Showing papers on "Antisymmetric relation published in 1989"
TL;DR: In this article, the Bernoulli-Euler theory of beam flexure was extended to allow warping of the beam cross-section, which can make a large difference to results for thin-walled beams of open section.
140 citations
TL;DR: In this article, the action for a massless relativistic point particle with a gauged N-extended worldline supersymmetry was discussed, which yields, upon quantization, a relativism wave equation for pure spin N/2.
Abstract: In a previous work the authors discussed the action for a massless relativistic point particle with a gauged N-extended worldline supersymmetry that yields, upon quantisation, a relativistic wave equation for pure spin N/2. They present further details, emphasising the N=2 particle model for which a wavefunction with O(2) charge q can be interpreted as the field strength of a (q-1)-form gauge potential. They present extensions of this model that yield field equations for massless and massive antisymmetric tensors in arbitrary spacetime dimension d. They show how to obtain chirality and generalised self-duality conditions.
119 citations
TL;DR: In this paper, the authors measured the symmetric and antisymmetric stretch spectra of a 1A1 CH2 with Doppler-limited resolution by infrared flashkinetic spectroscopy between 2600 and 3050 cm−1.
Abstract: The symmetric and antisymmetric stretch spectra of a 1A1 CH2 are measured with Doppler‐limited resolution by infrared flash‐kinetic spectroscopy between 2600 and 3050 cm−1. The spectra are significantly perturbed by spin–orbit interactions between near‐resonant levels of X 3B1 in both lower and upper levels of the transitions, and by Coriolis interaction between symmetric and antisymmetric stretch states. The triplet character of the perturbed levels is detected by observing broadening of MJ structure in a magnetic field of about 1 kG. The levels that are likely to be perturbed by triplet methylene are identified using the experimentally observed and theoretically calculated 3B1 energy level structure. The term values of the remaining symmetric and antisymmetric stretch levels are simultaneously fit to Watson’s Hamiltonian including Coriolis coupling. This analysis provides the remaining information needed to determine the equilibrium rotational constants [Ae =19.8054(206), Be=11.2489(45), and Ce =7.238...
97 citations
TL;DR: In this paper, the authors proposed a method of analysis based on the complex variable approach of Savin and Lekhnitskii for branched crack problems in two-dimensional, anisotropic elastic homogeneous solids.
Abstract: Branched crack problems are analyzed in two-dimensional, anisotropically elastic homogeneous solids. The method of analysis is based on the complex variable approach of Savin and Lekhnitskii. The Hilbert problem in an anisotropic body is defined, and a pair of singular integral equations are derived for dislocation density functions associated with a branched crack. For both symmetric and nonsymmetric geometries, and under symmetric and antisymmetric loads, the stress intensity factors and the energy release rate are computed numerically by extrapolation for infinitesimally small lengths of branched cracks. The results are compared with those of the isotropic case given in the literature and the effects of anisotropy are discussed.
87 citations
TL;DR: In this article, a closed-form least-squares solution to the design problem of two-dimensional real zero-phase finite-impulse-response (FIR) filters with quadrantally symmetric or antisymmetric frequency response is obtained.
Abstract: A closed-form least-squares solution to the design problem of two-dimensional real zero-phase finite-impulse-response (FIR) filters with quadrantally symmetric or antisymmetric frequency response is obtained. An in-depth study of the matrices involved in the development of the design technique reveals a number of useful properties. It is shown that these properties lead to an optimal analytical solution for the filter coefficients, making it unnecessary to use the time-consuming methods of optimization, matrix inversion, and iteration. Because of the reduced order of the matrices involved, their specific characteristics, and the analytical approach, the computational complexity is greatly reduced. Simplicity and efficiency of the design technique is illustrated through examples. The results in terms of error in frequency response compare favorably with those obtained by using other techniques. It is shown that the design time using the proposed technique is significantly smaller than that required by the I/sub p/-optimization technique or weighted least-squares technique using Harris' ascent algorithm or modified Lawson's algorithm. >
83 citations
TL;DR: In this article, the analysis of the acoustic scattering by thin-walled, evacuated, elastic spherical shells immersed in water is studied, and the analytic structure of the scattering amplitude in the complex-k plane is directly analyzed using Cauchy's residue theorem, and dispersion curves are presented for the lowest elastic modes of the fluidloaded shell.
