show that, after suitable truncations of the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy, and a multiple time scale analysis, we obtain a self-consistent equation involving only the one-body density. This study extends to arbitrary dimensions previous work on a one-dimensional fluid and highlights the subtelties of kinetic theory in the derivation of dynamical density functional theory.
|
Publisher Summary With respect to the quality problems of groundwater, the streamlines and travel times in a flow region should be assessed. Especially in flow problems in the vertical plane, that is, underneath a waste disposal, the presence of inhomogeneities, such as clay layers, is very important. This chapter presents a method for the calculation of the stream function all through the flow domain based upon the finite-element method. In this flow domain, which is divided in elements with various transmissivities, internal sources or sinks may be present. Also, the porous medium can be anisotropic.
|
eng_Latn
| 797,560 |
A lower bound for first eigenvalue with mixed boundary condition
|
Let M be an n-dimensional compact Riemannian manifold with or without boundary, and its Ricci curvature Ric M⩾n−1. The paper obtains an inequality for the first eigenvalue η 1 of M with mixed boundary condition, which is a generalization of the results of Lichnerowicz, Reilly, Escobar and Xia. It is also proved that η 1⩾n for certain n-dimensional compact Riemannian manifolds with boundary, which is an extension of the work of Cheng, Li and Yau.
|
We consider a family of 4-dimensional Hamiltonian time-periodic linear systems depending on three parameters, λ1, λ2 and e such that for e=0 the system becomes autonomous. Using normal form techniques we study stability and bifurcations for e>0 small enough. We pay special attention to the d'Alembert case. The results are applied to the study of the linear stability of homographic solutions of the planar three-body problem, for some homogeneous potential of degree −α, 0
|
eng_Latn
| 797,565 |
A Finite Set Intersection Theorem
|
Suppose 0, ⩽ r m , and ℱ is a family of k -subsets of an n -set such that the intersection of any two different members of ℱ has cardinality congruent to r (mod m ). If k ≢ r (mod m ) then ❘ℱ❘ ⩽ n . The case of equality is also investigated.
|
In this paper, we study the nonnegative periodic dynamics of the delayed Cohen-Grossberg neural networks with discontinuous activation functions and periodic interconnection coefficients, self-inhibitions, and external inputs. Filippov theory is utilized to study the viability, namely, the existence of the solution of the Cauchy problem. Under some conditions, the existence and the asymptotical stability of a periodic solution are derived. Numerical examples are provided to illustrate the theoretical results.
|
kor_Hang
| 797,569 |
Alignment of columnar phase confined in polydimethylsiloxane microchannels
|
ABSTRACTThe alignment of a discotic liquid crystal confined in polydimethylsiloxane (PDMS) channels with a rectangular cross-section is studied. The microchannels were produced in PDMS using the mold-replica technique. In the PDMS channels, the disc-like molecules of the disogen were found to adopt an edge-on anchoring at the PDMS surface, and macroscopically, the discogen layer is planarly aligned. Using Newton colour scale technique it was revealed that discotic columns were aligned parallel to the channels.
|
We study multiple orthogonal polynomials of Meixner-Pollaczek type with respect to a symmetric system of two orthogonality measures. Our main result is that the limiting distribution of the zeros of these polynomials is one component of the solution to a constrained vector equilibrium problem. We also provide a Rodrigues formula and closed expressions for the recurrence coefficients. The proof of the main result follows from a connection with the eigenvalues of block Toeplitz matrices, for which we provide some general results of independent interest. ::: The motivation for this paper is the study of a model in statistical mechanics, the so-called six-vertex model with domain wall boundary conditions, in a particular regime known as the free fermion line. We show how the multiple Meixner-Pollaczek polynomials arise in an inhomogeneous version of this model.
|
eng_Latn
| 797,571 |
of One-Dimensional Cosmological Density Fluctuations
|
Wavelet analysis is proposed as a new tool for studying the large-scale structure formation of the universe. To reveal its usefulness, the wavelet decomposition of one-dimensional cosmological density fluctuations is performed. In contrast with the Fourier analysis, the wavelet analysis has advantage of its ability to keep the information for location of local density peaks in addition to that for their scales. The wavelet decomposition of evolving density fluctuations with various initial conditions is examined. By comparing the wavelet analysis with the usual Fourier analysis, we conclude that the wavelet analysis is promising as the data analysis method for the
|
Abstract : The paper presents a discussion of the structure of hereditary differential systems defined on a Banach space with initial data in the space of p-integrable maps. Both finite and infinite time histories are allowed. A unified approach to Global and Local Cauchy problems on finite or infinite time intervals is presented. An existence theorem for Caratheodory systems and an existence and uniqueness theorem for Lipschitz systems are derived. In both cases continuity of a solution with respect to the initial data is established. (Author)
|
eng_Latn
| 797,573 |
Radial rapid decay property for cocompact lattices
|
Abstract We study Haagerup inequality for radial functions on uniform lattices in semisimple Lie groups, with respect to Riemannian metrics and, in some case, to word metrics. In particular we extend the Swiatkowski–Valette results to any lattice acting properly and essentially transitively on classical buildings.
