A novel inverse scattering approach is developed to the reconstruction of electrical property distributions of a two-dimensional biaxial anisotropic object using time-domain scattering data. The approach is an extension of the forward-backward time-stepping (FBTS) algorithm previously described for an isotropic object. Synthetic examples of inversion are given to assess the effectiveness of the proposed method.

Footprint assembly was proposed to reduce the blurriness of texture mapped image by mipmapping. Even though it can improve the quality of texture mapped image, there are yet blurring due to the limitation of it's filter kernel. This paper proposes a novel texture filtering, called adaptive footprint assembly (AFA), to overcome the limitation of footprint assembly. The proposed method greatly improves the quality of texture mapped images.

The contribution of the paper is two-fold: Firstly, a review of the point set registration literature is given, and secondly, a novel covariance weighted least squares formulation of the multiple view point set registration problem is presented. Point data for surface registration is commonly obtained by non-contact, 3D surface sensors such as scanning laser range finders or structured light systems. Our formulation allows the specification of anisotropic and heteroscedastic (point dependent) 3D noise distributions for each measured point. In contrast, previous algorithms have generally assumed an isotropic sensor noise model, which cannot accurately describe the sensor noise characteristics. For cases where the point measurements are heteroscedastically and anisotropically distributed, registration results obtained with the proposed method show improved accuracy over those produced by an unweighted least squares formulation. Results are presented for both synthetic and real data sets to demonstrate the accuracy and effectiveness of the proposed technique.

An analytical solution of the London equation for the weakly coupled grain model of high Tc superconducting thin films has been obtained in the case of finite thickness by taking full account of anisotropic conductivities. Using the solution, we provide general expressions for the transmission-line parameters of high Tc superconducting transmission lines. Dependences of the inductance and resistance on the grain size, coupling strength and film thickness have been numerically evaluated and discussed.

Thermal stability of anisotropic and isotropic Co alloy thin-film media is investigated. The orientation ratio of CoCrTa(Pt)/Cr media was controlled by the mechanical texture of the NiP/Al substrates. Bulk magnetic properties, delta M curves and time decay of magnetization in the circumferential and radial directions were measured. The maximum magnetic viscosity coefficient calculated from the time decay of magnetization in the circumferential direction was higher than that in the radial direction for a mechanically textured sample, while it was similar in both directions for a non-textured sample. The magnetic viscosity coefficient in the circumferential direction is smaller than that in the radial direction when the reverse field is in the range of the demagnetization field for thin-film recording media. This implies that an anisotropic sample (namely, a sample with a high orientation ratio) will be more thermally stable when it is not exposed to a large external magnetic field.

We address, in this paper, the main features of hybrid modes propagating in a rectangular waveguide partially filled with pseudochiral Ω-slabs. For the particular case of a uniaxial Ω-slab, we show that LSE and LSM hybrid modes can propagate in this inhomogeneously filled rectangular waveguide. The influence of the Ω-parameter, which characterizes the magnetoelectric tensors of the bianisotropic slab, on LSM modes is analyzed--namely an increase in the bandwidth for monomodal operation is reported. In addition, a field displacement effect and a variable phase shift proportional to the change of the Ω-parameter are attained. Finally, it is shown that the propagation characteristics are independent of the direction of propagation and so, unlike the case of magnetically biased ferrite loading, reciprocal devices can be achieved.

A method of visualization of multimodal images by one monochromatic image is presented on the basis of the projection pursuit approach of the inverse process of the anisotropic diffusion which is a method of image restoration enhancing contrasts at edges. The extension of the projection from a linear one to nonlinear sigmoidal functions enhances the contrast further. The deterministic annealing technique is also incorporated into the optimization process for improving the contrast enhancement ability of the projection. An application of this method to a pair of MRI images of brains reveals its promising performance of superior visualization of tissues.

This paper implements some new techniques to analyze the light beam scattering from a magneto-optical (MO) disk using the three-dimensional finite-difference time-domain (FDTD) method. The anisotropic FDTD update equations are implemented to calculate the propagation of a coherent monochromatic light in the MO material. An anisotropic absorbing boundary condition based on Berenger's perfectly matched layer (PML) concept is also developed. The Gaussian incident light beam is introduced into FDTD computation region exactly by using equivalent electric and magnetic currents. The scattering pattern of light beam from the MO disk is computed and in part compared with that obtained by using the boundary element method. The scattering patterns by the circular recording bit of different radius are calculated to indicate the optimum radius of the recording bit.

A method for analyzing the scattering of electromagnetic waves by a general bianisotropic slab is presented by extending the author's previous approaches for anisotropic, chiral, and those periodic media. The analysis is formulated in a unified matrix form, so that scattering characteristics can be obtained by system matrix calculations. The method can be extended straightforwardly to multilayerd and periodic structures. The scattering efficiencies are obtained for the incidence of not only linearly polarized waves but also circularly polarized waves.

44 matrix-based analysis of electromagnetic waves scattered by an infinite array of slots with polar-type anisotropic media are presented. In the analysis, the total fields are given as sum of the fields which exist even if the apertured plane are replaced by a ground plane and the fields scattered from the magnetic currents within the apertures. The scattered fields are expanded in terms of two-dimensional Floquet modes. Expression of each fields are obtained through eigenvalue problem for 44 coupled wave matrix. Unknown magnetic currents in the apertures are determined by applying Galerkin's method to the continuity condition about the magnetic fields in the apertures. Calculated results for isotropic cases are compared with other results for the complementary problem available in the literature using Babinet's principle. Further numerical calculations are performed in the case of gratings with polar-type anisotropic slab.

