In retrieving information from databases widely distributed in a network, the first thing to do is to search and find the database where the required information is stored. We call this the information searches rather than the retrievals. In this paper, we present a search and retrieval method for multimedia information, especially images. First, we formalize the general elements of information search and introduce a new search concept based on entropy reduction. Next, we discuss recent new technologies for image retrieval and introduce a new image retrieval system called VideoReality. Third, we present several methods of searching in the network- for example, the Internet robot TITAN, and a new search method for images distributed in the network that is based on the hierarchical structure of image retrieval. Finally, we discuss the network control and design concepts appropriate for information search and retrival.

The up and coming multimedia services are based on real-time high-speed networks. For efficient operation of such services, real-time and precise network management is essential. In this paper, we show that presently available MIB designs are severely inadequate to support real-time network management. We point out and analyze the management constraints and bottlenecks. The concept of quality of management of management information is introduced and its importance in practical network management is discussed. We have proposed a new MIB architecture that will raise the quality of management information to meet the requirements of managing high-speed networks and multimedia services. Experimental results from a prototype implementation of the new MIB architecture are presented.

This paper provides an architectural study of optical ring trunk-transmission networks using either Time Division Multiplexing (TDM) or Wavelength Division Multiplexing (WDM). A timeslot arrangement algorithm for distributed controlled TDM rings is proposed that minimizes the number of slots (wavelengths) required in bi-directional ring networks. This algorithm is applied in a straightforward manner to wavelength arrangement in WDM ring networks. The technique, characterized by timeslot (or wavelength) conversion, realizes common add/drop procedures in all Add/Drop Multiplexers (ADMs) when they are connected logically in a mesh topology. A self-healing algorithm is also proposed for network restoration. It offers good performance in terms of protection line-capacity, restoration delay, and survivability against multiple failures.

The characteristics of a-Si bottom-gate TFT test devices with several kinds of inorganic "quasi-black matrix," such as metal, semiconductor, and insulator, on the top were investigated for various black matrix(BM) resistivities. In the Ia-Vg characteristics, for a BM sheet resistance of about1 1012 Ω/, a high off current and large Vth shift were observed due to the back-gating effects when the BM is charged up. Accrding to the ac dynamic characteristics, there was almost no leakage due to the capacitive coupling between source and drain after 16.6 msec(one frame) when the BM sheet resistance was above 7 1013 Ω/ . It was found that hydrogenated amorphous silicon germanium(a-SiGe:H) film, which has enough optical density, with the sheet resistance above the order of 1014 Ω/ is a promising candidate for an inorganic BM on TFT array.

In this work is first presented that a PDLC film with a ferroelectric alignment layer realizes a bistable switching in similar to the surface-stabilised ferroelectric liquid crystal display devices. Such a bistability is found to critically depend on the squareness parameter of the ferroelectric layer as well as such material properties of the dispersed nematics as the elastic and the dielectric constants. It is also found that there exists an appropriate elastic constant to improve the optical transmittance. The dependence of the distribution of the radii of the nematic droplets on the electro-optic bistability is also investigated in detail by means of the numerical computations assuming a fractal distribution. The fundamental electro-optic properties of the presently, proposed PDLC cells imply the advantage beyond the conventional PDLC without any ferroelectric alignment layer.

Super twisted nematic (STN) liquid crystal displays(LCDs) using spiral polymer aligned nematic (SPAN) liquid crystals have been achieved by photo-polymerization of some kinds of chiral monoacrylates in liquid crystalline hosts.The spiral polymer made of a chiral monoacrylate in STN LCD has effect to reduce the driving voltage without any disadvantages for the STN LCD. The relation of chemical structure of a chiral monoacrylate and nature of spiral polymer is discussed.

The effect of silicone vapour concentration on the contact failure was examined by using micro relays and motor brush-slip ring(commutator) contacts, [(CH3) 2SiO]4: D4 was used as a vapour source of silicone contamination. Because the influence of the vapour of the silicone on the contact surface can not be avoided at all times due to its gradual evaporation in the atmosphere. The contact failure caused by the silicone vapour was confirmed as formation of SiO2 on the contact surfaceby analysis of EPMA and XPS. A minimum limiting concentration level which does not affect contact reliability was found. This limiting level was 10 ppm(O.13mg/l). Validity of the limiting level was confirmed by the relationships among concentration, temperature, SiO2 film thickness and contact resistance. Furthermore, the effect of the degree of silicone polymerization on the limiting concentration was derived by an empirical formula. This silicone is found to have polymerization degree larger than D7: n=7. These results were confirmed by the contact failure data due to the silicone contamination.

