Some new differential input ideal differentiator and integrator function circuits using the current feedback amplifier (CFA) device are presented. The time constant (τo) is tunable by the control voltage (Vc) of a multiplier element connected appropriately around the feedback loop. The CFA device port errors () have insignificant effects on (τo). Test results based on hardware implementation and macromodel simulation are included; the proposed circuits exhibited good high frequency response with low phase errors (θe 2) upto about 450 kHz.

A mathematical expression for the received signal power in a severe frequency-selective fading channel is derived. Using the derived expression, the signal power distributions are obtained by Monte-Carlo simulation and compared with the Nakagami m-power distribution. It is found that the power distribution matches well with the Nakagami m-power distribution when the multipath channel has a uniform power delay profile.

A fast winner search method based on separating all codewords in the original codebook completely into a promising group and an impossible group is proposed. Group separation is realized by using sorted both L1 and L2 norms independently. As a result, the necessary search scope that guarantees full search equivalent PSNR can be limited to the common part of the 2 individual promising groups. The high search efficiency is confirmed by experimental results.

Constraints have been used extensively for the construction of graphical user interfaces. User interface constraints that are declarative are more favorable but require sophisticated constraint planning algorithms. Constraint planning algorithms proposed previously are getting more and more complicated as they were asked to handle more general requirements. We believe that the difficulty is mainly caused by the complicated data structure that is translated directly from the problem. By a transformation, we propose a simplified graph model for the problem and prove that the constraint planning problem can be reduced to finding feedback vertex sets on the simplified graph model. We also consider the general problem of handling non-uniform user interface constraints.

Autonomous distributed manufacturing systems(ADMS) consist of multiple intelligent components with each component acting according to its own judgments. The ADMS objective is to realize more agile and adaptive manufacturing systems. This paper presents the introduction of context-dependent agents (CDAs) in ADMS, and switch strategies depending on system conditions to achieve better performance can be realized by agents that use the same strategies under all system conditions. For the real-time job scheduling problem, the present paper recalls a basic CDA architecture, and presents the results of an extensive empirical evaluation its performance relative to other rule-based schemes based on several common indices for real-time dispatch.

In this paper, a new grouping method for Group Technology using Self-Organizing Map (SOM) is proposed. The purpose of our study is to divide machines in a factory into any number of cells so that the machines in each cell can process a similar set of parts to increase productivity. A main feature of our method is to specify not only the number of the cells but also the maximum and minimum numbers of machines in a cell. Some experimental results show effectiveness of our proposed algorithm.

The boundary element method (BEM), a representative method of numerical calculation of electromagnetic wave scattering, has been used for solving boundary integral equations. Using BEM, however, we finally have to solve a linear system of L equations expressed by dense coefficient matrix. The floating-point operation is O(L2) due to a matrix-vector product in iterative process. Greengard-Rokhlin's fast multipole algorithm (GRFMA) can reduce the operation to O(L). In this paper, we describe GRFMA and its floating-point operation theoretically. Moreover, we apply the fast Fourier transform to the calculation processes of GRFMA. In numerical examples, we show the experimental results for the computation time, the amount of used memory and the relative error of matrix-vector product expedited by GRFMA. We also discuss the convergence and the relative error of solution obtained by the BEM with GRFMA.

The propagator method (PM) belongs to a class of subspace based methods for direction-of-arrival estimation which only requires linear operations but does not involve any eigendecomposition or singular value decomposition as in common subspace techniques. In this paper, we apply the PM for estimating the frequencies of multiple real sinusoids in noise and a computationally simple as well as high resolution multiple frequency estimation algorithm is developed. The estimation accuracy of the proposed method is contrasted with the conventional MUSIC and Cramer-Rao lower bound under different noise conditions.

This article describes a new method for converting an arbitrary topology mesh into one having subdivision connectivity. First, a base mesh is produced by applying a sequence of edge collapse operations to the original mesh with irregular connectivity. Then, the base mesh is iteratively subdivided. Each subdivided mesh is optimized to reduce its distance from the original mesh and to improve its global smoothness and compactness. A set of corresponding point pairs, which is required to compute the distance from the original mesh to the subdivided mesh, is determined by combining the initial parameterization and the multi-resolution projection. Experimental results show that the proposed method yields good performance in terms of global smoothness, small distortion, and good compactness, compared with conventional methods.

