380 likes | 624 Views
ICT619 Intelligent Systems. Topic 8: Intelligent Agents. Intelligent Agents. What is an intelligent agent? Why intelligent agents? What intelligent agents can do for us Characteristics of a good agent Types of agents Building intelligent agents Intelligent agents in E-Commerce
E N D
ICT619 Intelligent Systems Topic 8: Intelligent Agents
Intelligent Agents • What is an intelligent agent? • Why intelligent agents? • What intelligent agents can do for us • Characteristics of a good agent • Types of agents • Building intelligent agents • Intelligent agents in E-Commerce • Intelligent agent design - state-of-the-art and future ICT619
What is an intelligent agent? Underlying concept - • An autonomous computational entity designed to perform a specific task, without direct initiation and continuous monitoring on part of the user • Emerged in the last 15 years or so • Distinct from conventional programs, in that it is automatic Additional properties: • Some level of intelligence (based on any AI technology from fixed rules to learning engines) for decisions and/or adaptation to environmental change • Acts reactively, but also proactively • Social ability - communicates with user, system, other agents as required • Might cooperate with other agents to carry out complex tasks • Agents might move from one system to another to access remote resources and/or meet other agents ICT619
What is an intelligent agent? (cont’d) • Intelligent agents (also called “software agents”) do not necessarily possess all these possible features • Wide range of variation in capabilities: • Some perform tasks individually while others are cooperative • Some are mobile- able to move across a network, others are not • Most communicate via coded messages or even natural language, some don't communicate at all • Multiple agents work in groups or swarms to solve problems collectively, some work as individual units • Not all agents learn and adapt themselves • Robots are physically embodied agents ICT619
Why intelligent agents? • More and more everyday tasks becoming computer-based • An increasing number of untrained users using computers • Current human-computer interfaces require users to initiate all tasks and monitor them - manually • Intelligent agents engage in a cooperative process with the user to leverage the effectiveness and efficiency of human-computer interaction • Staggering growth in information availability • Intelligent agents can be a tool for relieving the user of this information overload • Intelligent agents can act as personal assistants to the user to manage information • Might one day take over routine tasks in personal management such as appointments, meetings and travel arrangements ICT619
What intelligent agents can do for us • Carry out tasks on the user’s behalf • Train or teach the user • Help different users collaborate • Monitor events and procedures • Specifically, intelligent agents can help us with • Information retrieval • Information filtering • Mail management • Recreational activities – selection of books, music, holidays • Booking of meetings, hotels, tickets ICT619
What intelligent agents can do for us (cont’d) Information filtering agent • One type is the selection of articles from a continuous stream to suit particular user needs • User can create “news agents” and train them by giving positive or negative feedback for articles recommended • The use of key words alone can be restrictive • Underlying semantics must be extracted for more effectiveness • Eg VPOP Technologies' Newshub - an automated, agent-based web news feeder service, which delivers customised updates of stories from major news outlets every 15 minutes ICT619
What intelligent agents can do for us (cont’d) Electronic mail agent • Assist users with electronic mail • Learn to prioritize, delete, forward, sort and archive mail messages on behalf of the user • May use intelligent system techniques like case-based reasoning • Can associate a level of confidence with its action or suggestion • Use of “do-it” and “tell-me” thresholds set by user • May involve multi-agent collaboration ICT619
Hi, I am Cybelle. What is your name? What intelligent agents can do for us (cont’d) Selection agents for entertainment • Conversational agents show potential for becoming popular and commercially successful eg Cybelle, ALICE • Use “social filtering” – correlation between different users to make recommendations on books, CDs, films etc. • So, if user A liked items X and Y, and user B liked item X and Z, then item Z may be recommended for user A • Amazon.com has been using this system for years -> ICT619
What intelligent agents can do for us (cont’d) Some other current and emerging applications of intelligent agents: • air traffic control • air craft mission analysis • control of telecommunications and network systems • provision and monitoring of medical care • monitoring and control of industrial processes • on-line fault diagnosis and malfunction handling • supervision and control of manufacturing environments • transactions management in banks and insurance companies • E-commerce, tourism ICT619
