High-Tc SQUID was applied to the detection of magnetized fine particle moving at high speed. Two types of SQUIDs were used. One was a large washer type and the other was a flux transformer type. Their Josephson junctions were step edge type. The iron particle was attached on a nylon wire and scanned under the SQUID. High-Tc SQUID detected an iron particle of 50 µm diameter running at 800 m/min. It was shown that the magnetic field measured by the SQUID was proportional to the volumer of the particle and is inversely proportional to the distance between the SQUID and the particle. This technique using high-Tc SQUID is hopeful not only to wire production line but also for the processing of food and medicine, etc.

An analysis is carried out about the reflection influence on the microwave attenuation measurement for moisture content determination. A new method taking into account the reflection influence is proposed and it is proved valid by the experiment results. Using this method, the density dependence of the attenuation is measured and the measured data can be fitted well by a straight line passing through the origin. Therefore, the attenuation per unit density and propagation distance is a function which depends only on the moisture content and the function is useful to the determination of the moisture content.

We report the strong microwave Josephson radiation from an array of high-Tc junctions on a MgO bicrystal substrate from centimeter- to millimeter-wave ranges. The dc bias current was fed to the junction array having parallel geometry with the pair of junctions shunted by superconducting loops. The configuration of bias leads was a series of interlocking dc SQUID's geometry which guaranteed the oscillation of all junctions at the same frequency. For a five-junctions array, we observed the coherent output power of about 13 pW at receiving frequency fREC22GHz without an external magnetic flux, which was nearly five times higher than that of a single bicrystal junction. We observed the Josephson linewidth of the selfradiation in coherent state less than 1 GHz by the adjustment of the external flux. The phase differences between adjacent junctions with different IcRn products could be controlled by an external small magnetic field. Submillimeter-wave detector response of the five-junction array was also studied experimentally at frequency f478 GHz.

This study shows the results of evaluating the flux noises at low frequency when the alternating current(AC) bias direct offset integrated technique(DOIT) with additional positive feedback (APF) is used in a high-Tc dc superconducting quantum interference device (SQUID). The AC-bias DOIT can reduce low-frequency noise without increasing the level of white noise because each operating point in the two voltage-flux characteristics with AC bias can always be optimum on the magnetometer in the high-Tc dc-SQUID. APF can improve the effective flux-to-voltage transfer function so that it can reduce the equivalent flux noise due to the voltage noise of the preamplifier in the magnetometer. The use of APF combined with the AC-bias DOIT reduced the noise of the magnetometer by factors of 1.5 (33µΦ0/Hz vs. 50 µΦ0/Hz) at100 Hz, 3.5 (43 µΦ0/Hz vs. 150 µΦ0/Hz) at 10 Hz, and 5.2 (67 µΦ0/Hz vs. 351 µΦ0/Hz) at 1 Hz as compared with the noise levels that were obtained with the static-current-bias DOIT. The contribution of the factors at 1 Hz is about 2 by APF and 2.6 by AC bias. The performance of improving the flux noise in the AC -bias DOIT with APF is almost equal to that of the flux locked loop (FLL) circuits in which the flux modulation uses a coupling system with a transformer and with the AC bias.

We successfully observed curent-voltage (I-V) curves which showed the behavior of intrinsic Josephson junctions using Tl2Ba2CaCu2Ox (Tl-2212) thin films on MgO substrates by structuring mesas and measuring the electrical transport properties along the c-axis. For a 55 µm2 mesa, a hysteretic I-V curve was observed up to 80 K, which showed that series-connected SIS-type junctions are formed. Compared with the critical current density (Jc) of more than 106 A/cm2 parallel to the ab-plane, an anisotropic Jc of 1.4102 A/cm2 along the c-axis was observed at 4.9 K. By focusing on the I-V curve at lower bias current, the constant voltage jumps measured at the first seven branches were estimated to be 26 mV. The normal resistance (Rnk) of a unit SIS junction was estimated to be 580 Ω by substituting the measured voltage jump in the Ambegaokar and Baratoff relation. Using the calculation for McCumber parameter (βc), the capacitance (Ck) of the unit SIS junction was estimated to be 3.610-10 F/cm2 at 77 K. The IckRnk product was estimated to be 6.4 mV and the cut-off frequency (fc1/2πRnkCk) was calculated to be 3.1 THz at 77 K. The Jc and the hysteresis decreased with an increase in the mesa area, and finally, for a 300300µm2 mesa, a resistively shunted junction (RSI) like curve without hysteresis was observed up to 98 K. A Jc of 5.6101 A/cm2 along the c-axis was observed at 6.4 K. This may be explained by the higher content of conductive grain boundaries for a larger mesa area.

