Muscle based face image synthesis is one of the most realistic approaches to the realization of a life-like agent in computers. A facial muscle model is composed of facial tissue elements and simulated muscles. In this model, forces are calculated effecting a facial tissue element by contraction of each muscle string, so the combination of each muscle contracting force decides a specific facial expression. This muscle parameter is determined on a trial and error basis by comparing the sample photograph and a generated image using our Muscle-Editor to generate a specific face image. In this paper, we propose the strategy of automatic estimation of facial muscle parameters from 2D markers'movements located on a face using a neural network. This corresponds to the non-realtime 3D facial motion capturing from 2D camera image under the physics based condition.

Fuzzy rule-based edge detection using multiscale edge images is proposed. In this method, the edge image is obtained by fuzzy approximate reasoning from multiscale edge images which are obtained by derivative operators with various window sizes. The effect of utilizing multiscale edge images for edge detection is already known, but how to design the rules for deciding edges from multiscale edge images is not clarified yet. In this paper, the rules are represented in a fuzzy style, since edges are usually defined ambiguously, and the fuzzy rules are designed optimally by a training method. Here, the fuzzy approximate reasoning is expressed as a nonlinear function of the multiscale edge image data, and the nonlinear function is optimized so that the mean square error of the edge detection be the minimum. Computer simulations verify its high performance for actual images.

The ATM multicast Tree (AMT) is the Mbone of video/audio conferencing and other multicasting applications in ATM (Asynchronous Transfer Mode) networks. However, real problems such as temporarily moving switches, changing optic fiber connections and/or tangible/intangible failures of ATM networks will cause many service disruptions. Thus we must carefully consider the system's SQOS (Survivable QOS) when we construct the system. A point-to-point self-healing scheme utilizing a conventional pre-planned backup mechanism is proposed to protect the AMT from failure. This scheme uses point-to-point pre-planned backup Root-to-Leaf Routes (RLR) as the root-to-leaf structure of an AMT. Though AMT protection via preplanned backup RLR requires no search time, duplicate paths may cause redundant bandwidth consumption. This paper also proposes a closest-node method, which can locate the minimum-length route structure during the initial design and also rebuild the AMT in the event of a network failure. To enhance the survivability of the system, we introduce two near optimal re-routing algorithms, a most-decent search algorithm, and also a predictive-decent search algorithm in order to find the minimum lost flow requirement. These near optimal schemes use search technique to guide the local optimal lost flow to the most-decent lost flow direction. The predictive way is an especially economical technique to reduce the calculation complexity of lost flow function. For the evaluation of the feasibility and performance of the new schemes, we simulate AMT restoration and the simulation results show the closest-node scheme provides superior AMT restoration compared to a system with a preplanned point-to-point backup scheme. In addition, the predictive-decent search algorithm is faster than the most-decent search one.

An increase in high quality of service (QoS) applications such as video conferencing and distribution, and the evolution of the Internet have popularized ATM-LAN use based on the private network node interface (PNNI). Also in public networks, which serve as backbone networks for LANs, ATM technology is being introduced for high-speed and broadband communication. These situations lead to a great demand for economically and seamlessly interconnecting remote ATM-LANs via ATM public networks, which are based on broadband ISDN user part (BISUP). This paper discusses a method of peer group configuration method for such internetworking architecture that can avoid an overload of the PNNI routing processing in each peer group. The paper also proposes a method for seamless interconnection of remote ATM-LANs. In this method, complete PNNI signaling and routing is executed between a local switch (LS) in a public network and each ATM-LAN. It also can reduce the PNNI routing processing load on each public network by emulating PNNI routing and signaling between LSs.

