This paper describes a radial open stub and its application to a simple design of a four-element planar Butler matrix. In the first stage of our work, we propose a 45-degree phase shifter composed of an eighth-wavelength delay line and a serial connection of a quarter-wavelength straight line and a quarter-wavelength straight open stub. Next, in order to improve relative-phase characteristics between output ports, we propose a 45-degree phase shifter configuration using a quarter-wavelength radial open stub instead of using a quarter-wavelength straight open stub. It is shown by simulation that relative-phase characteristics of the configuration using the radial open stub are better than that using the straight open stub at the high frequencies. Finally, an experimental UHF-band four-element planar Butler matrix is presented. Over the frequency range from 0.83 to 0.92 GHz, the experimental four-element planar Butler matrix exhibits power splits of -6.510.29 dB, return losses of greater than 13 dB, errors in the desired relative-phase difference between output ports of less than 2 degrees.

In this paper, we present the division algorithm (DA) for the computation of b=c/a over GF(2m) in two aspects. First, we derive a new formulation for the discrete-time Wiener-Hopf equation (DTWHE) Ab = c in GF(2) over any basis. Symmetry of the matrix A is observed on some special bases and a three-step procedure is developed to solve the symmetric DTWHE. Secondly, we extend a variant of Stein's binary algorithm and propose a novel iterative division algorithm EB*. Owing to its structural simplicity, this algorithm can be mapped onto a systolic array with high speed and low area complexity.

In Ref.[5], the author defines "approximate eigenvalues" and "approximate eigenvectors," which are, in short, Taylor series expansions of eigenvalues and eigenvectors of a polynomial matrix. In this paper, an efficient algorithm to compute the approximate eigenvalues and eigenvectors is presented. The algorithm performs the computations with an arbitrary degree of convergence.

The periodicity of a target scattering matrix is studied when the target is rotated about the sight line of a monostatic radar. Except for the periodicity and invariance of the scattering matrix diag(a,a), it is proved that only helixes have the quasi-invariance, and that only N-targets have the quasi-periodicity, demonstrating that a target with some angle rotation symmetry also has the scattering matrix form diag(a,a). From this result, we conclude that it is impossible to extract the shape characteristics of a complex target from its scattering matrix or its Kennaugh matrix.

Tree canopies contain various scattering elements such as leaves, branches and trunks, which contribute to complex backscattering, depending on frequency and polarization. In this paper, we propose to use the polarimetric correlation coefficient for classifying trees, forests, and vegetations. The polarimetric correlation coefficient can be derived by the elements of Sinclair scattering matrix. Since the scattering matrix can be defined in any polarization basis, we examined the coefficient in the linear HV, circular LR, and optimum polarization bases. First, the change of correlation coefficient inside trees along the range direction is examined using small trees in a laboratory. The wider the range, the better the index. The coefficient defined in the LR polarization basis showed the largest change within tree canopy, which also contribute to retrieve scattering mechanism. Second, this index for discrimination is applied to polarimetric SAR data sets (San Francisco and Briatia area) acquired by AIRSAR and SIR-C/X-SAR. It is shown that polarimetric correlation coefficient in the LR basis best serves to distinguish tree types.

We analyzed the performance of adaptive array antennas with a RAKE receiver by employing a common correlation matrix of the sample matrix inversion (CCM-SMI) algorithm in a multipath Rayleigh fading environment for W-CDMA reverse link. A common correlation matrix is usually used to provide adaptive weights for multiple users and multiple delay paths and can be used in packet communications transmitted using frame units. The proposed CCM-SMI algorithm had a better BER and SINR for lower computational complexity compared with the conventional SMI algorithm, even when using a RAKE receiver in multipath Rayleigh fading environment.

We show some results concerning the number of solutions of the equation y+Ax=b (yTx=0, y0, x0) which plays a central role in the dc analysis of transistor circuits. In particular, we give sufficient conditions for the equation to possess exactly 2l (ln) solutions, where n is the dimension of the vector x.

