Induced noises from breaking contact arc discharge and sliding contact discharge of dc motor are measured by pick up coil and current probe. Statistical properties, amplitude distribution probability (APD), of induced noise waveform are analyzed by simple method using intermediate frequency of spectrum analyzer. It is shown that APD characteristics can be used to estimate statistical characteristics and peak value of induced noise. Simulation model of the noise made by the combination of Gaussian noise is mentioned. The model called the composite noise generator (CNG) can be good fit to the real characteristics of both noises from breaking arc and dc motor. Applications of the CNG for noise filter using toroidal coil shows that the CNG is useful to realize the test of noise suppression characteristics. What parameters of the CNG should be considered is described for further applications.

The local moment functions for discrete Wigner trispectrum are examined in ambiguity and in time-frequency domain. A concept of multiple and multidimensional circular convolution in frequency domain is introduced into the discrete Wigner higher order time-frequency signal representation of any order. It is shown that this concept based on the 1st order spectra of the signal offers an insight into the properties of inconsistent local moment functions and their representation both in ambiguity and time-frequency domain. It allows to prove that midfrequency crossterms of a multicomponent signal can not be removed by any generalized 4th order ambiguity function which employ kernel function in the ambiguity domain. It is shown, that the concept of multiple convolution in frequency domain can lead to the crossterm-reduced discete time-frequency representations of any order

This paper presents a combinatiorial characterization of broadcast authentication in which a transmitter broadcasts v messages e1(s), , ev(s) to authenticate a source state s to all n receivers so that any k receivers cannot cheat any other receivers, where ei is a key. Suppose that each receiver has l keys. First, we prove that k < l if v < n. Then we show an upper bound of n such that n v(v - 1)/l(l - 1) for k = l - 1 and n /+ for k < l - 1. Further, a scheme for k = 1 - 1 which meets the upper bound is presented by using a BIBD and a scheme for k < l - 1 such than n = / is presented by using a Steiner system. Some other efficient schemes are also presented.

We have developed inlaid copper interconnects employing amorphous Ti-Si-N barrier metal. The interconnect resistivity is 1.90.1 µΩcm. Ti-Si-N films were shown to be amorphous by X-ray diffraction measurements. The amorphous structure was thermal stable, even after annealing at 600 for 30 minutes in an Ar ambient. The atomic composition of the film was identified as Ti : Si : N=1 : 0.6 : 1.6. The films were found to be under tensile stress of 0.3 Gpa. The resistivity is about 0.5 mΩcm at room temperature. The diffusion barrier characteristics were evaluated by n+/p and p+/n junction leakage measurements. No degradation of leakage characteristics was observed for these diodes, even after annealing at 600 for 30 minutes in an N2/H2 ambient. The amorphous Ti-Si-N barrier metal is a promising candidate for application in deep-submicron high-speed ULSIs.

A new superresolution technique is proposed for high-resolution estimation of the scattering analysis. For complicated multipath propagation environment, it is not enough to estimate only the delay-times of the signals. Some other information should be required to identify the signal path. The proposed method can estimate the frequency characteristic of each signal in addition to its delay-time. One method called modified (Root) MUSIC algorithm is known as a technique that can treat both of the parameters (frequency characteristic and delay-time). However, the method is based on some approximations in the signal decorrelation, that sometimes make problems. Therefore, further modification should be needed to apply the method to the complicated scattering analysis. In this paper, we propose to apply a time-domain null filtering scheme to reduce some of the dominant signal components. It can be shown by a simple experiment that the new technique can enhance estimation accuracy of the frequency characteristic in the Root-MUSIC algorithm.

In the business systems design learning environment, there may be more than one solution to any given problem. For instance, the data model will be different depending on each learner's perspective. Accordingly, group learning systems are very effective in this domain. We have developed CAMELOT (Collaborative and Multimedia Environment for Learners on Teams) [18] using the Nominal Group Technique for group problem solving. In this paper, the basic framework of the collaborative learning system and the effectiveness of collaborative learning in designing the Data Model are described. By using CAMELOT, each learner learns how to analyze through case studies and how to cooperate with his or her group in problem solving. Learners come to a deeper understanding from using CAMELOT than from studying independently because they are enabled to reach better solutions through discussion, tips from other learners, and examination of one another's works.

