We introduce a generalized cln grammar (gclng), a generalization of a completely linearly nested context-free grammar (clncfg), of which variables are partitioned linearly and each rule satisfies similar conditions as those of clncfg related to its partition. We show that the class of languages generated by gclng's coincides with the class of quasi-rational languages, and consider the inclusion relations between languages generated by gclng's and those generated by clncfg's.

There are two approaches to implementing the international standard video coding algorithms such as H.261 and MPEG: a programmable DSP approach and a building block approach. The advantages and disadvantages of each are discussed here in detail, and the video coding algorithms and required throughput are also summarized. For more complex standard such as MPEG-, VLSI architecuture became more sophisticated. The DSP approach incorporates special processing engines and the building block approach integrates general-purpose microprocessors. Both approaches are capable of MPEG- NTSC coding in a single chip. Reduction of power consumption is a key issue for video LSIs. Architectures and circuits that reduce the supply voltage while maintaining throughput are summarized. A 0.25-µm, 3-GOPS, 0.5-W, SIMD-VSP for portable MPEG- systems could be made by using architecture-driven voltage scaling as well as feature-size scaling and SOI devices.

This paper describes two main technologies for achieving reliable real-time distributed communications systems. One is the technology to prevent the influence of a fault in an autonomous distributed system from spreading to the whole system (called autonomous distributed system control). The other is a software structure based on distributed processing, the object-oriented approach, and layering for better maintainability and expandability (called OO software structure). For the autonomous distributed system control, several inter-subsystem communication methods are proposed and evaluated. From the standpoints of the fault processing and processing load, frames should be sent through a data link over ATM connection and when a fault occurs the link should be switched over without loss of data. A pilot system achieved good reliability without an excessive number of dynamic steps. This autonomous control method will lead to a highly reliable communications system with large capacity. For the OO software structure, this paper gives experimental results from the implementation of a prototype system. Its distributed environment should lead to high reliability by extending the CHILL run-time routine (RTR). This software structure promises to provide service quickly, to reduce costs, and to make the development of each layer's software independent. A real-time OS, e.g., CTRON kernel combined with RTR can give real-time performance, high reliability and high productivity over the distributed system. The use of RTR can reduce the time for the call recovery process.

A new algorithm, which is incorporated into the waveform relaxation analysis, for efficiently simulating the transient response of single lossy transmission lines or lossy coupled multiconductor transmission lines, terminated with arbitrary networks will be presented. This method exploits the inherent delay present in a transmission line for achieving simulation efficiency equivalent to obtaining converged waveforms with a single iteration by the conventional iterative waveform relaxation approach. To this end we propose 'line delay window partitioning' algorithm in which the simulation interval is divided into sequential windows of duration equal to the transmission line delay. This window scheme enables the computation of the reflected voltage waveforms accurately, ahead of simulation, in each window. It should be noted that the present window partitioning scheme is different from the existing window techniques which are aimed at exploiting the non–uniform convergence in different windows. In contrast, the present window technique is equivalent to achieving uniform convergence in all the windows with a single iteration. In addition our method eliminates the need to simulate the transmission line delay by the application of Branin's classical method of characteristics. Further, we describe a simple and efficient method to compute the attenuated waveforms using a particular form of lumped element model of attenuation function. Simulation examples of both single and coupled lines terminated with linear and nonlinear elements will be presented. Comparison indicates that the present method is several times faster than the previous waveform relaxation method and its accuracy is verified by the circuit simulator PSpice.

This paper describes that a neural network, which consists of neurons with piecewise–linear sigmoid characteristics, is able to approximate any piecewise–linear map with origin symmetry. The neural network can generate "deterministic diffusion" originating from its diffusive trajectory.

We are developing GENESIS, a new seamless total environment for designing, developing, installing, and operating various types of telecommunication networks as extremely large distributed processing applications in the future network integrated by ATM. Similar uniform architectures for quick introduction and easy management of service or operation applications have been proposed, such as by TINA, but there has been insufficient study on how to operate and con figure those applications. This paper discusses the implementation model and execution environment in GENESIS from the viewpoint of flexible operation according to network conditions. The implementation model can describe detailed configurations under various conditions on design or operation, independently of the execution environment. To achieve the goals of GENESIS, our execution environment provides message handling functions and a transparent interface for controlling network resources independently of the configuration, and dynamic reconfiguration functions that are independent of the execution. This paper also reports the prototype system GENESIS-1. The GENESIS-1 message handling mechanism and the effect of the reconfiguration functions are described.