This paper presents a robust and nonblocking group membership protocol for large-scale distributed systems. This protocol uses the causal relation between membership-updating messages (i. e. , those specifying the adding and deleting of members) and allows the messages to be executed in a nonblocking manner. It differs from conventional group membership protocols in the following points: (1) neither global locking nor global synchronization is required; (2) membership-updating messages can be issued without being synchronized with each other, and they can be executed immediately after their arrival. The proposed protocol therefore is highly scalable, and is more tolerant to node and network failures and to network partitions than are the conventional protocols. This paper proves that the proposed protocol works properly as long as messages can eventually be received by their destinations. This paper also discusses some design issues, such as multicast communication of the regular messages, fault tolerance and application to reliable communication protocols (e. g. , TCP/IP).

Two different examples have been respectively given by Aggarwal and Viswanathan to establish the necessity of (n + 2)/5 edge guards for spiral polygons. However, the former example is incorrect. To show why it is wrong, we give an alternate proof of sufficiency of (n + 2)/5 edge guards for spiral polygons. Our proof is simpler than the sufficiency proof given by Viswanathan.

A multi-QoS scalable-distributed-arbitration (MSDA) ATM switch is described that supports both high- and low-priority traffic under the head-of-line-priority discipline. It uses crosspoint and transit buffers, each consisting of a high- and low-priority buffer. The buffers arbitrate in a distributed manner the selection of which cellsto transmit. The MSDA switch supports multiple QoS classes while still providing the scalability of a previously described single-QoS scalable-distributed-arbitration (SSDA) switch. A problem occurs when the delay-time-based cell-selection mechanism used in the SSDA switch is applied to the low-priority traffic: it cannot achieve fairness in terms of throughput. This problem is overcome by introducing a distributed-ring-arbiter-based cell-selection mechanism at each crosspoint for the low-priority traffic. The low-priority transit buffer at each crosspoint has virtual queues, one for each upper input port. Cells for the low-priority traffic are selected by distributed-ring arbitration among the low-priority crosspoint buffer and these virtual queues. For the high-priority traffic, the same delay-time-based cell-selection mechanism is used as in the SSDA switch. Simulations show that the MSDA switch ensures fairness interms of delay time for the high-priority traffic and ensures fairness in terms of throughput for the low-priority traffic.

This paper describes the roles and benefits of an ATM transport network composed of ATM transport systems, such as ATM cross-connect systems and/or ATM add-drop multiplexers. The ATM transport network is an economical way of providing the ATM public network and a virtual path service for enterprise users. This paper exemplifies the effectiveness of a VP grooming function in the ATM transport system by comparing it to the network costs with direct fiber connection, an alternative to VP grooming. Main and junction module architecture for the ATM cross-connect system is proposed to realize an economical network that supports small to large traffic. For implementing a large-scale cross-connect switch, a cell congestion control method that employs re-arrangement control and a concentration network is proposed. Implementation of multiple service classes and VP protection switching in the ATM cross-connect system are mentioned. We also describe an SDH signal transmission method based on ATM cells, that offers a cost effective and reliable transport network.

Increasing traffic on the Internet and intranets has raised demands for high-speed, large-scale and cost-effective computer networking techniques. ATM connectionless service provides high-speed, highly scalable, and flexible services because connectionless networks are constructed logically over high-speed ATM networks. This paper described the self-sizing operation for high-speed, large-scale connectionless service over an ATM network. Self-sizing is an autonomous adjustment mechanism for virtual path (VP) bandwidths based on traffic conditions observed in real time. We confirmed its feasibility on a test-bed network. The self-sizing operation caused the VP bandwidth to approach the necessary value while satisfying the target cell loss ratio (CLR). We developed an operations system (OpS) that achieves self-sizing in an ATM connectionless network. The OpS suggests necessary bandwidth for VP that may exceed the target CLR. The algorithm utilized in the OpS does not require observation or logical processes, which would be a heavy load on each node. Self-sizing operation will provide easy and cost-effective management because it adjusts VP bandwidth flexibly depending on the current traffic demand.

