Data communication by using TCP/IP is one of important services on ATM networks. At one approach in traffic control of this service, the dedicated bandwidth for data transfer is not guaranteed and the feedback congestion control to prevent cell loss is performed in the congestion case. However, when a large quantity of data is transferred within a short period, this traffic control cannot be expected to achieve high efficiency. In this case, it is suitable that the dedicated bandwidth is guaranteed by FRP (Fast Reservation Protocol) before the data is transferred. This paper describes that FRP is superior to the feedback congestion control for large size data transmission. Next, it proposes a selectable traffic control which selects adaptively one of the feedback congestion control and FRP.

Board-to-board signal transmission in a rack system is affected by various types of noise. Signal transmission capability is evaluated on the basis of physical construction parameters and signal conditions, such as rise time and amplitude. This paper examines noise in a rack system and shows that the maximum single-ended transmission capability is 100Mbps when pin-type connectors are used with a signal/ground pin assignment ratio of 1/1.

This paper discusses two approaches to statistical multiplexing: rate envelope multiplexing, allowing resource sharing with small delays for low peak rate connections, and rate sharing, based on the use of large multiplexer buffers to ensure high link utilization for high speed data traffic. We argue that the weighted fair queueing scheduling algorithm provides an efficient means for combining both kinds of multiplexing in the B-ISDN. A feasible implementation known as Virtual Spacing is outlined. We illustrate the flexibility of the proposed scheme by showing how different service categories could be provided.

In this study, we investigate the synchronization phenomena of coupled Wien bridge oscillators. The oscillator is characterized by a voltage controlled resistor with saturation. We use linear resistance to couple the oscillators. Two different kinds of coupling techniques, called current and voltage connections are proposed and they show completely opposite mode of synchronized oscillations. The dynamics of the two circuits are also derived to study the amplitude and phase dynamics of the synchronized state. The current connection has a simple resistive effect but stable phase mode is opposite to that of the voltage connection. The voltage connection has the coupling effect which is a combination of resistive and reactive couplings. Coupled three oscillators with current and voltage connection are also studied and stable tri-phase and in-phase synchronizations are observed, respectively. Averaging method is used to investigate the stability of synchronized mode of oscillations. Experimental results are also stated which agree well with the theory.

This paper proposes a novel updating technique, dynamically updating, for achieving extension or modification of functions in a distributed system. Usual updating technique requires synchronous suspension for multiple processes for avoiding unspecified reception caused by the conflict of different versions of processes. Thus, this technique needs very high overhead and it must restrict the types of distributed systems, to which it can be applied, to RPC (remote procedure call) type or client-server type. Using the proposed dynamically updating technique, updating management can be invoked asynchronously by each process with assurance of correct execution of the system, i.e., the system can cope with the effect of unspecified reception caused by mixture of different version processes. Therefore, low overhead updating can be achieved in partner type distributed systems, that is more general type including communications systems or computer networks. Dynamically updating technique is implemented by using a novel distributed algorithm that consists of group communication, checkpoint setting, and rollback recovery. By using the algorithm proposed in this paper, rollback recovery can be achieved with the lowest overhead, i.e., a set of checkpoint determines the last global state for consistent rollback recovery and a set of processes that need to rollback simultaneously is the smallest one. This paper also proves the correctness of the proposed algorithm.

In this paper, we present a method for extracting the Japanese printed characters from unformatted document images. This research takes into account the multiple general features specific to the Japanese printed characters. In our method, these features are thought of as the constraints for the regions to be extracted within the constraint satisfaction approach. This is achieved by minimizing a constraint function estimating quantitative satisfaction of the features. Our method is applicable to all kinds of the Japanese documents because it is no need of a priori knowledge about the document layout. We have favorable experimental results for the effectiveness of this method.

A 10-kW (53V/200A), forced-air-cooled DC-DC converter has been developed for fuel cell systems. This converter uses new high-voltage bipolar-mode static induction transistors (BSIT), a new driving method, a zero-voltage-switched pulse-width-modulation technique, and a new litz wire with low AC resistance. It weighs only 16.5kg, has a volume of 26,000cm3, operates at 40kHz, and has a power conversion efficiency of about 95%. The power loss of this converter is 20% less than that of conventional natural-air-cooled DC-DC converters, and the power density is 3 times as high.

A method for painting a sequence of monochromatic images is proposed. In this method, a color model, whose base components are hue, saturation and intensity, is used to keep the lightness of images unchanged before and after painting. Two successive frames in the monochromatic image sequence and a colored image of the first frame which is interactively painted, are analyzed in order to paint the next monochromatic frame. The painting process is composed of two phases, that is, an automatic coloring phase and an interactive retouching phase. In the automatic coloring phase, hierarchical image segmentation and region matching procedures are performed, and the two attributes of hue and saturation are mapped from the painted image of the first frame to the next image. In the retouching phase, using an interactive paint system based on the color model, users can modify the chromatic components of pixels whose colors were not mapped correctly. Several experiments show that our method is very effective in reducing tedious painting.

