A method is described for improving cooperation in supervisory control and data acquisition (SCADA) systems that uses multi-agent (MA) intelligent field terminals (IFTs). The MA function of each IFT evaluates the control conditions of the overall system and the conditions of the other IFTs. To shorten the turn-around time for data transfer among IFTs, the conflicts that occur when the data processed by different IFTs is inconsistent or irregular are cooperatively and autonomously resolved by predictive agents incorporated into each IFT. Experimental results showed that this method not only provides adequate control but also reduces the load on the network and the turn-around time when the number of IFTs is less than 30.

As a center of mobile multimedia of the 21st century, it is very much looking forward to explosion of R&D and business of the next generation of mobile communication systems and the ITS (Intelligent Transport Systems) because ITS will enable information-oriented in the field of the road, traffic and vehicles, by using the most advanced technologies of mobile communications and devices, for the various purposes such as decrease of the traffic accident, the reduction of traffic jam, the increase in efficiency of the logistics and the harmony with the earth environment. This invited paper will first briefly introduce evolution of mobile communications and ITS in ministries, industries and academia in Japan. Then core communication technologies for ITS will be overviewed such as spread spectrum CDMA, adaptive antenna array, and software radio or software defined radio. Demands of SoC (System on a Chip) to carry out the core technologies will be addressed.

As the network speed becomes faster and requirements about various services are increased, a number of groups are currently developing technologies aimed at evolving and enhancing the capabilities of existing network. A Next-Generation Network (NGN) is defined as a hybrid telecommunications network that employs new distributed processing techniques to provide all types of services. By integrating the Intelligent Network (IN) technology and the Mobile Agent (MA) technology we can support service flexibility and service portability in NGN. In this paper, we propose a caching-based mobile agent model for NGN and analyze the performance of this model. The mobile agent technology increases the service portability and the caching strategy does the service reusability. Each Physical Entity (PE) has MAs within their repository through the caching strategy and processes service requests from users without the control of the central system such as Service Control Point (SCP). Therefore, we can decrease the total network load and the response time for user requests.

A new architecture and methods for an enhanced autonomous decentralized production system (EADPS) are described. This EADPS was developed to ensure high flexibility of production systems consisting of intelligent devices based on the autonomous decentralized system model and to guarantee the time used for communication to simultaneously maintain high productivity. The system architecture of the EADPS guarantees the time by managing groups of nodes and the priorities in these groups. A bit-arbitration method is used to prevent collision of messages. The nodes autonomously check the waveforms in the network and terminate transmission when the nodes with a higher priority are transmitting. A parallel-filtering method is used to speed up message acceptance. The nodes check the identifiers of the messages using parallel-filtering circuits and each node determines autonomously where a message should be accepted or not. Implementing the system architecture and these methods as circuits and integrating the circuits into a chip using system LSI technologies resulted in low-cost implementation of the system. Experimental evaluation demonstrated the effectiveness of this system.

Focusing on a distributed control service-control-node (SCP) that houses a database (DB) distributed across multiple modules, this paper proposes an autonomous distributed SCP architecture using multicasting access to the distributed DB, and highlights its application areas. We assume as a basic condition that neither the network nor the other modules in the system are aware of the DB configuration. Based on this condition, we propose two basic methods: a unicast approach in which the DB management module that is selected at random by the network routes the DB access request to the module where the target data resides (Method A), and a multicast method in which DB access requests are broadcast to all modules (Method B). A quantitative evaluation is made of the number of required modules and required communications performance between modules which is determined by the capacity of the main memory and processing capacity of the processors. Based on the results, we conclude that Method B better exploits the advantages of module autonomous distribution technology within the limits that the economy of inter-module communication overhead is not impaired. Furthermore, in the event a module fails in Method B, a scheme is proposed in which the defective module is cut out of the multicast group, and multicasting continues. This could be implemented most effectively using a separate route under hardware control that is independent of the on-line communications route between modules.

