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This article introduces an information collecting method for shop and service information from the Internet. Because the shop information is heterogeneous and distributed, it is difficult for users to gather and handle it.Although it is heterogeneous, it can be semistructured insofar as it usually has a name, address, etc. We introduce the telephone directory information as an ontology server that defines relationships between the user's abstract expression of shops and the concrete expression, such as shop names. We designed a software agent architecture. Agents work together to support creating queries for users, to search and locate the information providers, and to organize the search results on behalf of the user. We applied this architecture to the Intelligent Pages and developed it on portable computers, a UNIX workstation, and Internet servers, including the telephone directory server we also developed. Intelligent Pages lists shops from the Yellow Pages with additional information from other sources. The advantage of this method is that it produces precise and well-organized information.For many years, several m agazines have provided inform ation on shops, markets, services, and busine sses around town. These magazines are useful for visitors to a city and even for local residents. Today, this kind of inform ation is available electronically on several network services and on computer media such as CDROMs. We can directly search for hotel inform ation by accessing a hotel' s Web page or search for a review of a restaurant by one of its patrons. As portable com puters We would like to thank the NTT Japan Telephone Directory project for providing the Yellow Pages database and the NTT TITAN project for providing the Internet Robot. We also thank M r. Toshifumi Enomoto of NTT, M r. Shigeru Ogura, Ms. Sachie M aeda, and M r. Yoshikatsu Iwasaki of NTT Software Corporation for their help in implementing this system.

This paper proposes a distributed channel allocation mechanism for ATM networks. In this mechanism, agents are assigned to traffic sources and allocate channels to incoming calls in a distributed manner. Channel allocation is based only on the sampled channel utilization values locally available to agents. There is no direct exchange of information assumed between agents.Due to the distributed nature of the proposed mechanism, this mechanism causes oscillations during channel utilization when there is a delay associated with the sampling of channel utilizations and the processing of sampled values at agents. This oscillation increases the cell loss in a channel. According we propose methods for estimating channel utilization in order to reduce the oscillations and show their effectiveness through simulations.The proposed mechanism requires little computational processing, is simple t o implement, and achieves efficient channel allocation even if highly bursty calls. It is therefore suitable for ATM networks.

SUMMARYExpectations for communication services in mobile environment grow with the spread of portable computers and cellular telephones. However, knowledge of users behavior in a mobile environment is necessary to judge the constraints imposed on users, and functions that agents must offer to users. The authors provided a variety of mobile services (not only conventional e-mail but also information guides related to conference schedule, area, and so on) to more than 100 participants of an international conference through portable terminals and mobile telephones; in so doing, massive usage data were acquired. These usage data were compared to those of commercial services using the same terminals, and mobile computing usage proved to be clearly reflective of users everyday activity patterns. The following facts that were revealed should be taken into account when designing information services under mobile environment. (1) A remarkable tradeoff exists between frequency of access to server, and size of data downloaded to terminals. (2) Impatient users are likely to cancel data acquisition, or to terminate communications. Proceeding from the obtained results, the following functions were shown to be necessary for agents in mobile environment: (1) distribution of information between server and terminals; (2) technological and psychological measures to encourage users to employ server connections. © 2001 Scripta Technica, Syst Comp Jpn, 32(7): 6270, 2001

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