Theoretical values of site attenuation for broadband receiving antenna or the antenna factor of broadband antenna over the frequency range from 30 MHz to 1 GHz have been calculated or measured by some researchers. For a frequency range over 1 GHz, wire antennas or horn antennas should be used. However, the theoretical site attenuation or antenna factor over 1 GHz have never yet been calculated. A CLS (Conical Log-periodic Spiral) antenna is generally used for EMC/EMI measurements in the microwave band as a broadband wire antenna for the swept frequency method. However, this antenna has the defect that its use results in the loss of polarization information. So we proposed an improved CLS antenna which has linear polarization. This new CLS antenna has another wire wound symmetrically to that of the standard CLS antenna. For this reason, we named it a double-wire CLS antenna. The double-wire CLS antenna loses no polarization information. We calculated the height pattern and the frequency characteristics of CSA (Classical Site Attenuation) for the double-wire CLS antenna when used for receiving, or used for both transmitting and receiving, as well as the antenna factor. Moreover, NSA (Normalized Site Attenuation) when the double-wire CLS antenna is used for receiving or used for both transmitting and receiving in free space were calculated.

The defects in the cold rolled strips have textural characteristics, which are nonuniform due to its irregularities and deformities in geometrical appearance. In order to handle the textural characteristics of images with defects, this paper proposes a surface inspection method based on textural feature extraction using the wavelet transform. The wavelet transform is employed to extract local features from textural images with defects both in the frequency and in the spatial domain. To extract features effectively, an adaptive wavelet packet scheme is developed, in which the optimum number of features are produced automatically through subband coding gain. The energies for all subbands of the optimal quadtree of the adaptive wavelet packet algorithm and four entropy features in the level one LL subband, which correspond to the local features in the spatial domain, are extracted. A neural network is used to classify the defects of these features. Experiments with real image data show good training and generalization performances of the proposed method.

This paper optimizes a hierarchical image transmission system based on the hierarchical modulation scheme in a band-limited Rayleigh fading channel. Authors analyze relations between hierarchical parameters and the image quality, and show that the existence of optimum hierarchical parameter that maximizes the received image quality.

In this paper,we propose general fast one dimensional (1-D) and two dimensional (2-D) slant transform algorithms. By introducing simple and structural permutations, the heavily computational operations are centralized to become standardized and localized processing units. The total numbers of multiplications for the proposed fast 1-D and 2-D slant transforms are less than those of the existed methods. With advantages of convenient description in formulation and efficient computation for realization, the proposed fast slant transforms are suitable for applications in signal compression and pattern recognition.

This paper reviews analog LSI design issues for optical transmission applications; covering ultra-high-speed transmission over 10 Gb/s, multi-Gb/s systems, optical interconnection systems, and optical access. In the future system development, further advancements in not only optical device technology but also LSI technology are eagerly required. More and more sophisticated circuit design techniques are needed to lower power and operation voltage, increase integration, eliminate external elements and adjustments.

We extend the Rabin cryptosystem to the Eisenstein and Gauss fields. Methods for constructing the complete representation class and modulo operation of the ideal are presented. Based on these, we describe the methods of encryption and decryption. This proposed cryptosystem is shown to be as intractable as factorization, and recently presented low exponent attacks do not work against it.

The numerical properties of the recursive least squares (RLS) algorithm and its fast versions have been extensively studied. However, very few investigations are reported concerning the numerical behavior of the predictor based least squares (PLS) algorithms that provide the same least squares solutions as the RLS algorithm. This paper presents a comparative study on the numerical performances of the RLS and the backward PLS (BPLS) algorithms. Theoretical analysis of three main instability sources reported in the literature, including the overrange of the conversion factor, the loss of symmetry and the loss of positive definiteness of the inverse correlation matrix, has been done under a finite-precision arithmetic. Simulation results have confirmed the validity of our analysis. The results show that three main instability sources encountered in the RLS algorithm do not exist in the BPLS algorithm. Consequently, the BPLS algorithm provides a much more stable and robust numerical performance compared with the RLS algorithm.