Characteristics of a good agent Action • Agent must be able to take some action and not just provide advice • Present state of web technology limits capability of Internet agents - still no standard interface for agents, but agent communication languages such as ACL and KQML might win out • As the Internet becomes more agent-friendly, more capable agents will emerge Autonomy • An agent can be much more useful if it can act autonomously • The right level of autonomy for a task must be found ICT619
Characteristics of a good agent (cont.) Communication • Must communicate well with the user • Should understand user’s goals, preferences and constraints • Useful communication requires shared knowledge on • language of communication • problem domain Example Problem: Web search engines • accept key words and phrases (some knowledge of the language) but • understand nothing about the documents they retrieve (no domain knowledge) • Solution: provision of a machine-readable ontology - a definition of a body of knowledge including its components and their relationships ICT619
Characteristics of a good agent (cont.) Adaptation • Can gain user confidence by learning user preferences • ML techniques such as ANNS, GAs or CBR can be used • Adapting to user preferences can be also achieved by using data mining techniques such as clustering • Agent forms clusters of users with similar features • User's needs can then be anticipated by placing the user in one of these clusters and analysing the cluster • Social problem solving method, similar to Amazon recommendations ICT619
Types of agents • Based on operational characteristics and functional objectives: • Collaborative agents • Work together to - integrate information and - negotiate with other agents to resolve conflict - Provide solutions to inherently distributed problems, e.g., air traffic control • Reactive agents • Act by stimulus-response to the current state of the environment • Each reactive agent is simple and interacts with others in a basic way ICT619
Types of agents (cont’d) Interface agents • Provide user support and assistance • Cooperate with user in accomplishing some task in an application. • Interface agents learn: • by observing and imitating the user • through receiving feedback from the user • by receiving explicit instructions • by asking other agents for advice (from peers) • Examples: • Personal assistants performing information filtering, email management. ICT619
Types of agents (cont.) Mobile agents • Programs that migrate from one machine to another. • Execute in a platform-independent execution environment, like Java applets running on a Java virtual machine • Practical but non-functional advantages: • Reduced communication cost • Asynchronous computing (when you are not connected) ICT619
Types of agents (cont.) Two types of mobile agents: • One-hop mobile agents (migrates to one other place) • Multi-hop mobile agents (roam the network from place to place) Example applications: • Distributed information retrieval • Telecommunication network routing ICT619
Types of agents (cont.) Information agents • Manage information • Manipulate or collate information from many distributed sources. • Can be mobile or static. • Examples: • BargainFinder compares prices among Internet stores for CDs • Jasper works on behalf of a user or community of users and stores, retrieves and informs other agents of useful information on the WWW ICT619
Types of agents (cont.) Multiple agent systems • Consist of collections, or swarms, of simple agents that interact with each other and the problem environment • Can be mobile or static, same or different agents • Complex patterns of behaviour emerge from collective interaction • Examples: • Swarm of bees finds an optimal location for the hive • xxxx ICT619
Building intelligent agents Two main problems to overcome: • Competence • How do we build agents with the knowledge needed to decide • when to help the user • what to help the user with, and • how to help the user? • Trust • How to guarantee user comfort (and protection!) in delegating tasks to the agent • Approaches to building agents • User-programmed agents - write specialised scripts • Knowledge-based agents • Machine-learning approach ICT619
Building intelligent agents (cont’d) • The main problem with user-programmed approach - requires high level of user competency - user must be able to • Recognise opportunity for employing an agent • Take initiative to create an agent • Impart specific knowledge to agent by codifying it in a special language • Maintain agent’s knowledge by updating rule base with time • The issue of trust is then reduced to users’ trust in their own programming skills ICT619