We extend the theorem of Gramlich on modular termination of term rewriting systems, by relaxing the disjointness condition and introducing the composability instead. More precisely, we prove that if R1, R-1 are composable, terminating term rewriting systems such that their union is nonterminating then for some a {1, -1}, Ra OR is nonterminating and R-aRa is Fa-lifting. Here, OR is defined to be the special system {or(x, y) x, or(x, y) y}, Fa is the set of function symbols associated with Ra, and an Fa-lifting system contains a rule which has either a variable or a symbol from Fa at the leftmost position of its right-hand side. The extended theorem is stronger than the original one in that it relaxed the disjointness and constructor-sharing conditions and allowed the two systems to share defined symbols in common under the restriction of composability. The corollaries of the theorem show several sufficient conditions for decomposability of termination, which are useful for proving termination of term rewriting systems defined by combination of several composable modules.

This paper describes a method for screening psychiatric patients based on a questionnaire consisting of simple yes/no questions regarding to physical, mental conditions and subjective symptoms which is provided at their first visit to the hospital. The analysis of the questionnaire is important to understand patients' background. One hundred filled out questionnaires were utilized for constructing and evaluating a pseude Bayesian classifier which classifies patients into three categories i.e. Schizophrenic, emotional and neurotic disorders with average correct prediction rate of 73.3%. The rate was 16.6% higher than the result given by experienced medical doctors and the method will be a useful mean for automatic screening of the psychiatric patients.

A uniquely-structured Usage Parameter Control (UPC) method named Virtual-shaping is proposed which considers cell arrival time jitter between user and UPC point. The method uses a modified Dangerous Bridge UPC circuit (Sliding window type) and virtually (logically) shapes cell traffic using cell arrival time compensation to offset cell delay variation (CDV). In addition, the proposed method is based on a cell-buffer-less structure and can be realized with reasonable hardware. The method yields precise and accurate monitoring. Computer simulations show that the method offers higher network utilization than the conventional Leaky Bucket based UPC method. The proposed method will make it possible to create more effective B-ISDNs, and more cost-effective broadband VBR services.

Complexity of Boolean functions satisfying the propagation criterion (PC), an extended notion of the perfect nonlinearity, is discussed on several computation models. The following topics are investigated: (i) relationships between the unateness and the degree of the PC, (ii) the inversion complexity of perfectly nonlinear Boolean functions, (iii) the formula size of Boolean functions that satisfy the PC of degree 1, (iv) the area-time-square complexity of VLSI circuits computing perfectly nonlinear Boolean functions, (v) the OBDD size perfectly nonlinear Boolean functions.

This paper studies congestion control schemes for integrated variable bit-rate (VBR) video and data communications, where the quality of service (QOS) of each medium needs to be satisfied. In order to control congestion, we exert here either dynamic resolution control or QOS control. The dynamic resolution control scheme in this paper dynamically changes the temporal or spatial resolution of video according to the network loads. The QOS control scheme here assigns a constant capacity of buffer to each connection and determines the video resolution in order to guarantee the QOS of each medium at the connection establishment. The performance of these schemes is evaluated through simulation in terms of throughput, video frame delay probability distribution, and video frame loss rate. We also examine the effects of priority scheduling and packet discarding on the performance. Numerical results indicate that both dynamic resolution and QOS control attain low delay jitters as well as large video and data throughput. In particular, the QOS control is shown to be more suitable for integrated VBR video and data communications.

Over the last decade, the Internet has been extremely successful by distinguishing between overlaying applications and underlying networking technologies. This approach allows rapid and independent improvement in both networking and application technologies. The internetworking layer that divides applications and the network enables the Internet to function as a general and evolving infrastructures for data communications. The current Internet architecture offers only best-effort data delivery. However, recent emerging computer and networking technologies, demand the Internet guaranteed performance. In particular, audio and video applications have more rigid delay requirement than those applications which the current Internet supports. To offer guaranteed services in addition to best-effort services, both a new service model and a new architecture are necessary in the Internet architecture. The paper surveys researches and experiments conducted in the Internet community to accommodate a wide variety of qualities of services.

