Kazuo SAKAI Shinji MIGITA Hiroyuki OTA Hiroshi OTERA Ryozo AOKI
Bi2Sr2CuOx (Bi(2201)) thin films have been fabricated by atomic layer-by-layer deposition using ion beam sputtering (IBS) method. During the deposition, 14 wt%-ozone/oxygen mixture gas of typical pressure of 5.010-5 Torr is supplied with ultraviolet light irradiation for oxidation. XRD and RHEED investigations reveal that a buffer layer with compositions different from Bi(2201) is formed at the early deposition stage of less than 10 units cell and then Bi(2201) oriented along the c-axis is grown.
Junghyun HWANG Yoshiteru OOI Shinji OZAWA
This paper describes an adaptive sensing system with tracking and zooming a moving object in the stable environment. Both the close contour matching technique and the effective determination of zoom ratio by fuzzy control are proposed for achieving the sensing system. First, the estimation of object feature parameters, 2-dimensional velocity and size, is based on close contour matching. The correspondence problem is solved with cross-correlation in projections extracted from object contours in the specialized difference images. In the stable environment, these contours matching, capable of eliminating occluded contours or random noises as well as background, works well without heavy-cost optical flow calculation. Next, in order to zoom the tracked object in accordance with the state of its shape or movement practically, fuzzy control is approached first. Three sets of input membership function--the confidence of object shape, the variance of object velocity, and the object size--are evaluated with the simplified implementation. The optimal focal length is achieved of not only desired size but safe tracking in combination with fuzzy rule matrix constituted of membership functions. Experimental results show that the proposed system is robust and valid for numerous kind of moving object in real scene with system period 1.85 sec.
Tsuyoshi KAWAGUCHI Etsuro HONDA
In this paper we propose an architecture and an algorithm for the parallel execution of OPS5 production systems. It is known that current OPS5 production system interpreters spend almost 90% of their execution time in the match step. Thus, in this paper we focus on the speedup of the match step. The match algorithm used in OPS5 is called Rete and the algorithm uses a special kind of a date-flow network compiled from the left hand sides of rules. To achieve the maximum degree of parallelism of a given OPS5 program by as few processors as possible, the proposed parallel machine uses loosely coupled multiprocessors. Parallel machines designed for fine-grain parallelism, such as DADO, also use loosely coupled multiprocessors. However, the proposed machine differs from such machines at the following points: use of powerful processors which have large amounts of memories and small cycle times; use of a shared Rete network (parallel machines designed for fine-grain parallelism use an unshared Rete network); high hardware utilization. Basic ideas of the proposed parallel machine are as follows. (1) Use of a modified Rete network in which node sharing is used only for constant-test nodes and each memory node is lumped with the child two-input node. (2) Static allocation of the nodes of the modified Rete network onto processors. (3) Partition of the set of processors into three subsets: constant-test node processors, two-input node processors and conflict-set processors. (4) Use of a ring network for the interconnection network among two-input node processors. In addition to an architecture for parallel execution of OPS5 production systems, we propose a scheme for mapping the modified Rete network into the proposed architecture. The results of simulation experiments showed that the proposed architecture is promising for parallel execution of OPS5 production systems.
Paul W. BAIER Tobias FELHAUER Anja KLEIN Aarne MÄMMELÄ
The well known optimum approach to detect spread spectrum signals transmitted in bursts over frequency selective radio channels is matched filtering, which performs despreading, and subsequent Viterbi equalization (VE) to cope with intersymbol interference (ISI). With respect to complexity, VE is feasible only if data modulation schemes with a few symbol levels as e.g. 2PSK are used and if the delay spread of the channel is not too large. The paper gives a survey of suboptimum data detectors based on linear block estimation. Such data detectors are less expensive than VE especially in the case of multilevel data modulation schemes as 4PSK or 16QAM. Special emphasis is laid on data detectors based on Gauss-Markoff estimation because these detectors combine the advantages of unbiasedness and minimum variance of the estimate. In computer simulations, the Gauss-Markoff estimation algorithm is applied to spread spectrum burst transmission over radio channels specified by COST 207. It is shown that the SNR degradation which is a measure of the suboptimality of the detector does not exceed a few dB, and that even moderate spectrum spreading considerably reduces the detrimental effect of channel frequency selectivity.