The use of Internet for various business applications and resource sharing has grown tremendously over the last few years. Internet security has become an important issue for both academic and industrial sectors. Much related network security research has been conducted such as user authentication, data confidentiality, and data integrity. In some applications, a critical document can be divided into pieces and allocated in different locations over the Internet for security access concern. To access such an important document, one must reconstruct the divided pieces from different locations under the given Internet environment. In this paper, a probability model for reconstructing secret sharing and algorithms to perform share assignment are presented. Also, an evaluation algorithm to measure the probability of secret sharing reconstruction is proposed. Illustrative examples and simulation results are provided to demonstrate the applicability of our method.

Broadband subscriber loop system and ATM switching system are the key equipment for construction of Broadband networks. In this paper, we describe the architecture of access network and the implementation of ATM switching system with multi-service interface for construction of broadband access network. We also represent the design of MAIN-AN (Multi-service Access Integrated Network--Access Node) system as integrated access network platform which enables to accommodate ATM/SDH-based and ATM/PON-based FTTx (Fiber-To-The-x) access architecture simultaneously. The system has a Cross-point ATM Switch Fabric with 10 Gbits/sec throughput and it has been implemented using 0.5 µm CMOS technology. For performance evaluation of it, we simulate it under burst traffic conditions. In addition, we show the implementation of prototype of ASIC (Application Specific Integrated Circuit), MAIN system and its core PBA (Printed circuit Board Assembly) and so on.

In this paper, we provide a bound of the continuous ARE solution in terms of a matrix associated with Lyapunov solutions. Based on the new matrix-type bound, we also consider various scalar bounds and compare them with existing bounds. The major advantage of our results over existing results is that the new bounds can be always obtained if the stabilizing solution exists, whereas all existing bounds might not be computed because they require other conditions additional to the existence condition.

A new phasor model of neural networks is proposed in which the state of each neuron possibly takes the value at the origin as well as on the unit circle. A stability property of equilibria is studied in association with the energy landscape. It is shown that a simple condition guarantees an equilibrium to be asymptotically stable.

The Communications Research Laboratory (CRL), the National Astronomical Observatory (NAO), the Institute of Space and Astronoutical Science (ISAS), and the Telecommunication Network Laboratory Group of Nippon Telegraph and Telephone Corporation (NTT) have developed a very-long-baseline-connected-interferometry array, maximum baseline-length was 208 km, using a high-speed asynchronous transfer mode (ATM) network with an AAL1 that corresponds to the constant bit-rate protocol. The very long baseline interferometry (VLBI) observed data is transmitted through a 2.488-Gbps [STM-16/OC-48] ATM network instead of being recorded onto magnetic tape. By combining antennas via a high-speed ATM network, a highly-sensitive virtual (radio) telescope system was realized. The system was composed of two real-time VLBI networks: the Key-Stone-Project (KSP) network of CRL (which is used for measuring crustal deformation in the Tokyo metropolitan area), and the OLIVE (optically linked VLBI experiment) network of NAO and ISAS which is used for astronomy (space-VLBI). These networks operated in cooperation with NTT. In order to realize a virtual telescope, the acquired VLBI data were corrected via the ATM networks and were synthesized using the VLBI technique. The cross-correlation processing and data observation were done simultaneously in this system and radio flares on the weak radio source (HR1099) were detected.

The rapid growth of the Internet impacts ATM networks to be furnished IP handling capability. This paper discusses networking issues for IP and ATM integration. First, it considers function allocation at the boundary of an ATM backbone network and the Internet. As the result, the paper explains the necessity of built-in IP handling capability into an ATM switching system, and summarizes functional requirements for the system architecture. According to the discussion above, the authors propose the system architecture of the IP/ATM integration in the ATM switching system. The implementation of the proposed architecture is evaluated, and the wire-speed IP handling capability in the ATM switch is confirmed.