|
We argue that in the measured $p_T$ domain of RHIC, collisional rather than the radiative energy loss is the dominant mechanism for jet quenching. Accordingly we calculate nuclear suppression factor for light hadrons by taking only the elastic energy loss in sharp contrast with the previous calculations where only the radiative loss are considered.
|
eng_Latn
| 797,578 |
Validation of marine geoid models by utilizing hydrodynamic model and shipborne GNSS profiles
|
AbstractAn essential role of the FAMOS international cooperation project is to obtain new marine gravity observations over the Baltic Sea for improving gravimetric geoid modelling. To achieve targe...
|
We study boundary regularity of maps from two-dimensional domains into manifolds which are critical with respect to a generic conformally invariant variational functional and which, at the boundary, enter perpendicularly into a support manifold. For example, harmonic maps, or $H$-surfaces, with a partially free boundary condition. In the interior it is known, by the celebrated work of Riviere, that these maps satisfy a system with an antisymmetric potential, from which one can derive regularity of the solution. We show that these maps satisfy along the boundary a system with a nonlocal antisymmetric boundary potential which contains information from the interior potential and the geometric Neumann boundary condition. We then proceed to show boundary regularity for solutions to such systems.
|
eng_Latn
| 797,582 |
Approximate “Controlled Lagrangian” stabilization of the furuta pendulum
|
Stabilization of mechanical control systems by the method of controlled Lagrangians in an approximate version, is used to analyze asymptotic stabilization of systems whose dynamics are governed by the Euler-Lagrange equations. The method is applied to the Furata pendulum. The approximation produces controlled near conservative stable orbits that can be asymptotically stabilized introducing dissipation.
|
In this paper, we study the almost periodic solutions for a class of Lasota-Wazewska models with patch structure on time scales. By using a fixed-point theorem and inequality techniques, some sufficient conditions are obtained which guarantee the existence and exponential stability of the almost periodic solutions. The criteria extend and improve some earlier results. Moreover, we give an examples to illustrate our main results.
|
eng_Latn
| 797,596 |
On the cause of luminosity−colour variation in the active binary system DH Leonis
|
The long term photometric activity of DH Leonis has been compared with the predictions of Applegate's theory that magnetic cycles cause luminosity variation due entirely to temperature variations. Observations show that DH Leo is bluer when it is brighter, but it is found that the slope Δ(B−V)/ΔV is not different from the main sequence slope, which indicates that radius change can not be ruled out
|
The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$.
|
eng_Latn
| 797,599 |
Solutions of the dirichlet problem for elliptic systems in a disk
|
We study 2×2 second-order elliptic systems, which can be written as a single equation with complex coefficients. In an arbitrary bounded region with smooth boundary, we obtain necessary and sufficient conditions on the trace relation of a solution, which we apply in the case of a disk. We prove existence and uniqueness theorems for a solution in a Sobolevskii space of an equation which is not properly elliptic. In particular, we prove that the properties of the problem determine the angle between the bicharacteristics. If it is π-rational, then there is no uniqueness, but if it is π-irrational, then the smoothness of the solution of the Dirichlet problem depends on the order of its approximation by π-rational numbers; but if it is nonreal, then the problem has the usual properties for the elliptic case.
|
Abstract We discuss random matrix-model representations of D = 1 string theory, with particular emphasis on the case in which the target space is a circle of finite radius. The duality properties of discretized strings are analyzed and shown to depend on the dynamics of vortices. In the representation in terms of a continuous circle of matrices we find an exact expression for the free energy, neglecting non-singlet states, as a function of the string coupling and the radius which exhibits exact duality. In a second version, based on a discrete chain of matrices, we find that vortices induce, for a finite radius, a Kosterlitz-Thouless phase transition that takes us to a c = 0 theory.
|
eng_Latn
| 797,603 |
A Symmetry Property for Fully Nonlinear Elliptic Equations on the Sphere
|
The goal of this paper is to study how the symmetry of the spherical domain influences solutions of elliptic equations on such domain. The method pursued is a variant of the moving plane method, discovered by Alexandrov (1962) and used for differential equations by Gidas, Ni and Nirenberg (1979). We obtain a reflectional symmetry result with respect to maxima and minima of solutions.
|
We prove existence of solutions for a class of systems of subelliptic PDEs arising from Mean Field Game systems with H\"ormander diffusion. These results are motivated by the feedback synthesis Mean Field Game solutions and the Nash equilibria of a large class of $N$-player differential games.