A novel CMOS half-wave rectifying transconductor is presented. The proposed circuit utilizes a simple new cascode current subtracter which is obtained from conventional cascode current mirror by a judicious reconfiguration to yield additional subtrahend signal path. The simulated DC transfer characteristics is highly linear with 1.1% linearity error up to 1.5V differential input voltage and the blunt corner at zero-crossing is 20mV. The output resistance is greater than 23MΩ and the total harmonic distortions at 100kHz with 1.5Vp-p in the positive half cycle are better than -46.5dB. The usable operating frequencies are up to 10MHz with maximum peak-to-peak input voltage and 75µW power consumption.

Recently, two new efficient server-aided RSA secret computation protocols were proposed. They are efficient and can guard against some active attacks. In this letter, we propose two multi-round active attacks which can effectively reduce their security level even break them.

In computer hardware there is a constant evolution towards smaller transistor sizes. At the same time, more and more transistors are placed on one chip. Both trends make the pin limitation problem worse. Scaling down chip sizes adds to the shortage of available pins while increasing the number of transistors per chip imposes a higher need for chip terminals. The use of three-dimensional systems would alleviate this pin limitation problem. In order to decide whether the benefits of such systems balance the higher processing costs, one must be able to characterize these benefits accurately. This can be done by estimating important layout properties of electronic designs, such as space requirements and interconnection length values. For a two-dimensional placement, Donath found an upper bound for the average interconnection length that follows the trends of experimentally obtained average lengths. Yet, this upper bound deviates from the experimentally obtained value by a factor of approximately 2 which is not sufficiently accurate for some applications. In this paper, we first extend Donath's technique to a three-dimensional placement. We then compute a significantly more accurate estimate by taking into account the inherent features of the optimal placement process.

This paper proposes a heuristic algorithm for state minimization of incompletely specified finite state machines (FSMs). The strategy is similar to that in ESPRESSO, a wellknown heuristic algorithm for two-level logic minimization. It consists of generating an initial solution, the set of maximal compatibles, and attempting to apply a series of transformations to the solution. The main transformation is to reduce each compatible in the solution and delete unnecessary compatibles by iterative improvements. Other transformations, such as expansion and merging of compatibles, are also introduced for further reduction. When the number of compatibles is likely to be too large to handle explicitly, they are represented by a Binary Decision Diagram. Experimental results show that the proposed method finds better solutions in shorter CPU times for most of the examples than conventional methods.

This paper presents a logic synthesis method for look-up table (LUT) based field programmable gate arrays (FPGAs). We determine functions to be mapped to LUTs by functional decomposition for each of single-output functions. To share LUTs among several functions, we use a new Boolean resubstitution technique. Resubstitution is used to determine whether an existing function is useful to realize another function; thus, we can share common functions among two or more functions. The Boolean resubstitution proposed in this paper is customized for an LUT network synthesis because it is based on support minimization for an incompletely specified function. Experimental results show that our synthesis method produces a small size circuit in a practical amount of time.

This is a review of our high-Tc superconductor (HTS) sampler development. The design and experimental demonstration of a Josephson sampler circuit based on YBa2 Cu3Ox(YBCO)/PrBa2Cu3Ox/YBCO ramp-edge junctions is described. The sampler circuit contains five edge junctions with a stacked YBCO groundplane and is based on single-flux quantum (SFQ) operations. Computer simulation results show that the time resolution of the sampler circuit depends strongly on the IcRn product of the junction and can be reduced to a few picoseconds with realistic parameter values. The edge junctions were fabricated using an in-situ process in which a barrier and a counter-electrode layer are deposited immediately after the edge etching without breaking the vacuum. The in-situ process improved the critical current uniformity of the junctions to 1σ20% in twelve 4-µm-width junctions. An YBCO groundplane was placed on the junctions in a multilayer structure we call the HUG (HTS cricuit with an upper-layer groundplane) structure. The inductance of YBCO lines was reduced to 1 pH per square without junction-quality degradation in the HUG structure. SFQ current-pulse generation, SFQ storage, and SFQ readout in the circuit have been confirmed by function tests using 3-kHz pulse currents. The successful operation of the sampler circuit has been demonstrated by measuring a signal-current waveform at 50K.

