This paper discusses the fixed-point smoothing and filtering problems given lumped covariance function of a scalar signal process observed with additive white Gaussian noise. The recursive Wiener smoother and filter are derived by applying an invariant imbedding method to the Volterra-type integral equation of the second kind in linear least-squares estimation problems. The resultant estimators in Theorem 2 require the information of the crossvariance function of the state variable with the observed value, the system matrix, the observation vector, the variance of the observation noise and the observed value. Here, it is assumed that the signal process is generated by the state-space model. The spectral factorization problem is also considered in Sects. 1 and 2.

A region-based adaptive perceptual quantization technique is proposed for video sequence coding, and applied to the MPEG coder. The visibility of coding artifacts in a macroblock (MB) is affected by perceptual characteristics of neighboring MBs as well as the MB itself. Therefore spacial and temporal activities of the MB and its surroundings are used to decide the quantization scaling factor. In comparison with the adaptive scheme in the encoding algorithm specified in MPEG-2 Test Model 5 (TM5), the proposed scheme is proven to improve perceptual quality further in video coding.

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.

Weather clutter was measured using an L-band long-range (200 nmi.) air-route surveillance radar (ARSR), from the stored data of five scans. It is shown that weather clutter obeys a Weibull distribution, and moreover such Weibull-distributed weather clutter also obeys a Weibull distribution after passing through a moving target indicator (MTI) processor realized by a double canceller. Some adaptive methods for suppressing Weibull-distributed clutter are summarized.

The reception level of a round-trip signal from a VSAT (Very Small Aperture Terminal) was monitored continuously for three years starting October 1991.For these experimental measurements, a commercial satellite channel (up-link 14GHz/downlink 12GHz, bandwidth 100kHz) was used and rainfall was measured simultaneously. Data gathering time interval of 2 seconds was adopted to elucidate very rapid variation and lower percentage statistics. In this paper, attenuation due to rainfall is shown using the data obtained in this three-year period. It is shown that so far, the measured rain attenuation agrees very well with the values estimated using the CCIR model, and limits the range where the cumulative time exceeds 0.01%, even for our VSAT system in Tagajo, Miyagi Prefecture, Japan.

We propose burst based bandwidth reservation method called FRP (Fast Reservation Protocol) in ATM LAN with general topology, and evaluate its performance. In FRP, the bandwidth is allocated on each link on burst basis, not on call basis. This enables an effective use of network resources when it is applied to highly bursty traffic, which can be typically found in data communications. The problem of FRP is that VCs traversing the different number of links experience different blocking probabilities as can be found in the conventional circuit-switching networks. In this paper, we treat a fairness issue in FRP-based ATM local area networks. The Max-Min flow control is adopted as the fair bandwidth allocation method to accomplish the fairness in the throughput. However, the original Max-Min flow control works in a centralized fashion, which is not desirable in the FRP-based ATM LAN. We therefore propose a "semi"-distributed Max-Min flow control suitable to FRP, in which each switch maintains its own local information about bandwidth usage of the connected links. Through simulation experiments, we show that the proposed semi-distributed Max-Min flow control can achieve the fairness among VCs as the original Max-Min flow control when the propagation delays are not large and the number of VCs is not so much.

This letter propose a fast frequency domain adaptive filter algorithm (FADF) for applications in which large order adaptive filters are required. Proposed FADF algorithm reduces the block delay of conventional FADF algorithms allowing a more efficient selection of the fast Fourier Transform (FFT) size. Proposed FADF algorithm also provides faster convergence rates than conventional FBAF algorithms by using a near-optimum convergence factor derived by using the FFT. Computer simulations using white and colored signals are given to show the desirable features of proposed scheme.

In this letter, we propose an adaptive multiuser receiver using a Hopfield network for code-division multiple-access communications and its performance is compared with that of the other types of multiuser receiver via computer simulation. The proposed adaptive receiver estimates both the signal amplitudes and spreading sequences for all the users using training data.

In this paper, we give an algorithm which, given a set F of at most (n - 1) - k faulty nodes, and two sets S = {s1,..., sk} and T = {t1,..., tk}, 1 k n - 1, of nonfaulty nodes in n-dimensional star graphs Gn, finds k fault-free node disjoint paths si tji, where (j1,..., jk) is a permutation of (1,..., k), of length at most d(Gn) + 5 in O(kn) optimal time, where d(Gn) = 3(n-1)/2 is the diameter of Gn.

In this paper, we give an algorithm which, given a set F of at most n-k faulty nodes, and two sets S={s1, , sk} and T = {t1,, tk}, 1kn, of non-faulty nodes in n-dimensional hypercubes Hn, finds k fault-tree node disjoint paths sitje, where (j1, , Jk) is a permutation of (1, , k), of length at most n + k in O(kn log k) time. The result of this paper implies that n disjoint paths of length at most 2n for set-to-set node disjoint path problem in Hn can be found in O(n2 log n) time.