Abstract: The acoustic scattering by thin‐walled, evacuated, elastic spherical shells immersed in water is studied. The analytic structure of the scattering amplitude in the complex‐k plane is directly analyzed using Cauchy’s residue theorem, and dispersion curves are presented for the lowest elastic modes of the fluid‐loaded shell. It is found that fluid loading has a profound effect on the vacuum dynamical characteristics of the shell; the spherical equivalent of the first antisymmetric, flat‐plate Lamb wave for the fluid‐loaded shell bifurcates into two distinct modes near the frequency that the vacuum dispersion curve transitions from a subsonic to a supersonic phase velocity. By way of contrast, the spherical equivalent of the first symmetric Lamb wave is essentially unaffected. The salient features of the free‐field scattering process are also analyzed in terms of the resonance excitation of these modes.
70 citations
TL;DR: It is shown that more elaborate models, in which a second nonlinear stage combines the output of local nonlinear mechanisms, are consistent with the data, provided that an appropriate spatial scale is chosen for the second stage of processing.
Abstract: We investigate the neural computations underlying pattern processing with stimuli based on textures balanced for spatial frequency content (and second-order correlations) but not for higher-order correlations (Julesz et al. 1978). Interchange between two such isodipole textures produces a robust human visual evoked potential (VEP). The difference in population activity driven by two isodipole textures is quantified by the antisymmetric component of the VEP. Statistical properties of the textures eliminate contributions from linear mechanisms to the antisymmetric VEP. The dependence of the antisymmetric VEP on check size and fourth-order correlation statistics is used to test nonlinear models for the underlying neural computations. Linear summation, followed by a simple nonlinearity (such as rectification, saturation, or threshold), is inconsistent with the data. More elaborate models, in which a second nonlinear stage combines the output of local nonlinear mechanisms, are consistent with the data, provided that an appropriate spatial scale is chosen for the second stage of processing. For checks 4 min or smaller, the deduced interaction length is 10-15 min. For checks larger than 4 min, the interaction length is proportional to check size.
52 citations
01 Oct 1989
TL;DR: In this paper, the authors compared various modeling techniques for the eigenmode analysis of integrated optical waveguides, and applied twelve different methods to the analysis of two typical III-V rib waveguide.
Abstract: In order to compare various modelling techniques for the eigenmode analysis of integrated optical waveguides, twelve different methods are applied to the analysis of two typical III–V rib waveguidesl Both a single and a coupled waveguide case are considered. Results focus on the effective refractive index value for the lowest order TE-mode in the case of the single waveguide, and on the coupling length between the lowest order symmetric and antisymmetric TE-modes of the coupled waveguides.This paper is the result of the joint effort of thirteen research groups in the framework of the Device Modelling group of the COST-216 project.
38 citations
TL;DR: In this article, the dimensional reduction of massless gauge-invariant free Lagrangians for totally symmetric and totally antisymmetric tensors of arbitrary integral spins is carried out for the covariant and light-cone gauges.
Abstract: The dimensional reduction of massless gauge-invariant free Lagrangians for totally symmetric and totally antisymmetric tensors of arbitrary integral spins is carried out for the covariant and light-cone gauges. The structure of the auxiliary fields for the massive Lagrangians so obtained is elucidated.
34 citations
TL;DR: In this article, a generalized Levy-type solution in conjunction with the state space concept is developed for the bending, buckling and vibration of antisymmetric angle-ply laminated plates.
32 citations
TL;DR: A classical wormhole solution is constructed for gravity couples to a positive energg, maplese scalar field, characterized by a scalarField configuration which is locally dual to the scalar Field.