This letter proposes the method using a filter to suppress the very large noise obstructive to the radio pulsar surveys. This noise suppression filter is constructed from the average of the amplitude spectrum of pulsar signal for each channel. Using this method, the dispersion measure, one of the important parameters in the pulsar surveys, can easily be extracted.

This paper describes a new method for pose estimation of human face moving abruptly in real world. The virtue of this method is to use a very simple calculation, disparity, among multiple model images, and not to use any facial features such as facial organs. In fact, since the disparity between input image and a model image increases monotonously in accordance with the change of facial pose, view direction, we can estimate pose of face in input image by calculating disparity among various model images of face. To overcome a weakness coming from the change of facial patterns due to facial individuality or expression, the first model image of face is detected by employing a qualitative feature model of frontal face. It contains statistical information about brightness, which are observed from a lot of facial images, and is used in model-based approach. These features are examined in everywhere of input image to calculate faceness" of the region, and a region which indicates the highest faceness" is taken as the initial model image of face. To obtain new model images for another pose of the face, some temporary model images are synthesized through texture mapping technique using a previous model image and a 3-D graphic model of face. When the pose is changed, the most appropriate region for a new model image is searched by calculating disparity using temporary model images. In this serial processes, the obtained model images are used not only as templates for tracking face in following image sequence, but also texture images for synthesizing new temporary model images. The acquired model images are accumulated in memory space and its permissible extent for rotation or scale change is evaluated. In the later of the paper, we show some experimental results about the robustness of the qualitative facial model used to detect frontal face and the pose estimation algorithm tested on a long sequence of real images including moving human face.

A novel optoelectronic mesoscopic neural device is proposed. This device operates in a neural manner, involving the electron interference and the laser threshold characteristics. The optical output is a 2–dimensional image, and can also be colored, if the light emitting elements are fabricated to form the picture elements in 3–colors, i.e. R, G, and B. The electron waveguiding in the proposed device is analyzed, on the basis of the analogy between the Schrödinger's equation and the Maxwell's wave equation. The nonlinear neural connection is achieved, as a result of the superposition an the interferences among electron waves transported through different waveguides. The sizes of the critical elements of this device are estimated to be within the reach of the present day technology. This device exceeds the conventional VLSI neurochips by many orders of magnitude, in the number of neurons per unit area, as well as in the speed of operation.

The warp model of the extended Hough transform (EHT) has been proposed to design the explicit expression of the transform function of EHT. The warp model is a skewed parameter space (R(µ,ξ), φ(µ,ξ)) of the space (µ,ξ), which is homeomorphic to the original (ρ,θ) parameter space. We note that the introduction of the skewness of the parameter space defines the angular and positional sensitivity characteristics required in the detection of lines from the pattern space. With the intent of contributing some solutions to basic computer vision problems, we present theoretically a dynamic and centralfine/peripheral-coarse camera vision architecture by means of this warp model of Hough transform. We call this camera vision architecture askant vision' from an analogy to the human askant glance. In this paper, an outline of the EHT is briefly shown by giving three functional conditions to ensure the homeomorphic relation between (µ,ξ) and (ρ,θ) parameter spaces. After an interpretation of the warp model is presented, a procedure to provide the transform function and a central-coarse/peripheralfine Hough transform function are introduced. Then in order to realize a dynamic control mechanism, it is proposed that shifting of the origin of the pattern space leads to sinusoidal modification of the Hough parameter space.

Some qualitative properties of an inductively coupled circuit containing two Josephson junction elements with a dc source are investigated. The system is described by a four–dimensional autonomous differential equation. However, the phase space can be regarded as S1×R3 because the system has a periodicity for the invariant transformation. In this paper, we study the properties of periodic solutions winding around S1 as a bifurcation problem. Firstly, we analyze equilibria in this system. The bifurcation diagram of equilibria and its topological classification are given. Secondly, the bifurcation diagram of the periodic solutions winding around S1 are calculated by using a suitable Poincar mapping, and some properties of periodic solutions are discussed. From these analyses, we clarify that a periodic solution so–called "caterpillar solution" is observed when the two Josephson junction circuits are weakly coupled.