This paper verifies the accuracy of PO as applied to the scattering of dipole waves by a finite size reflector which is composed of strips on a grounded dielectric slab. By using the closed form expressions of reflected waves from the surface, PO calculation can be conducted straightforwardly. The calculated results are compared with the experimental ones for vertical and horizontal dipoles over a circular reflector.

This paper presents a theoretical study on transmission properties of bent optical waveguides of uniaxial anisotropic material. The waveguiding structure consists of two parallel straight slab waveguides connecting by an oblique section. By arranging the direction of the optical axis in the oblique section so that the wave normal always points to the same direction throughout the waveguiding structure, low loss transmission can be realized. The analysis of wave propagation through the structure is based on the finite difference beam propagation method. Numerical results indicate that by optimally arranging the direction of the optical axis in the oblique section power coupling coefficients better than 95% can be obtained for any tilt angle of the oblique section when the tilt angle is smaller than 2 degrees. Some field distributions are also presented along the waveguiding structure.

The emphasis on nonisotropic media in the electromagnetics research community has recently brought forward a large amount of new literature on the material effects. The material phenomena affecting the electromagnetic characterization are contained in the constitutive relations between an electric and a magnetic excitation and an electric and a magnetic response. Starting from the constitutive equations, this article is an attempt to cast light on the labels, terms, notation, and classification of linear electromagnetic materials. Using dyadic analysis and physical concepts like reciprocity and magnetoelectric coupling, the different classes within bi-anisotropic media are presented in systematic form. Simple isotropic media can be characterized by two material parameters: the electric polarizability is measured by permittivity ε, and the magnetic polarizability by the permeability µ. For bi-isotropic media, there exists magnetoelectric coupling, but due to isotropy (independence of the direction of the field vectors) the two additional material parameters are scalars. The physical interpretation to these two parameters are chirality and nonreciprocity. The two subclasses of bi-isotropic materials are Pasteur and Tellegen media. If there is direction dependence in the medium, we call the material anisotropic, and a scalar quantity has to be described by a dyadic with nine components. Finally, the most general material is called bi-anisotropic, which means that in addition to a dyadic permittivity and permeability, the two magnetoelectric material parameters are dyadics. The essential feature in the classification of the present paper is the separation of all the four material parameter dyadics into symmetric and antisymmetric parts. For permittivity and permeability, the symmetric parts correspond to reciprocal media and the antisymmetric parts are nonzero for nonreciprocal media. In the cross-coupling dyadics the decomposition into symmetric and antisymmetric parts disriminates chiral media, omega media, classical magnetoelectric media, and moving media. Finally, possible alternative characterrizations of bi-anisotropic materials are discussed.

In practical applications of the artificial boundary surfaces, such as corrugation and strips on a grounded dielectric slab, the surfaces have finite sizes. The diffraction fields from anisotropic surface of this kind can not be calculated using conventional diffraction coefficients. In this paper, uniform diffraction coefficients for the strips on a grounded dielectric slab are given in the sense of physical optics, as functions of incident angle, polarization and structural parameters of the surface. Firstly, the incident plane wave is decomposed into the two special polarization directions. Then uniform diffraction coefficients originally derived for isotropic surfaces with arbitrary impedance can be applied for each polarization component. Finally, expressions for the diffraction coefficients from the anisotropic surface are given as the sum of those for two polarization components. The validity of the diffraction coefficients is verified theoretically and experimentally.

We present a 44 matrix-based analysis of scattering form a two-dimensional rectangular resistive plane gratings placed on an anisotropic dielectric slab. The solution procedure used is formulated by extending the 44 matrix approach. The fields are expanded in terms of two-dimensional Floquet modes. Total fields can be given as sum of primary and secondary fields whose expression are obtained through eigenvalue problem of coupled wave matrix. Unknown currents on resistive patches are determined by applying Galerkin's method to the resistive boundary condition on resistive grating. Results are compared with other numerical examples available in the literature for isotropic cases. Further, numerical calculation are performed in the case of gratings with polar-type anisotropic slab.

Fabrication methods of novel silicon quantum wires and dots using anisotropic wet chemical etching and thermal oxidation are newly proposed. The method realizes fine Si quantum wires, which are fully surrounded by the thermal SiO2 without any defects. The wires are straight and the Si/SiO2 interfaces are fairly flat. The 10 nm width wires are confirmed by Transmitting Scanning Microscopy observation in minimum size. The fine quantum dots are also fabricated using this method. The characteristics of the wires are investigated and the current oscillations in variation with the gate voltage are observed in low temperature. We believe the origin of these oscillations arise from one-dimensional subband conduction.

Electromagnetic power absorption in multilayered tissue media including anisotropic muscle regions whose principal dielectric axes (that is, muscle fibers) have various directions are analyzed by using 44 matrix method. Numerical calculations in 10kHz-10MHz show the effects of orientation of muscle fibers and polarization of incident wave on absorbed power density in tissues.

Power transmission properties are investigated for a butt-joint which contains an air gap between an isotropic planar waveguide and an anisotropic one whose optical axis is lying in the plane defined by the propagation axis and the normal of the waveguide surface. New transmission coefficients are introduced for estimating the optical-power which is launched out into the gap from the incoming waveguide. Wave propagation through the gap is analyzed on the basis of the BPM concept. And the power transmitted across the interface between the gap and the outgoing waveguide is evaluated by means of the overlap integral of the field profiles. The effects of the air gap and the refractive index of filling liquid as well as axial displacement and angular misalignment are discussed on the basis of numerical results.