|
eng_Latn
| 797,610 |
The flow near non-trivial minimal sets on 2-manifolds
|
In this paper we give a description of the qualitative behaviour of the orbits near a non-trivial compact minimal set of a continuous flow on a 2-manifold. The first results in this direction were obtained in [1] and the present paper can be regarded as a continuation of that work. The main result can be stated as follows: Theorem 1·1. Let (ℝ, M, f) be a continuous flow on a 2-manifold M and A ⊂ M a non-trivial compact minimal set.
|
A weightedL2 norm is introduced in which Markov operators, e.g., associated with noisy maps, are contracting provided the kernel (i.e., the transitional distribution) is smooth enough. This results in strong relaxational properties of noisy maps. Similar to this norm, integral functionals appear useful when studying spatiotemporal chaos and random fields.
|
eng_Latn
| 797,617 |
Geometrical properties of Sine-Gordon Abelian Higgs sunspots
|
Abstract We discuss a slightly modified Abelian Higgs model of sunspots in which the potential term V(Φ) has a ‘Sine-Gordon’-like form, V( Φ ) = −( α β 2 )[1 − sin β( ΦΦ ∗ ) κ ] . The model accounts not only for the observed diversity of the absolute dimensions of sunspots, but is also compatible with a more-or-less constant value of their penumbra-to-umbra radius ratios provided the parameter κ is close to unity.
|
The main objective of this article is to study dynamic of the ::: three-dimensional Boussinesq equations with the periodic boundary ::: condition.We prove that when the Rayleigh number $R$ crosses the ::: first critical Rayleigh number $R_c$, the Rayleigh-Benard problem ::: bifurcates from the basic state to an global attractor $\Sigma$, which is homeomorphic to $S^3$.
|
eng_Latn
| 797,629 |
Coastal line feature extraction method for optic remote sensing images: a threshold-based morphological approach
|
Fuzzy mathematical morphologies: A comparative study
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,711 |
Novel amino acids indices based on quantum topological molecular similarity and their application to QSAR study of peptides
|
Systematic Identification and Comparative Analysis of Human Cartilage-Derived Self-peptides Presented Differently by Ankylosing Spondylitis (AS)-Associated HLA-B*27:05 and Non-AS-associated HLA-B*27:09
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,737 |
Case study - using stil as test pattern language
|
Structuring STIL for incremental test development
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,770 |
Optical/Near-IR spatially resolved study of the H II galaxy Tol 02
|
Astrophysics of gaseous nebulae and active galactic nuclei
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,789 |
A reputation-based strategy towards sustainable services by third party logistics (3PLs) in closed-loop supply chains (CLSCs)
|
Managing product returns to achieve supply chain sustainability: an exploratory study and research propositions
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,802 |
The neural implementation of task rule activation in the task-cuing paradigm: An event-related fMRI study
|
Voluntary orienting is dissociated from target detection in human posterior parietal cortex
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,878 |
Case study of a gearbox-like routing algorithm selection in runtime
|
Implementation issues for Modified Dijkstra's and Floyd-Warshall algorithms in OpenFlow
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,909 |
Numerical study on crack problems in segments of shield tunnel using finite element method
|
Effect of Deficiencies in the Tunnel Crown Thickness on Pressure Tunnels with Posttensioned Concrete Linings
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,925 |
Candidate early detection protein biomarkers for ER+/PR+ invasive ductal breast carcinoma identified using pre-clinical plasma from the WHI observational study
|
Efficacy of screening mammography. A meta-analysis.
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,953 |
Lyophilised Receptor Preparation for A Radioreceptor Assay for Anticholinergics
|
Application of a radioreceptor assay in a pharmacokinetic study of oxitropium bromide in healthy volunteers after single i.v., oral and inhalation doses
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,966 |
Relevance of Angiopoietin-2 and Soluble P-Selectin Levels in Patients with Pulmonary Arterial Hypertension Receiving Combination Therapy with Oral Treprostinil: A FREEDOM-C2 Biomarker Substudy
|
Angiopoietin-1 and angiopoietin-2 share the same binding domains in the Tie-2 receptor involving the first Ig-like loop and the epidermal growth factor-like repeats.
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 797,988 |
Population study of global and local fatigue with prolonged threshold testing in automated perimetry
|
Automated perimetry in glaucoma--room for improvement?