This paper presents an accurate method for finding the 3D control points of the B-Spline curves. This method can automatically fit a set of data points with piecewise geometrically continuous cubic B-Spline curves. Iterating algorithm has been used for finding the 2D control points. And a new approach for shape reconstruction based on the control points of the curves on the object's surface is proposed. B-Spline patch, the extension of the B-Spline curves to surface, provides recovering the shape of the object in 2D approach. The 3D control points of the cubic B-Spline curves are computed from the factor decomposition of the measurement matrix of 2D control points. The multiple object approach is also proposed to reconstruct the 3D shape of each curves of an object. Some experiments are demonstrated to confirm the effectiveness of our proposed method.

New equivalent characterizations are derived for Schur stability property of real polynomials. They involve a single scalar parameter, which can be regarded as a freedom incorporated in the given polynomials so long as the stability is concerned. Possible applications of the expressions are suggested to the latest results for stability robustness analysis in parameter space. Further, an extension of the characterizations is made to the matrix case, yielding one-parameter expressions of Schur matrices.

Recently, biometrics such as a person's fingerprint, face, and voice has come to be used for personal authentication. At present, most biometrics authentication systems depend on verification (one-to-one matching) because such verification takes a short period of time and is expected to provide a quick response. In these systems, however, every single user has to enter an ID number for each authentication session and might feel incovenienced as a result. To improve the operation efficiency, identification (one-to-many matching) is required, but identification is currently assumed to require much more time than verification (i.e., the response time is not practical). After probing these problems, we developed a new method to achieve identification in a short period of time. This method shortens the response time by using a matching score matrix, which is constructed in the enrollment phase. The proposed method is shown to need only about 45 one-to-one matchings to identify data in a database with two thousand fingerprints, a count much less than by conventional methods.

In this paper, we present an image compression algorithm using two concepts, subdividing an image matrix and stratifying submatrices into FD-submatrices (feature distribution submatrices). According to the feature distribution and the view that an image can be decomposed into some feature layers, we generate a compression tree by setting up a logic process of decomposition and stratification. To get better compression ratios, the set of submatrices having one and zero as elements, including logic flag sequences is compressed by vector space theory.

Linear discriminant analysis (LDA) is a basic tool of pattern recognition, and it is used in extensive fields, e.g. face identification. However, LDA is poor at adaptability since it is a batch type algorithm. To overcome this, new algorithms of online LDA are proposed in the present paper. In face identification task, it is experimentally shown that the new algorithms are about two times faster than the previously proposed algorithm in terms of the number of required examples, while the previous algorithm attains better final performance than the new algorithms after sufficient steps of learning. The meaning of new algorithms are also discussed theoretically, and they are suggested to be corresponding to combination of PCA and Mahalanobis distance.

In this paper, a novel adaptive beamforming scheme is described. This scheme basically employs the GSC algorithm which is one of the famous adaptive interference suppression schemes. The implementation of the GSC algorithm requires complex computations due to the adaptive filtering. Therefore, we propose an efficient GSC algorithm based on the split RLS algorithm. In order to reduce the estimation error caused by the correlation between the splitted blocks, the modified GSC is employed with Walsh blocking matrix instead of Bi-diagonal one. In conclusion, the SINR of the proposed method is very close to the SINR obtained by the full tap solution, e.g. when the system complexity decreases nearly half, the SINR of the proposed method becomes 1 dB worse than that of full tap solution.

Recently, antenna selection diversity has been widely used for hand-held phones to overcome a fading problem. A monopole antenna (MPA) and an inverted-F antenna (IFA) are the typical antennas used for this purpose. However, strong mutual coupling generally appears between these two antennas and often makes the diversity antenna design difficult. In particular, in the case that the MPA is unselected antenna the mutual coupling can be minimized using the open terminating impedance. On the other hand, in the case that the IFA is unselected antenna the terminating impedance, which can minimize the mutual coupling, has not been clarified. This paper presents a novel analytical method for optimizing the terminating impedance of the IFA. The method exploits the Z-matrix, and the final expression of the terminating impedance is expressed by self- and mutual-impedance. The numerical and experimental results confirm that the proposed optimization method is effective for minimizing the mutual coupling.