Building intelligent agents (cont.) In the knowledge-based approach, • The agent is supplied with knowledge about the application and user • At run-time, agent uses the knowledge to recognise user’s plans and find opportunities to contribute to them • Example of knowledge-based agent: the UCEgo - designed to help users solve problems in using the UNIX operating system. ICT619
Building intelligent agents (cont.) Problems with knowledge-based approach - • Both competence and trust are issues of concern • The problem of competence relates to the competence of the knowledge engineer • Knowledge-base is fixed and cannot be customised to specific user needs • User’s trust is affected as agent is programmed by someone else ICT619
Building agents – the machine learning approach • Metaphor of a personal office assistant • Agents start with minimum knowledge and learn from: • Observation and imitation of user • User feedback – direct, indirect • Training by user • Other agents • User can build up model of agent decision making – more trust • Agent capable of explanation ICT619
Building agents – the machine learning approach Advantages: • Less work from end-user and developer • Agent customises to user/organisation habits/preferences • Helps distribute know-how and competence among different users Some examples: • Agent for e-mail handling • Agent for meeting scheduling • Agent for electronic news filtering • Agent for recommending books, music ICT619
Intelligent agents in E-commerce • Rapid growth continues in e-commerce • Information about products and vendors is easily accessible • But transactions are still mostly not automated • Six fundamental stages of the buying process: • Need identification • Product brokering • Merchant brokering • Negotiation • Purchase and delivery • Product service and evaluation ICT619
Intelligent agents in E-Commerce (cont’d) • In the need-identification stage, agents can help in purchases that are repetitive or predictable • Continuously running agents can monitor a set of sensors or data streams and take actions when certain pre-specified conditions apply • Agents can use rule-based systems or data mining techniques to discover patterns in customer behaviour to help customers find products ICT619
Intelligent agents in E-commerce (cont.) • In the merchant brokering stage, on-line shopping agents can look up prices for a chosen product for a number of merchants • Many business-to-business transactions are canvassed • In a web auction, customers are required to manage their own negotiation strategies • Intelligent agents can help with this ICT619
Examples of on-line shopping framework with agent mediation ICT619
Examples of on-line shopping framework with agent mediation ICT619
Examples of on-line shopping framework with agent mediation ICT619
Examples of on-line shopping framework with agent mediation (cont’d) • Software agents are helping buyers and sellers cope with information overload and expedite the online buying process • Agents are creating new markets (eg, low-cost consumer goods) and reducing transaction costs • Use of agents in e-commerce still at an early stage • Visit http://agents.umbc.edu/Applications_and_Software/Applications/Electronic_Commerce/index.shtml for more ICT619
Intelligent agent design - state-of-the-art and future • Few agents are available with all the desired characteristics • Agent technology still in experimental stage • Autonomy and mobility already achievable • Example: Java applets which execute independently across networks • But autonomy limited so far in practical use due to the agent-unfriendliness of the current web technology ICT619
Intelligent agent design - state-of-the-art and future (cont’d) • A major limiting factor is lack of ontologies essential for effective communication • Building and maintaining ontologies remains a major challenge • Some of the proposed capabilities to be developed in future intelligent agents include: • Learning as well as reasoning, which are characteristics of machine intelligence • Interacting with the external environment through sensors ICT619
REFERENCES • Chin, D.,Intelligent Interfaces as Agents. In Intelligent User Interfaces, J. Sullivan and S. Tyler(eds), ACM Press, New York, 1991. • Hendler, J., Making Sense out of Agents, IEEE Intelligent Systems, March/April 1999, pp.32-37. • Hendler, J., Is There an intelligent Agent in Your Future? http//www.nature.com/nature/webmatters/agents/agents.html • Maes, P., Agents that Reduce Work and Information Overload, Communications of the ACM, Volume 37 , Issue 7 (July 1994), pp. 30-40. • Maes, P., Agents that Buy and Sell, Communications of the ACM, Volume 42 , Issue 3 (March 1999), pp. 81-91. • Sheth, B. and Maes, P. Evolving Agents for Personalized Information Filtering. In Proceedings of the Ninth Conf. on Artificial Intelligence for Applications. IEEE Computer Society Press, 1993 • UMBC Agent News - http://agents.umbc.edu/agentnews/current/ • http://www.agentland.com/ ICT619