Mitsuo OHTA Kiminobu NISHIMURA
A new trial of statistical evaluation for an output response of power linear type acoustic systems with nonstationary random input is proposed. The purpose of this study is to predict the output probability distribution function on the basis of a standard type pre-experiment in a laboratoty. The statistical properties like nonstationarity, non-Gamma distribution property and various type linear and non-linear correlations of input signal are reflected in the form of differential operation with respect to distribution parameters. More concretely, the pre-experiment is carried out for a power linear acoustic system excited only by the Gamma distribution type sandard random input. Considering the non-negative random property for the output response of a power linear system, the well-known statistical Laguerre expansion series type probability expression is first employed as the framework of basic probability distribution expression on the output power fluctuation. Then, the objective output probability distribution for a non-stationary case can be easily derived only by successively employing newly introduced differential operators to this basic probability distribution of statistical Laguerre expansion series type. As an application to the actual noise environment, the proposed method is employed for an evaluation problem on the stochastic response probability distribution for an acoustic sound insulation system excited by a nonstationary input noise.
Toshiyuki YOSHIDA Akinori NISHIHARA Nobuo FUJII
In multidimensional signal sampling, the orthogonal sampling scheme is the simplest one and is employed in various applications, while a non-orthogonal sampling scheme is its alternative candidate. The latter sampling scheme is used mainly in application where the reduction of the sampling rate is important. In three-dimensional (3-D) signal processing, there are two typical sampling schemes which belong to the non-orthogonal samplings; one is face-centered cubic sampling (FCCS) and the other is body-centered cubic sampling (BCCS). This paper proposes a new design method for 3-D band-limiting FIR filters required for such non-orthogonal sampling schemes. The proposed method employs the McClellan transformation technique. Unlike the usual 3-D McClellan transformation, however, the proposed design method uses 2-D prototype filters and 2-D transformation filters to obtain 3-D FIR filters. First, 3-D general sampling theory is discussed and the two types of typical non-orthogonal sampling schemes, FCCS and BCCS, are explained. Then, the proposed design method of 3-D bandlimiting filters for these sampling schemes is explained and an effective implementation of the designed filters is discussed briefly. Finally, design examples are given and the proposed method is compared with other method to show the effectiveness of our methos.
Ryozo AOKI Hironaru MURAKAMI Tetsuro NAKAMURA
The Cooper pairing interaction in high Tc oxide superconductor is discussed in terms of an empirical expression; TcDexp[1/g], gc
It is concluded from numerical examples for the well-known linear PN sequence families of a large range of periods that the mean-square cross-correlation value between sequences is the dominating parameter to the average signal-to-noise power ratio performance of an asynchronous direct-sequence (DS) code-division multiple-access (CDMA) system. The performance parameters derived by Pursley and Sarwate are used for numerical evaluation and the validity of conclusion is supported by reviewing the other related works. The mean-square periodic cross-correlation takes the equal value p (code period) for the known CDMA code families. The equal mean-square cross-correlation performance results from the basic results of coding theory.
Hiromasa HABUCHI Takaaki HASEGAWA
Recently, there has been increasing interest in Code Division Multiplex (CDM) systems. We reported the CDM system using the -chip shift multiplex operation. So far the performance of this system evaluated under the optimum . In this letter, we evaluate an influence of the phase difference between the groups on BER performance in 2M-plex system.
Masanobu OHHATA Minoru TOGASHI Koichi MURATA Satoshi YAMAGUCHI Masao SUZUKI Kazuo HAGIMOTO
This letter reports a high-sensitivity GaAs decision IC for ultra-high-speed optical transmission systems. The IC was designed using LSCFL (Low-power Source Coupled FET Logic) and fabricated with 0.2-µm-gate-length MESFETs with a cut-off frequency of 50GHz. The input voltage sensitivity was 35mV at 10Gbit/s. This is the highest sensitivity ever reported for a MESFET decision IC.
We observed a ship as a radar target embedded in sea clutter using a millimeter wave radar. The shape of the ship and sea clutter were discriminated by using texture analysis in image processing. As a discriminator, a nonlinear transformation of a local pattern was defined to deal with high order statistics.
Masahiro HASHIMOTO Eiji FUJIWARA
Since semiconductor memory chip has been growing rapidly in its capacity, memory testing has become a crucial problem in RAMs. This paper proposes a new RAM test algorithm, called generalized marching test (GMT), which detects static and dynamic pattern sensitive faults (PSF) in RAM chips. The memory array with N cells is partitioned into B sets in which every two cells has a cell-distance of at least d. The proposed GMT performs the ordinary marching test in each set and finally detects PSF having cell-distance d. By changing the number of partitions B, the GMT includes the ordinary marching test for B1 and the walking test for BN. This paper demonstrates the practical GMT with B2, capable of detecting PSF, as well as other faults, such as cell stuck-at faults, coupling faults, and decoder faults with a short testing time.
