A method is presented for detecting impulsive noises in chaotic time series, based on a new nonlinear prediction algorithm. A multi-dimensional trajectory is reconstructed from a time series using delay coordinates. The future value of a point on the trajectory is predicted using a local approximation technique revised by adding the Biweight estimation method and then the prediction error is calculated. Impulsive noises are detected by examining the prediction errors for all points on the trajectory. The proposed method is applied to the time series of the pupil area and the refractive power of the lens in the human eye. The Lyapunov exponent analysis for thses time series is conducted. As a result, it is shown that the proposed method is effective in detecting impulsive noises caused by blinking in these time series.

The Guaranteed Bandwidth Protocol (GBW) is an access scheme being proposed for implementation of connection oriented services in DQDB networks. Connection oriented services are expected to handle both constant bit rate (CBR) and variable bit rate (VBR) traffic that have delay and jitter constraints. It has been reported that the GBW protocol can provide guaranteed bandwidth and lower delays compared to the ordinary DQDB protocol. However, the intensity of the jitter introduced by this scheme has not been made clear. This paper compares the jitter results for the GBW scheme to those obtained by a new access method called Modified Guaranteed Bandwidth (MOD_GBW) protocol, which is proposed here. It is shown through simulation that MOD_GBW also provides guaranteed bandwidth and that its delay and jitter characteristics are significantly better than those of the GBW protocol. In the simulation model, the DQDB stations are divided into two groups: 1)Real-Time (RT) stations that generate either CBR or VBR real-time traffic; and 2)Data stations that generate memoryless type of traffic. Data stations operate according to the ordinary DQDB protocol only. The main performance measure adopted here for the real-time traffic is the interdeparture time distribution of consecutive segments from an RT-station. We define the variance of this distribution as jitter. This paper also shows the impact of GBW/MOD_GBW on the performance of the data stations by evaluating their throughput and average bus access delay. Finally, we show that the network performance is weakly related to the number of RT-stations under MOD_GBW, but it depends strongly on the overall loading.

In the paper a new type of Multilayer Perceptron, developed in Quaternion Algebra, is adopted to realize short-time prediction of chaotic time series. The new introduced neural structure, based on MLP and developed in the hypercomplex quaternion algebra (HMLP) allows accurate results with a decreased network complexity with respect to the real MLP. The short term prediction of various chaotic circuits and systems has been performed, with particular emphasys to the Chua's circuit, the Saito's circuit with hyperchaotic behaviour and the Lorenz system. The accuracy of the prediction is evaluated through a correlation index between the actual predicted terms of the time series. A comparison of the performance obtained with both the real MLP and the hypercomplex one is also reported.

In this paper, an extention for Haddad's method, which is the time-domain stability analysis on scalar nonlinear control systems, to multi-variable nonlinear control systems are proposed, and it is shown that these results are useful for the stability analysis of nonlinear control systems with various types of fuzzy controllers.

This paper presents a new Frequency Shift Keying (FSK) demodulation method using the Short Time-Discrete Fourier Transform (ST-DFT) analysis to combat large frequency offset with time variation in low earth orbit (LEO) satellite communications systems. This demodulation method can demodulate the received signal only by searching for the instantaneous spectrum energy peaks without complicated carrier recovery. In addition, it is insensitive to the signal-to-noise ratio (SNR) degradation caused by the excessively wide bandwidth of the receiver front-end band pass filter. Furthermore, the ST-DFT analysis combined with a differential encoding scheme gives FSK demodulation method a potential robustness against large and fast time-varying frequency offset.

For two devices whose quality is described by non-negative one-dimensional time-homogeneous diffusion processes of the Wiener and Ornstein-Uhlenbeck types sufficient conditions are given such that their failure times, modeled as first-passage times through the zero state, are ordered according to the likelihood ratio ordering.

In this study, we analyze the system which simultaneously transmits spread-spectrum signals with different processing gains. The main purpose of this study is to give an analytical framework that describes the influence of the interfering signals with different processing gains. For this purpose, we define a crosscorrelation function between the spreading sequences with different code lengths, and discuss the effects of interaction between the signals. As the results, we show that the power of the interference component after despreading procedure, the power ratio of the desired to undesired components, and thus the bit error rate are not constant but vary symbol by symbol.

We propose a new QOS routing algorithm for finding a path that guarantees several quality of service (QOS) parameters requested by users, for ATM networks. It is known that a routing problem is NP-complete, if the number of additive QOS parameters, such as delay and cost, are more than or equal to two. Although a number of heuristic algorithms have been proposed recently to solve this problem, the appropriate choice of routing algorithms is still an open issue. In this paper, we propose a new heuristic routing algorithm, while being compliant with PNNI routing and signaling specification in the ATM Forum. The performance of algorithms is evaluated by simulation with a various network topologies and loading scenarios. This simulation results demonstrate that the proposed scheme improves the performance while reducing computational complexity.

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.