Kenya UOMORI Shinji MURAKAMI Mitsuho YAMADA Mitsuru FUJII Hiroshi YOSHIMATSU Norihito NAKANO Hitoshi HONGO Jiro MIYAZAWA Keiichi UENO Ryo FUKATSU Naohiko TAKAHATA
To clarify the stereopsis disturbance in patients with Alzheimer's disease (AD), we analyzed binocular eye movement when subjects shifted their gaze between targets at different depths. Subjects are patients with Alzheimer's disease, Mluti-infarct dementia (MID), or Olivopontocerebellar atrophy (OPCA), and healthy controls. Targets are arranged in two ways: along the median plane and asymmetrically crossing the median plane, at distances from the eyes of 1000 mm and 300 mm. When the targets are switched at the onset of a beep, the subjects shifted their gaze to the lit target. The experiment is conducted in a dimly lit room whose structure is capable of providing good binocular cues for depth. In AD subjects, especially in the subjects whose symptoms are moderate (advanced stage), vergence is limited and the change in the convergence angle is small, unstable, and non-uniform. These results are different from those of other patients (MID) and OPCA) or healthy controls and suggest a disturbance of stereopsis in the parietal lobe where AD patients typically have dysfunctions.
Yoshinao MIZUGAKI Koji NAKAJIMA Tsutomu YAMASHITA
The threshold characteristics of mutually coupled SQUIDs (Superconducting Quantum Interference Devices) have been analytically and numerically investigated. The mutually coupled SQUIDs investigated is composed of an rf-SQUID and a dc-SQUID. Here, the rf-SQUID is a flux quantum generator and the dc-SQUID is a flux detector. The linearization method substituting sin-1x by (π/2)x (1x1) is found valid when it is applied to the mutually coupled SQUIDs, because it is possible to obtain the superconducting regions analytically. By computer implementation of linearization method, we found this method is very effective and very quick compared to the ordinary methods. We report the internal flux on an rf-SQUID, the threshold of a dc-SQUID, and that of mutually coupled SQUIDs obtained by Lagrange multiplier formulation and linearization. The features of the threshold characteristics of the mutually coupled SQUIDs with various parameters are also reported. The discontinuous behavior of threshold of the mutually coupled SQUIDs are attractive for digital applications. We suggest three applications of the mutually coupled SQUIDs, that is, a logic gate for high-Tc superconductors (HTSs), a neuron device, and an A/D converter.
This letter presents a new algorithm for echo cancellers, which prevents the reduction of echo return loss due to a double-talk. The essence of the algorithm is to introduce signal delays to avoid the reduction. A convergence condition in the algorithm was examined by using the IIR filter expression of the NLMS algorithm, and it was concluded that the IIR filter should be a low pass filter with unity gain. The condition is accomplished by selecting a small step gain.
The authors examined the effect of feedbacking information on learners of their test results obtained through computerized tests. The learner's acceptability of computerized tests was revealed to be improved by distribution and explanation of newly devised feedback charts including data on one's response history and response latency during computerized testing that was carried out in formative evaluation. The feedback chart composed of graphic representation of relationship between degree of difficulty of each question and its response latency got a particularly high evaluation among learners. It was revealed that types of feedback chart that stood highest in learner's estimate varied with the learner traits. This observation will serve to develop educational systems that incorporate computerized tests into school lessons.
Kazuo NAKAMURA Narumi SAKASHITA Yasuhiko NITTA Kenichi SHIMOMURA Takeshi TOKUDA
A fuzzy inference processor which performs fuzzy inference with 12-bit resolution input at 200 kFLIPS (Fuzzy Logical Inference Per Second) has been developed. To keep the cost performance, not parallel processing hardware but processor type hardware is employed. Dedicated membership function generators, rule instructions and modified add/divide algorithm are adopted to attain the performance. The membership function generators calculate a membership function value in less than a half clock cycle. Rule instructions calculate the grade of a rule by one instruction. Antecedent processing and consequent processing are pipelined by the modified add/divide algorithm. As a result, total inference time is significantly reduced. For example, in the case of typical inference (about 20 rules with 2 to 4 inputs and 1 output), the total inference needs approximately 100 clock cycles. Furthermore by adding a mechanism to calculate the variance and maximum grade of the final membership function, it is enabled to evaluate the inference reliability. The chip, fabricated by 1 µm CMOS technology, contains 86k transistors in a 7.56.7 mm die size. The chip operates at more than 20 MHz clock frequency at 5 V.