A mesh spiral network (MSnet) and a mesh random (MRnet) are proposed. The MSnet consists of the 2-D torus and bypass links that keep the degree at six. The MRnet consists of the 2-D torus and random bypass links that keep the degree at six. The diameter and the average distance are calculated by using a computer program. The cost of the MSnet is slightly higher than that of the de Bruijn graph, and is about the same as the Star graph. The cost of the MRnet is better than that of the de Bruijn graph. The MSnet is proven to be maximally fault-tolerant. The upper bound of the MRnet size is also discussed.

This paper proposes a fast timing recovery method with a decision feedback equalizer for baudrate sampling. The proposed method features two special techniques. The first one is for coarse estimation of the sampling phase. Internal signals of the oversampled analog-to-digital converter at different phases are directly taken out for parallel evaluation. The second technique provides fine tuning with a phase-modification stepsize which is adaptively controlled by the residual intersymbol interference. Simulation results by a full-duplex digital transmission system with a multilevel line code show superiority of the proposed method. The coarse timing estimation and the fine tuning reduce 75% and 40% of the time required by the conventional method,respectively. The overall saving in timing recovery is almost 60% over the conventional method. The proposed method could easily be extended to other applications with a decision feedback equalizer.

The objective of this paper is to find a parametric representation for the vocal-tract log-area function that is directly and simply related to basic acoustic characteristics of the human vocal-tract. The importance of this representation is associated with the solution of the articulatory-to-acoustic inverse problem, where a simple mapping from the articulatory space onto the acoustic space can be very useful. The method is as follows: Firstly, given a corpus of log-area functions, a parametric model is derived following a factor analysis technique. After that, the articulatory space, defined by the parametric model, is filled with approximately uniformly distributed points, and the corresponding first three formant frequencies are calculated. These formants define an acoustic space onto which the articulatory space maps. In the next step, an independent component analysis technique is used to determine acoustic and articulatory coordinate systems whose components are as independent as possible. Finally, using singular value decomposition, acoustic and articulatory coordinate systems are rotated so that each of the first three components of the articulatory space has major influence on one, and only one, component of the acoustic space. An example showing how the proposed model can be applied to the solution of the articulatory-to-acoustic inverse problem is given at the end of the paper.

This paper describes a trial of evaluating the proper characteristics of multiple sound insulatain systems from their output responses contaminated by unknown background noises. The unknown parameters of sound insulation systems are first estimated on the basis of hte linear time series on an intensity scale, describing functionally the input-output relation of the systems. Then, their output probability distributions are predicted when an arbitrary input noise passes through these insulation systems.

THe decimation-in-time (DIT) and the decimation-in-frequency (DIF) algorithms are the most well-known fast algorithms for computing the discrete Fourier transform(DFT). These algorithms constitute the basis of the fast Fourier transform (FFT) implementations, including the pipeline implementation and other parallel configurations. This paper derives an alternative generalization of the algorithms which applies for sequences whose lengths are not a power of two. The treatment is consistent with the radix-two DIF and DIT algorithms, and the generalization is useful for utilizing the accumulated technologies of the FFT algorithm for such sequences.

We propose the Kernel MUSIC algorithm as an improvement over the conventional MUSIC algorithm. This algorithm is based on the orthogonality between the image and kernel space of an Hermitian mapping constructed from the received data. Spatial smoothing, needed to apply the MUSIC algorithm to coherent signals, is interpreted as constructing procedure of the Hermitian mapping into the subspace spanned by the constituent vectors of the received data. We also propose a new spatial smoothing technique which can remove the redundancy included in the image space of the mapping and discuss that the removal of redundancy is essential for improvement of resolution. By computer simulation, we show advantages of the Kernel MUSIC algorithm over the conventional one, that is, the reduction of processing time and improvement of resolution. Finally, we apply the Kernel MUSIC algorithm to the Laser Microvision, an optical misroscope we are developing, and verify that this algorithm has about two times higher resolution than that of the Fourier transform method.

This paper proposes a three-dimensional (3-D) band-limiting technique for a conversion of Simple Cubic Sampling into Body-Centered Cubic Sampling. Based on spectral distribution of the original signal, the proposed method adaptively varies the passband shape of a band-limiting filter in order to preserve informations of the original picture. By applying this method to 3-D moving pictures, we can preserve resolution on each axis without introducing heavy aliasing error and avoid degradation of picture quality such as ringing in still pictures or blurring in moving pictures. The examples given in this paper demonstrate these advantages.

