A Method for Changing Sound-Image Position Using the Linear Loudspeaker Array and Two-Dimensional FIR Digital Filter

Author(s):  
Kiyoshi Nishikawa ◽  
Tetsuya Yokoyama ◽  
Mikiko Miyagishi
Author(s):  
Wei-Der Chang ◽  
Tai-Ming Chang

This paper proposes a novel method which is based on particle swarm optimization (PSO) algorithm for the two-dimensional FIR digital filter design. In the PSO algorithm, it simply uses two adjusting mechanisms including particle’s velocity and position updating to achieve the optimization. In addition, numerical representations for each candidate solution are completely real numbers. The PSO algorithm is utilized to design the two-dimensional FIR digital filter with linear-phase characteristic so that its frequency response can approximately meet the desired specification. Finally, we will illustrate the design performance of the proposed method with two experiments. Simulation results reveal that the proposed scheme has a good design performance on the two-dimensional FIR digital filter.


Author(s):  
L. Reimer ◽  
R. Oelgeklaus

Quantitative electron energy-loss spectroscopy (EELS) needs a correction for the limited collection aperture α and a deconvolution of recorded spectra for eliminating the influence of multiple inelastic scattering. Reversely, it is of interest to calculate the influence of multiple scattering on EELS. The distribution f(w,θ,z) of scattered electrons as a function of energy loss w, scattering angle θ and reduced specimen thickness z=t/Λ (Λ=total mean-free-path) can either be recorded by angular-resolved EELS or calculated by a convolution of a normalized single-scattering function ϕ(w,θ). For rotational symmetry in angle (amorphous or polycrystalline specimens) this can be realised by the following sequence of operations :(1)where the two-dimensional distribution in angle is reduced to a one-dimensional function by a projection P, T is a two-dimensional Fourier transform in angle θ and energy loss w and the exponent -1 indicates a deprojection and inverse Fourier transform, respectively.


1986 ◽  
Vol 29 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Christian Constanda

Kirchhoff's kinematic hypothesis that leads to an approximate two-dimensional theory of bending of elastic plates consists in assuming that the displacements have the form [1]In general, the Dirichlet and Neumann problems for the equilibrium equations obtained on the basis of (1.1) cannot be solved by the boundary integral equation method both inside and outside a bounded domain because the corresponding matrix of fundamental solutions does not vanish at infinity [2]. However, as we show in this paper, the method is still applicable if the asymptotic behaviour of the solution is suitably restricted.


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