This paper describes a new approach to analyze nonlinear characteristics of propagating waves in a ferrite material. As to the formulation of the wave in a ferrite medium, the analysis in this paper is not taken under the assumption of a sinusoidal steady state using Polder tensor permeability, but taken by directly differentiating the gyromagnetic equation in time domain without any linear approximations. Then it is combined with Maxwell equation in FDTD procedure. As a result, intensity-dependent nonlinear responses of the propagating wave are confirmed, and the nonlinearity is seen in only the right-hand polarization wave. It is also found that an effect of the damping term in the equation of the motion of the magnetization has nonlinear characteristics for wave propagation.

Page-based DSM systems suffer from false sharing since they use a large page as a coherence unit. The optimal page size is dynamically affected by application characteristics. Therefore, a fixed-size page cannot satisfy various applications even if it is small as a cache line size. In this paper we present a software-only coherence protocol called BCP (Buddy Coherence Protocol) to support multiple page sizes that vary adaptively according to the behavior of each application during run time. In BCP, the address of a remote access and the address of the most recent local access is compared. If they are to the different halves of a page, BCP considers it as false sharing and demotes the page to two subpages of equal size. If two contiguous pages belong to the same node, BCP promotes two pages to a superpage to reduce the number of the following coherence activities. We also suggest a mechanism to detect data sharing patterns to optimize the protocol. It detects and keeps the sharing pattern for each page by a state transition mechanism. By referring to those patterns, BCP selectively demotes the page and increases the effectiveness of a demotion. Self-invalidation of the migratorily shared page is also employed to reduce the number of invalidations. Our simulations show that the optimized BCP outperforms almost all the best cases of the write-invalidate protocols using fixed-size pages. BCP improves performance by 42.2% for some applications when compared against the case of the fixed-size page.

Object-oriented analysis methods can be grouped into data-driven and behavior-driven approaches. With data-driven approaches, object models are developed based on a list of objects and their inter-relationships, which describe a static view of the real world. With behavior-oriented approaches, a system usage scenario is analyzed before developing the object models. Although qualitative comparisons of these two types of methods have been made, there was no statistical study has evaluated them based on controlled experiments. This paper proposes the patterned object-oriented method, POOM, which is a behavior-oriented approach, and compares it to OMT, a data-driven approach, using small team experiments. The effectiveness of POOM is shown in terms of productivity and homogeneity.

In this paper, we propose a test methodology for core-based system LSIs. Our test methodology aims to decrease testing time for core-based system LSIs. In our method, every core is supplied with several sets of test vectors. Every set of test vectors guarantees sufficient fault coverage. Each set of test vectors consists of two parts. One is based on built-in self-test (BIST) and the other is based on external testing. These sets of test vectors are designed to have different ratio of BIST to external testing each other for every core. We can minimize testing time for core-based system LSIs by selecting from the given sets of test vectors for each core. The main contributions of this paper are summarized as follows. (i) BIST is efficiently combined with external testing to relax the limitation of the external primary inputs and outputs. (ii) External testing for one of cores and BISTs for the others are performed in parallel to reduce the total testing time. (iii) The testing time minimization problem for core-based system LSIs is formulated as a combinatorial optimization problem to select the optimal set of test vectors from given sets of test vectors for each core.

In this paper, we propose a new register transfer level (RT level) testability analysis method. Controllability and observability measures are defined for signal vectors based on the numbers of values they can take. The control part and the datapath part are automatically identified in the given RT level model and distinctive analysis methods are applied. We also describe a DFT point selection method based on our testability measures. In a experiment on a signal processing circuit whose gate count is 7690 including 578 FFs, almost the same fault coverage is achieved with fewer scan FFs than a conventional method based on gate level testability analysis.

Since most digital phase-locked loops (DPLLs) used in digital data transmission receivers require both fast acquisition of input frequency and phase in the beginning and substantial jitter reduction in the steady-state, the DPLL loop bandwidth is preferred to being adjusted accordingly. In this paper, a bandwidth adjusting (adaptive) algorithm is presented, which allow both fast acquisition and significant jitter reduction for each different noise environment and hardware requirement. This algorithm, based on the recursive least squares (RLS) criterion, suggest an optimal sequence of control parameters for a dual-loop DPLL which achieves the fastest initial acquisition time by trying to minimize the jitter variance in any given time instant. The algorithm can be used for carrier recovery or clock recovery in mobile communications, local area networks and disk drivers that require a short initial preamble period.

Since manufacturing processes inherently fluctuate, LSI chips which are produced from the same design have different propagation delays. However, the difference in delays caused by the process fluctuation has rarely been considered in most of existing high-level synthesis systems. This paper presents a new approach to module selection in high-level synthesis, which exploits the difference in functional unit delays. First, a module library model which assumes the probabilistic nature of functional unit delays is presented. Then, we propose a module selection problem and an algorithm which minimizes the cost per faultless chip. Experimental results demonstrate that the proposed algorithm finds optimal module selections which would not have been explored without manufacturing information.