In this paper, the time-frequency separation algorithm (TFS) proposed by Belouchrani and Amin is applied to ground penetrating radar (GPR) data to reduce ground clutter, that hides reflected waves from a near-surface planar interface. We formulated the problem with several assumptions so that narrow band signals, whose center frequency and baseband signal depend on propagation paths, are received at the receiver, when a wideband signal is radiated from a transmitter. These phenomena can be clearly seen in time-frequency distribution (TFD) of the received signal. In this paper, we adopted the TFS utilizing the TFD signature as a blind separation technique to separate the ground clutter from the target signals. We show numerical and experimental results in order to verify the validity of the problem formulation and the TFS. We carried out GPR measurements to measure permafrost in Yakutsk, Russia. We found the difference in TFD signatures between the ground clutter and the target signal in the experimental data. We could detect the upper boundary of the permafrost with the TFS in spite of the unstable ground clutter.

Suica is our contact-less IC card's nickname: Super Urban Intelligent CArd. There are two types of IC Card: One for Suica IO (SF) Card and the other for Suica Commuter Pass, which has a function of stored fare card and commuter pass. There are 6.54 million Suica holders (about 3.33 million Suica Season Pass holders and 3.21 million Suica IO Card holders) as of 16, June 2003.

RF diamond FETs have been realized on a hydrogen-terminated diamond surface conductive layer. By utilizing the self-aligned gate fabrication process which is effective for the reduction of the parasitic resistance, the transconductance of diamond FETs has been greatly improved. Consequently, the high frequency operation of 22 GHz has been realized in 0.2 µ m gate diamond MISFETs with a CaF2 gate insulator. This value is the highest in diamond FETs and is comparable to the maximum value of SiC MESFETs at present.

In order to clarify the mechanism of gate leakage in AlGaN/GaN heterostructure field effect transistors (HFETs), temperature (T)-dependent current-voltage (I-V) characteristics of Ni/n-AlGaN Schottky contact were measured in detail. Large deviations from the thermionic emission transport were observed in I-V-T behavior with anomalously large reverse leakage currents. An analysis based on the thin surface barrier (TSB) model showed that the nitrogen-vacancy-related near-surface donors play a dominant role in the leakage through the AlGaN Schottky interface. As a practical scheme for suppressing the leakage currents, use of an insulated gate (IG) structure was investigated. As the insulator, Al2O3 was selected, and an Al2O3 IG structure was formed on the AlGaN/GaN heterostructure surface after an ECR-N2 plasma treatment. An in-situ XPS analysis exhibited successful formation of an ultrathin stoichiometric Al2O3 layer which has a large conduction band offset of 2.1 eV at the Al2O3/Al0.3Ga0.7N interface. The fabricated Al2O3 IG HFET achieved pronounced reduction of gate leakage, resulting in the good gate control of drain currents up to VGS = +3 V. The maximum drain saturation current and transconductance were 0.8 A/mm and 120 mS/mm, respectively. No current collapse was observed in the Al2O3 IG-HFETs, indicating a remarkable advantage of the present Al2O3-based insulated gate and passivation structure.

We have developed a novel self-alignment process using the surface tension of the liquid resin for assembly of electronic and optoelectronic devices. Due to their characteristics of low surface tension, however, the parametric design guidelines are necessary for resin self-alignment capability. In this paper, a shape prediction mathematical model and a numerical method are developed. The developed system is capable of achieving the liquid joint geometry and the parametric design for self-alignment capability. The influences of geometric parameters such as liquid volume, component weight, pad radius, liquid surface tension on the shape of liquid joint are investigated. Furthermore, the parametric design guidelines considered the process-related practical matters of misalignment level, distribution of the supplied liquid volumes and coplanarity deviation includes difference of the height between the pads are provided.