In this letter we propose an interpolation technique for low-quality fingerprint images for highly reliable feature extraction. To improve the feature extraction rate, we extract fingerprint features by referring to both the interpolated image obtained by using a directional Laplacian filter and the high-contrast image obtained by using histogram equalization. Experimental results show the applicability of our method.

Fractal image coding using iterated transformations compresses image data by exploiting the self–similarity of an image. Its compression performance has already been discussed in [2] and several other papers. However the relation between the performance and the self–similarity remains unclear. In this paper, we evaluate fractal coding from the perspective of this relationship.

For the purpose of detecting the intracranial vascular deformations noninvasively, transducer for bruit sound emanated from diseased lesion and analyzing system were developed and applied clinically. Several aspects of the bruit signals were clarified and the possibility of early diagnosis was increased.

A systematic method for locating and computing branches of connecting orbits developed by the authors is outlined. The method is applied to the sine–Gordon and Hodgkin–Huxley equations.

A new approach using radiation mode expansions is presented for calculating radiated fields from arbitrary distribution of electromagnetic sources in the half space region partitioned by a dielectric layer with a ground conductor. This method is applied to the calculation of radiation from microstrip-type antennas with a dielectric substrate of theoretically infinite extent. To be able to use this method, it is necessary to obtain first the field distribution around antenna patches, which is accomplished rather easily by using the FD-TD method. Radiation pattern calculations are presented for a rectangular patch antenna to verify the feasibility of this approach.

Numerical simulations for the (3+1)-dimensional optical-field dynamics of nonstationary pulsed beams that propagate down Kerr-like nonlinear channel waveguides are carried out for what is to our knowledge the first time. Time-resolved intrapulse switching due to spontaneous symmetry breaking of optical fields from a quasilinear symmetric field to a nonlinear asymmetric field is analyzed. A novel instability phenomenon triggered by the symmetry breakdown is found.

An optimal control theory has been applied to a biological compartment system to show a method to analyze the control principle of biological system represented by compartments. Present theory has been proposed to afford a theoretical back ground and validity for the strategy of drug administration or control of the anesthetic agent in practical medicine. The instantaneous change of the concentration of a given material within a biological system has been expressed by differential equations. Each compartment has been set to be transferred a material from all other compartments and conversely each compartment sends it to all other compartments. The control input was restricted to be one kind. The performance function involved the deviation from the target value, the rate of change in concentration and the amount of the control variables. The biological system was defined to operate optimally only when the performance function has been minimized during a given time period. By the optimal control theory of Pontoriagin, above biological problem has been converted to a mathematical problem and was solved numerically by multiple shooting method. The calculated trajectory of the optimal control has been asymmetric parabolic one with the maximum at its initiation and the minimum at the middle of total reaction time. This pattern has been consistent with that of probable transient change of the concentration of anesthetic agent when it has been inhalated under the most up to date "Rapid Inhalation Induction" method. The optimal trasient change of the concentration at each compartment has beeb affected by the difference in time dependent nature and the magnitude of the transfer rate. Present theory afforded a method to analyze the control strategy of biological system expressed by compartments model and showed an availability for actual clinical medicine. The optimal control principle must be a most adequate one to describe the Homeostasis in biological system.

Synchronization has been one of the problems in M–ary spread spectrum communication systems. In this letter, we propose the frame synchronization method using the Hadamard matrix and a frame synchronization method of PCM communication systems. Moreover, we analyze the probabilities of keeping synchronous state and frame renewal rates, and we evaluate the relationship between these probabilities and the number of stages of counters.

We report on an experimental hysteresis in the Hopfield networks and examine the effect of the hysteresis on some important characteristics of the Hopfield networks. The detail mathematic description of the hysteresis phenomenon in the Hopfield networks is given. It suggests that the hysteresis results from fully–connected interconnection of the Hopfield networks and the hysteresis tends to makes the Hopfield networks difficult to reach the global minimum. This paper presents a T–Model network approach to overcoming the hysteresis phenomenon by employing a half–connected interconnection. As a result, there is no hysteresis phenomenon found in the T–Model networks. Theoretical analysis of the T–Model networks is also given. The hysteresis phenomenon in the Hopfield and the T–Model networks is illustrated through experiments and simulations. The experiments agree with the theoretical analysis very well.