This paper describes a method to represent m output functions using shared multi-terminal binary decision diagrams (SMTBDDs). The SMTBDD(k) consists of multi-terminal binary decision diagrams (MTBDDs), where each MTBDD represents k output functions. An SMTBDD(k) is the generalization of shared binary decision diagrams (SBDDs) and MTBDDs: for k=1, it is an SBDD, and for k=m, it is an MTBDD. The size of a BDD is the total number of nodes. The features of SMTBDD(k)s are: 1) they are often smaller than SBDDs or MTBDDs; and 2) they evaluate k outputs simultaneously. We also propose an algorithm for grouping output functions to reduce the size of SMTBDD(k)s. Experimental results show the compactness of SMTBDD(k)s. An SMTBDDmin denotes the smaller SMTBDD which is either an SMTBDD(2) or an SMTBDD(3) with fewer nodes. The average relative sizes for SBDDs, MTBDDs, and SMTBDDs are 1. 00, 152. 73, and 0. 80, respectively.

This paper discusses a method to evaluate mutual couplings of cavity-backed slot antennas using the FDTD technique. The antenna fed by the short-ended probe is considered, which is investigated as an element of the power transmission antenna, Spacetenna, for the solar power satellite SPS2000. It is found from the FDTD computation on E-plane two- and four-element array antennas that the size of the problem space should be larger for the evaluation of the mutual coupling than for the estimation of the input impedance. Since enlarging the size of the problem space requires a large amount of computer storage, it is not practical for computer simulations. In order to carry out accurate estimations of the mutual coupling with relatively small amount of computer memory, the problem space is extended only in the broadside of the array antenna and in the other directions there are ten cells between the antenna surface and the outer boundary. Computer simulations demonstrate that there are no differences between the results of the proposed problem space geometry and the problem space extended in each direction of the axis coordinate by the same number of cells. Furthermore comparisons of computed and experimental results demonstrate the effectiveness of the approach after discussing how large the size of the problem space is required to estimate the mutual coupling.

In this paper, we present an analysis of the microstrip lines whose strip conductors are of various cross-sections, such as rectangular cross-section, triangle cross-section, and half-cycle cross-section. The method employed is the boundary integral equation method (BIEM). Numerical results for these microstrip lines demonstrate various shape effects of the strip conductor on the characteristics of lines. The processing technique on the convergence of the Green's function is also described.

In the spatial network method (SNM) for the vector potential, both the current continuity law including polarization vector and the conservation law of generalized momentum including vector potential field can introduce simpler expressions for dispersive property than that by the electromagnetic field variables. But for the anisotropic medium conditions, the conventional expanded node expression has some difficulties in treating the coupling mechanism among field variables. On the other hand, in the condensed node expression, in which all field components exist at each node, every connections among field components can be simply formulated. In this paper, after proposing the condensed node spatial network method for the vector potential, the advantage of the method such as performing the simplified formulation by utilization of both the vector potential and the condensed node expressions is presented for the magnetized plasma which has the gyro-anisotropy. The validity of the computation is shown by some examples such as Faraday rotation.

This paper shows an analysis of electromagnetic scattering from an open-ended rectangular cylinder for a plane wave incidence. The internal region is separated into two areas by additional plates to investigate the cavity resonance in detail. The applied numerical technique is the point matching method taking account of the edge condition. As numerical examples, the radar cross section is presented for E - polarized case and H - polarized case. Physical meanings of the computational results are discussed with a view to the contribution of the iris.

MOSFETs with sub-0.1 µm gate length were fabricated, and their low temperature operation was investigated. The drain current for drain voltage of 2 V increased monotonously as temperature was lowered to 15 K without an influence of the freeze-out effect. Moreover, the increase in the drain current was enhanced by the gate length reduction. The hot-carrier effect at low temperature was also investigated. Impact-ionization decreased as temperature was lowered under the condition of drain voltage 2 V. The decreasing ratio was enhanced as gate length became shorter. We consider this phenomenon is attributed to the non-steady-stationary effect. As a result, device degradation by DC stressing was reduced at 77 K in comparison with room temperature. In the case of 0.1 µm MOSFET, drain current was not degraded in condition of DC stress with gate- and drain-voltage was 1.5 V.

A thin-film waveguide amplifier based on Er-doped Garnet crystals is proposed and transient amplification characteristics, studied numerically using time-dependent rate equations and mode evolution equations, are presented. The potential of the amplifier for integration with active devices operating at the present communication wavelength of 1. 53 µm band is revealed. Pump wavelengths in the visible and near infrared lead to excited state absorption, and will affect the gain characteristics, which has been included in the present study. Steady state response of the Er doped Garnet crystal waveguide amplifiers has been analyzed in order to optimize the gain characteristics, which are further used in the dynamic response analysis. Accordingly, it is shown that a high gain of 20 dB/cm is possible to be achieved. Experimentally determined parameters such as waveguide loss, absorption and emission cross-sections have been used for the simulations. Comparisons of the present simulation results with our earlier reported results of quasi-two-level laser model and other reported results are also presented. Understanding the dynamic characteristics of the integrated optic waveguide amplifiers is necessary when the input signal is modulated in various formats. Because of the slower gain dynamics of the Er doped Garnet amplifier medium, it is shown that the longer signal input pulses are observed to be distorted upon amplification. Very short single pulse of nano- and pico-second duration are amplified without change in the pulse shape. Input pulses of square, Gaussian and Lorentzian shapes have been considered for the numerical examples.

