Metallic pair lines transmitting high-frequency information signals above several tens MHz are often used without being twisted, as flat floor cable installed in buildings, ribbon-type cables installed in computer equipment, and traces in printed circuit boards. However, the conversion characteristics of untwisted unbalanced metallic pair lines connecting unbalanced circuits have not been investigated over a wide range of frequencies in the MHz region. First, we developed a method to estimate effective power conversion factors using a cascade connection of F matrices, where the unbalance in impedance and admittance of each pair line is distributed uniformly along the line. As a result some useful information was obtained about the balance-unbalance conversion characteristics of the effective power which can be used to suppress EMI phenomena in wiring, especially over several decades of high frequencies. Next, we attempted to apply the conversion characteristics of untwisted unbalanced pair lines obtained at frequencies below several MHz to techniques for searching for the return circuits of conductors installed in buildings. It was clarified experimentaly that the depth of the equivalent ground plane can be estimated by comparing the measured conversion values of TV feeder lines installed at the place being tested with reference values measured in advance on a copper plate .

This paper analyzes what structural features of graph problems allow efficient parallel algorithms. We survey some parallel algorithms for typical problems on three kinds of graphs, outerplanar graphs, trapezoid graphs and in-tournament graphs. Our results on the shortest path problem, the longest path problem and the maximum flow problem on outerplanar graphs, the minimum-weight connected dominating set problem and the coloring problem on trapezoid graphs and Hamiltonian path and Hamiltonian cycle problem on in-tournament graphs are adopted as working examples.

This paper describes the mechanisms of power-distribution-plane resonance in multilayer printed circuit boards and the techniques to control the resonance. The power-distribution-plane resonance is responsible for high-level emissions and circuit malfunctions. Controlling the resonance is an effective technique, so adequate characterization of the resonance is necessary to achieve control. The resonance characteristics of four-layer printed circuit boards are investigated experimentally and theoretically by treating the power-distribution planes as a parallel-plate transmission line with decoupling circuits. Analysis of the forward traveling wave shows that the resonance frequency is determined by the phase delay due to wave propagation and by the phase progress of interconnect inductance in the decoupling circuit. Techniques to control the resonance characteristics are investigated. The resonance can be shifted to a higher frequency by adding several decoupling circuits adjacent to the existing decoupling capacitor or by increasing the number of via holes connecting the capacitor mounting pads to the power-distribution planes.

High-speed and low-power DSPs have been developed for versatile applications, especially for digital communications. These DSPs contain a 16-bit fixed point DSP core with multiple buses, highly tuned instruction set and low-power architecture, featuring 0.45 mA/MIPS, 100-120 MIPS performance by a single CPU core, 200 MIPS performance by dual CPU core architecture, respectively and also contain a 1.2 V low-voltage DSP core with 30 MIPS performance for super low-power applications. In this paper, new architecture VIA2 programming ROM for high-speed and new D flip-flop circuit considering the impact of pocket implantation process for low power are discussed, including key C-MOS process technology.

In this paper, we describe our superconducting digital technology that uses Nb/AlOx/Nb Josephson junctions. Superconducting devices have intrinsically superior characteristics than those of semiconductor devices, and Nb/AlOx/Nb junctions have ideal current-voltage characteristics for digital applications. Superconducting devices that use Nb/AlOx/Nb junctions have being actively developed because of their high speed and low power characteristics. Presently, we can fabricate more than twenty thousand junctions on one chip. Using niobium technology, a superconducting 4-kbit RAM has been already successfully developed. We have demonstrated the operation of a network system with a superconducting network chip. Some problems, such as difficulty in high-speed testing, disturbance from trapped magnetic flux and so on, have been overcome by techniques such as a clock-driven testing method, moat structures and so on. The developed technologies, such as the fabrication technology, the design technology for moat structures and so on, must become the basic keys for the development of digital applications based on a single flux quantum device, which will be a promising component for ultra-high speed systems in the twenty-first century.

This paper presents a simple and generic conversion from a public-key encryption scheme that is indistinguishable against chosen-plaintext attacks into a public-key encryption scheme that is indistinguishable against adaptive chosen-ciphertext attacks in the random oracle model. The scheme obtained by the conversion is as efficient as the original encryption scheme and the security reduction is very tight in the exact security manner.

Linear signal analysis (LSA) is the conventional method of estimating the playback voltage and pulse width in linearly operating shielded GMR heads. To improve the accuracy of LSA, a new, highly precise LSA which includes the effect of the magnetization distribution in the medium and inhomogeneous biasing by domain control magnets, was developed. Utilizing this new LSA to calculate the playback waveforms, the calculated peak voltage and pulse width were compared with the experimental values and agreement within 10% was obtained. As the result of estimation using the new LSA, it is considered that the use of a vertical-type spin-valve head will make it possible to achieve a recording areal density of 40 Gb/in2.