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 798,002 |
AMPA receptor potentiation by acetylcholinesterase is age-dependently upregulated at synaptogenesis sites of the rat brain
|
Exploring the functional role of the CHRM2 gene in human cognition: results from a dense genotyping and brain expression study
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 798,003 |
Damage tolerance of an elastic-brittle diamond-celled honeycomb
|
Preliminary study on ductile fracture of imperfect lattice materials
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 798,028 |
Medial Moraines and Surface Melt on Glaciers of the Torngat Mountains, Northern Labrador, Canada
|
Effects of debris on ice-surface melting rates: an experimental study
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 798,061 |
Manganese Oxides with Rod-, Wire-, Tube-, and Flower-Like Morphologies: Highly Effective Catalysts for the Removal of Toluene
|
A study on simultaneous catalytic ozonation of Hg0 and NO using Mn–TiO2 catalyst at low flue gas temperatures
|
Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo
|
eng_Latn
| 798,124 |
Microleakage of new crown and fixed partial denture luting agents
|
In-vitro study analysing the impact of gluma desensitizer on long-term shear bond strength to dentin
|
Ileocolic intussusception in adult due to malignant lymphoma in the cecum with intramural metatasis
|
eng_Latn
| 798,210 |
SUMMARY: The T'ang strain of trachoma virus was titrated in chick embryo yolk sac by a single-dilution method (Golub, 1948), using 3-6 eggs/dilution. The limitations incurred by the use of small numbers of eggs are discussed. The method was used to make observations on the fate of virus after inoculation into the yolk sac, and to study the sensitivity of virus to oxytetracycline. The method was found to be unsuitable for titration of neutralizing antibodies in fowl serum.
|
SUMMARY: The effects of intranasal inoculation of mice more than 6 weeks old with the TE 55 strain of trachoma virus were studied. The histology and course of the pulmonary lesions produced are described. Infected mice showed a poor response of complement-fixing antibodies after infection. Precipitating antigens were detected in infected mouse lungs.
|
We consider the scattering of an H-polarized plane wave by an infinite dielectric rod with a conformal graphene strip of arbitrary angular width, placed at the rod rear side. Our analysis is based on the hypersingular integral equation for the current induced on the strip. Discretization of this equation is carried out by the Nystrom-type method, which has a guaranteed convergence. This meshless trusted computational instrument enables us to plot the dependences of the absorption cross-section (ACS) and the total scattering cross-section (TSCS) on the frequency and strip angular width. We concentrate our analysis on studying the interplay between the broadband photonic-jet effect of dielectric rod and the reasonably high-Q resonances on the plasmon modes of graphene strip.
|
eng_Latn
| 798,312 |
We perform a detailed study of the phenomenon of resonant absorption that occurs at an oblique incidence in the vicinity of the zero refractive index transition in graded index metamaterials with the refractive index changing from positive to negative values. We compare the results of numerical simulations with analytical predictions for the case of the linear gradient index profile. Furthermore, we numerically study the transition phenomena in graded index layers with more complex index profiles. A detailed understanding of the phenomenon of resonant absorption may be of considerable importance in the context of transformation optics as it strongly modifies the field distribution near the zero index transition.
|
The mode conversion and the resonant absorption and amplification phenomena occurring in inhomogeneous chiral media are theoretically studied. Mode conversion is found to occur when the medium contains regions where at least one of the effective refractive indices corresponding to two circular polarizations vanishes. Resonant absorption and enhancement phenomena are useful for designing efficient absorbers and nonlinear photonic devices.
|
Blunt trauma abdomen rarely leads to gastrointestinal injury in children and isolated gastric rupture is even rarer presentation. We are reporting a case of isolated gastric rupture after fall from height in a three year old male child.
|
eng_Latn
| 798,319 |
Coupling plasmons and dyakonons
|
We study the coupling of plasmons and Dyakonov surface waves propagating at the interfaces between isotropic-birefringent-metal layered structures. Efficient coupling is shown to occur with a proper choice of the crystal birefringence, the refractive index of the isotropic medium, and the light propagation direction relative to the crystal optical axis. In the case of low-loss metals, coupling efficiencies as high as 90% are predicted to be possible.
|
A scarce NN=C…π interaction, which plays an essential role in defining the crystal packing patterns, has been found widespread in benzaldehyde (cyanoacetyl)hydrazones, and is rationalized by density functional theory calculations. Molecular electrostatic potential analyses offer an effective further support for the interaction.
|
eng_Latn
| 798,324 |
3D stand-up metamaterials with a purely magnetic resonance at terahertz frequencies
|
In this paper we present a copper-based 3-dimensional (3D) stand-up metamaterial which displays a purely magnetic resonance at terahertz (THz) frequencies. A multilayer-electroplating technique is used to fabricate these arrayed structures and experimental results demonstrate a strong LC resonance at 1.38 THz with quality factor of 18.7. The successful design, fabrication and characterization of these 3D structures provides a new pathway for implementing novel electromagnetic properties at terahertz frequencies.
|
In this paper, a modeling and simulation method for planar interdigitated ruthenium oxide MEMS supercapacitor was proposed based on the electrochemical reaction mechanism of supercapacitor. The study simulated the planar interdigitated ruthenium oxide MEMS super capacitor using Comsol software. The highly accurate charge and discharge curves of the super capacitor, electric potential distribution graph and the concentration distribution graph were got through simulation. The effects of two structure-parameters were discussed in the research.