Polynomials are called permutation polynomials if they induce bijective functions. This paper investigates algebraic properties of permutation polynomials over a finite field, especially properties associated with permutation cycles. A permutation polynomial has a simple structure but good randomness properties suitable for applications. The cycle structure of permutations are considered to be related to randomness. We investigate the algebraic structure from the viewpoint of randomness. First we show the relationship between polynomials and permutations using a matrix equation. Then, we give a general form of a permutation polynomial corresponding to a product C1C2Ck of pairwise disjoint cycles. Finally, permutation polynomials with fixed points -or with 2, 3 and 4-cycles -and their compositions are given together with distribution of degree of the permutation polynomials.

This paper proposes a mutual exclusion method that is unified for the parallel and distributed systems. The method partially serializes requests into partial queues of requests, which are next totally serialized into a main queue. A request in the main queue is authorized to enter the critical section (CS) when the request receives the privilege token from the previous request in the queue. In the distributed system of N sites that each is a parallel system, mutual exclusion is performed by cooperation of two algorithms based on the same method. The algorithm for the distributed system works on a logical network (that is a directed tree) of S ( N) sites. The algorithm for each site produces a local-main queue of requests. The chunk of requests in the local queue is concatenated at a time to the partial queue of the distributed system. The the cost of mutual exclusion -- the number of intersite messages required per CS entry -- is reduced to O(1) (between 0 and 3).

We present a 64-b adder having a 2.6-ns delay time at 3.3 V power supply within 0.27 mm2 using 0.5-µm CMOS technology. We derived our adder design from architectural level considerations. The considerations include not only the gate intrinsic delay but also the wiring delay and the gate capacitance delay. As a result, a 64-b adder, (56-b Carry Look-ahead Adder(CLA) +8-b Carry Select Adder (CSA)), was designed. In this design, a new carry select scheme called Modified Carry Select (MCS) is also proposed.

A directed graph G = (V,E) is called the n-rotator graph if V = {a1a2an|a1a2an is a permutation of 1,2,,n} and E = {(a1a2an,b1b2bn)| for some 2 i n, b1b2bn = a2aia1ai+1an}. We show that for any pair of distinct nodes in the n-rotator graph, we can construct n - 1 disjoint paths, each length < 2n, connecting the two nodes. We propose a nonadaptive fault-tolerant file transmission algorithm which uses these disjoint paths. Then the probabilistic analysis of its reliability is given.

The synergistic effects obtained by adopting both space diversity reception and adaptive equalization play a very important role in circuit outage reduction. This paper quantitatively analyzes these synergistic effects when dispersive and flat fading occur simultaneously. Analytical results show that the synergistic effects are of the same magnitude as the adaptive equalizer improvement factor when only dispersive fading causes outage. The synergistic effects gradually disappear when noise is the predominant cause of outage.

The coupling response of an external transient electromagnetic field to a transmission line is considered. An experiment has been conducted to verify the line equations for a transmission line excited externally by a transient near field. The model field is generated by a monopole antenna installed in the vicinity of the transmission line and driven by a step waveform. The waveform is analyzed into discrete spectrum components using a Fourier transform. The frequency-domain field components affecting the transmission line are estimated by the moment method, and then the induced frequency-domain voltage at the terminal load is converted into a time-domain voltage using an inverse Fourier transform. Comparison between the measured and the computed values provides verification of the line equations. The coupling mechanism is discussed from the experimental results. It seems equivalently that the transmission line picks up the field, generated at the feed point and the top point of the monopole antenna, at both terminal ends.

It is known that the problem of determining, given a planar graph G with maximum vertex degree at most 4 and integers m and n, whether G is embeddable in an m n grid with unit congestion is NP-hard. In this paper, we show that it is also NP-complete to determine whether G is embeddable in ak n grid with unit congestion for any fixed integer k 3. In addition, we show a necessary and sufficient condition for G to be embeddable in a 2 grid with unit congestion, and show that G satisfying the condition is embeddable in a 2 |V(G)| grid. Based on the characterization, we suggest a linear time algorithm for recognizing graphs embeddable in a 2 grid with unit congestion.