Non-stationary glint noise is often observed in a radar tracking system. The distribution of glint noise is non-Gaussian and heavy-tailed. Conventional recursive identification algorithms use the stochastic approximation (SA) method. However, the SA method converges slowly and is invalid for non-stationary noise. This paper proposes an adaptive algorithm, which uses the stochastic gradient descent (SGD) method, to overcome these problems. The SGD method retains the simple structure of the SA method and is suitable for real-world implementation. Convergence behavior of the SGD method is analyzed and closed-form expressions for sufficient step size bounds are derived. Since noise data are usually not available in practice, we then propose a noise extraction scheme. Combining the SGD method, we can perform on-line adaptive noise identification directly from radar measurements. Simulation results show that the performance of the SGD method is comparable to that of the maximum-likelihood (ML) method. Also, the noise extraction scheme is effective that the identification results from the radar measurements are close to those from pure glint noise data.

A standard of Advanced Storage Magneto Optical (AS-MO) having a 6 Gbyte capacity in a 120 mm-diameter single side disk was established by using a magnetically induced superresolution readout method. Transition from in-plane to perpendicular magnetization for exchange-coupled readout layer (GdFeCo) and in-plane magnetization mask layer (GdFe) of the AS-MO disk has been investigated using the noncontinuous model. The readout resolution was sensitive to the thickness of the readout layer. To evaluate readout characteristics of AS-MO disks, the simulation using micro magnetics model was performed and the readout layers were designed. The readout characteristics of the AS-MO disk is improved by making the readout layer thinner.

This paper focuses on flow control in high-speed and large-scale networks. Each node in the network handles its local traffic flow only on the basis of the information it knows. It is preferable, however, that the decision making of each node leads to high performance of the whole network. To this end, the relationship between local decision making and global performance of flow control is the essential object. We propose phenomenological models of flow control of high-speed and large-scale networks, and investigate the stability of these models.

An approximate formula is proposed for the equivalent susceptance of a circular iris in a parallel plate waveguide when the TEM mode cylindrical wave is incident from the center of the iris. Schwinger's variational method for a linear iris is generalized to the cylindrical case, and an approximate closed form formula is obtained which recovers the result of the linear iris when the radius of the circular iris is sufficiently larger than the wavelength. For verification of the formula, an exact integral equation is formulated and solved numerically by Galerkin's method. A comparison between them shows good agreement.

With the proliferation of the transistor count in VLSI design, more and more design groups try to figure out an efficient way to combine their designs. The Internet features distributed computing and resource sharing. Consequently, a hierarchical design can adequately be solved in the Internet environment. In this paper, we demonstrate the facilitation of the Internet environment by solving the area minimization floorplan problem. We propose the RMG algorithm taking advantage of the Internet. Based on the model of transfer latencies, the RMG algorithm reduces the computing time by shortening the critical path in the floorplan tree. Our experimental results show that the Internet is suitable for Electronic Design Automation (EDA).

Millimeter-wave systems increasingly are entering into commercial systems, both for communication and sensors for traffic or industrial applications. In many cases, circuit technology of the involved front-ends includes monolithic and hybrid integrated circuits and even waveguide components like filters or antenna feeds. In addition to the standard technical and environmental requirements, these front-ends have to be fabricated in large quantities at very low cost. After a short review of the problems and some general interconnect and packaging techniques for mm-wave front-ends, achievements of a research program will be presented at the example of components for a 28 GHz communication front-end. Emphasis is put on a novel feed-through structure using multilayer carrier substrates for mm-wave circuits, some advances in electromagnetic field coupling for interconnects to mm-wave MMICs, and the realization of packages including waveguide components by plastic injection molding and electroplating. Results of filters and a diplexer produced in this way are shown, including pretuning of the filters to compensate the shrinking of the plastic parts during cooling.

The paper argues that a radical shift in the market for communications services is emerging, driven by the mass availability of cheap bandwidth, computing and global mobility combined with the pervasive rise of Internet based data services. At the same time, the Operation Support Systems (OSS's*) that are essential in order to create business value from these technologies are lagging behind market need. The authors argue for a re-think of the humble management system into a complete software wrap-around of the network to deliver a value creation platform - as different from yesterday's OSS as the bakelite telephone is from today's tri-band mobile handsets. This software will be based on product standards, not paper ones and will require a major shift of gears from the position of today. This value creation platform will be built from advanced, component based software delivered through a very different market model to that of today. Much of this technology exists; we simply need critical mass behind a common approach. The discussion in this paper represents the personal views of the authors and does not necessarily represent the views of any organisation.

The flip-chip structure for millimeter-wave MMICs has been investigated to obtain high performance and high reliability. In our approach, an air gap between the MMIC and the alumina substrate was determined so as not to change electrical characteristics from those of the unflipped MMIC. We calculated the proximity effect between the MMIC and the substrate by using 3D-electromagnetic simulator, and found that the air gap should be controlled to be greater than 20 µm. Since the discontinuity of transmission lines at bump interconnects is not negligible above 60 GHz, we constructed the LCR-equivalent circuit for the bump interconnect and confirmed its validity by comparing measurement with calculation. Based on these investigations, the 60- and 76-GHz-band CPW three-stage low noise amplifiers were successfully mounted on the alumina substrate using a thermal compression bonding process. The gain of the flipped 60- and 76-GHz-band MMICs are greater than 18 dB at around 60 GHz and 17 dB at around 76 GHz, respectively. The noise figures are 3.6 dB and 3.9 dB, respectively. The gain and noise performances showed little degradation compared to those of the unflipped MMICs when appropriate bonding conditions are given. We confirmed that the flip-chip structure has high reliability under a thermal cycle test. From these results, flip-chip technology is promising for millimeter-wave applications.