This paper describes the effects of operating temperature on delay time in a 1-V multi-threshold CMOS(MTCMOS) circuit, Delay-time analysis including the temperature factor shows that the delay-time variation of the CMOS circuit becomes amall for low-voltage operation and the variation is mainly determined by the threshold voltage and its variation-rate with temperature. As a design method of a MTCMOS circuit with both high-threshold and low-threshold MOSFETs, optimization of the low-threshold voltage at which the delay-time of the circuit is independent of operating temperature is described in detail. The validity of the design method is confirmed by the evaluation of a gate-chain TEG and a 1-V 12 K-gate digital-filter LSI fabricated with o.5-µm MTCMOS technology.

We proposed a graphical user interface (GUI) that provides users with multimedia information, including dynamic images. On the Internet, there are many WWW browsers that read the Hypertext Markup Language (HTML). As various browsers extend the HTML tags and attributes independently to expand and/or improve layout, the HTML compatibility between browsers is lost. We have developed a WWW browser to solve this problem. Our browser presents all multimedia information, including text, images, and dynamic images as a block and renders them without the need to extend the HTML specifications. It independently interprets and draws HTML objects using a layout manager. It has a layout rule, and manages the hierarchical data structure and the block data of HTML documents. This browser also allows layout-rule changes. The layout manager efficiently displays information while checking the available display area size. The structure of this browser is such that the portion that manages the formatting of the document is separated from the portion that displays the individual parts. In this browser, the layout rule allows text to be placed around an image without the need to modify the existing HTML contents. It is also relatively easy to change the presentation of multiple screens, such as a two-page book-like layout or the conventional single-page scroll-bar format by changing the layout rule. The incorporation of media decoders into the browser enables the displaying of various multimedia information, such as sounds, pictures, and moving images.

We present a minimal lattice realization of MIMO linear discrete-time systems which interpolate the desired Markov and covariance parameters. The minimal lattice realization is derived via a recursive construction algorithm based on the state space description and it parametrizes all the interpolants.

Intending to contribute to constructing better multimedia network systems, we propose a new concept of image database system of which form of storage is featuring exponential or graceful oblivion and abrupt recollection like the human memory property. By virtue of this property of database storages that is realized by employing hierarchical or pyramidal image coding, the database memory and transmission costs can be significantly reduced. In this paper we will describe the details of the concept, the results of theoretical analysis based on a simplified model which reveals the effectiveness of the proposed system, the structure of an experimental prototype system and the result of an experimental image retrieval service carried out by implementing it over ATM high speed channels.

Three techniques are proposed for reducing the time required for protocol processing: protocol data unit management using page management, assembly and disassembly of data packet header and contents in hardware, and rescheduling of protocol processing. These techniques were shown to be feasible by applying them to the TCP/IP over a fiber-distributed data interface network. The maximum communication throughput was 91.6 Mbps; the total throughput for 64 sessions was 89.6 Mbps, only 2% less than the maximum. These techniques will enable the development of more effcient video-on -demand systems.

Many activities are being promoted for the coming multimedia age. In this paper, background information for multimedia communications is followed by an outline of joint tests in multimedia communications with some examples of the projects and applications. These trials are also explained from the aspects of project specifications, which include application classifications and details of multimedia-on-demand offerings, as well as technical issues in experimental environments which mainly include those related to ATM technology.

As the rise of the Internet greatly affects the construction of networks in the coming era of multimedia, we try to find the factors of development and problems of the Internet. Furthermore, we give light to the requirements on networks based on multimedia applications tailored to each homes. As a result of those two analyses, we point out that the Asynchronous Transfer Mode (ATM) type Internet utilizing ATM technology, which makes up for the drawbacks of information management function of the Internet, is promising. Furthermore, we point out that intelligence, which provides the network with the information management and information search functions, is necessary to be introduced into networks. So we propose a network function model, which will realize such functions.

For the successful realization of the multimedia information environment, it is strongly required to develop very cost effective optical access networks. Accordingly, ways of reducing system cost are described. At the same time, the development of attractive new services is indispensable to drive network modernization. The connectionless networking service for community user groups is proposed together with the new concept of group communication.

A new multi-functional card with a display, sounder and input keys, and related communication equipment, including a microwave base station and a contactless surface reader/writer, have been developed to perform the functions of positioning, paging, returning a message and identity certification. We confirmed that a prototype subsystem was capable of providing a simple and automatic call forwarding service. The multi-functional card as an ID card and a personal data terminal, and its subsystem can provide new personal services for a multimedia office.

In this paper, the real-time scheduling mechanism which could support multimedia retrieval services more efficiently is investigated. In order to support multimedia service, the MEDF (modified earliest deadline first) algorithm that takes advantage of the priority queue and the virtual deadline mechanism is proposed. Additionally, its performance is analyzed and compared with conventional RR (round robin), FCFS (first come first serve), SS (sporadic server), MRF (minimum remained-time first), and EDF (earliest deadline first) algorithms. According to the simulation results, the proposed MEDF algorithm shows better performance than other scheduling algorithms in the multimedia environments.

A GTL/LV-CMOS interfaced 1 M bit(32k words 36bits/64k words18bits) BiCMOS cache SRAM is designed within a 5.65 10.54mm2 chip size. The process is 0.4µm BiCMOS with 4 poly-Si layers, 3 Metal layers, and TFT memory cells(2.66 4.94µm2). The late write operation is newly adopted. The late write operation method improvements make the fast access time 6 ns and the shorter cycle time 5 ns.