A simple and convenient approach for a radial symmetrical point detection is proposed. In this paper the real part-only synthesis is utilized in order to make an origin symmetric pattern of the original image and to perform automatically the calculation of its autocorrelation for the detection of the symmetry center of the image.

It is well recognized that the electromagnetic interference due to indirect electrostatic discharge (ESD) is not always proportional to the ESD voltage and also that the lower voltage ESD sometimes causes the more serious failure to high-tech information equipment. In order to theoretically examine the peculiar phenomenon, we propose an analytical approach to model the indirect ESD effect. A source ESD model is given here using the spark resistance presented by Rompe and Weizel. Transient electromagnetic fields due to the ESD event are analyzed, which are compared with the experimental data carefully given by Wilson and Ma. A model experiment for indirect ESD is also conducted to confirm the validity of the ESD model presented here.

This paper describes the design of a high-speed 4-2 compressor for fast multipliers. Through the survey of the six kinds of representative conventional 4-2 compressor (RBA 1-3 and NBA 1-3) in both the redundant binary (RB) and the normal binary (NB) scheme, we extracted two problems that degrades the operating speed. The first is the use of multi-input complex gates and the second is the existence of transmission gates (TG) at the input and/or output stages. To solve these problems, we propose high-speed 4-2 compressors using the RB scheme, which we call the high-speed redundant binary adders (HSRBAs). Six kinds of HSRBAs, HSRBA 1-6, were derived by making the Boolean equations suitable for high-speed CMOS circuits. Among them, HSRBA2, HSRBA4 and HSRBA6 have no multi-input complex gate and input/output TG, and perform at a delay time of 0.89 ns which is the fastest of all 4-2 compressors. We investigated the logical relation between HSRBAs and conventional 4-2 compressors by analyzing the Boolean equations for each circuit. This investigation shows that all the conventional redundant binary adders RBA1-3 have the same logic structures as HSRBA2. We also showed the conventional normal binary adders NBA1-3 have the same logic structures as HSRBA1, HSRBA3 and HSRBA5, respectively. This implies all 4-2 compressors can be derived from the same equation regardless of RB or NB. We applied the HSRBA2 to a 5454-bit multiplier using 0.5-µm CMOS technology. The multiplication time at the supply voltage of 3.3 V was 8.8 ns. This is the fastest 5454-bit multiplier with 0.5-µm CMOS so far, and 83% of the speed improvement is due to the high speed 4-2 compressor.

Discussed here is progress achieved in the development of video codec LSIs.First, the amount of computation for various standards, and signal handling capability (throughput) and power dissipation for video codec LSIs are described. Then, general technologies for improving throughtput are briefly summarized. The paper also reviews three approaches (i.e., video signal processor, building block and monolithic codes) for implementing video codes standards. The second half of the paper discusses various high-throughput technologies developed for programmable Video Signal Processor (VSP) LSIs. A number of VSP LSIs are introduced, including the world's first programmable VSP, developed in February 1987 and a monolithic codec ship, built in February 1993 that is sufficient in itself for the construction of a video encoder for encoding full-CIF data at 30 frames per second. Technologies for reduction of power dissipation while keeping maintaining throughput are also discussed.

An ordered binary decision diagram (OBDD) is a directed acyclic graph for representing a Boolean function. OBDDs are widely used in various areas which require Boolean function manipulation, since they can represent efficiently many practical Boolean functions and have other desirable properties. However, there is very little theoretical research on the complexity of constructing an OBDD. In this paper, we prove that the optimal variable ordering problem of a shared BDD is NP-complete, and briefly discuss the approximation hardness of this problem and related OBDD problems.

We propose a parallel parsing algorithm based on Earley's method, which works in O(log2n) time using O(n4.752) processors on CREW PRAM. This algorithm runs with less number of precessors compared with previously proposed W. Rytter's algorithm.

The Voronoi diagram is the most fundamental and useful concept in computational geometry. To understand impacts of non-Euclidean geometry on computational geometry, this paper investigates the Voronoi diagram in hyperbolic space. We first present characterizations of this diagram by means of the Enclidean Voronoi diagram, and based on them propose efficient algorithms to construct it. Some applications are also mentioned.