Human visual system can perceive 3-D structure of an object by binocular disparity, gradient of illumination (shading), occlusion, textures, perspective and so forth. Among them, binocular disparity seems to be the essentially important cues for the 3-D space perception and it is used widely for displaying 3-D visual circumstances such as in VR (virtual reality) system or 3-D TV. Visual illusions seem to be one of the phenomena which are purely reflecting the mechanism of human visual system. In the recent several years, the authors found several new types of 3-D visual illusions with binocular viewing. Entire 3-D illusory object including volume perception, transparency, dynamic illusions can be perceived only from the visual stimuli of disparity given by some inducing objects arranged with suitable relations. In this report, the authors introduced these newly found visual illusions and made some considerations on the human visual mechanism of 3-D perception and on their exploitation for new effective techniques in 3-D display. They introduced especially on the visual effect in two kinds of arrangement with occlusion and sustaining relationship between the illusory object and inducing objects. In the former case, the inducing objects which provide the stimuli were named as occlusion cues and classified into two types: contour occlusion cues and bulky occlusion cues. In the later case, those inducing objects were named as sustaining cues and a 3-D fully transparent illusory object was perceived. The perception was just like imagined from the scenes of the actions and positions of the pantomimists; then this phenomena was named as "Mime (Pantomime) Effect. " According to the positions of sustaining cues, they played different actions in this perception, and they are classified into three types: front sustaining cues, side sustaining cues and back sustaining cues. In addition, dynamic fusion and separation of volumetrical illusory objects were perceived when the visual stimuli were moving continuously between two structurally different conditions. Then the hysteresis was recognized in geometrical position between the fusion and separation. The authors believe that the occlusion cues and sustaining cues introduced in this paper could be effective clues for exploiting the new techniques for 3-D display.

Reinforcement learning is an efficient method for solving Markov Decision Processes that an agent improves its performance by using scalar reward values with higher capability of reactive and adaptive behaviors. Q-learning is a representative reinforcement learning method which is guaranteed to obtain an optimal policy but needs numerous trials to achieve it. k-Certainty Exploration Learning System realizes active exploration to an environment, but, the learning process is separated into two phases and estimate values are not derived during the process of identifying the environment. Dyna-Q architecture makes fuller use of a limited amount of experiences and achieves a better policy with fewer environment interactions during identifying an environment by learning and planning with constrained time, however, the exploration is not active. This paper proposes a RTP-Q reinforcement learning system which varies an efficient method for exploring an environment into time constraints exploration planning and compounds it into an integrated system of learning, planning and reacting for aiming for the best of both methods. Based on improving the performance of exploring an environment, refining the model of the environment, the RTP-Q learning system accelerates the learning rate for obtaining an optimal policy. The results of experiment on navigation tasks demonstrate that the RTP-Q learning system is efficient.

For the realization of low-voltage full-color FEDs, requirements for phosphor for the FED are proposed. Especially, the influence of released gases or substances from phosphors on the field emission within the FED was made clear. It was clarified that the analysis of F-N plots of the V-I curve of field emission characteristics was helpful to know the interaction of field emission and phosphors. In the experiment, we first obtained the depth from the phosphor surface of the low voltage electron excitation in case of ZnGa2O4, where the region available for cathodoluminescence at the anode voltage of 400 V is about 63 nm deep from the surface. The characteristic of the 12.4 cm-320(trio)240 pixels low-voltage full-color FED is reported. The luminance of 154 cd/m2 was attained at the anode voltage of 400 V and the duty factor of 1/241. Supported by the high potential of the FED as a flat panel, each problem shall be steadily solved to secure the firm stand as a new full color flat display in new applications.

In this paper, we describe an experimental evaluation of visual fatigue in a binocular disparity type 3-D display system. To evaluate this fatigue, we use a subjective assessment method and focus on mismatching between convergence and accommodation, which is a major weakness of binocular disparity 3-D displays. For this subjective assessment, we use a newly-developed binocular disparity 3-D display system with a compensation function for accommodation. Because this equipment only allowed us to compare the terms of the mismatching itself, the evaluation is more accurate than similar previous works.

We have realized excellent viewing angle characteristics for the π cell, by combining a discotic negative birefringence film, which has a hybrid alignment structure, and a positive a-plate. The negative birefringence of the film completely compensates the positive birefringence of the π cell liquid crystals in the dark-state. The roll of a c-plate, which should be accompanied by the a-plate to suppress the light leakage from crossed polarizer at oblique incident angles, was substituted for the vertically aligned component of the π cell liquid crystal. Taking into account the fast electrooptical response, which is one order faster than that of the twisted-nematic liquid-crystal display, the π cell is one of the most promising liquid-crystal-display modes.