It is important to establish the technology to accommodate best effort TCP/IP traffic over wide area ATM networks. The UBR (Unspecified Bit Rate) service category is the most typical service category for the best effort traffic, especially in the LAN environment. On the other hand, the VBR (Variable Bit Rate) service category with SCD (Selective Cell Discard) option is considered as the service category which is appropriate for wide area networks due to its fairness and minimum guarantee of the cell transmission using not only PCR (Peak Cell Rate) but SCR (Sustainable Cell Rate) and MBS (Maximum Burst Size). However, there is no actual evaluation for such service. We have, therefore, performed the experimental studies on TCP/IP over VBR with SCD along with UBR and VBR without SCD by VC (Virtual Channel) level policing when each TCP connection is mapped to a different VC. Through these experiments, we measured the link utilization of the effective data and the fairness between each obtained TCP throughput during the congestion of the ATM switch. From the results of the link utilization, the value is over 95% under the various conditions. Therefore, even in the case of the cell losses due to SCD or buffer overflow in ATM switch congestion, average throughput is almost the same as the value which equals the trunk line speed divided by the number of the accommodated TCP connections. From the results of the fairness, VBR with SCD per VC is better than UBR and also obtains better TCP throughput than VBR without SCD. Furthermore, to confirm those characteristics more generally, we adopt the accommodated TCP connections not only with the same TCP send/receive socket buffer size but with different sizes. Finally, we discuss the effectiveness between VBR with SCD and the other service categories, such as UBR and ABR (Available Bit Rate) and GFR (Guaranteed Frame Rate), and conclude that VBR with SCD is one of the most suitable ATM service categories for accommodating best effort traffic.

Future high-speed switches and routers will be expected to support a large number of ports at high line rates carrying traffic with diverse statistical properties. Accordingly, scheduling mechanisms will be required to handle Tbit/sec aggregated capacity while providing quality of service (QoS) guarantees. In this paper a novel high-capacity switching scheme for ATM/WDM networks is presented. The proposed architecture is contention-free, scalable, easy to implement and requires no internal "speedup. " Non-uniform destination distribution and bursty cell arrivals are examined when studying the switching performance. Simulation results show that at an aggregated throughput of 1 Tbit/sec, low latency is achieved, yielding a powerful solution for high-performance packet-switch networks.

A nonlinear inverse filter is proposed for restoring signals degraded by a linear system and additive Gaussian noise. The proposed filter consists of combination of a linear high pass filter and an ε-filter, which is modified from the cascaded linear filter. The nonlinear property of the ε-filter is utilized to suppress pre-enhanced additive random noise and to restore sharp edges. It is demonstrated that the filter can be reduced to a multi-layered neural network model, and the optimal design is described by using the back propagation algorithm. The nonlinear function is approximated by a piecewise linear function, which results in simple and robust training algorithm. An application to image restoration is also presented, illustrating the effectiveness over the linear filter, especially when the amplitude of additive noise is small.

We introduce a new wavelet image coding framework using context-based zerotree quantization, where an unique and efficient method for optimization of zerotree quantization is proposed. Because of the localization properties of wavelets, when a wavelet coefficient is to be quantized, the best quantizer is expected to be designed to match the statistics of the wavelet coefficients in its neighborhood, that is, the quantizer should be adaptive both in space and frequency domain. Previous image coders tended to design quantizers in a band or a class level, which limited their performances as it is difficult for the localization properties of wavelets to be exploited. Contrasting with previous coders, we propose to trace the localization properties with the combination of the tree-structured wavelet representations and adaptive models which are spatial-varying according to the local statistics. In the paper, we describe the proposed coding algorithm, where the spatial-varying models are estimated from the quantized causal neighborhoods and the zerotree pruning is based on the Lagrangian cost that can be evaluated from the statistics nearby the tree. In this way, optimization of zerotree quantization is no longer a joint optimization problem as in SFQ. Simulation results demonstrate that the coding performance is competitive, and sometimes is superior to the best results of zerotree-based coding reported in SFQ.

This paper summarizes power reduction methods applicable for VLSI bus systems in terms of reduction of signal swing, effective capacitance reduction and reduction of signal transition, which have been studied in authors' research group. In each method the basic concept is reviewed quickly along with some examples of its application. A future perspective is also described in conclusion.