In this paper, we show that without any unproven assumption, there exists a "four" move blackbox simulation perfect zero-knowledge interactive proof system of computational ability for any random self-reducible relation R whose domain is in BPP, and that without any unproven assumption, there exists a "four" move blackbox simulation perfect zero-knowledge interactive proof system of knowledge on the prime factorization. These results are optimal in the light of the round complexity, because it is shown that if a relation R has a three move blackbox simulation (perfect) zero-knowledge interactive proof system of computational ability (or of knowledge), then there exists a probabilistic polynomial time algorithm that on input x ∈ {0, 1}*, outputs y such that (x, y)∈R with overwhelming probability if x ∈dom R, and outputs "⊥" with probability 1 if x
Wataru CHUJO Masayuki FUJISE Hiroyuki ARAI Naohisa GOTO
In a two-layer self-diplexing antenna fed at two ports, theoretical analysis has already shown that the isolation characteristics can be improved by adjusting the angle between the feed locations of the transmitting and receiving antennas. In this letter, we experimentally investigate the isolation characteristics of the self-diplexing array antenna. First, calculated and experimental results for each feed location of the element antenna are compared and good agreement is found. Second, experimental results with a 19-element planar array indicate that a self-diplexing antenna with suitably chosen feed configuration is effective in improving the isolation in a phased array antenna.
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.
Kazuki ITO Masanori HAMAMOTO Joarder KAMRUZZAMAN Yukio KUMAGAI
A new neural network system for object recognition is proposed which is invariant to translation, scaling and rotation. The system consists of two parts. The first is a preprocessor which obtains projection from the input image plane such that the projection features are translation and scale invariant, and then adopts the Rapid Transform which makes the transformed outputs rotation invariant. The second part is a neural net classifier which receives the outputs of preprocessing part as the input signals. The most attractive feature of this system is that, by using only a simple shift invariant transformation (Rapid transformation) in conjunction with the projection of the input image plane, invariancy is achieved and the system is of reasonably small size. Experiments with six geometrical objects with different degrees of scaling and rotation shows that the proposed system performs excellent when the neural net classifier is trained by the Cascade-correlation learning algorithm proposed by Fahlman and Lebiere.
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.
Yasufumi SASAKI Masanobu KOMINAMI Shinnosuke SAWA
Numerical solutions for the near-field of microstrip antennas are presented. The field distribution is calculated by taking the inverse Fourier transform involving the current distribution with the help of the spectral-domain moment method. A new technique to save the computation time is devised, and the field pattern of the circularly polarized antenna is illustrated.
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.
We discuss possible new principles of information processing by utilizing microscopic, semi-microscopic and macroscopic phenomena occuring in nature. We first discuss quantum mechanical universal information processing in microscopic world governed by quantum mechanics, and then we discuss superconducting phenomena in a mesoscopic system, especially an information processing system using flux quantum. Finally, we discuss macroscopic self-organizing phenomena in biology and suggest possibility of self-organizing devices.
Intermittent chaos was observed in the silicon thyristor circuit without external elements of L and C, under the condition of ac excitation at the anode. Lorenz plot reconstructed from the experimental waveform and the numerical simulation of this kind of intermittency fairly agreed with each other.
Masayuki OKUNO Akio SUGITA Tohru MATSUNAGA Masao KAWACHI Yasuji OHMORI Katsumi KATOH
A strictly nonblocking 88 matrix switch was designed and fabricated using silica-based planar lightwave circuits (PLC) on a silicon substrate. The average insertion loss was 11 dB in the TE mode and 11.3 dB in the TM mode. The average switch element extinction ratio was 16.7 dB in the TE mode and 17.7 dB in the TM mode. The accumulated crosstalk was estimated to be 7.4 dB in the TE mode and 7.6 dB in the TM mode. The driving power of the phase shifter required for switching was about 0.5 W and the polarization dependence of the switching power was 4%. The switching response time was 1.3 msec. The wavelength range with a switch extinction ratio of over 15 dB was 1.31 µm30 nm.
Hitoshi OHMURO Takehiro MORIYA Kazunori MANO Satoshi MIKI
This letter proposes an LSP quantizing method which uses interframe correlation of the parameters. The quantized parameters are represented as a moving average of code vectors. Using this method, LSP parameters are quantized efficiently and the degradation of decoded parameters caused by bit errors affects only a few following frames.