CRL (Communications Research Laboratory, Independent Administrative Institution Japan) is developing a road to vehicle multiple-service communication system based on RoF (Radio over Fiber) technology in a millimeter-wave frequency region of 36-37 GHz. In the experimental system, vehicle can receive three wireless services such as PHS (Personal Handy-phone System), ETC (Electronic Toll Collection system), SB (Satellite Broadcasting). In this paper, the system concept and experimental system configuration are introduced. Furthermore, SDR (Software Defined Radio) mobile terminal technology is mentioned and a new concept for a next generation mobile communication network system based on RoF is proposed.

Modeling a complicated system as a multi-agent system is one of the most promising ways of designing a large, complex system. If we can assume that each agent in a multi-agent system has mental states (beliefs, knowledge, desires and so on), we can formalize each agent's behaviors in an abstract way without being bothered by system implementation details. We present semantic structures that are useful for representing belief states in multi-agent environments. One of the structures is a restriction of partial Kripke structures studied by Jaspars and Thijsse: we assume that each agent can access from a state of a structure to at most one state. We call the restricted structures only-child partial Kripke structures. We show some properties of only-child partial Kripke structures. Another structure is a restriction of the alternate nonstandard structures defined by Fagin et al. to deal with the logical-omniscience problem. We show several relationships between partial Kripke structures and the restriction of alternate nonstandard structures. Using the results, we show that the outputs of a belief estimation algorithm we previously developed can be characterized by using only-child partial Kripke structures. Finally, we show that only-child partial Kripke structures are more appropriate for the belief estimation problem than the restricted nonstandard structures.

A new method of sequential control has been developed in order to increase the productivity and flexibility of production systems. This advanced sequential control (ASC) method is proposed for sequential control systems based on the autonomous decentralized system (ADS) architecture. The ADS defines the system software and message formats and makes it easy to expand the number of devices and software modules. The ASC method increases productivity because it minimizes the processing and adjustment times of production lines by adjusting the starting times of production processes automatically. Experimental evaluation results of the ASC method showed that it increases the productivity of production systems. It is also applied to an actual production system and the results are reported.

We have developed a new method to improve cooperation in concurrent systems for distributed control by using multi-agent (MA) functions. Since field terminals (FTs) work concurrently, cooperation among them is essential to the effectiveness and efficiency of the overall system. When FTs are modeled as agents, it is easy to explicitly deal with the interactions among them because those interactions can be modeled naturally as communication among agents with cooperation and negotiation. In conventional central control systems, the host computer supervises and controls all FTs in accordance with a pre-installed control algorithm. Our method instead uses intelligent field terminals (IFTs) that can evaluate the diverse information from devices of other IFTs autonomously. In the work reported here, we have evaluated the effectiveness and efficiency of our cooperative control method experimentally and have developed a system using this method to control various kinds of water delivery systems. The IFT providing MA functions that can evaluate the control parameters (CPs) and conditions of the other IFTs. If turn-around time is to be shortened, the conflicts that occur when the data processed by different IFTs is inconsistent or irregular must be resolved autonomously. Each IFT therefore cooperates with diverse functional agents (FA)s of other IFTs by using priority levels, conditions, and evaluation points in order to maintain the continuity of water delivery.

Mobile computing networks make it possible to offer information access to mobile users. In order to transfer data over mobile networks efficiently, appropriate data transmission control methods for mobile terminals must be established. This paper focuses on spot communication systems to transmit data at high speeds between base stations and mobile terminals. It proposes a flexible and efficient data transmission method that is suitable for spot communication systems. The proposed method transfers subsets of the data to the base stations that are best sited relative to the mobile terminal. This helps to reduce the traffic load of the network significantly. Simulation results confirm the validity of the proposed method. Furthermore, the data receiving time of the mobile terminal, which is an important measure in evaluating the Quality of Service (QoS) for data transmission is analyzed. The result shows that the traffic load in the network is reduced significantly while the QoS is well maintained.