TL;DR: In this article, a simple method for measuring Lamb wave phase velocities is used to obtain data for the lowest symmetric Lamb mode (S0) and the lowest antisymmetric Lamb modes (A0) for composite laminates.
Abstract: A simple method for measuring Lamb wave phase velocities is used to obtain data for the lowest symmetric Lamb mode (S0) and the lowest antisymmetric Lamb mode (A0) for composite laminates. The experimental data are compared with the results from an approximate theory for the lowest Lamb modes in the low frequency, long wavelength region for a unidirectional laminate, a symmetric cross-ply laminate, a symmetric quasi-isotropic laminate and an aluminum plate. There is good correlation between the data and the results from the approximate theory, which suggests that the approximate theory works well in the low frequency, long wavelength region in these cases. Also, this experimental procedure of measuring phase velocities of the lowest symmetric and antisymmetric modes can be used to characterize laminated composite plates with and without damage since each material and stacking sequence gives distinct lowest symmetric and antisymmetric curves.
TL;DR: In this paper, the spectral index method was applied to closely coupled rib waveguides, and analytical expressions in terms of the propagation constant β were given for symmetric and antisymmetric polarised modes.
Abstract: The spectral index method is applied to closely coupled rib waveguides. Analytical expressions in terms of the propagation constant β are given for symmetric and antisymmetric polarised modes. The calculated coupling lengths are in excellent agreement with those obtained by mainframe programs.
TL;DR: In this paper, a hierarchical partitioning strategy is presented for the nonlinear dynamic analysis of unsymmetric structures on vector multiprocessor systems, which is based on a novel Hierarchical Partitioning strategy in which the response vectors (modes) are obtained by using only a fraction of the degrees of freedom of the original finite element model.
TL;DR: In this paper, the degeneracy of stable temporal Orr-Sommerfeld eigenmodes for plane Poiseuille flow was studied and the responses of the degeneracies were investigated through the initial value problem.
Abstract: Degenerating stable temporal Orr-Sommerfeld eigenmodes are studied for plane Poiseuille flow. The discrete spectrum of the eigenmodes is shown to possess infinitely many degeneracies, each appearing at a certain combination of k (the modulus of resultant wavenumber) and α R (the streamwise wavenumber time the Reynolds number). The eigenmodes are found to degenerate in a specific manner which confines the streamwise phase velocities of the degeneracies to be around $\frac{2}{3}$ of the centreline velocity. The responses of the degeneracies are investigated through the initial-value problem. The responses of the first four symmetric and the first two antisymmetric degeneracies are evaluated numerically for arbitrary initial disturbances expanded in terms of Chebyshev polynomials. The first symmetric and the first antisymmetric degeneracies exhibit temporal growth of the amplitudes in the wavenumber space. The maximum amplitudes are at most 7 times larger than the corresponding initial amplitudes. The amplitudes of the responses of the other four degeneracies decay rapidly owing to their higher damping rates. The time for which the degeneracy-response is in the growing phase is shown to be stretched with increasing Reynolds number. The degeneracies can therefore be active for longer periods of time at larger Reynolds numbers.
TL;DR: In this article, analytical solutions of the classical, first-order and third-order laminate plate theories are used to study the transient response of antisymmetric cross-ply simply supported rectangular plates.
TL;DR: In this paper, the static and dynamic behavior of a cable dome was studied by testing a 1/50 scale model under a symmetric and an antisymmetric loading, and three different pretension levels were considered.
Abstract: The static and dynamic behavior of a cable dome was studied by testing a 1/50 scale model. Three different pretension levels were considered. The static response of the model under a symmetric and an antisymmetric loading was investigated. The cable dome's behavior changes from a compressive to a tensile membrane with increasing applied central load. The cable model exhibits a hardening response, especially in the antisymmetric mode. The nonlinearity becomes more pronounced with decreasing pretension. The stiffness in the antisymmetric mode is dominated by the geometric stiffness from pretensioning. In the vertical acceleration (symmetric) test at the intermediate pretension the first dominant mode was antisymmetric. A small exciter was also used to apply a single asymmetric controlled force. Up and down harmonic excitation sweeps showed a dynamic instability. The frequency range over which the response is unstable decreases with increasing pretension. The dynamic to static strain ratio decreased from 20%...