Kazutoshi KOBAYASHI Keikichi TAMARU Hiroto YASUURA Hidetoshi ONODERA
We propose a new architecture of Functional Memory type Parallel Processor (FMPP) architectures called bit-parallel block-parallel (BPBP) FMPP. Design details of a prototype BPBP FMPP chip are also shown. FMPP is a massively parallel processor architecture that has a memory-based simple two-dimensional regular array structure suitable for memory VLSI technology. Computation space increases as integration density of memory increases. Computation time does not depend on the number of processors. So far, a bit-serial word-parallel (BSWP) implementation based on a content addressable memory (CAM) is mainly investigated as one of promising architectures of FMPP. In a BSWP FMPP, each word of a CAM works as a processor, and the amount of hardware is minimized by abopting a bit-serial operation, thus maximizing integration scale. The BSWP FMPP, however, does not allow operations between two words, which restriction limits the applicability of the BSWP FMPP. On the other hand, the proposed BPBP FMPP is designed to execute logical and arithmetic operations on two words. These operations are performed simultaneously on every group of words called a block. BPBP FMPP hereby achieves a high performance while maintaining high integration density of the BSWP, and is suitable for various applications.
Yoshikazu MIYANAGA Koji TOCHINAI
This paper proposes a multi-layer cellular network in which a self-organizing method is implemented. The network is developed for the purpose of data clustering and recognition. A multi-layer structure is presented to realize the sophisticated combination of several sub-spaces which are spanned by given input characteristic data. A self-organizing method is useful for evaluating the set of clusters for input data without a supervisor. Thus, using these techniques this network can provide good clustering ability as an example for image/pattern data which have complicated and structured characteristics. In addition to the development of this algorithm, this paper also presents a parallel VLSI architecture for realizing the mechanism with high efficiency. Since the locality can be kept among all processing elements on every layer, the system is easily designed without large global data communication.
Takashi MORIE Yoshihito AMEMIYA
This paper describes the learning performance of the deterministic Boltzmann machine (DBM), which is a promising neural network model suitable for analog LSI implementation. (i) A new learning procedure suitable for LSI implementation is proposed. This is fully-on-line learning in which different sample patterns are presented in consecutive clamped and free phases and the weights are modified in each phase. This procedure is implemented without extra memories for learning operation, and reduces the chip area and power consumption for learning by 50 percent. (ii) Learning in a layer-type DBM with one output unit has characteristic local minima which reduce the effective number of available hidden units. Effective methods to avoid reaching these local minima are proposed. (iii) Although DBM learning is not suitable for mapping problems with analog target values, it is useful for analog data discrimination problems.
Seungjik LEE Jaeho SHIN Seiichi NOGUCHI
In this letter, we study on the sensitivity to the electrical stimulus pulse for biomedical electronics for the purpose to make a tactile vision substitution system for binds. We derive the equivalent circuit of finger by measuring sensitive voltages with various touch condition and various DC voltage. And we consider to the sensitivity of finger against electrical stimulus pulse. In order to convert the sense of sight to tactile sense, we consider four types of touch condition and various types of pulse. It is shown that the sensitivity of finger to electrical stimulus pulse is determined by duty-ratio, frequency, hight of pulse and the type of touch condition. In the case that duty-ratio is about 20%, frequency is within about 60-300Hz and touch condition is A-4 type, the sensitive voltage becomes the lowest. With this result, a tactile vision substitution system can be developed and the system will be used to transfer various infomations to blinds without paper.
Yoshihiro KANEKO Jiguang ZHANG Shoji SHINODA Kazuo HORIUCHI
In a file transmission net N with vertex set V and arc set B, copies of a file J are distributed from a vertex to every vertex, subject to certain rules on file transmission. A cost of making one copy of J at each vertex µ is called a copying cost at µ, a cost of transmitting one copy of J through each arc (x, y) is called a transmission cost (x, y), and the number of copies of J demanded at each vertex u in N is called a copy demand at u. A scheduling of distributing copies of J from a vertex, say s, to every vertex on N is called a file transfer from s. The vertex s is called the source of the file transfer. A cost of a file transfer is defined, a file transfer from s is said to be optimal if its cost is not larger than the cost of any other file transfer from s, and an optimal file transfer from s is said to be optimum on N if its cost is not larger than that of an optimal file transfer from any other vertex. In this note, it is proved that an optimal file transfer from a vertex with a minimum copying cost is optimum on N, if there holds M U where M and U are the mother vertex set and the positive demand vertex set of N, respectively. Also it is shown by using an example that an optimal file transfer from a vertex with a minimum copying cost is not always optimum on N when M ⊃ U holds.
