EEL 5937 Applications. Environments. EEL 5937 Multi Agent Systems Lotzi Bölöni

EEL 5937 Applications

EEL 5937 Electronic commerce User interface agents on e-commerce sites Bidding agents Controversy: –Acting on behalf of the customer? –On behalf of the seller? –No mechanisms for guaranteeing “loyalty” of agents

EEL 5937 Spacecraft control The ground crew is usually required to track the spacecraft’s progress and decide how to deal with eventualities –Remember the control room for the Apollo moon missions? Expensive Very long reaction time if the spacecraft is far NASA is investigating making the probes more autonomous Example: Deep Space 1

EEL 5937 Virtual communities Agents as placeholders for user –Temporarily –Permanently –Avatars Virtual corporations –Consumer management agents –Economic recession (the burst of the “internet bubble”) slowed down innovation in –It is picking up again, as companies see agents as an alternative to outsourcing. Massively multiplayer role playing games –E.g. Everquest, Asheron’s Call etc. –As many times, gaming community is in the technical forefront. –We will see many of these ideas going into the virtual corporations

EEL 5937 Grid computing New paradigm for distributed computing –Similar to the electric grid –Providers and consumers. Contracts, requests, resource management Popular in the scientific computing community Has the potential to become a widespread approach –If we manage the complexity of use Managing a long running computation: –Reacting to events (e.g. hardware failure) –Computation steering –Reconfiguring systems for changing priorities

EEL 5937 Sensor networks Sensors: –Small hardware devices with sensing and wireless capabilities (e.g. “motes”). –Agents which collect data, communicate to pass them to a “sink” –In-network processing (data fusion, data correlation possible) Negotiation: –Active vs. passive sensors –Who covers which target Newest trend: sensor/actuator networks –Sensors: limited power, capabilities, fixed: mostly sensing –Actuators: more power, may be mobile: act on the environment

EEL 5937 And many others… Military applications Health care Intelligent home, intelligent car Dynamic spectrum management: –Negotiate spectrum resource allocations … maybe you will propose the next one?

EEL 5937 Conclusion Many interesting research issues Many interesting business opportunities –“Agent technology” image hurt by many marketing pushes without significant technology behind them –But real advances were made

EEL 5937 Environments, events, actions

EEL 5937 Environments, events and actions The agents live in an environment –The operating system –The internet –The world of Quake / the world of Everquest –For an AIBO robot: the home of the owner –The battlefield The environment is usually not fixed. It is changing through events and actions. Events: changes in the environment, for which we do not know the source. Actions: changes in the environment whose source is the agent or another known entity We usually consider events and actions to be discrete in time and space.

EEL 5937 Environments: Accessible vs. inaccessible An accessible environment is one in which the agent can obtain complete, accurate, up-to-date information about the environment’s state. Most moderately complex environments (including for example, the everyday physical world and the Internet) are inaccessible. Accessible environments: –Allows a more formal treatment of the agents –Sensing is not an issue –Planning, combinatorical computations become predominant (e.g. chess!) Inaccessible environments: –Sensing should be a large part of the agents work –Exact planning less important than short time reactions

EEL 5937 Environments: Deterministic vs. non-deterministic A deterministic environment is one in which any action has a single guaranteed effect. There is no uncertainty about the state that will result from performing an action. Operating in a non-deterministic environment means that we need to verify the result of our actions. Deterministic environment: –Single program computing environment with strong reservations … and optimism Non-deterministic –The physical world –The internet –Multi-agent systems

EEL 5937 Environments: Static vs. dynamic A static environment is one that can be assumed to remain unchanged except by the performance of actions by the agent A dynamic environment: independent changes happen (events, actions of other agents). A physical world is a highly dynamic environment. Some computer environments can be made static, but the interesting ones are dynamic.

EEL 5937 Environments: Episodic vs. non-episodic In an episodic environment, the performance of an agent is dependent on a number of discrete episodes, with no link between the performance of the agent in different scenarios. Episodic environments are simpler, because the agent developer can ignore the long term history of the agent. Example: –A battery powered robot lives in a non-episodic environment. –Everquest is non-episodic, Unreal Tournament is.

EEL 5937 Environments: Discrete vs. continuous An environment is discrete is there are a fixed finite number of entities and percepts in it (e.g. a chess game) Continuous: no isolatable entities, events as analog change etc. (e.g. the ocean) Discussion: –Computers are usually perceived as discrete. –Nature is usually perceived as continuous, at least at the macro level. –We can usually isolate actions, because they are performed by the agent –Isolating events is more difficult.

EEL 5937 Physical Environment: embodied agents Special case of the environment where the environment is the physical world or a simulation of it. Agents have a physical location (x,y) or (x,y,z). The environment has a geography. Actions and sensing are dependent of physical proximity. There is a continuity property: you need to traverse locations to get from place to place. Communication can be helped or hindered by geography. The physical and virtual environment can coexist!

EEL 5937 Virtual environment / Internet Locations are “hosts”. Multiple agents can occupy the same host. Mobility between hosts is possible – the agents move directly from host to host. Communication capabilities are independent of the location. The actions of the agents are “software actions”. Communication with user interfaces: the location of the user still matters!!!