In order to achieve high speed measurements of acoustic parameters needed for evaluating pathological voice, an integrated voice analyzer (IVA) has been developed by using a digital signal processor and a general purpose microprocessor. By utilizing a personal computer as a controller of the IVA, a versatile system can be constructed for the acoustic evaluation of pathological voice.

This paper describes the characteristics of multipath fading in aeronautical satellite communications by mainly applying the maritime fading model.

A normalized norm between the time series of radar and gauge rain rates is defined as a measure of agreement between them. The calibration constant of a radar for rain measurements is determined to be the value which minimizes the normalized norm between the radar and gauge rain rates. The results of the experiment show the rain-to-rain variation of the calibration constant. The variation can be partly explained as due to the variation of raindrop size distribution.

This paper presents the development of high-speed logic ICs having the same function as the ECL100K family for high-speed digital system applications such as for time division switching systems. A Super-Self-Aligned process Technology (SST) and a low-voltage swing differential circuit technique are used. The ICs operate up to about 2 Gb/s under a chip power dissipation of 170 mW570 mW.

Monolithic integrated-optical matrix switches (LD matrix SW's) using laser diode gain guides have been proposed. LD matrix SW's have been fabricated on a 1.5 µm-DH wafer by a dry process and optical switching has been demonstrated.

By using complementary SIT, a new type of power negative-resistance device with lambda-type I-V characteristic is presented. It is expected to be realized that the peak current of the proposed device is more than 1500 mA. The new device is characterized by advantageous features such as high-speed performance and wide current-voltage range.

A radar-type microwave imaging system utilizing a Doppler sensor which contains a Gunn oscillator is described. In the system, the synchronous detector is modified to dual diode detection in order to obtain complex hologram. Experimental results are also described.

The computational complexity of several problems in compacting LSI layouts are reviewed from the viewpoint of network flow theory and algorithms. It is shown that the general one-dimensional compaction problem of an LSI layout with n elements, such that the basic building blocks are rectilinear polygons connected by stretchable/shrinkable and movable wires, can be solved in O(n log n) time. Related problems of updating constraints on the layout are also considered.

On the basis of the controllability gramians, the observability gramians and the second order modes, this paper shows that optimal realizations (filter structures having minimum roundoff noises) of quarter-plane-causal, recursive and separable in denominator 2-D digital filters (CRSD filters for short) are scaled and rotated balanced realizations. Two applications of this relation are given. The first one gives a simple proof of the absence of overflow oscillations in optimal realizations. The second one, which is the main result of this paper, gives a direct design method of CRSD filters in the spatial domain. This method simplifies traditional two-step design (approximation and synthesis) into a one-step design with much less computational complexity. Resulting filters of this direct design method can approximate given 2-D impulse responses closely. In addition, they are always guaranteed to be stable, nearly optimal with respect to roundoff noise and free of overflow oscillations. The efficiency of the direct design method is shown by numerical examples.

The distance resolution of an OTDR has been investigated by taking into account the first and second order dispersion terms in single-mode fibers when an optical source with finite spectral width is modulated by a Gaussian-shaped pulse. It is found that the effects of the source spectral width and the first and second order dispersions on the distance resolution of OTDRs are insignificantly small so long as the input pulse width is greater than lnsec and the relative spectral width of the optical source (λ/λ) is less than 0.1 %.

Two kinds of cyclic switched-capacitor A/D converters using only one Op-Amp are presented. The effects of the nonidealities of the circuit such as a capacitor-ratio mismatch, an Op-Amp's offset voltage, and a parasitic capacitance, on a conversion accuracy are discussed.

A fast parallel sorting algorithm on a mesh-connected processor array is presented. The algorithm is based on a pseudo-merge algorithm that roughly merges four roughly sorted subfiles. Its computing time for sorting N items is 6+3log₂13 steps. We also discuss lower bounds on computing times for four classes of parallel sorts, bubble merge sorts, bubble-exchange merge sorts, bubble pseudo-merge sorts and bubble-exchange pseudo-merge sorts. It is shown that 4.54log₂ steps, 3.52log₂1 steps, 34log₂+3 steps and 2.5log₂1 steps, are lower bounds for these classes, respectively.

The parsing method which analyzes sentences into trees may be divided into two categories, the procedural method and the filtering method. The former composes a tree avoiding the occurrence of improper analysis in the course of the analysis procedure by strictly defining the order of application of transformation rules concerning tree structure. The latter obtains the proper tree by obtaining, first, many analysis results through unlimited application of existing rewriting rules and by, later, eliminating improper trees with a filter. The former includes the parsers in the ARIANE 78 at Grenoble University and also at the group led by Kyoto University. This paper proposes a parsing method using the above-mentioned filtering scheme. The method is based on extended LINGOL which is included in the latter category and uses forbidden trees and exclusive trees which respectively forbid and foster the sentence pattern contained in these trees. These trees, cooperating together, work to filter out spurious results. The paper also treats OR nodes for expression of multiple trees in a single tree, giving an algebraic means to allow coexistence of OR nodes and the above-mentioned forbidden and exclusive trees. The algorithm presented in this paper has proved to act well in practical computer experiment showing that it is extensible for practical use.

This paper shows a novel automatic classification method for the electroencephalogram (EEG) based on syntactical pattern recognition. The syntactical method is effective to represent the complicated structure of the features of the EEG which contains transient-waves as well as the background-wave. For the extraction of transient-waves an adaptive autoregressive-moving average (ARMA) model fitting is utilized where the input to the model is replaced by the modified input if the prediction error grows more than a given threshold. By the adaptive ARMA model transient-waves and the spectrum of the background-wave are obtained from the prediction error and ARMA parameters, respectively. Since transient-waves may contain noisy patterns or variances, a relaxation scheme is applied. As the second stage all of the features of the EEG including the spectrum are described syntactically according to the generative grammar. Then the syntactical description T_i inherent to the diagnosis is obtained. In order to reduce the ambiguity and to suppress the complexity of syntactical descriptions, numerical values representing the details of EEG are separated from the syntactical description, and are added as the attributes (this method is generally called the attributed grammar). For the input EEG having syntactical description T_i, the final diagnostic decision is made by using the statistical Bayes estimation about the attributes within the group for T_i. As the result of automatic EEG classification for 200 EEG samples correct recognition of about 80 percent is observed.