A new method to obtain the coefficients of Daubechies's scaling functions is given, in which it is not necessary to find the complex zeros of polynomials. Consequently it becomes easier to obtain the coefficients of arbitrary order from 2 to 40 with high accuracy.

A factorization method for a string polynomial called the constant method is proposed. This uses essentially three operations; classification of monomials, gcrd (greatest common right divisor), and lcrm (least common rigth multiple). This method can be applied to string polynomials except that their constants cannot be reduced to zeros by the linear transformation of variables. To factorize such excluded string polynomials, the naive method is also presented, which computes simply coefficients of two factors of a given polynomial, but is not efficient.

We describe our implementation of the Hypercube variation of the Multiple Polynomial Quadratic Sieve (HMPQS) integer factorization algorithm on a Parsytec GC computer with 128 processors. HMPQS is a variation on the Quadratic Sieve (QS) algorithm which inspects many quadratic polynomials looking for quadratic residues with small prime factors. The polynomials are organized as the nodes of an n-dimensional cube. We report on the performance of our implementations on factoring several large numbers for the Cunningham Project.

SCI (Scalable Coherent Interface) is pointerbased coherent directory scheme for massively parallel multiprocessors. Large message latency is one of the problems with SCI because of its linked list structure: the searching latency of messages could grow as a linear order of the number of processors. In this paper, we focus on a hierarchical architecture to propose a new schemeEST(Extending SCI-Tree), which may reduce the message traffic and also take the advantages of the topology property. Simulation results show that the EST scheme is effective in reducing message latency and communication cost when compared with other schemes.

A wireless tag system has been designed and developed for maintaining and managing outdoor communication facilities. This system employs an infrared (IR) beam and an electromagnetic wave with a radio frequency (RF), and is constructed using IR-RF tags, an IR commander, and an RF receiver. The IR command radiation with strong directivity enables a maintenance operator to recognize a target facility, and the RF response without directivity enables a management system to obtain data from within a large circular area. Solar and secondary batteries are also adopted as the power module in the tag to allow easy maintenance at long intervals. IR signal communication is possible up to a distance of 9 m, and RF signal communication is possible within a circle with a radius of 9 m.

For bonded SOI wafers with active silicon layers thinner than 1 µm, controlling thickness uniformity of active layers has been developed recently. A Plasma Assisted Chemical Etching (PACE) technology is one of methods to realize 0.1 µm bonded SOI. When this technology was proposed for the first time, it was believed that 0.1 µm thick bonded SOI wafers were easily produced independent of initial SOI layer thickness prior to the PACE process. It was true to create 0.1 µm SOI thickness in average. However, the uniformity appeared to be dependent on initial SOI material as well as the PACE machine capability itself. The SOI thickness uniformity pattern after PACE looked like surface morphology of polished silicon wafers. After the experiment to apply various polishing methods to each polishing process in the bonded SOI process, it was verified that the final SOI thickness uniformity after the PACE process was dependent on the waviness of wafer surfaces created in polishing.

The designed converter has a two-input-winding transformer powered by single-phase AC voltage and an energy storage capacitor. Small size and enhanced conversion efficiency are achieved, because more than half of the energy is supplied to the load via a single conversion stage, and fast output-voltage regulation is achieved by controlling the charging and discharging of the storage capacitor. The design and control methods for the converter take into account the reset conditions of the transformer and stability in the output voltage control. An almost unity power factor and a low output voltage ripple were achieved with this converter fabricated as a breadboard circuit using small capacitors.

This paper studies stabilization of timed discrete event systems with forcible events. We present an algorithm for computing the region of weak attraction for legal states.