Various kinds of new architectures have been proposed to enhance operating performance of the DRAM. This paper reviews these architectures including EDO, SDRAM, RDRAM, EDRAM, and CDRAM. The EDO slightly modifies the output control of the conventional DRAM architecture. Other innovative architectures try to enhance the performance by taking advantage of DRAM's internal multiple bits architecture with internal pipeline, parallel-serial conversion, or static buffers/on-chip cache. A quantitative analysis based on an assumption of wait cycles was made to compare PC system performance with some architectures. The calculation indicated the effectiveness of external or on-chip cache. Future trends cover high-speed I/O interface, unified memory architecture, and system integrated memory. The interface includes limited I/O swing such as HSTL and SSTL to realize more than 100MHz operation. Also, Ramlink and SyncLink are briefly reviewed as candidates for next generation interface. Unified memory architecture attempts to save total memory capacity by combining graphics and main memory. Advanced device technology enables system integration which combine system logic and memory. It suggests one potential direction towards system on a chip in the future.

This paper describes a new active pull-up (APU) interface for high-speed point-to-point transmission. The APU circuit is used to speed up a low-power-consumption open-drain-type interface. It pulls up the output at a fixed duration and this limiting of the pull-up duration prevents the pull-up operation from going into a counter phase at over 1-Gbps operation. Measurements of test chips fabricated with 0.25-µm bulk CMOS show. 1.7-Gbps error-free operation for the APU interface and 1.2-Gbps operation for the open-drain-type interface: The APU interface is 1.4 faster than the open-drain type. The application of a 0.25-µm SIMOX-CMOS device to the APU interface increases the bit rate 1.5 times compared with 0.25-µm bulk CMOS. Altogether the interface covers the bit rate of 2.4 Gbps, which is a layer of the communication hierarchy. The APU interface circuit can be applied to large-pin-count LSIs because of its full-CMOS single-rail structure.

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.

Surface discharge is widely used for industrial ozonizers and toxic gas treatments, and is noise source. In this paper, an experimental investigation from the point of view of electromagnetic compatibility (EMC) has been conducted to evaluate the noise characteristics of surface discharge combustion flue gas cleaning systems. Mechanisms of propagation, coupling and formation are proposed based on the experimental observations.

When circuits which include inductive loads are turned off by contact, showering noise generates across contact gap. Showering noise waveforms seem not to be stable in the case that wire-spring relay contact is used to turn on/off inductive load. It seems that various factors are concerned in the irregularity of showering noise waveforms. This paper clarifies the relation between showering noise waveform and the cathodic contact surface variation with the number of contact operation, and moving velocity of contact.

A speedup of Lenstra's Elliptic Curve Method of factorization is presented. The speedup works for integers of the form N = PQ2, where P is a prime sufficiently smaller than Q. The result is of interest to cryptographers, since integers with secret factorization of this form are being used in digital signatures. The algorithm makes use of what we call Jacobi signatures. We believe these to be of independent interest.

A new observation technique for process-induced micro-defects in ULSI using a combination of anodic oxidation and chemical removal of the oxide has been developed. Enhanced oxidation has occurred at the defect region due to the stress field and then craterlike delineation has been formed after oxide removal. AFM and SEM observation of the micro-defects induced by ion implantation and applications using this tech-nique to the failure analysis of MOS device fabrication are presented.

An adaptive algorithm for a single sinusoid detection using IIR bandpass filter with parallel block structure has been proposed by Nishimura et al. However, the algorithm has three problems: First, it has several input frequencies being impossible to converge. Secondly, the convergence rate can not be higher than that of the scalar structure. Finally, it has a large amount of computation. In this paper, a new algorithm is proposed to solve these problems. In addition, a new structure is proposed to reduce the amount of computation, in which the adaptive control signal generator is realized by the paralel block structure. Simulation results are given to illustrate the performance of the proposed algorithm.

The scaling laws between the design rules and the smallest sizes and numbers of particles capable of causing pattern defects and scrapping dies in semiconductor device manufacturing are described. Simulation with electromagnetic waveguide model indicates the possibility that particles, the sizes of which are of comparable order or even smaller than the wavelength of the lithography irradiation sources, are capable of causing pattern defects. For example, in the future 0.25 µm-design-rule era, the critical sizes of Si, Al, and SiO2 particles are simulated as 120 nm 120 nm, 120 nm 120 nm, and 560 nm 560 nm, respectively, in the case of 0.7 µm-thick chemically-amplified positive photoresist with 47 nm-thick top anti-reflective coating films. Future giga-scale integration era is also predicted.