Today's market share of Intelligent Network (IN) service is growing rapidly in wireless networks due to the rapid advances in wireless telecommunication and IN technology. To guarantee network independent IN services, mobility of IN service subscribers has to be taken into account. This paper proposes new designs of Global Service Logic for the IN service enhancement, which increase call completion rates in wired and wireless intelligent networks. In order to apply this logic to wireless service subscribers as well as wired service subscribers, we implement a Queue Manager applied to the call queuing service feature in the Service Control Point (SCP). In the case of wireless service subscribers, the Home Location Register (HLR) handles the service registration flags to notify the Queue Manager of the corresponding service subscribers' mobility. In addition, we present a dynamic queue management mechanism, which dynamically manages the queue size based on the parallel server queuing model as the wireless subscribers roam the service groups due to their mobility characteristics. In order to determine the queue size allocated by the dynamic queue manager, we simulate the relationship between the number of the subscriber's terminals and the drop rate by considering the service increment rate. Moreover, the appropriate waiting time in the queue as required is simulated according to the above relationship. We evaluate call completion rates of the proposed mechanism in the paper by comparing to that of the existing mechanism.

The sign-language can be used as a communication means between avatars having no common language. As a trial to overcome the linguistic barrier, we have previously developed a 2D model-based sign-language chatting system between Korean and Japanese on the the Internet. In that system, there have been some problems to be solved for natural animation and real-time transmission. In this paper, we employ a 3D character model for stereoscopic gestures in the sign-language animation. We also utilize CG animation techniques which use the variable number of frames and a cubic spline interpolation in order to generate realistic gestures. For real-time communication, on the other hand, we make use of an intelligent communication method on a client-server architecture. We implement a preliminary communication system with Visual C++ 5.0 and Open Inventor on Windows platforms. Experimental results show a possibility that the system could be used for avatar communications between different languages.

High accuracy, high reliability, and high performance have to be simultaneously satisfied to achieve high productivity of the latest processing equipment. High flexibility is also required because many options are available and processing equipment is modified frequently. A high-assurance-system (HAS) model for processing equipment has been developed according to the concept of an Autonomous Decentralized System (ADS). Heterogeneous devices, that have same function and diverse qualities, are utilized to assure the different requirements of high accuracy, high reliability, and high performance simultaneously. The Data Property (DP) and Assurance Manager (AM) are proposed in this model. Different accuracy, reliability, and performance indices characterize each device, and the DP describes the differences of the properties of the data transmitted from these heterogeneous devices. The AM assures not only high reliability but also high performance and high accuracy by utilizing the heterogeneity of data described by the DP. The HAS model was applied to a device-level system used in processing equipment, and its effectiveness was verified by simulating a pressure-control system.

In order to investigate the possibility of avatar communication using sign-language, in this paper, we develop a sign-language chatting system on the Internet using CG aniamtion techniques between Korea and Japan. We construct the system in server-client architecture, where images of Korean or Japanese sign-language are analyzed into a series of parameters for sign-language animation by server. We transmit the parameters, which are text data instead of images or their compression, to clients and regenerate the corresponding CG animation using the received data. The chatting system is implemented with Visual C++ 5.0 on Windows platforms. Experimental results show that the sign-language could be used as a communication means between avatars of different languages.

This paper proposes a fast encoding algorithm for iterated function system (IFS) coding of gray-level homogeneous fractal images. In order to realize IFS coding of high order fractal images, it is necessary to solve a set of simultaneous equations with many unknowns. Solving the simultaneous equations using a multi-dimensional, numerical root-finding method is however very time consuming. As preprocessing of numerical computation, the proposed algorithm employs univariate polynomial manipulation, which requires less computation time than multivariate polynomial manipulation. Moreover, the symmetry of the simultaneous equations with respect to the displacement coefficients enables us to derive an equation with a single unknown from the simultaneous equations using univariate polynomial manipulation. An experimental result is presented to illustrate that the encoding time of the proposed algorithm is about 5 seconds on a personal computer with a 400 MHz Pentium II processor.