|
eng_Latn
| 798,328 |
Application of the Semiconductor Breaker/Relay on vehicle circuits
|
In this paper, the modified Semiconductor Breaker/Relay (SBR) and related control modules, and some new methods to solve the problems of vehicle fire, battery service life and engine cold start emission have been presented. By theoretical and experimental analysis on applying the modified SBR etc, vehicle fire relating to circuit system may be avoided because of the fast and accurate control, battery service life can be extended because of the cyclic charging effect, and engine cold start emissions can be decreased because of the lower power consumption and the faster reaction of the catalytic converter during a cold start. Further study for the detailed numerical values still needs to do.
|
This paper presents the design, prototype realization and measurement results of the liquid crystal bias voltage-tunable ::: microwave band stop filter. A possible use of liquid crystals for tunable band stop filters was shown.
|
eng_Latn
| 798,329 |
Trends and Volatilities in Heterogeneous Patent Quality in Taiwan
|
This study analyzes patent trends and volatilities for three heterogeneous quality patents in the Taiwan patent system from January 1973 to June 2006. The estimated models are symmetric GARCH and asymmetric EGARCH, providing full sample, rolling sample, and out-of-sample evidence. Three different patent types exhibit increasing trends, using monthly time series data from our samples. ”New design” patents also show time-varying volatility but other types of patents fail to reject the ARCH LM test. Findings show the asymmetric EGARCH model suitable for “new design” patent type through out of sample forecasts.
|
The polarisation dependent optical properties of silver nanowire arrays are investigated by angular resolved transmission ::: measurements. The corresponding spectra show clear Fabry-Perot oscillations, which exhibit an unusual shift towards ::: longer wavelengths for the extraordinary waves. From the peak shift both principal dielectric functions of the ::: metamaterial are determined and compared with effective medium theories. Furthermore the equifrequency contours in ::: wave vector diagrams were mapped from the experimental data and compared with theoretical plots confirming the ::: hypberbolic dispersion relation for TM polarised waves.
|
eng_Latn
| 798,345 |
Simple synthesis of tetra-n-butylphosphonium benzimidazolate/benzimidazole mixture as a thermally stable proton conductor
|
A mixture of tetra-n-butylphosphonium benzimidazolate and benzimidazole is readily prepared as a proton conductive liquid having thermal stability up to 300 °C.
|
A theoretical study was carried out to determine the dielectric response and tunability of a composite consisting of a linear, low-loss dielectric matrix with uniformly sized, randomly distributed paraelectric Ba0.60Sr0.40TiO3 (BST 60/40) particles as functions of the volume fraction and size of the particles. The field dependence of the polarization and the dielectric response of the inclusions are specified through a nonlinear thermodynamic model and then incorporated into a two-dimensional finite element analysis. Near the percolation threshold for BST particles (∼27% to 45% depending on the particle size), high dielectric tunabilities with a lower effective permittivity than monolithic BST can be realized.
|
eng_Latn
| 798,362 |
A theoretical study on a circular microstrip antenna in a parallel plate waveguide
|
An evaluation of transmission performance for wireless harness systems using propagation models in an automobile engine compartment
|
Handbook of microstrip antennas
|
eng_Latn
| 798,409 |
The input impedance predicted by the modified formulation presented in this paper were compared against measurements as well as data predicted by the formulation used in [Polycarpou et al., 1998]. The comparison showed that the effect of the non-uniformities in the applied magnetic field is to broaden the input impedance response vs. frequency. It was observed that such broadening resulted in predicted curves having better agreement with the measured curves. As a result, such observation validates the initial premise that the non-uniformities of the applied magnetic field have to be taken into account if a most accurate analysis of ferrite-loaded CBS antennas is to be achieved.
|
General Survey. Quantum Theory and Magnetism. Spin and Magnetization, Statics and Dynamics. Magnetostatics, Magnetic Domains and Magnetic Design. Survey of Magnetic Materials. Special Topics. Appendices. Indexes.
|
Crickets are suitable for studying the effects of single gene mutations on single nerve cells. In one mutant, three classes of sensilla are lost sequentially. The absence of one class of mechanoreceptors throughout postembryonic development deprives certain sensory neurons of normal stimulation and results in abnormal physiological and structural development of an identified interneuron.
|
eng_Latn
| 798,414 |
A novel PE-MoM hybrid technique to study the oversea electromagnetic propagation
|
An Efficient 3-D FDTD-PE Hybrid Model for Radio Wave Propagation With Near-Source Obstacles
|
Parent compliance: a bad predictor of resolution and a problem in the application of EAU guidelines on vesicoureteral reflux in children
|
eng_Latn
| 798,427 |
A three-dimensional finite element analysis was carried out to determine the annual variation of temperature and thermal stresses of a concrete arch dam. Appropriate heat transfer boundary conditions in the dam body were used for air and reservoir temperature as well as solar radiation variations. Karaj arch dam in Iran was used as a case study. The rate of convergence of the numerical solution is examined. Results of the finite element analysis show that probable cracks occur in a very narrow region of the downstream face. Thermal loads have the most significant effects for causing downstream cracks in comparison with self-weigh and hydrostatic loads. The cracked areas of downstream face conform to the regions that have the highest temperature in downstream face. It can be associated to the solar radiation, which shows two-dimensional analysis of an arch dam cannot yields accurate results and three-dimensional analysis is necessary.Copyright © 2004 by ASME
|
The determination of temperature fields is usually required for the calculation of structural deformation and stress induced by temperature variation. To guarantee the serviceability and safety of ...
