A system based on application of Fuzzy Cognitive Map (FCM) to perform on-line fault diagnosis is presented. The diagnostic part of the system is composed of two diagnostic schemes. The first one (basic diagnostic algorithm) can be considered as a simple transition of Shiozaki's signed directed graph approach to FCM framework. The second one is an extended version of the basic diagnostic algorithm where an important concept, the temporal associative memories (TAM) recall of FCM, is adopted. In on-line application, self-generated fault FCM model generates predicted pattern sequence through the TAM recall process, which is compared with observed pattern sequence to declare the origin of fault. As the resultant diagnosis scheme takes short computation time, it can be used for on-line fault diagnosis of large and complex processes, and even for incipient fault diagnosis. In practical case, since real observed pattern sequence may be different from predicted one through the TAM recall owing to propagation delay between process variables, the time indexed fault FCM model incorporating delay time is proposed. The utility of the proposed system is illustrated in fault diagnosis of a tank-pipe system.

Low-power, high-speed match-detection circuits for a content addressable memory(CAM) are proposed and evaluated. The circuits consist a current supply to a match-line, a differential amplifier, and 9-MOSFET CAM cells. The implementation of these circuits made it possible to realize a 16-entry, 32-bit data-compare CAM TEG of 1.2-ns matchdetection time with 5-mW power dissipation in 10-ns cycle-time.

When a natural language specification is translated into a formal one, it is important for objects and operations appearing in the natural language specification to be appropriately classified according to the framework of data types in the formal specification. In this paper, we propose a semi-automatic method of constructing a context-free grammar (cfg) representing an assignment of data types to words in a given natural language specification. In our method, a cfg is mechanically constructed from sample sentences in a natural language specification, where the cfg represents type declarations of expressions and type hierarchy. Then, the cfg is appropriately modified by adding nonterminals/production rules that represent type inclusion relations. In this modification process, candidates for the productions to be added are presented to the user. Finally, the cfg is simplified based on structural equivalence. The result of applying this method to a part of the OSI session protocol specification (39 sentences) is also presented. There was an example in which ambiguity of anaphoric bindings was solved by type checking based on the resulting cfg.

A new airborne rain radar named CAMPR (CRL Airborne Multiparameter precipitation Radar) has been developed for the major purpose of calibrating PR (Precipitation Radar) onboard TRMM (Tropical Rainfall Measuring Mission; scheduled to be launched in 1997) in orbit by observing the same rain with both CAMPR and TRMM satellite. CAMPR operates as a coherent radar at 13.8 GHz, the same frequency as TRMM-PR, and has polarimetric and Doppler capabilities. It is installed on a relatively small aircraft and can scan the antenna over a wide angle range, from the nadir to the near-horizon. These functions have been verified to work well and it is shown that the radar system is accurately calibrated. Examples of measurement data show CAMPR's high capability to extract various quantities relating to precipitation and cloud physics. Before the TRMM launch, CAMPR is being used to obtain TRMM-PR simulation data to help its algorithm development as well as to obtain data concerning precipitation and cloud physics.

The problem of TM-wave scattering and radiation from a finite number of thick slits in a parallel plate waveguide is solved. The Fourier transform and the mode matching are used to obtain simultaneous equations for the field inside the slits. The simultaneous equations are solved to obtain a series solution which is amenable to numerical computation. The numerical computations are performed to illustrate the behaviors of scattering, transmission, and reflection in terms of incident angle, slit size and operating frequency. The presented solution is computationally very efficient and useful for slotted-waveguide leaky-wave antenna applications.

A family of single-switch ZVS-CV (Zero-voltage switchingclamped voltage) dc-to-dc converters is presented. This class of converter is realized by employing a commutation inductor circuit which is connected in parallel with either the transistor or the freewheeling diode in a conventional PWM converter. The technique described here is simple and output-voltage control is easy. The converters that comprise this family are derived form Buck, Boost, Buck/Boost, Cuk, Sepic and Zeta PWM converters. The steady-state characteristics of these converters such as the voltage conversion ratio, the ZVS conditions, and the input and output current ripples are analyzed. The analysis is confirmed by experiment.

One of the important properties of multihop network is the mean internodal distance to evaluate the transmission delay, and the connective semi-random network achieves smaller mean internodal distance than other networks. However, the results are shown only by computer simulation and no theoretical analysis is investigated. Moreover, the network connective probability of the connective semi-random network is relatively small. In this paper, we propose the restricted connective semi-random network whose network connective probability is larger than that of the conventional connective semi-random network. And we theoretically analyze the mean internodal distance and the network connective probability of these two networks. It is shown that if the restriction is loose, the mean internodal distance of our model is almost the same as that of the conventional model, whereas the network connective probability of our model is larger than that of the conventional model. Moreover, the theoretical analyzed results of the mean internodal distance agree well with the simulated results in the conventional model and our model with small restriction.