This article clarifies the requirements of VHE (Virtual Home Environment), issues and resolution for realization of VHE, when the environment will use Intelligent Network (IN) within IMT-2000 networks that is targeted to start in the year 2000. The IN aims the applicability of it's architecture to any kind of network. However, the following subjects need to be considered when IN will be used in the IMT-2000 network; The approach of the service related capabilities' extraction and specification; security management; cooperation between the service switching function within a core network and the IN function(s); cooperation between the mobility management function and the IN function(s); and consideration of mobile and fixed network convergence/integration. This article mainly focuses on these subjects. Some open issues like service/feature interaction and their tentative solutions are identified. Main results are; expandability of current IN to supporting IMT-2000 requirements, identification of key issues in providing VHE in IMT-2000, identification of candidate relationships, and associated issues for VHE. The currently available scenarios for VHE are evaluated from these points, and it is proposed that the specification to be common both for mobile and fixed network.

By integrating three networks, namely, Public Switched Telephone Network (PSTN), Personal Handy-Phone System (PHS) and Intelligent Network (IN) to work together as a Personal Communication Telephone (PCT) service to be offered in the Bangkok metropolis area, the PCT service enables the advent of three new concepts, first, using the same telephone number as that of the fixed line to become a "Personal Number," second, a cell coverage designed to cover larger areas than that of the PHS (by changing hand-out threshold level from 33 dBµV to 30 dBµV and hand-in threshold level from 30 dBµV to 25 dBµV) in order to reduce the muting time during the handover process and provide higher mobility at up to 60 kilometers per hour, and third, a technique of "2 carriers per area" to reduce "call drop." All these techniques will be described in this paper.

The world of mobile communications has undergone dramatic changes in recent years. Since the Personal Digital Cellular (PDC) system of digital mobile communications became commercially available in Japan in 1993, the number of subscribers has increased to the extent that almost 30% of the Japanese population are subscribed. Furthermore, the increasing sophistication of communications, such as the growing popularity of the Internet and expansion of our spheres of existence, have led to demand for new applications, such as use on a global scale. Many new technologies are also being introduced, such as the IMT-2000 system and the IN system which are slated to be introduced at the end of 2000. Based on the above and in view of the increasing scale and sophistication of mobile communications networks, the time has come to reexamine the configuration within networks of SCPs, which perform subscriber data management and service control. This paper focuses on the functions of subscriber data management and service control, classifies data necessary for mobile networks and using the signal number of common networks as a guide considers the optimum arrangement of data and control nodes. The paper also examines reliability measures for SCPs to ensure the reliability of increasingly large-scale networks.

A service control node in the Advanced Intelligent Network (AIN) allocates data for customers among multiple modules and performs distributed processing of multiple transactions. In such a node, load can vary among the modules due to dispersion in the amount of traffic for each customer. It is therefore important to balance out this load variation and raise the utilization of each module in order to achieve an efficient distributed processing system. We first propose a method for balancing the load among modules by dynamically transferring customer data in units of records from high-load modules to low-load modules. Then, based on this method, a method for selecting records to be transferred between modules is also proposed. And we clarify the processor overhead for transferring records. The effect of the reduction of number of modules by load balancing is also evaluated. Based on the these results, it is shown that dynamic transferring of records is an effective scheme for balancing load among modules in a service control node of the AIN.

Cerebellar Model Articulation Controller (CMAC) has been proposed as one of artificial neural networks. This paper describes a design scheme of intelligent control system consists of some CMACs. Each of CMACs is trained for the specified reference signal. A new CMAC is generated for unspecified reference signals, and the CMAC whose reference signal is nearest for the new reference signal, is eliminated. Therefore, since the reference signals are removed from the input signals of the CMAC, the proposed intelligent controller can be designed with fairly small memories.