|
Several approaches for miniaturization TEM horn antenna while maintaining and/or improving its frequency and time domain performances and peak voltage/field strength handling are described. Understanding the sources of reflection and discontinuities including the methods of elimination thereof are considered first, followed by the loading approaches including dielectric, ferrite, and resistive. Analysis is performed using finite element method (FEM) and finite integration technique (FIT) full wave modeling as respectively implemented in ANSYS HFSS and CST Microwave Studio (MWS).
|
eng_Latn
| 798,493 |
Paramagnetic relaxation of E' centers in gamma-irradiated fused quartz
|
Pulse methods were used to study the longitudinal and transverse paramagnetic relaxation of E' centers in ..gamma..-irradiated fused quartz. The E' center concentrations studied ranged from 10/sup 16/ to 10/sup 18/ cm/sup -3/. It was found that the transverse relaxation is due to the dipole--dipole interactions of the centers. The longitudinal relaxation is mainly due to the interaction with thermal vibrations of the matrix, although a cross-relaxation mechanism dependent on the E' center concentration begins to operate when this is of the order of 10/sup 17/--10/sup 18/ cm/sup -3/. The spectral diffusion mechanism contributes to the decay of the stimulated echo signal.
|
The antenna of the present invention includes: a ground pattern and the ground pattern toward the side notch from the position farthest from the edge portion of the planar element power supply, the ground pattern and the planar element are juxtaposed. By providing cutouts, it can be downsized, and ensures a path for the current to achieve emission of the low frequency band. Further, since the ground pattern and the planar element are juxtaposed, thereby reducing the volume set, and easy to control the antenna characteristic, especially impedance characteristics, which can achieve a wide band.
|
eng_Latn
| 798,499 |
Bumps and waves in a two-dimensional multilayer neural field model
|
s - A single PDF containing all abstracts in this Supplement is available here http://www. biomedcentral.co m/content/pdf/14 71-2202-8-S2-in fo.pdf
|
A new estimator for a four-element plane array is introduced in order to get acoustic-passive direction estimation of targets.We concern much about the performance of the estimator under a two-target situation.In this paper,the two targets concerned are of the same type of acoustic source.Under different signal to interfere ratios,we propose the change of the precision of the direction estimation as the angle between the two targets changes.Our study was done under the real time Warfield situation,and may help the design of small acoustic-passive direction estimation arrays.
|
eng_Latn
| 798,506 |
Arc-designed hardware features that facilitate spray coating applications and features
|
A method and apparatus for forming a coating on a sputter chamber, the work (workpiece) is provided. In general, a coating forming apparatus, a sputtering chamber having at least one workpiece. In general, at least one of the processing member, includes at least one trench formed in the workpiece and configured to at least one trench is limited to an arc spray coating area. In general, a coating forming method, comprising applying a metal coating on the coated area by a step of forming at least one trench defining a coating area on the workpiece, and the arc spray. Coating, sputter chamber, the trench, the workpiece, the arc spray deposition ring
|
Abstract : This thesis presents a study of radiation patterns for low-gain antennas installed on aircraft. With the aid of the computer program APATCH, a simulation of the radian on patterns for a given antenna located at various points on an aircraft structure can he evaluated. The program uses a technique referred. to as Shooting and Bouncing Rays (SBR), which is valid for structures that have typical dimensions of ten wavelengths or more. A Cessna 172 aircraft with a quarter-wavelength monopole antenna and an F-18 aircraft with a telemetry antenna are analyzed.
|
eng_Latn
| 798,513 |
Qualitative analysis of oscillations in isolated populations of flies
|
Populations oscillations in isolated populations of flies are considered. Qualitative methods of analysis are applied to the functional differential equation representing the system and conditions for the occurrence of oscillations are derived. These conditions are readily visualized in terms of parameters which are easily measured and have a straightforward biological interpretation.
|
The generation and behavior of the fractal Koch array factor from a Kaiser window generator is studied. The main advantage of using Kaiser windows is that pattern parameters become much more flexible through altering the Kaiser window. The mainlobe width, current distribution, side-lobe ratio are now adjustable. Different reduced array structures can be obtained by using different threshold levels. Higher threshold values result in a highly reduced number of elements but they may highly distort the pattern and, hence, the multiband behavior. Finally, we study the effect of quantization of the feeding values. Quantization is necessary for implementation and simplification purposes. Several configurations of current distributions with the corresponding patterns are illustrated for different quantization levels. It is shown that moderate quantization keeps the same interesting similarity properties at several bands.