This paper describes a new method for permittivity measurement using microwave free-space technique. The general consideration is to measure the amplitudes of transmission and reflection coefficients and calculate the permittivity from the measurement values. Theoretical analysis shows that the permittivity of the sample can be calculated solely from the measurement values of the amplitudes of transmission and reflection coefficients when the sample is prepared with so large attenuation that the multiple reflections between the two surfaces of the sample can be neglected. Using this method, the permittivity measurement can be performed without reflection influence, and on-line measurement of the permittivity becomes possible because the permittivity can be measured instantaneously and without contact with the material.

The equivalence between Aperture Field Integration Method (AFIM) and Physical Optical (PO) is discussed for polyhedron surfaces in this paper. The necessary conditions for the equivalence are summarized which demand complete equivalent surface currents and complete apertures. The importance of the exact expressions for both incident and reflected fields in constructing equivalent surface currents is emphasized and demonstrated numerically. The fields from reflected components on additional surface which lies on the Geometrical Optics (GO) reflection boundary are evaluated asymptotically. The analytical expression enhances the computational efficiency of the complete AFIM. The equivalent edge currents (EECs) for AFIM (AFIMEECs) are used to extract the mechanism of this equivalence between AFIM and PO.

This paper presents a new compound constructive algorithm of neural networks whereby the fuzzy logic technique is explored as an efficient learning algorithm to implement an optimal network construction from an initial simple 3-layer network while the genetic algorithm is used to help design an improved network by evolutions. Numerical simulations on artificial life demonstrate that compared with the existing network design algorithms such as the constructive algorithms, the pruning algorithms and the fixed, static architecture algorithm, the present algorithm, called FuzGa, is efficient in both time complexity and network performance. The improved time complexity comes from the sufficiently small 3 layer design of neural networks and the genetic algorithm adopted partly because the relatively small number of layers facilitates an utilization of an efficient steepest descent method in narrowing down the solution space of fuzzy logic and partly because trappings into local minima can be avoided by genetic algorithm, contributing to considerable saving in time in the processing of network learning and connection. Compared with 54. 8 minutes of MLPs with 65 hidden neurons, 63. 1 minutes of FlexNet or 96. 0 minutes of Pruning, our simulation results on artificial life show that the CPU time of the present method reaching the target fitness value of 100 food elements eaten for the present FuzGa has improved to 42. 3 minutes by SUN's SPARCstation-10 of SuperSPARC 40 MHz machine for example. The role of hidden neurons is elucidated in improving the performance level of the neural networks of the various schemes developed for artificial life applications. The effect of population size on the performance level of the present FuzGa is also elucidated.

We introduce an ontology for transportation systems demand forecasting and its implementation into a decision support system (DSS) generator. The term ontology, as we use it here, means a collection of building blocks necessary and sufficient to construct a skeleton of a specific DSS, that is a task ontology. The ontology is specified in constraint logic, which also ensures a good support for modularity.

A Multi-Agent Learning Language (MALL) is defined as being necessary for agents in environments where they encounter crucial situations in which they have to learn about the environment, other parties moves and strategies, and then construct an optimal plan. The language is based on two major factors, the level of certainty in fully monitoring (surveying) the agents and the environment, and optimal plan construction, in an autonomous way. Most of the work related to software agents is based on the assumption that other agents are trustworthy. In the growing Internet environment this may not be true. The proposed new learning language allows agents to learn about the environment and the strategies of their opponents while devising their own plans. The language is being tested in our project of software agents for Electronic Commerce that operates in various security zones. The language is flexible and adaptable to a variety of agents applications.

Development of large-scale software is usually conducted through a project to unite a work force. In addition, no matter what kind of life cycle model is employed, a development plan is required for a software development project in order for the united work force to function effectively. For the project to be successful, it is also necessary to set management objectives based on this plan and confirm that they are achieved. This method is considered to be effective, but actually making a software development project and following the achievement of the management objectives at each step is not easy because predicting the necessary work amount and risks that the project involves is difficult in software development. Therefore, it is necessary to develop a system to support software project management so that the project manager can manage the entire project and the work load is reduced. This paper proposes a meta-model of work structure of software development projects for project management by using an object-oriented database with constraints as well as a framework for software project management systems based on this meta-model. Also proven, through an example of a system that analyzes repercussions on progress of a software development project, is that the meta-model and framework are effective in software project management.