Amane Nakajima

A multimedia self-service terminal with conferencing functions

We developed a new platform for personal computer based self-service terminals with multimedia conferencing functions in order to provide networked multimedia capability and face-to-face interface. The platform is based on extending our desktop conferencing system called ConverStation/2. It provides ITU-T H.320 motion video audio communication, and shared chalkboard function between a self-service terminal and an operator terminal. It also provides scanned image data transmission for browsing and co-editing of images between a customer and an operator. We clearly separate the platform with application modules, by providing a string command interface between them; we enhanced our conferencing features to meet the requirements of self-service applications. The major new features include: 1) asymmetric operation and user interface of a shared chalkboard; 2) dynamic line connection/disconnection control, and 3) dynamic media (video/audio/data) control on ISDN communication. With these conferencing functions, more complex services such as consultation can be provided through self-service terminals.

ConverStation/2: an extensible and customizable realtime multimedia conferencing system

Multimedia desktop conferencing systems provide several functions, such as connection, a shared chalkboard, a motion video and file transfer. For future extensions, the systems should provide the ability of adding or changing a module without affecting other modules. In addition, a user needs the ability of customizing each module and the ability of selecting modules. The paper describes the extensibility and customizability of the real time multimedia conferencing system called ConverStation/2. The conference kernel of ConverStation/2 is independent from conference tools, and provides an interface to tool modules. A new tool module can be added and work under the conferencing kernel by using the interface. The conferencing kernel provides a common communication interface so that tool modules are unaware of the difference of communication protocols. By developing a communication driver that works under the common communication interface, a new protocol will be easily supported. A chalkboard of ConverStation/2 also has the extensibility. A user can add a new function by writing a program in a script language or by providing the function as a dynamic link library. Moreover, a user can define parameters of each module. For example, the default size and position of the chalkboard window can be easily changed by specifying them in a parameter file.

Research: Telepointing issues in desktop conferencing systems

In WYSIWIS desktop conferencing systems with shared spaces, telepointers are used to point to items in spaces shared with other participants. This paper discusses issues in telepointing from several viewpoints. The first part discusses design issues such as the number of pointers and the extent of the shared area. The next part focuses on the relationship between telepointing and the autonomy of each machine. Our tests and discussions show that the more autonomy each machine has, the more telepointing problems arise, and the less WYISWIS is supported. The paper also compares implementation methods.

Using a finite projective plane with a duality for decentralized consensus protocols

An efficient communication structure based on a finite projective plane with a duality is presented. The communication structure halves the number messages required in two rounds as compared to a communication structure based on a finite projective plane. It is shown that a finite projective plane with a duality can be constructed from a difference set, and that the communication structure presented has two kinds of symmetry.<<ETX>>

Interactive Web forms based on assistance rules

The paper describes techniques for developing assistance functions for Web form input operations. The techniques allow developers to define input-assistance functions as a set of assistance rules. The assistance rules are converted into a program that implements the assistance functions defined in the rules by a software module called a rule compiler. The program is embedded into a Web form to monitor a users input operations on a Web browser and to provide assistance functions such as help-message displays, validation checks of input values, and automatic inputs in accord with the users input operations. By defining assistance functions as a set of assistance rules, developers can implement interactive Web forms without any complicated script programming. Therefore, it is possible to rapidly prototype assistance functions and reduce the development cost of the interactive Web forms.

A telepointing tool for distributed meeting systems

In distributed real-time meeting systems that use personal computers, telepointing tools are used for showing a position in a shared space to remote machines. Telepointing tools are discussed from the network management perspective. A telepointing tool called the loosely coupled shared pointer is proposed. In a shared pointer approach, problems are (i) conflict between local operation and telepointing from a remote machine, and (ii) switching between these two modes. These two problems are solved by giving higher priority to local operation to telepointing. The solution is based on a band model and realizes the relaxed shared-space concept WYSIWIS (what you see is what I see).<<ETX>>

Multimedia communication and collaboration for remote loan contracting

Multimedia conferencing systems have been applied to several areas. In their applications, multimedia conferencing functions are used only for a video phone and data sharing in explicit collaboration. This paper describes a new type of a multimedia system, which tightly integrates an information kiosk and a multimedia conferencing system. It provides local interactive data input, paper form processing, implicit and explicit remote collaboration, event monitoring by sensors, workflow control, and host communication. The architecture, configuration, and functions of the system are explained through an example of a remote contract system, which automates a loan contract procedure.

A symmetric and resilient configuration scheme for multiple name servers

A configuration scheme is presented for multiple name servers and name service protocol. The scheme creates a configuration with any number of name servers, and realizes a symmetric and fault-tolerant name service. Name data are distributed to name servers equally and the cost of the name service is independent of the server location. The scheme is efficient because it realizes a lower bound of communication complexity. An investigation is also made of the relations among the number of nodes, the number of name servers, fault-tolerance, the number of data in a server, and the total number of data in all servers to obtain equations for these relationships. Changes in the resiliency and the number of data are shown as functions of the number of nodes and the number of servers in three cases.<<ETX>>

Decentralized voting protocols

Decentralized voting protocols, in which all nodes execute the same protocol and reach the same result in a decentralized and autonomous way, are proposed. When a decentralized voting protocol is implemented by using one-round message exchange, it requires n(n-1) messages, where n is the number of nodes. The number of messages can be reduced by using multiple-round message exchange. The computation in each node is described in terms of a finite-state automaton, and communication structures for it are given. It is shown that kn(n/sup 1/k/ - 1) messages are sufficient when messages are exchanged in k rounds.<<ETX>>

Construction of optimal communication structures for weighted distributed match-making

Abstract Several distributed issues such as name service and replicated data management need a communication structure with an intersection property. This paper discusses the efficiency of communication structures for cases in which the issues are weighted. We first provide a lower bound of communication complexity, using a distribution vector, and then give a method for constructing an efficient and symmetric communication structure. Our method achieves the lower bound 2 √abn in the symmetric case, where √an/b and √bn/a are integers, a and b are weights, and n is the number of nodes.