Transportable Information Agents

Transportable agents are autonomous programs. They can move through a heterogeneous network of computers under their own control, migrating from host to host. They can sense the state of the network, monitor software conditions, and interact with other agents or resources. The network-sensing tools allow our agents to adapt to the network configuration and to navigate under the control of reactive plans. In this paper we describe the design and implementation of the navigation system that gives our agents autonomy. We also discuss the intelligent and adaptive behavior of autonomous agents in distributed information-gathering tasks

Fast compression of transportable Tcl scripts

An information agent is charged with the task of searching a collection of electronic resources for information that is relevant to the user\u27s current needs. These resources are often distributed across a network and can contain tremendous quantities of data. One of the paradigms that has been suggested for allowing efficient access to such resources is transportable agents -- the agent is sent to the machine that maintains the information resource; the agent executes on this remote machine and then returns its results to the local machine. We have implemented a transportable agent system that uses the Tool Command Language (Tcl) as the agent language. Each Tcl script can suspend its execution at an arbitrary point, transport itself to another machine and resume execution on the new machine. The execution state of the script -- which includes the commands that have not been executed -- must be transmitted to the new machine. Although the execution state tends to be small, there will be a large number of agents moving across the network in a large-scale system. Thus it is desirable to compress the execution state as much as possible. Furthermore any compression scheme must be fast so that it does not become a bottleneck between the transportable agent system and the network routines. In this paper we explore several fast compression methods

TIAS: A Transportable Intelligent Agent System

In recent years, there has been an explosive growth in the amount of information available to our society. In particular, the amount of information available on-line through vast networks like the global Internet has been growing at a staggering rate. This growth rate has by far exceeded the rate of growth in network speeds, as has the number of individuals and organizations seeking access to this information. There is thus a motivation to find abstract methods of manipulating this on-line data in ways that both serve the needs of end users efficiently and use network resources intelligently. In lieu of a traditional client-server model of information processing, which is both inflexible and potentially very inefficient, a Transportable Intelligent Agent system has the potential to achieve a more efficient and flexible network system. An intelligent agent is a program that models the information space for a user, and allows the user to specify how the information is to be processed. A transportable agent can suspend its execution, transport itself to a new location on a network, and resume execution at the new location. This is a particularly attractive model for both wireless and dialup networks where a user might not be able to maintain a permanent network connection, as well as for situations where the amount of information to be processed is large relative to the network bandwidth. Preliminary work in the field has shown that such agent systems are possible and deserve further study. This thesis describes a prototype transportable intelligent agent system that extends work already done in the field. Agents are written in a modified version of the Tcl programming language and transported using TCP/IP connections. Several simple examples demonstrate the properties of the system

SAFE: Secure-Roaming Agents for E-commerce

The development of the Internet has made a powerful impact on the concept of commerce. E-commerce, a new way to conduct business, is gaining more and more popularity. Despite its rapid growth, there are limitations that hinder the expansion of e-commerce. The primary concern for most people when talking about on-line shopping is security. Due to the open nature of the Internet, personal financial details necessary for on-line shopping can be stolen if sufficient security mechanism is not put in place. How to provide the necessary assurance of security to consumers remains a question mark despite various past efforts. Another concern is the lack of intelligence. The Internet is an ocean of information depository. It is rich in content but lacks the necessary intelligent tools to help one locate the correct piece of information. Intelligent agent, a piece of software that can act on behalf of its owner intelligently, is designed to fill this gap. However, no matter how intelligent an agent is, if it remains on its owner’s machine and does not have any roaming capability, its functionality is limited. With the roaming capability, more security concerns arise. In response to these concerns, SAFE, Secure roaming Agent For E-commerce, is designed to provide secure roaming capability to intelligent agents

Ph.D. Thesis Proprosal: Transportable Agents

One of the paradigms that has been suggested for allowing efficient access to remote resources is transportable agents. A transportable agent is a named program that can migrate from machine to machine in a heterogeneous network. The program chooses when and where to migrate. It can suspend its execution at an arbitrary point, transport to another machine and resume execution on the new machine. Transportable agents have several advantages over the traditional client/server model. Transportable agents consume less network bandwidth and do not require a connection between communicating machines -- this is attractive in all networks and particularly attractive in wireless networks. Transportable agents are a convenient paradigm for distributed computing since they hide the communication channels but not the location of the computation. Transportable agents allow clients and servers to program each other. However transportable agents pose numerous challenges such as security, privacy and efficiency. Existing transportable agent systems do not meet all of these challenges. In addition there has been no formal characterization of the performance of transportable agents. This thesis addresses these weakness. The thesis has two parts -- (1) formally characterize the performance of transportable agents through mathematical analysis and network simulation and (2) implement a complete transportable agent system