Service interaction resolution is an important study subject to realize a network supporting various advanced communication services. This paper proposes service interaction resolution by service node connected with the communication network via the user-network interface. By executing various advanced services on the service node, service interactions can be efficiently resolved without adding new functions to the existing network. In other words, the service node enables a unified execution control of all the services including those for the originating side and those for the terminating side. This prevents the signalling system and the signalling procedure from being expanded to resolve service interactions. Moreover, the interactions between the services initiated at the conversation active state can be resolved by the service node equipped with function of receiving plural types of in-band signals. This avoids functional expansion of the switching systems in the network. In this paper, feasibility of the proposed resolution scheme is proved by showing a structure of the service node and a detailed procedure to resolve interactions on that service node. In the proposed service node, the application part is divided into basic call processing part and service processing part, and the basic call processing part is represented by three kinds of basic call processing state models. The proposed method for resolving service interactions can control services execution with high flexibility by using feature interaction table.

This paper proposes cell-attached frame encapsulation schemes in which encapsulation processing can be performed without cell reassembly. The proposed schemes are especially useful for a global networking service platform to integrate widely distributed user LANs into a single internetwork. The platform itself is an ATM-based frame forwarding network composed of access networks and a core network. These elemental networks are interconnected via edge nodes. In order to improve network interworking performance, these edge nodes should perform encapsulation processing without cell reassembly. Our proposal solves this problem. In the proposed schemes, when the first cell of a cell-divided access network frame arrives at an ingress edge node, a core-header-cell is generated from the IP header described in the first cell payload. This core-header-cell is first transmitted and then succeeding incoming cells including the first cell are forwarded cell-by-cell as soon as they arrive. Since cell-by-cell forwarding-processing reduces frame forwarding latency and cell buffer capacity, these schemes are effective from the viewpoint of both performance improvement and cost reduction.

JUMP-1 is currently under development by seven Japanese universities to establish techniques for building an efficient distributed shared memory on a massively parallel processor. It provides a coherent cache with reduced hierarchical bit-map directory scheme to achieve cost effective and high performance management. Messages for coherent cache are transferred through a fat tree on the RDT (Recursive Diagonal Torus) interconnection network. RDT router supports versatile functions including multicast and acknowledge combining for the reduced hierarchical bit-map directory scheme. By using 0.5µm BiCMOS SOG technology, it can transfer all packets synchronized with a unique CPU clock (50MHz). Long coaxial cables (4m at maximum) are directly driven with the ECL interface of this chip. Using the dual port RAM, packet buffers allow to push and pull a flit of the packet simultaneously.

We present a novel replication technique for parallel applications where instances of the replicated application are active on different group of processors called replicas. The replication technique is based on the FTAG (Fault Tolerant Attribute Grammar) computation model. FTAG is a functional and attribute based model. The developed replication technique implements "active parallel replication," that is, all replicas are active and compute concurrently a different piece of the application parallel code. In our model replicas cooperate not only to detect and mask failures but also to perform parallel computation. The replication mechanisms are supported by FTAG run time system and are fully application-transparent. Different novel mechanisms for checkpointing and recovery are developed. In our model during rollback recovery only that part of the computation that was detected faulty is discarded. The replication technique takes full advantage of parallel computing to reduce overall computation time.