Hiroaki IWASHITA Tsuneo NAKATA Fumiyasu HIROSE
We Propose an integrated design and test assistance method for pipelined processors. Our approach generates behavioral-level test environments for pipeline control mechanisms from a machine-readable specification. It includes automatic generation of test programs and behavioral descriptions. Verification can be done by applying logic simulation to both the designers' descriptions and the behavioral descriptions, and then comparing the results. We have implemented an experimental system that enumerates all hazard patterns--instruction patterns that cause pipeline hazards--from the specifications, and generates the test programs and the behavioral descriptions for the pipeline controllers. The test programs cover all of the hazard patterns. The behavioral descriptions can manipulate any instruction stream. Experimental results for several RISC processors show that actual hazard patterns are too numerous to be easily enumerated by hand. Using workstations, our system can generate the test programs that cover all of the patterns, taking a few minutes. Results suggest that the system can be used to evaluate pipeline design.
Kiyoshi FURUYA Edward J. McCLUSKEY
A method to analyze two-pattern test capabilities of autonomous test pattern generator (TPG) circuits for use in built-in self-testing are described. The TPG circuits considered here include arbitrary autonomous linear sequential circuits in which outputs are directly fed out from delay elements. Based on the transition matrix of a circuit, it is shown that the number of distinct transitions in a subspace of state variables can be obtained from rank of the submatrix. The two-pattern test capabilities of LFSRs, cellular automata, and their fast parallel implementation are investigated using the transition coverage as a metric. The relationships with dual circuits and reciprocal circuits are also mentioned.
This paper reviews the historical aspect of contributions on the theory of analysis and diagnosis of linear circuits, which have been made by Japanese researchers in these twenty years. On papers of diagnosis, those related to element-value solvability (or determinability) are mainly reviewed. Some important problems are suggested.
Three dimensional (3-D) optics offers potential advantages to the massively-parallel systems over electronics from the view point of information transfer. The purpose of this paper is to survey some aspects of the 3-D optical interconnection technology for the future massively-parallel computing systems. At first, the state-of-art of the current optoelectronic array devices to build the interconnection networks are described, with emphasis on those based on the semiconductor technology. Next, the principles, basic architectures, several examples of the 3-D optical interconnection systems in neural networks and multiprocessor systems are described. Finally, the issues that are needed to be solved for putting such technology into practical use are summarized.
Japan's PARTNERS Project, one of the programmes of ISY advocated by UN, has just started. This letter is a brief introduction of the trials being carried out by the partners in the University of Electro-communications under the Project. The focus is on the distance education and training via ETS-V overcoming the geographical extent and the cultural diversity of the Asia-Pacific Region.
The design of complex VLSI systems relies more and more heavily on scientific computing for numerical simulation and configuration/performance optimization. Especially, computer simulation is becoming a component of VLSI design methodology, for which a variety of computation evolutions have been accomplished for the past two decades. There are many different forms of simulation which are used for verification of VLSI design at various stages of the whole design process. They may be classified into functional or behavioral simulators, register transfer level (RTL) simulators, gate-level logic, or simply logic, simulators, timing simulator, circuit simulators, device simulator, and process simulators. Among these simulation tasks, a series of logic, timing, and circuit simulation is most strongly related to the design stage which deals with logic/electric waveform performance of VLSI circuits. This article surveys the state of the art of VLSI simulation, putting stress mainly on the domain of logic, timing, and circuit simulation, since the reader of the Transactions may be interested exclusively in this field.
We propose a method of diagnosing any logical fault in combinational circuits through a repetition of the single fault-net location procedure with the aid of probing, called SIFLAP-G. The basic idea of the method has been obtained through an observation that a single error generated on a fault-net often propagates to primary outputs under an individual test even though multiple fault-nets exist in the circuit under test. Therefore, candidates for each fault-net are first deduced by the erroneous path tracing under the single fault-net assumption and then the fault-net is found out of those candidates by probing. Probing internal nets is done only for some of the candidates, so that it is possible to greatly decrease the number of nets to be probed. Experimental results show that the number seems nearly proportional to the number of fault-nets (about 35 internal nets per fault-net), but almost independent of the type of faults and the circuit size.