Catálogo de publicaciones - libros

Future computing systems interact with a large number of users moving around buildings and streets. In this paper, we propose an example of such systems and how to evaluate ubicomp systems equipped with a large-scale physical environment that includes a large number of people inside. In our emergency guidance system, off-site guiding staff monitors a crowded large-scale public space to understand its situation, and instruct on-site guiding staff how to guide crowds effectively. Our system tracks and synthesizes the public space to enable the off-site staff to grasp it, and support communication between the on-site and the off-site staffs. Because it is not affordable to use the physical public space and a lot of human subjects to evaluate the system, we used our social interaction platform to simulate our guidance system. We could successfully construct simulations, in which the crowds are replaced with social agents in the virtual public space.

Computing environments are now evolving into ubiquitous environments upon this new infrastructure. The mobile device in a ubiquitous environment provides services that do not restrict the user from accessing the data wherever the person may be. Various mobile services have been modeled upon this environment, and due to the increasingly refined tastes and desires of the customers, intelligent agents with high performance levels along with user view interface are in demand.

Diverse tools and information resources undergo interactions and mutual communication in a ubiquitous environment. To improve such interoperability, this article suggests a multi-agent system through web ontology links. In particular, the work presents an effective model for an Emergency Search and Rescue System based on the mobile service and multi-agents which aid in improving the existing system, and also discusses the base technology and limitations that may occur in the process of establishing this system.

Demand Bus System, a new public transportation system, is expected to be a convenient service for special transportation demands to solve more and more serious traffic problems concerning metropolises as Shanghai. Under this background, this paper focuses on evaluating the usability of the demand bus system rather than on the algorithms as the previous researches did. As a useful evaluation tool for achieving this objective, Multi-Agent Based Simulation is used to obtain a better understanding of such system in particular when lacking real applications for a large scale. By using the participatory solution, we propose a multiagent simulation framework to include domain experts, stakeholders, system users, as well as computer scientists to build and modify the computational model directly. The implementation of the prototype system shows that it is easy to build such system from scratch to mega by this mechanism. Initial analysis shows the demand bus system is a convenient service supplement to the fast transportation for community in Shanghai.

Evaluation of scalability and usability of dial-a-ride systems is reported as a case study to assess utilities of ubiquitous mass user support. One of applications of ubiquitous and multi-agent systems is transportation system in urban area. While multi-agent and ubiquitous systems are considered to support next-generation social systems, it is not clear how it provides advantage in usability and benefit. We will show a result of comparison between dial-a-ride bus systems, one of possible multi-agent application of transportation systems, and traditional fixed-route bus systems.

We conduct experiments of various situation and show how the advantage of dial-a-ride is robust to the variation of social conditions. For example, when many demands occur from/to a certain point like railway stations or shopping centers, improvement of usability of dial-a-ride systems is better than one of fixed-route systems so that a break-even point between the two systems is reduced. This means that dial-a-ride systems are useful even in ’rush-hour’. Through these experiments, we will figure out the conditions where multi-agent like systems have advantage against traditional systems.

A distributed visitors coordination system is proposed as an application of a massively multi-agent system. In the system, some agents register their next destination using an information device such as a cellular phone, and this information is used to reduce the effect of the time delay between decision-making and effect-emergence. This delay causes queue lengths to oscillate. However, it is troublesome for agents to continuously register their next destination. To compensate them, exclusive queues are made available to agents registering their next destination. Computer simulation of the theme park problem, showed that when all agents avoid the congestion by registering their next destination, the total waiting time is minimized and queue length oscillation is reduced.