Gulliver project: performers and visitors

This paper discusses two projects in our research environment. The Gulliver project, an ambitious project conceived by some artists connected to our research efforts, and the Aveiro-project, as well ambitious, but with goals that can be achieved beause of technological developments, rather than be dependent on artistic and 'political' (read: financial) sources. Both projects are on virtual and augmented reality. The main goal is to design inhabited environments, where 'inhabited' refers to autonomous agents and agents that represent humans, realtime or off-line, visiting the virtual environment and interacting with other agents. The Gulliver environment has been designed by two artists: Matjaz Stuk and Alena Hudcovicova. The Aveiro project is a research effort of a group of researchers trying to design models of intelligence and interaction underlying the behavior of (groups of) agents inhabiting virtual worlds. In this paper we survey the current state of both projects and we discuss current and future attempts to have music performances by virtual and real performers in these environments

Using C to build a satellite scheduling expert system: Examples from the Explorer Platform planning system

A C-based artificial intelligence (AI) development effort which is based on a software tools approach is discussed with emphasis on reusability and maintainability of code. The discussion starts with simple examples of how list processing can easily be implemented in C and then proceeds to the implementations of frames and objects which use dynamic memory allocation. The implementation of procedures which use depth first search, constraint propagation, context switching, and blackboard-like simulation environment are described. Techniques for managing the complexity of C-based AI software are noted, especially the object-oriented techniques of data encapsulation and incremental development. Finally, all these concepts are put together by describing the components of planning software called the Planning And Resource Reasoning (PARR) Shell. This shell was successfully utilized for scheduling services of the Tracking and Data Relay Satellite System for the Earth Radiation Budget Satellite since May of 1987 and will be used for operations scheduling of the Explorer Platform in Nov. of 1991

Urban Swarms: A new approach for autonomous waste management

Modern cities are growing ecosystems that face new challenges due to the increasing population demands. One of the many problems they face nowadays is waste management, which has become a pressing issue requiring new solutions. Swarm robotics systems have been attracting an increasing amount of attention in the past years and they are expected to become one of the main driving factors for innovation in the field of robotics. The research presented in this paper explores the feasibility of a swarm robotics system in an urban environment. By using bio-inspired foraging methods such as multi-place foraging and stigmergy-based navigation, a swarm of robots is able to improve the efficiency and autonomy of the urban waste management system in a realistic scenario. To achieve this, a diverse set of simulation experiments was conducted using real-world GIS data and implementing different garbage collection scenarios driven by robot swarms. Results presented in this research show that the proposed system outperforms current approaches. Moreover, results not only show the efficiency of our solution, but also give insights about how to design and customize these systems.Comment: Manuscript accepted for publication in IEEE ICRA 201

Using C to build a satellite scheduling expert system: Examples from the Explorer platform planning system

Recently, many expert systems were developed in a LISP environment and then ported to the real world C environment before the final system is delivered. This situation may require that the entire system be completely rewritten in C and may actually result in a system which is put together as quickly as possible with little regard for maintainability and further evolution. With the introduction of high performance UNIX and X-windows based workstations, a great deal of the advantages of developing a first system in the LISP environment have become questionable. A C-based AI development effort is described which is based on a software tools approach with emphasis on reusability and maintainability of code. The discussion starts with simple examples of how list processing can easily be implemented in C and then proceeds to the implementations of frames and objects which use dynamic memory allocation. The implementation of procedures which use depth first search, constraint propagation, context switching and a blackboard-like simulation environment are described. Techniques for managing the complexity of C-based AI software are noted, especially the object-oriented techniques of data encapsulation and incremental development. Finally, all these concepts are put together by describing the components of planning software called the Planning And Resource Reasoning (PARR) shell. This shell was successfully utilized for scheduling services of the Tracking and Data Relay Satellite System for the Earth Radiation Budget Satellite since May 1987 and will be used for operations scheduling of the Explorer Platform in November 1991