Hetero-interface properties of SiO2/4H-SiC on (0001), (11-20), and (03-38) crystal orientations are presented. Epitaxial growth on new crystal orientations, (11-20) and (03-38), is described by comparing with the growth on (0001). Using thermal oxidation with wet oxygen, metal-oxide-SiC (MOS) structure was fabricated. From high-frequency capacitance-voltage characteristics measured at 300 K and 100 K, the interface properties were characterized semi-quantitatively. The interface state density was precisely determined using the conductance method for the MOS structure at 300 K. The new crystal orientations have the lower interface state density near the conduction band edge than (0001). From the characteristics of inversion-type planar MOSFETs, higher channel mobilities were obtained on (03-38) and (11-20) than on (0001). The cause of the difference in the channel mobility is speculated by the difference bond configuration of the three crystal orientations.

This report describes face image recognition by 2-dimensional discrete Walsh transform and multi-layer neural networks. Neural network (NN) is one of the powerful tools for pattern recognition. In the previous researches of face image recognition by NN, the gray levels on each pixel of the face image have been used for input data to NN. However, because the face image has usually too many pixels, a variety of approaches have been required to reduce the number of the input data. In this research, 2-dimensional discrete Walsh transform is used for reduction of input data and the recognition is done by multi-layer neural networks. Finally, the validity of our method is varified.

Ranking fuzzy numbers is one of very important research topics in fuzzy set theory because it is a base of decision-making in applications. However, fuzzy numbers may not be easily ordered into one sequence according to their magnitudes because they represent uncertain values. When two fuzzy numbers overlap with each other, a fuzzy number may not be considered absolutely larger than the other. That is, even when a fuzzy number may be considered larger than the other, it may also be considered smaller than the other. It means that for a given set of fuzzy numbers, several ranking sequences possibly exist. However, most of the existing ranking methods produce only one ranking sequence. They ignore other possible sequences due to the overlap between fuzzy numbers. We propose a ranking method which generates possible ranking sequences of given fuzzy numbers. Our method takes a viewpoint from users, and uses it for evaluation of fuzzy numbers. Fuzzy numbers will be ranked based on the evaluations and a fuzzy set of sequences of fuzzy numbers will be produced as a ranking results. Numeric examples and comparisons with other methods are also presented.

Information service provision and utilization is an important infrastructure in the high-assurance distributed information service system. In order to cope with the rapidly evolving situations of providers' and users' heterogeneous requirements, one autonomous information service system has been proposed, called Faded Information Field (FIF). FIF is a distributed information service system architecture, sustained by push/pull mobile agents, through a recursive demand-oriented provision of the most popular information closer to the users to make a tradeoff between the cost of service allocation and access. In this system, users' requests are autonomously driven by pull mobile agents in charge of finding the relevant service. In the case of a mono-service request, the system is designed to reduce the time needed for users to access the information and to preserve the consistency of the replicas. However, when the user requests joint selection of multiple services, synchronization of atomic actions and timeliness have to be assured by the system. In this paper, the relationship that exists among the contents, properties and access ratios of information services is clarified. Based on these factors, the ratio of correlation and degree of satisfaction are defined and the autonomous integration and optimal allocation of information services for heterogeneous FIFs to provide one-stop service for users' multi-service requirements are proposed. The effectiveness of the proposed technology is shown through evaluation and the results show that the integrated services can reduce the total users access time and increase services consumption compared with separate systems.

Software rejuvenation is a proactive fault management technique that has been extensively studied in the recent literature. In this paper, we focus on an example for a telecommunication billing application considered in Huang et al. (1995) and develop the discrete-time stochastic models to estimate the optimal software rejuvenation schedule. More precisely, two software availability models with rejuvenation are formulated via the discrete semi-Markov processes, and the optimal software rejuvenation schedules which maximize the steady-state availabilities are derived analytically. Further, we develop statistically non-parametric algorithms to estimate the optimal software rejuvenation schedules, provided that the complete sample data of failure times are given. Then, a new statistical device, called the discrete total time on test statistics, is introduced. Finally, we examine asymptotic properties for the statistical estimation algorithms proposed in this paper through a simulation experiment.

Multipath is a big problem for TCP traffic in traffic engineering. To solve it, hash functions such as CRC-16 are usually applied over source and destination address segments in packet headers. Through simulations and performance comparison of several multipath algorithms, it is found out that high network utilization achieved by using hash functions is at the expense of low fairness among coexisting TCP flows. It is also illustrated that packet size has significant influence on performance.