Periodic solutions of slow-fast systems called "canards," "ducks," or "lost solutions" are examined in a second order autonomous system. A characteristic feature of the canard is that the solution very slowly moves along the negative resistance of the slow curve. This feature comes from that the solution moves on or very close to a curve which is called slow manifolds or "rivers." To say reversely, solutions which move very close to the river are canards, this gives a heuristic definition of the canard. In this paper, the generation mechanism of the canard is examined using a piecewise linear system in which the cubic function is replaced by piecewise linear functions with three or four segments. Firstly, we pick out the rough characteristic feature of the vector field of the original nonlinear system with the cubic function. Then, using a piecewise linear model with three segments, it is shown that the slow manifold corresponding to the less eigenvalue of two positive real ones is the river in the segment which has the negative resistance. However, it is also shown that canards are never generated in the three segments piecewise linear model because of the existence of the "nodal type" invariant manifolds in the segment. In order to generate the canard, we propose a four segments piecewise linear model in which the property of the equilibrium point is an unstable focus.

This paper is concerned with two important planning problems for transport network planning; circuit routing problems and facility planning problems. We treated these optimization problems by taking into account survivability requirements. In the circuit routing problem tackled in this paper, therefore, optimization of circuit restoration plans, namely allocation of spare capacity for assumed failure scenarios is considered together with optimization of circuit routing in a no failure case. In the facility planning problems, failure scenarios of new facilities whose installation is yet to be determined are considered. In this paper, we present a formulation of these two optimization problems, and give 1) optimization algorithms based on the IA (Increment Assignment) method for routing problems and 2) optimization algorithms based on a combination of the GA (Genetic Algorithm) and the IA method for facility planning problems. The IA based routing algorithm can cope flexibly with various constraints on practical network operations and is applicable to large-scale complicated network models without causing a rapid increase in computation time. The GA based facility planning algorithm includes the IA based algorithm as a function for evaluating objective function values. Taking advantage of the important features of the IA based algorithm, we propose an acceleration technique for the GA based facility planning algorithm. In this paper, several numerical examples are provided and the effectiveness of the proposed algorithms is numerically evaluated.

For down-link communication in a DS/CDMA cellular mobile radio system, the transmitted power of the base station must be effectively adjusted in real-time fashion to achieve good communication quality because the system exists multipath short-term fading and near-far problem. In this paper, we propose two down-link power control mechanisms: one is the centralized SIR-balancing method and the other is the distributed SIR-based method. We investigate how the outage probability is affected by system parameters and optimally design the parameters for these two down-link power control mechanisms. Also, the two down-link power control mechanisms are compared and discussed.

The present paper describes a novel approach to interconnecting and assembling components of MEMS at room temperature. The main drawback of the conventional bonding methods is their rather high process temperatures. The new method, which is referred as the surface activated bonding (SAB), utilizes the phenomena of the adhesion between two atomically clean solid surfaces to enable the bonding at lower temperature or even at room temperature. In the bonding procedure, the surfaces to be bonded are merely brought into contact after sputter-cleaning by Ar fast atom in ultrahigh vacuum conditions. TEM observations of the bonded interfaces show that a direct bonding in atomic scale is achieved in the interface between the micro-components. Based on the concept of this new bonding technology, a micro-assembly system was developed. The micro-assembly system is operated by means of a virtual manipulation system in which 3D model of the micro-components are manipulated virtually in a computer graphics constructed in the world wide web (WWW) scheme. The micro-assembly system will provide a new design tool of three dimensional MEMS by combining the possibility of the flexible assembly and the intuitive operations.

We propose an nn optical switch that is suitable for flexible and reliable optical access networks and for reconfigurable optical inter-module connections in large-scale processing systems. The switch consists of an intersecting waveguide matrix, matching oil, and microactuators. Switching is based on the movement of oil due to capillary pressure, which is controlled by the microactuator. The necessary switching conditions were calculated and the results showed that both the oil volume and the microactuator position must be controlled. A trial optical switch was fabricated to test the switching principle, and switching and self-holding were both confirmed. These results show the feasibility of a very small self-holding nn optical switch that uses a waveguide matrix and microactuators made by using microfabrication technologies.