TL;DR: In this article, an exact solution to the buckling of angle-ply laminated plates is developed for a variety of boundary conditions, based on a generalized Levy type solution considered in conjunction with the state space concept.
Abstract: An exact solution to the buckling of antisymmetric angle‐ply laminated plates is developed for a variety of boundary conditions The procedure, based on a generalized Levy type solution considered in conjunction with the state space concept, is applicable to rectangular plates with two opposite edges simply supported and the remaining ones subjected to a combination of clamped, simply supported, and free boundary conditions The solutions are obtained for the Yang, Norris, and Stavsky (YNS) theory which is a generalization of Mindlin's theory for isotropic plates to laminated anisotropic plates and includes shear deformation
TL;DR: In this paper, the switch characteristics of three-arm integrated optic directional couplers with both symmetric and antisymmetric drive voltages are examined and the symmetry properties of these devices, predicted by previous theory, are discussed in terms of scalar strong coupling coefficients normally neglected as small.
Abstract: The switch characteristics of three-arm integrated optic directional couplers with both symmetric and antisymmetric drive voltages are examined. The symmetry properties of these devices, predicted by previous theory, are shown to be violated and the reasons for this are discussed in terms of scalar strong coupling coefficients normally neglected as small. It is also shown that the inclusion of modal overlaps introduces additional coupling terms and causes significant power redistribution in the bend sections. Experimental measurements for the antisymmetric configuration are presented, and it is shown that different electrode loading of the center and outer guides affects device operation. >
TL;DR: In this article, the response of composite laminated plates subjected to nonstationary random excitation is determined using first-order shear deformation theory for the analysis of symmetric cross-ply and antisymmetric angle-ply plates.
TL;DR: In this article, a complete vibration Hamiltonian for the hydrogen-bonded ionic system OH − ·H 2 O is developed following the general idea of the Hougen-Bunker-Johns approach.
TL;DR: In this article, the Fourier series expansion of field variables has been generalized further by including more expansion terms, an efficient decomposition of kernels into symmetric and antisymmetric forms, improved evaluation of matrix coefficients and developing more general computer implementation to include surface stress calculations, effects of body forces and extensive substructuring facilities to analyse multi-zone problems.
Abstract: It is well known that there are many benefits in solving axisymmetric solids subjected to non-axisymmetric loading by using Fourier series expansion of field variables. Although many researchers have utilized this technique to solve problems of cooling towers and rocket nozzles, etc. by the Finite Element Method, the BEM formulation and implementation of such a method have been available only recently, mainly due to the efforts of Rizzo and Shippy3 and Mayr et al.4 In this paper these early developments have been generalized further by including more expansion terms, an efficient decomposition of kernels into symmetric and antisymmetric forms, improved evaluation of matrix coefficients and developing more general computer implementation to include surface stress calculations, effects of body forces and extensive substructuring facilities to analyse multi-zone problems.
TL;DR: In this article, the authors studied the time harmonic elastodynamic response of two semi-infinite elastic plates of dissimilar material properties perfectly bonded along their lateral faces, where the wave field in either half-plate can be written as a superposition of the so-called Rayleigh-Lamb eigenmodes of an infinite plate.
Abstract: The time harmonic elastodynamic response of two semi-infinite elastic plates of dissimilar material properties perfectly bonded along their lateral faces is studied. The wave field in either half-plate can be written as a superposition of the so-called Rayleigh–Lamb eigenmodes of an infinite plate. The interaction of a time harmonic incident wave with the interface results in reflected and transmitted fields that contain contributions from all of the real, imaginary, and complex eigenmodes of an infinite plate. Attention is focused on the distribution of energy among the various reflected and transmitted eigenmodes over a range of frequencies. The fundamental symmetric and the fundamental antisymmetric Lamb modes are each used as input excitations. Such excitations can be approximately realized in experiments. It is assumed that the solution of such a canonical problem will facilitate the solution of problems with complicated time-dependent sources.