In this paper, we present an error concealment method to recover damaged blocks for block-based image coding schemes. Imperfect transmission of image data results in damaged blocks in the reconstructed images. Hence recovering damaged image blocks is needed for reliable image communications. To recover damaged blocks is to estimate damaged blocks from the correctly received or undamaged neighborhood information with a priori knowledge about natural images. The recovery problem considered in our method is to estimate a larger block, which consists of a damaged block and the undamaged neighborhood, from the undamaged neighborhood. To find an accurate estimate, a set of the feature vectors is introduced and an estimate is expressed as a linear combination of the feature vectors. The proposed method recoveres damaged blocks by projecting the undamaged neighborhood information onto the feature vectors. The sequential projections onto the feature vectors algorithm is proposed to find the projection coefficients of the feature vectors to minimize the squared difference of an estimate and the undamaged neighborhood information. We tested our algorithm through computer simulations. The experimental results showed the proposed method ourperforms the frequency domain prediction method in the PSNR values by 4.0-5.0dB. Tthe reconstructed images by the proposed method provide a good subjective quality as well as an objective one.

An implementation of photometric stereo is described in which all directions of illumination are close to and rotationally symmetric about the viewing direction. THis has practical value but gives rise to a problem that is numerically ill-conditioned. Ill-conditioning is overcome in two ways. First, many more than the theoretical minimum number of images are acquired. Second, principal components analysis (PCA) is used as a linear preprocessing technique to determine a reduced dimensionality subspace to use as input. The approach is empirical. The ability of a radial basis function (RBF) neural network to do non-parametric functional approximation is exploited. One network maps image irradiance to surface normal. A second network maps surface normal to image irradiance. The two networks are trained using samples from a calibration sphere. Comparison between the actual input and the inversely predicted input is used as a confidence estimate. Results on real data are demonstrated.

In order to construct fuzzy systems automatically, there are many studies on combining fuzzy inference with neural networks. In these studies, fuzzy models using self-organization and vector quantization have been proposed. It is well known that these models construct fuzzy inference rules effectively representing distribution of input data, and not affected by increment of input dimensions. In this paper, we propose a destructive fuzzy modeling using neural gas network and demonstrate the validity of a proposed method by performing some numerical examples.

Materials for a new reinforcement method using an internal heating technique have been developed experimentally for fusion splices. The method employs a protective package of a carbon-fiber composite and a hot-melt adhesive in a heat-shrinkable tube. The most appropriate heating current and heating time were determined from a consideration of the decomposition temperature of the adhesive (300) and the complete shrinking temperature (115) and the minimum welding temperature of Nylon 12 (about 180). The protective package can be installed in less than 30 seconds at a power of 10 W. Air bubbles which might cause microbending were completely eliminated by using Nylon 12 as the hot-melt adhesive, irradiated polyethylene as the heat-shrinkable tube and a carbon-fiber-composite electrical heating rod which also acted a tension member. The key for preparing the carbon-fiber composite was to remove its impurities. Under the condition of temperature difference larger than 40 deg. between the shrinking temperature of the heat-shrinkable tube and the melting temperature of the hot-melt adhesive. Nylon 12 and irradiated polyethylene were needed for the complete elimination of residual bubbles. By using Nylon 12 as the hot-melt adhesive, a reliable protective package could be achieved for a fusion spliced optical fiber with a low excess loss of less than 0.06 dB/splice between -60 and +70 and a high tensile strength of 3.9 kg.

Recently, the spatio-temporal filter using linear analog Cellular Neural Network (CNN), called CNN filter array, has been proposed for the purpose of dynamic image processing. In this paper, we propose a design method of descrete-time cellular neural network filter which selectively extracts the particular moving object from other moving objects and noise. The CNN filter array forms a spatio-temporal filter by arranging cells with a same function. Each of these cells is a simple linear analog temporal filter whose input is the weighted sum of its neighborhood inputs and outputs and each cell corresponds to each pixel. The CNN filter is formed by new model of discrete time CNN, and the filter parameters are determined by applying backpropagation algorithm in place of the analytic method. Since the number of connections between neurons in the CNN-type filter is relatively few, the required computation in the learning phase is reasonable amount. Further, the output S/N ratio is improved by introducing nonlinear element. That is, if the ratio of output to imput is smaller than a certain value, the output signal is treated as a noise signal and ought to be rejected. Through some examples, it is shown that the target object is enhanced in the noisy environment.