This paper provides an overview of research and development activities in the field of autonomous agents and multi-agent systems. It aims to identify key concepts and applications, and to indicate how they relate to one-another. Some historical context to the field of agent-based computing

cation is the `pager system'. In order to locate a person a signal is sent out by a central facility that addresses a particular receiver unit (beeper) and produces an audible signal. In addition, it may display a number to which the called-party should phone back (some systems allow a vocal message to be conveyed about the call-back number). It is then up to the recipient to use the conventional telephone system to call-back confirming the signal and determine the required action. Although useful in practice there are still circumstances where it is not ideal. For instance, if the called party does not reply the controller has no idea if they: 1) are in an area where the signal does not penetrate 2) have been completely out of the area for some time 3) have been too busy to reply or 4) have misheard or misread the call-back number. Moreover, in the case where there are a number of people who could respond to a crisis situation, it is not known which one is the nearest to the crisis an

Our goal is to develop a visual monitoring system that passively observes moving objects in a site and learns patterns of activity from those observations. For extended sites, the system will require multiple cameras. Thus, key elements of the system are motion tracking, camera coordination

Active networks are a novel approach to network architecture in which the switches of the network perform customized computations on the messages flowing through them. This approach is motivated by both lead user applications, which perform user-driven computation at nodes within the network today

and the application. We illustrate the concept of context widgets with the beginnings of a widget library we have developed for sensing presence, identity and activity of people and things. We assess the success of our approach with two example context-enabled applications we have built and an existing application

Active networks allow their users to inject customized programs into the nodes of the network. An extreme case, in which we are most interested, replaces packets with "capsules" -- program fragments that are executed at each network router/switch they traverse. Active architectures permit

The increasing amount of genomic and molecular information is the basis for understanding higherorder biological systems, such as the cell and the 15 organism, and their interactions with the environment, as well as for medical, industrial and other practical applications. The KEGG resource

We exploit differences in early colonial experience to estimate the effect of institutions on economic performance. Our argument is that Europeans adopted very different colonization policies in different colonies, with different associated institutions. The choice of colonization strategy was, at least in part, determined by the feasibility of whether Europeans could settle in the colony. In places where Europeans faced high mortality rates, they could not settle and they were more likely to set up worse (extractive) institutions. These early institutions persisted to the present. We document these hypotheses in the data. Exploiting differences in mortality rates faced by soldiers, bishops and sailors in the colonies during the 18th and 19th centuries as an instrument for current institutions, we estimate large effects of institutions on income per capita. Our estimates imply that a change from the worst (Zaire) to the best (US or New Zealand) institutions in our sample would be associated with a five fold increase in income per capita.

A system of rules for transforming programs is described, with the programs in the form of recursion equations An initially very simple, lucid. and hopefully correct program IS transformed into a more efficient one by altering the recursion structure Illustrative examples of program transformations are given, and a tentative implementation !s described Alternative structures for programs are shown, and a possible initial phase for an automatic or semiautomatic program manipulation system is lndmated KEY WORDS AND PHRASES program transformation, program mampulatlon, optimization, recursion CR CATEGORIES' 3 69, 4 12, 4 22, 5 24, 5 25 1.

In this work, algorithms are developed and evaluated to detect physical activities from data acquired using five small biaxial accelerometers worn simultaneously on different parts of the body. Acceleration data was collected from 20 subjects without researcher supervision or observation