Novel structure of GaAs-based interdigital-gated HEMT plasma devices for solid-state THz wave amplifier

Theoretical analysis of potential distribution in the interdigital-gated high electron mobility transistor (HEMT) plasma wave device was carried out. The dc I–V characteristics of capacitively coupled interdigital structure showed that uniformity of electric field under the interdigital gates was improved compared to the dc-connected interdigital gate structure. Admittance measurements of capacitively coupled interdigital gate structure in the microwave region of 10–40 GHz showed the conductance modulation by drain–source voltage. These results indicate the existence of plasma wave interactions.     

A Gait Phase Measurement System Using Treadmill Motor Current

The article describes the development of a gait phase time-based split-belt treadmill measurement system. Conventional methods of measuring gait phase, such as the foot switch and force plate, require significant preparation and are costly. In this article, we propose a simple, cheap, and accurate gait phase measurement system that utilizes only the treadmill motor current value. Comparison of this algorithm with conventional methods reveals that the proposed algorithm is as accurate as the foot switch. Moreover, the proposed algorithm can estimate stance phase within a 0.2?s error of the measured value of the force plate in most cases (four out of five healthy subjects). This accuracy is higher than that of the foot switch which is widely used in the clinical field.     

Cellular array processor CAP and applications

The general-purpose, highly parallel, cellular array processor (CAP) we developed features multiple-instruction stream, multiple-data stream (MIMD) processing and image display. Processor elements can number in several hundreds. The present system uses 256 processors. Each processor element consists of a general-purpose microprocessor, memory, and a special VLSI chip that performs parallel-processing-specific functions such as processor communication and synchronization. The VLSI has two 2M byte/s independent common bus interfaces for data broadcating and six 15M bit/s serial communication ports for local data communication. The chip also can process image data in real time for multiple processors. Use of the communication interfaces enables a variety of processor networks to be configured. One CAP application has been computer graphics, in which ray tracing is used to generate quality images.     

Effect of rule weights in fuzzy rule-based classification systems

This paper examines the effect of rule weights in fuzzy rule-based classification systems. Each fuzzy IF-THEN rule in our classification system has antecedent linguistic values and a single consequent class. We use a fuzzy reasoning method based on a single winner rule in the classification phase. The winner rule for a new pattern is the fuzzy IF-THEN rule that has the maximum compatibility grade with the new pattern. When we use fuzzy IF-THEN rules with certainty grades, the winner is determined as the rule with the maximum product of the compatibility grade and the certainty grade. In this paper, the effect of rule weights is illustrated by drawing classification boundaries using fuzzy IF-THEN rules with/without certainty grades. It is also shown that certainty grades play an important role when a fuzzy rule-based classification system is a mixture of general rules and specific rules. Through computer simulations, we show that comprehensible fuzzy rule-based systems with high classification performance can be designed without modifying the membership functions of antecedent linguistic values when we use fuzzy IF-THEN rules with certainty grades     

Further design considerations for unevacuated horizontal multi-layer insulation systems

Two design criteria for unevacuated horizontal multi-layer insulation systems, with equal spacings of the intermediate plates yielding the minimum heat transfer rate, are described.     

Theoretical Estimation of Changes in Plane Elastic Waves due to Cylindrical Inclusions

Changes in amplitude and phase shifts in plane elastic waves were theoretically estimated when they propagated through an elastic body containing cylindrical inclusions. Based on the integral equation suggested by Lavrov et al., these changes were calculated in the case when only one cylindrical inclusion was located in the body and the propagating waves have a single frequency. These calculations were expanded to more practical case when multiple cylindrical inclusions aligned in the body and the waves have some frequency band. The changes in amplitude and phase shifts calculated were associated to the changes in apparent sonic velocity and attenuation coefficient due to a structural change in the material. This theoretical approach contributes to a quantitative damage evaluation based upon structural changes in various materials by measuring the acoustical parameters such as apparent sonic velocity and attenuation coefficient.     

An optimal part sending policy for a production system in a generalconfiguration with a new control strategy

We consider a production system in a general configuration with a new control strategy: the push mechanism for the part transport and the kanban technique for the work-in-process (WIP). The production system is composed of many stations such as an entrance station, a set of work stations, a central station, and an exit station, that are arranged in a general configuration. The push mechanism is followed for transporting a part from a station to a destination station. The kanban technique is adopted for controlling the WIP in a work station. The production system is modeled by a closed queuing network in a general configuration with a Markov part sending mechanism and a machine no blocking (MNB) technique. An optimal part sending policy that maximizes the expected system throughput is formulated into a long run average semi-Markov decision process. Three solution approaches are developed for obtaining optimal or suboptimal solutions. Numerical examples are given to evaluate the quality of the solutions obtained by the solution approaches