This paper is concerned with bandwidth reservation for circuit groups which handle calls requesting asymmetric forward and backward multi-connections. A model of circuit group with sub-group configuration is treated, and two types of the bandwidth reservation schemes for the model are studied in this paper. One is a global scheme with monitoring the whole circuit group, and the other is a local scheme with monitoring each sub-group independently. The problems of optimizing the reservation parameters are formulated, and optimization methods for the problems are proposed. Numerical example are presented, and effectiveness of the reservation schemes with using the optimized parameters is numerically examined.

Several major aircraft accidents have been attributed to low-altitude wind shears, which are normally caused by microbursts or gust fronts. Terminal Doppler Weather Radar (TDWR) systems are being installed near major airports for the detection of low-altitude wind shears. In order to develop a TDWR system further, low-altitude wind shears were numerically simulated in this study. The basic equations, which contain prognostic equations for air velocity, pressure, temperature, water vapor, and rainwater, were solved using a finite difference scheme. A terrain-following coordinate transformation was employed to simulate terrain effects. The simulation results are presented in this paper.

Leaky Bucket based traffic parameters are widely used for traffic declaration and enforcing in an ATM network. In this paper, we investigate the characteristics of the system that every traffic source is policed by a dual leaky bucket before entering the network. In addition to mean cell rate, peak cell rate of traffic is also taken into consideration. We find the worst output pattern from the dual leaky bucket and derive the performance bound of maximum cell loss ratio encountered in the multiplexer. It is obtained as every source transmits cells according to the criteria for extreme synchronous transmission in a coincident token-generating condition.

A maximum diameter (Dmax) of raindrop should be assumed when rainfall rate (R) is estimates from the differential reflectivity (ZDR) and the horizontal reflectivity (ZH) measured with dual-polarization radar. If the assumed Dmax is different from actual Dmax, the estimated R contains errors. Using distrometer data, it was found that ZDR correlates with Dmax, and it was verified that when Dmax is adaptively determined by an empirical relationship between ZDR and Dmax, errors in estimated R can be reduced.

Winter thundercloud on the coast of the Sea of Japan is difficult for the detection and forecast. This paper reports the new method of thundercloud detection using C-Band weather radar data and meteorological data from rawin sonde. This method includes the thunderclouds echo tracking and chronological evaluation of thundercloud life-cycle stages. The detection probability of critical area for cloud-to-ground lightning is over 90% on winter cloud echo data. This method is workable on realtime processing in work-station computer.

This paper describes a newly developed sensing scheme with a bit-by-bit program verify technique for NAND flash disk systems. This sensing scheme achieves good noise immunity for large capacitive coupling between bitlines, and makes NAND flash memories operable for flexible power supply voltages including both 3.3V and 5V. A highly reliable read operation is performed for power supply voltages above 3V and a bitline-bitline coupling ratio below 50%. The sensing scheme also achieves an intelligent page copy function with 20% reduction in time and without external buffers and CPU resources.

A verification is made on the accuracy of Radar-AMeDAS precipitation, which represents hourly precipitation over the Japanese Islands and the surrounding sea area with a spatial resolution of 5km using data from 5cm conventional radars, 10cm Fujisan Radar, and Automated Meteorological Data Acquisition System (AMeDAS) raingauge network. By comparing with data from a very dense raingauge network of the Tokyo Metropolitan Government, it is found that 1) Radar-AMeDAS precipitation shows good agreement if a positioning error of one pixel of 5km square is allowed 2) Radar-AMeDAS precipitation represents almost the average of raingauge measurements in the 5km square for most of the precipitation caused by a large scale disturbance, and 3) Radar-AMeDAS precipitation is close to the maximum raingauge measurement in the pixel when precipitation is extremely localized such as thunderstorms or showers. Radar-AMeDAS precipitations are compared also with AMeDAS measurements statistically with respect to the appearance rates, that is (total number of pixels where specific intensity is observed) / (total number of all pixels), for different precipitation intensities. The rate of Radar- AMeDAS precipitation shows excellent agreement with that of AMeDAS if radar echoes are observed at the altitude lower than 2km. Since Radar- AMeDAS precipitation on land sometimes represents the maximum of precipitation in a pixel for the purpose of unfailingly detecting extremely localized severe precipitation, it shows a high appearance rate at high precipitation intensity than AMeDAS, which is considered to represent statistically the average of a pixel. As a result, in estimating areal rainfall amounts, Radar- AMeDAS precipitation overestimates AMeDAS measurement by 8% at 5mm/h and by 12% at 40mm/h. Radar- AMeDAS precipitation over the sea, with no local calibration by AMeDAS and with little influence of orography, is 2% weaker in intensity than AMeDAS at 10mm/h, and 12% at 40mm/h.