|
eng_Latn
| 798,525 |
EFFECTS OF GROUND ON ANTENNA MUTUAL IMPEDANCE FOR DOA ESTIMATION USING DIPOLE ARRAYS
|
This paper investigates the efiects on received mutual coupling of ‚=2 dipole arrays placed near real-earth. As a rule of thumb, estimation of mutual coupling can be divided in two regions of antenna height that is very near ground 0 < h < ‚ and fairly freespace region h ‚ ‚. The receiving antenna mutual coupling remains fairly unafiected from ground conductivity, when antenna height h ‚ ‚. Both vertical and horizontal polarization cases showed the same trend. Investigation of efiects of nearness of good-ground to the array on DOA estimation revealed that for azimuth DOA estimation, the proposed method of removing mutual coupling works well even for near ground.
|
Abstract : The purpose of this thesis is to evaluate the systems engineering effort by the Aviation Research and Development Activity (AVRADA), the Airborne Engineering Research Activity (AERA), and support contractor DOSS to install the Trimble Global Positioning System (GPS) receiver onto Army helicopter platforms. This study is an example of a successful systems engineering effort to install a non-developmental item (NDI) onto existing aircraft platforms in response to an urgent requirement created by the deployment of aircraft for Operation Desert Shield.
|
yue_Hant
| 798,527 |
GAMMA RADIATION-INDUCED TRANSFORMATIONAL CHANGE IN IR SPECTRUM OF EBHA NEMATIC LIQUID CRYSTAL
|
Gamma ray irradiation technique is the powerful technique to modify the dielectric and electro-optical properties of liquid crystals. It prefers than any other modification technique because no catalysts or additives are required to initiate the reaction. The present paper reports a comparative study of IR spectrum for both irradiated and unirradiated EBHA NLC. The dielectric spectrum and ionic conductivity is also evaluated and well explained in this paper. In addition to this, we have also suggested the concept of the peak data information graph for better understanding of IR spectrum.
|
A MMW radiometer is widely used in remote sensing and guidance. In order to obtain the real brightness temperature distribution of the target, we need to solve the first kind of ill Fredholm integral equation of radiometric antenna temperature. The paper presents a kind of inversion method for modifying antenna pattern and the approach of error compensation. Compared with the theoretical calculation model of 3mm smooth water surface, the results show this algorithm has a higher accuracy for the measurement application.
|
yue_Hant
| 798,552 |
End plate biasing experiments in linear magnetized plasmas
|
Meso-scale streamer has a radially elongated structure and is believed to enhance the radial transport. In order to study the control of the streamer, we demonstrated an end plate biasing to the streamer state in the PANTA linear plasma. During the end plate biasing, the electron density profile became more peaked, fluctuation was suppressed, the streamer structure was deconstructed, and the waveform became a periodic solitary state. The radial electric field only induced at around the end plate was found to play an important role for the streamer suppression.
|
In this paper, a free space power combining oscillator antenna array using a metamaterial based injection locking coupling network is described and demonstrated. The unique metamaterial series coupling network utilizes the infinite wavelength phenomenon which allows it to support an infinitely long wave at a non-zero frequency. It is demonstrated that equal phase/amplitude oscillator synchronization can be achieved without regards to the antenna element spacing in the array. A small scale prototype oscillator array is designed to have compact, non-uniform element spacing to demonstrate the concept. An EIRP of 18 dBm at 2.37 GHz is measured.
|
eng_Latn
| 798,554 |
A phantom and simulation study on body-shields to cope with radioactivity outside the field of view in 3D PET
|
Basic physics characteristics of body-shields to screen out radioactivity outside the field of view were analyzed by phantom experiments and Monte-Carlo simulation. The shielding effect depended primarily on the geometrical condition as in the case of end-shields. However, body-shields became more effective by increasing the shield thickness more than 10 mm as not in the case of end-shields. This characteristic difference was related with the fractions of un-scattered and shield-scattered components. A body-shield could be as effective as an end-shield if a good geometrical condition was kept with sufficient shield thickness.
|
We consider the cross area of the PP_ and PSV_wave window as the best window for joint PP_ and PSV_wave acquisition in VTI media. Within the effective window, the PP_ and PSV_wave's raypathes and phase angles at all reflection points are calculated, and the reflection (or transmission) coefficients' ratios of PSV- to PP_wave solved from Zoeppritz equations are defined as the controlling factor G. Then we use G values as the main controlling parameters of joint PP_ and PSV_wave acquisition design in VTI media, determine the best receiving window of detectors by analyzing G values, and derive the method of optimizing the receiving window for acquisition of multi_component converted seismic data in VTI media.