Patent•
12 Dec 1989
TL;DR: In this article, two optical waveguides coupled by an optical wave propagating in the symmetric mode are excited and subjected to the action of an electromagnetic traveling wave having the effect of shifting the frequency of the optical wave which undergoes a transition from the asymmetric mode to the antisymmetric mode.
Abstract: In a device for shifting the frequency of an optical wave, two optical waveguides coupled by an optical wave which propagates in the symmetric mode are excited and subjected to the action of an electromagnetic traveling wave having the effect of shifting the frequency of the optical wave which undergoes a transition from the symmetric mode to the antisymmetric mode. A transfer device supplied with a direct-current voltage V O serves to re-convert the antisymmetric mode to the symmetric mode in order to add the two light signals and to obtain a single output signal translated by the frequency F. This permits the construction of BLU optical modulators.
TL;DR: In this article, explicit formulas for the characters of symmetric and antisymmetric powers of an arbitrary representation up to the sixth are given, and a general method for obtaining the higher ones is described.
Abstract: Explicit formulas are given for the characters of symmetric and antisymmetric powers of an arbitrary representation up to the sixth, and a general method for obtaining the higher ones is described. The results allow, among others, the determination of nonvanishing higher force constants in symmetrical molecules. The benzene molecule, for instance, has 237 nonvanishing cubic and 1890 quartic force constants. Other potential applications are a general method for the symmetry species of vibrational overtones, the determination of the number of independent centrifugal distortion constants, and the symmetry classification of vibrational multiplets.
TL;DR: In this article, the interaction of null strings and null membranes with an arbitrary background T lm … n (x ) in (2 + 1) and (3 + 1), described by means of the Wess-Zumino-like actions is studied.
TL;DR: In this paper, the F-spin structure of a general proton-neutron interacting boson model Hamiltonian and of the corresponding electromagnetic operators was studied, using a separation into parts which are symmetric and antisymmetric under the interchange of proton and neutron degrees of freedom.
Abstract: We study the F-spin structure of a general proton-neutron interacting boson model Hamiltonian and of the corresponding electromagnetic operators, using a separation into parts which are symmetric and antisymmetric under the interchange of proton and neutron degrees of freedom. We also use a formal procedure in which we couple proton and neutron operators to a given F-tensor rank. We deduce conditions of F-spin symmetry and F-spin invariance for the Hamiltonian, as well as selection rules for electromagnetic transition matrix elements. We use first order perturbation theory to obtain the (F, Fz)-dependence of the energy and wave functions, when F-vector and F-tensor (rank 2) parts are added to an “unperturbed” Hamiltonian, which is F-spin invariant.
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TL;DR: It is shown that these wormholes and the one of Giddings and Strominger, Hawking, Halliwell and Laflamme, and Myers can be obtained by slicing five-dimensional spaces with horizons.
Abstract: We solve the Euclidean Einstein equations with three-index antisymmetric and two-index antisymmetric (electromagnetic) tensors for monopole configurations on a space with three-surfaces of topology {ital S}{sup 1}{times}{ital S}{sup 2} and describe wormhole solutions. We show that these wormholes and the one of Giddings and Strominger, Hawking, Halliwell and Laflamme, and Myers can be obtained by slicing five-dimensional spaces with horizons.
TL;DR: In this paper, a generic presentation of the large deflection, postbuckling and nonlinear flexural vibration behavior of antisymmetric angle-ply laminated plates is investigated, and a transformation between on-axis and off-axis stiffnesses is presented such that all the stiffnesses, including bending-stretching coupling, in the nonlinear governing equations of angle laminates can be expressed in terms of bounded global constants in orthotropic plates.
TL;DR: In this paper, the ground state of the (110) torelon sector is found to be antisymmetric under x − y interchange, which has a bearing on 't Hooft's conjecture concerning the energy at large volumes of torelons and their string-like nature.