In this paper, a post-layout optimization technique for power dissipation and timing of cell-based Bipolar ECL LSIs is proposed. An ECL LSI can operate at a frequency of a few GHz but the power dissipation is very high compared to CMOS LSIs, which makes the systems using ECL quite expensive. Therefore it is crucial to develop of CAD techniques that minimize the power dissipation of an ECL LSI without decreasing its performance. To begin with, power and delay models of an ECL gate are presented as functions of its switching current. The power dissipation is a linear function of the switching current and the delay time is its hyperbolic function. These functions are obtained considering the post-layout interconnect capacitance and resistance to make the optimization results accurate enough. Using the delay model, a set of timing constraints specifying the max/min cell delay and the clock skew are extracted. This set of constraints in then given to a nonlinear programming package. The objective functions are clock skew time, the clock cycle time and the power dissipation, which are optimized in this order. With the minimum delay and hold constraints, the problem is not convex so that conventional convex programming approach cannot be used. As a result of the optimization, the switching currents for cells are obtained. These are realized within cells by regulating programmable resistors", which is a special feature of our ECL cell library. Since the above optimization is carried out after the placement and routing of the circuit, it can take accurate delay and power estimation into consideration. Experimental results show more than 40% power reductions for circuits including a real communication system chip, compared to the max power versions. The clock cycle time was maintained or even made faster due to the efficient clock skew optimization.

This paper describes the results obtained of a prototype system, VeriProc/1, based on an algorithm we first presented in [13] which can prove the correctness of pipelined processors automatically without pipeline invariant, human interaction, or additional information. No timing relations such as an abstract function or β-relation is required. The only information required is to specify the location of the selectors in the design. The performance is independent of not only data width but also memory size. Detailed analysis of CPU time is presented. Further, don't-care forcing using additional data easily prepared by the user can improve performance.

In this paper, a simple method to investigate the dynamics of continuous-time neural networks based on the force (kinetic vector) derived from the equation of motion for neural networks instead of the energy function of the system has been described. The number of equilibrium points and limit cycles of one-dimensional neural networks with the asymmetric cyclic connection matrix has been investigated experimently by this method. Some types of equilibrium points and limit cycles have been theoretically analyzed. The relations between the properties of limit cycles and the number of connections also have been discussed.

In general, a learning machine will behave better as the number of training examples increases. It is important to know how fast and how well the behavior is improved. The average prediction error, the average of the probability that the trained machine mispredicts the output signal, is one of the most popular criteria to see the behavior. However, it is not easy to evaluate the average prediction error even in the simplest case, that is, the linear dichotomy (perceptron) case. When a continuous deterministic dichotomy machine is trained by t examples of input-output pairs produced from a realizable teacher, these examples limits the region of the parameter space which includes the true parameter. Any parameter in the region can explain the input-output behaviors of the examples. Such a region, celled the admissible region, forms in general a (curved) polyhedron in the parameter space, and it becomes smaller and smaller as the number of examples increases. The present paper studies the shape and volume of the admissible region. We use the stochastic geometrical approach to this problem. We have studied the stochastic geometrical features of the admissible region using the fact that it is dual to the convex hull the examples make in the example space. Since the admissible region is related to the average prediction error of the linear dichotomy, we derived the new upper and lower bounds of the average prediction error.

In order to produce high quality multimedia contents efficiently, DTPP -desktop program production system- has been proposed. The DTPP is capable of supporting all the necessary procedures of program production, from planning to broadcasting, by molding each process into the desktop environment of program producers. The DTPP system consists of multimedia terminals, a media server, a computing server, and network system. In the DTPP, new technological concepts such as cooperative program production, indexing and utilization of attribute information of images, and video components and spatio-temporal editing will be installed.

This paper presents the design concept of the MEMORI, MHEG Engine for Multimedia information Object Retrieval and Interchange, which consists of three functional modules; the decoder, the object manager, and interpreter. Based on our modular design, the MEMORI has been implemented on the UNIX workstation. The menu-driven object generator has also been developed to generate the test objects conforming to the MHEG. Using the object generator, several multimedia/hypermedia test objects have been composed on the basis of presentation scenarios. The results show that the MEMORI correctly decodes, manages, and interprets the MHEG objects. The MEMORI can be utilized for the interactive multimedia server as well as the multimedia presentation system.