An image obtained by ultrasonic medical equipment is poor in quality because of speckle noise, that is caused by the quality of ultrasonic beam and so on. Thus, it is very difficult to detect internal organs or the diseased tissues from a medical ultrasonic image by the processing, which is used only gray-scale of the image. To analyze the ultrasonic image, it is necessary to use not only gray-scale but also appropriate statistical character. In this paper, we suggest a new method to extract regions of internal organs from an ultrasonic image by the discrimination function. The discrimination function is based on gray-scale and statistical characters of the image. This function is determined by using parameters of the multi-dimensional autoregressive model.

In this paper, quantization method which can keep the phase and gain characteristics of a reference filter is proposed. The proposed method uses a genetic algorithm and a simulated annealing algorithm. The objective function used in this method is described with two kinds of weighting functions for identifying the phase and gain characteristics respectively. Therefore, the quantization accuracy on the gain characteristic is independent of the accuracy on the phase characteristic. Further, the proposed algorithm can be applied to any types of filters, because the chromosome expresses only their coefficients values. The efficiency of the proposed algorithm is verified by some experiments.

This paper presents a new method for designing IIR Nyquist filters with zero intersymbol interference. It is shown that IIR Nyquist filters with zero intersymbol interference have some constraints on frequency response, i.e., both magnitude and phase error in passband are dependent on stopband error. Therefore, the frequency response is required to optimize only in stopband. The proposed procedure is based on the formulation of an eigenvalue problem by using Remez multiple exchange algorithm in stopband. Then, the filter coefficients can be computed by solving the eigenvalue problem, and the optimal solution with equiripple stopband response is easily obtained by applying an iteration procedure. The proposed procedure is more computationally efficient than the conventional methods.

The medial axis transform (MAT) is an image representation scheme. For a binary image, the MAT is defined as a set of upright maximal squares which consist of pixels of value l entirely. The MAT plays an important role in image understanding. This paper presents a parallel algorithm for computing the MAT of an n n binary image. We show that the algorithm can be performed in O(log n) time using n2/log n processors on the EREW PRAM and in O(log log n) time using n2/log log n processors on the common CRCW PRAM. We also show that the algorithm can be performed in O(n2/p2 + n) time on a p p mesh and in O(n2/p2 + (n log p)/p) time on a p2 processor hypercube (for 1 p n). The algorithm is cost optimal on the PRAMs, on the mesh (for 1 p n) and on the hypercube (for 1 p n/log n).

This paper presents a method for mechanically transforming a parallel algorithm on an original network so that the algorithm can work on a target network. It is assumed that the networks are of cube-type such as the shuffle-exchange network, omega network, and hypercube. Were those networks isomorphic to each other, the algorithm transformation is an easy task. The proposed transformation method is based on a novel graphembedding scheme <φ: δ, κ, π, ψ>. In addition to the dilating operation δ of the usual embedding scheme <φ: δ>, the novel scheme uses three primitive graph-transformation operations; κ (= δ-1) for contracting a path into a node, π for pipelining a graph, and ψ (= π-1) for folding a pipelined graph. By applying the primitive operations, the cube-type networks can be transformed so as to be isomorphic to each other. Relationships between the networks are represented by the composition of applied operations. With the isomorphic mapping φ, an algorithm in a node of the original network can be simulated in the corresponding node(s) of the target network. Thus the algorithm transformation is reduced to routine work.

2D (two-dimensional) convolution is a basic operation in image processing and requires intensive computation. Although the SIMD model is considered suitable for 2D convolution, previous 2D convolution algorithms on the SIMD model assume unbounded number of PEs (Processing Elements) available, which we call unbounded case. Unbounded case could not be satisfied on real computers. In this paper, time-optimal data-parallel 2D convolution is studied on mesh-connected SIMD computers with bounded number of PEs. Because the optimal computation complexity is not difficult to achieve, the main concern of this paper is how to achieve optimal communication complexity. Firstly the lower bound computation complexity is analyzed. Then the lower bound communication complexities are analyzed under two typical data-distribution strategies: block-mapping and cyclic-mapping. Based on the analysis result, an optimal algorithm is presented under the block-mapping. The algorithm achieves the lower bound complexity both in computation and in communication.