The Sinclair scattering matrix is defined in a fixed radar range. If a radar target extends in the range direction, the reflected signal or the compound scattering matrix will undergo interaction of multiple reflections. Since scattering matrix is subject to target parameters such as shape, size, orientation, material, and radar parameters as frequency, polarization, and incidence angle, it is difficult to specify a representative scattering matrix of a general target. Therefore we choose the simplest target, wire, and its scattering matrix to examine the effect of targets aligned in the range direction with respect to the compound scattering matrix. First, we present a simple formula for the compound scattering matrix of wires with the phase difference due to spacing. Then, we employed the FDTD method to examine the scattering phenomena, changing the spacing in the range direction. The FDTD result reveals that two wires can become sphere (plate) and dihedral corner reflector (diplane) component generators; and that four wires can become a good helix component generator. These phenomena are verified with a laboratory measurement. From the result, the target decomposition should be carefully carried out in terms of range. If a range resolution of a radar is not high enough, the scattering matrix of the desired target may be affected by the targets behind.

In this paper, we describe a method of determining meat quality using the concepts of "marbling score" and texture analysis. The marbling score is a measure of the density distribution of fat in the rib-eye region. Based on the results of an investigation carried out by handing out questionnaires to graders, we consider the marbling of meat to be a texture pattern and propose a method for the implementation of a grading system using a texture feature. In this system, we use a gray level co-occurrence matrix as the texture feature, which is a typical second-order statistic of gray levels of a texture image, and determine standard texture-feature vectors for each grade based on it. The grade of an unevaluated image is determined by comparing the texture-feature vector of this unevaluated image with the standard texture-feature vectors. Experimental results show the proposed method to be effective.

This paper analyses the performance of a joint receiving structure for DS-CDMA communications systems. To reduce undesirable performance degradation due to the multiple access interferences and the near-far problem in multipath fading channel environment, this paper exploits the receiving structure for the multiuser communication composed of a beamformer-RAKE receiver and a decorrelating multiuser detector. The proposed DS-CDMA receiving structure mitigates the performance impairment invoked from the noise enhancement and reveals less computational complexity by utilizing the multipath temporal combiner prior to accessing the decorrelating detection. Also an efficient block Toeplitz inversion technique using the matrix Levinson polynomials is introduced to further diminish the computational burden encountered from applying the decorrelating multiuser detection process as in usual. Simulation results are conducted to demonstrate the superior performance of the proposed multiuser detection structure in multipath fading CDMA channel.

In this paper, the effective uses of Gerschgorin radii of the similar transformed covariance matrix for source number estimation are introduced. A heuristic approach is used for developing the detection criteria. The heuristic approach applying the visual Gerschgorin disk method (VGD), developed from the projection concept, overcomes the problems in cases of small data samples, an unknown noise model, and data dependency. Furthermore, Gerschgorin disks can be formed into two distinct, non-overlapping collections; one for signals and the other for noises. The number of sources can be visually determined by counting the number of Gerschgorin disks for signals. The proposed method is based on the sample correlation coefficient to normalize the signal Gerschgorin radii for source number detection. The performance of VGD shows improved detection capabilities over Gerschgorin Disk Estimator (GDE) in Gaussian white noise process and was used successfully in measured experimental data.

This paper presents an efficient algorithm for computing the characteristic polynomial of a matrix, which utilizes Cayley-Hamilton's theorem. The algorithm requires no condition on input matrix and can be performed only with basic matrix operations except only one computation of inverse of constant matrix. Though the algorithm can be applied to a constant matrix, it is the most effective when applied to a matrix with polynomial entries. Computational tests are given to compare the algorithm with conventional ones.

The 1 4 optical switch array for wavelength division multiplexing system has been demonstrated where four 14 waveguide digital optical switches have been integrated into one chip. Tape fiber is used as the connection between switch modules to avoid an interconnection fiber jungle. The architecture can be adapted to any number of wavelength channels. Redundant optical switch stage for crosstalk rejection has been used to attain a low crosstalk level. Electro-optic switching is used to attain low power consumption indispensable for routing large wavelength channels.