|
eng_Latn
| 798,569 |
Properties of a large scale multibeam antenna using a phased array fed reflector with radially aligned elements
|
Communication satellites achieve global communication coverage by using high-gain multibeam satellite antennas. These antennas fall into two types: direct radiating phased arrays for low Earth orbit (LEO) satellites and large reflector antennas fed by cluster feeds for geostationary orbit (GEO) satellites. This paper provides an analytical study of the phased array fed single reflector antenna that can cover wide regions like Asia by 127 beams based on our design techniques. To confirm the feasibility of the designed phased array fed reflector antenna a partial model of the array feed was manufactured and its electrical properties tested. Evaluation of the measured properties proves the feasibility of the phased array fed single reflector antenna as a large scale multibeam antenna.
|
The name of the present invention is "secondary radio wave propagation characteristic prediction system and method." A radio-wave propagation characteristic prediction assistance system includes a storage portion, the attribute information input and output portions. Attribute information storage section area and radio wave propagation characteristics of the reference region useful predictive information stored in association with each other. Attribute information input section inputs attribute information to predict the radio-wave propagation characteristic of the region. Output information stored in the storage portion of the search section to specify the region having the attribute information matching attribute input attribute information input section, and outputs the specified region associated with the reference information.
|
eng_Latn
| 798,573 |
Two-dimensional modulation and instability of a short wave riding on a finite-amplitude long wave
|
Abstract We study the effects of a long wave of finite amplitude on a short wave propagating in a different direction. To facilitate analytical treatment, the long wave is modelled by Gerstner's exact solution, and Lagrangian coordinates are used. Focus is first on the moderately long-scale modulation within a duration comparable to the period of the long wave. The angle of inclination is allowed to be arbitrary. Extension to the evolution over much longer time and distance of propagation is then made for a short wave colinear with the long wave but modulated slowly in both longitudinal and transverse directions. The instability of the short wave due to oblique side bands is examined, and is found to be significantly enhanced by the presence of the long wave.
|
This paper presents design and characteristics of a compact, highly integrated Ka-band T/R module built by using a miniature magnetron in the transmitter chain. By implementing a solid-state modulator and microstrip design in the microwave part of the receiver, the overall size of the module has been reduced significantly. The module provides capabilities to realize Doppler date processing by using a digital coherent-on-receiver technique.
|
eng_Latn
| 798,575 |
Radiation Patterns of Antennas Installed on Aircraft.
|
Abstract : This thesis presents a study of radiation patterns for low-gain antennas installed on aircraft. With the aid of the computer program APATCH, a simulation of the radian on patterns for a given antenna located at various points on an aircraft structure can he evaluated. The program uses a technique referred. to as Shooting and Bouncing Rays (SBR), which is valid for structures that have typical dimensions of ten wavelengths or more. A Cessna 172 aircraft with a quarter-wavelength monopole antenna and an F-18 aircraft with a telemetry antenna are analyzed.
|
We propose and analyse three different power selection schemes for slotted ALOHA random access protocol operating under multiple power levels. Through analysis and numerical examples we demonstrate that these schemes can significantly improve the performance of slotted ALOHA, in terms of throughput and stability, under heavy load. The proposed schemes are truly distributive in nature and can be easily implemented in wireless access systems without requiring any centralised control.
|
eng_Latn
| 798,576 |
Electromagnetic Emergence in Metamaterials
|
This chapter focuses on the emergent electromagnetic properties in such heterogeneous materials that are, in today’s discussion, being more and more often called “metamaterials.” More precisely, the very concept of metamaterial is under study as also are the preconditions under which such a term is appropriate.
|
Wireless connectivity, the internet of things, smart technologies and applications will all create new EMC challenges, in both expected and unexpected forms. Traceable metrology needs to be developed, both to characterize and optimize these future systems, and to minimize interference and EMC problems. This paper looks at metrology and EMC challenges related to 5G and beyond communications, and what NIST is doing towards solutions.
|
eng_Latn
| 798,582 |
MNDO study of the tautomers of nucleic bases: Part III. Reinvestigation of the amino-type tautomers structure
|
Abstract MNDO recalculations with full geometry optimization for the amino-type tautomers of cytosine, adenine and guanine predict noncoplanarity of the amino nitrogen atom with heteroaromatic rings. These molecular structures are about 2.1 kJ mol −1 more stable in comparison with “coplanar” structures. Bond lengths, valence angles, dipole moments and ionization potentials of the “coplanar” and “noncopolanar” forms do not differ significantly.
|
This paper presents design and characteristics of a compact, highly integrated Ka-band T/R module built by using a miniature magnetron in the transmitter chain. By implementing a solid-state modulator and microstrip design in the microwave part of the receiver, the overall size of the module has been reduced significantly. The module provides capabilities to realize Doppler date processing by using a digital coherent-on-receiver technique.
|
eng_Latn
| 798,590 |
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