A high-speed high-density self-aligned pnp technology for complementary bipolar ULSIs has been developed to achieve high-speed and low-power performance simultaneously. It is fully compatible with the npn process. A low sheet-resistance p+ buried layer and a low sheet-resistance extrinsic n+ polysilicon layer with U-grooved isolation enable the transistor size to be scaled down to about 20 µm2. Current gain of 85 with 4-V collector-emitter breakdown voltage was obtained without any leakage current arising from emitter-base forward tunneling or recombination, which indicates no extrinsic base encroachment problem. A shallow emitter junction depth of 45 nm and narrow base width of 30 nm, obtained by utilizing an optimized retrograded p-well, an arsenic-implanted intrinsic base, and emitter diffusion from BF2-implanted polysilicon, improve the maximum cutoff frequency to 35 GHz. The power dissipation of the pnp pull-down complementary emitter-follower ECL circuit with load capacitances is calculated to be reduced to 20-40% of a conventional ECL circuit.

The selection of an appropriate key search algorithm for a specific application field is an important issue in application systems development. This is because data retrieval is the most time-consuming part of many application programs. An automatic selection method for key search algorithms is presented in this paper. The methodology has been implemented in a system called KESE2 (KEy-SEarch ALgorithm SElection). Key search algorithms are selected according to the user's requirements through interaction with KESE2 which bases its inferences on an evaluation table. This evaluation table contains values rating the performance of each key search algorithm for the different searching properties, or characteristics. The selection algorithm presented is based on step by step reduction of unsuitable key search algorithms and searching properties. The paper also proposes assistance facilities that consist of both a support function and a program synthesis function. Experimental results show that the appropriate key search algorithms are effectively selected, and that the necessary number of questions asked, to select the appropriate algorithm, is reduced to less than half of the total number of possible questions. The support function is useful for the user during the selection process and the program synthesis function fully translates a selected key search algorithm into high level language in an average of less than 1 hour.

Low-power technology for front-end GaAs ICs and hybrid IC (HIC) for a mobile communication equipment will be presented. For low-power operation of GaAs front-end ICs, new techniques of the intermediate tuned circuits, the single-ended mixer, dualgate MESFETs, and the asymmetric self-aligned LDD process were investigated. The designed down-converter IC showed conversion gain of 21 dB, noise figure of 3.5 dB, 3rd-order intercept point in output level (IP3out) of 4.0 dBm, image-rejection ratio of 20 dB at 880 MHz, operating at 3.0 V of supply voltage and 5.0 mA of dissipation current. The down-converter IC was also designed for 1.9 GHz to obtain conversion gain of 20 dB, noise figure of 4.0 dB, IP3out of 4.0 dBm, image-rejection ratio of 20 dB at 3.0 V, 5.0 mA. The up-converter IC was designed for 1.9 GHz using the same topology of circuit and showed conversion gain of 15 dB, IP3out of 7.5 dBm, and 1 dB compression level of -8 dBm with -20 dBm of LO input power, operating at 3.0 V, 8.0 mA. Another approach to the low-power operation was carried out by HIC using the GaAs down-converter IC chip. The HIC was designed for 880 MHz to show conversion gain of 27 dB, noise figure of 3.3 dB, IP3out of 3.0 dBm, image-rejection ratio of 12 dB, at 2.7 V, 4.5 mA. The HIC measures only 8.0 mm6.0 mm1.2 mm.

Voting is a general way of achieving mutual exclusion and synchronization in distributed systems with replicated data. In centralized voting protocols, a requesting node, which works as a central controller, exchanges messages in order to collect votes from other nodes. This paper proposes decentralized voting protocols, in which all nodes execute the same protocol and reach the same result in a decentralized and autonomous way. When a decentalized voting protocol is implemented by using one-round message exchange, it requires n(n1) messages, where n is the number of nodes. The number of messages can be reduced by using multiple-round message exchange. The paper describes the computation in each node in the form of the finite state automaton, and gives communication structures for it. It is shown that kn(n1/k1) messages are enough when messages are exchanged in k rounds.

This paper proposes a practical training algorithm for artificial neural networks, by which both the optimally pruned model and the optimally trained parameter for the minimum prediction error can be found simultaneously. In the proposed algorithm, the conventional information criterion is modified into a differentiable function of weight parameters, and then it is minimized while being controlled back to the conventional form. Since this method has several theoretical problems, its effectiveness is examined by computer simulations and by an application to practical ultrasonic image reconstruction.

First, the necessity of examining the numerical calculation of the Bessel function Jν(x) of complex order ν is explained. Second, the possibility of the numerical calculation of Jν(x) of arbitrary complex order ν by the use of the recurrence formula is ascertained. The rounding error of Jν(x) calculated by this method is investigated next by means of theory and numerical experiments when the upper limit of recurrence is sufficiently large. As a result, it was known that there is the possibility that the rounding error grows considerably when ν is complex. Counterplans against the growth of the rounding error will be described.