Adaptive, Composite Trading based on Agents ACTAS
-
Upload
aspen-rowland -
Category
Documents
-
view
32 -
download
0
description
Transcript of Adaptive, Composite Trading based on Agents ACTAS
![Page 1: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/1.jpg)
SIT- Institute Secure Telecooperation Agent Group, Dep. of Computing
Fraunhofer, Darmstadt, Germany City University, London, UK
[email protected] [email protected] Supervisors: Dr. Michael Schroeder, City University
Dr. Rolf Reinema, FhG-SIT
Dipl.-Inform. Reinhold Kloos
Adaptive, Composite Trading based on Agents ACTAS
![Page 2: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/2.jpg)
Communication Connection: A Non-directed Composition
User 2
H323-Device
User 1
H320-DeviceGateway
User1 wants to communicate with User2 with a video conference
![Page 3: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/3.jpg)
Booking of a Flight: A Directed Composition
User wants to fly to Lisbon
Travel Agency 1
Travel Agency 2 Bank
Wants to get payment
Challenges for the Trading:
Composition Possibilities?
Current Service Offers?
Schedule of the Services?
User
![Page 4: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/4.jpg)
Adaptive, Composite Trading based on Agent Systems (ACTAS)
• Agent based Trading in five phases– Phase1: Managing the Composition Model– Phase2: Collect Service Offers– Phase3: Composition of requested service– Phase4: Observe constraints, security, resources– Phase5: Schedule of the services
• Includes: transaction management and dynamic reschedule of requests
![Page 5: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/5.jpg)
Principle Agents of ACTASService Provider
Facility Agent
(FA)
Collecting Traders for Service Offers
Ontological RepositoryAdministrators of
the Facility Agents
Trader Agent for Composition
Request Agent Request
Users
Personal Agent
![Page 6: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/6.jpg)
Phase1 - Ontological Repository
Property Types
Characteristics
Service Templates
Property Type
Name, Description of Semantic
Declaration of Features with a
Basic Type or
another Property Type
Constraints for the Features
Methods for the access, comparison of features declared in this Property Type
Property Types
![Page 7: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/7.jpg)
Phase1 - Ontological Repository
Property Types
Characteristics
Service Templates
Characteristic
Name, Description of Semantic
Declaration of Property with a
Property Type
Constraints for the Properties
(Semantic Concept Description)
A characteristic defines the semantic context of properties for describing of requests and service compatibility
Characteristics
![Page 8: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/8.jpg)
Phase1 - Ontological Repository
Property Types
Characteristics
Service Templates
Service Template
Name, Description of Semantic
[List of General Characteristics with constraints for Properties]
...
Mode i
[General Characteristics]
...
Socket j
Characteristic
Service Templates
A service template describes potential service modes (services) of a Facility Agent (FA)
An administrator of a FA describes the Service Template => Advantage of local administration
![Page 9: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/9.jpg)
Phase2 – Service OffersService TemplateName, Description of Semantic
[List of General Characteristics with constraints for Properties]
modes and sockets
Mode i
[General Characteristics]
Socket j
Characteristic
other modes and sockets
Facility Agent
(FA)
Service Offer
Service Template + Interface Information to FA + current constraints for modes and properties
exporting
![Page 10: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/10.jpg)
Characteristics (Re-visited)
• A Characteristic defines a semantic context• Two main kinds of Characteristics exist:
– General Characteristicfor description of Service and Service Modecan be used for pre-selecting of Service Offers
– Compatibility Characteristicfor description of Compatibility between Service Offers (one per Service Socket or User-Request)
• A Request Characteristic is a special Compatibility Characteristic, which can be used in a User-Request
![Page 11: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/11.jpg)
Compatibility• A Service Offer is compatible with another Service Offer
if both Service Offers have a Service Socket, which holds an identical Compatibility Characteristic.
• The used Service Socket determines the Service Mode. All other Service Sockets of this Service Mode must also be connected to compatible Service Offers.
• A Service Socket can contain constraints for the Compatibility.
• In a directed composition the Service Socket has a direction attribute, declaring IN or OUT. A Service Offer with a OUT socket is only compatible to a Service Offer with a IN socket.
![Page 12: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/12.jpg)
RequestA request contains:
– One or more User-Requests:(user name, request characteristic,constraints for the properties of characteristic).
– If necessary, Compatibility Characteristics, which shall be in composition and constraints for their properties.
– If necessary, General Characteristics and constraints for selecting of Service Offers.(Federated traders could help with selection).
– If necessary, already pre-selected Service Offers.
![Page 13: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/13.jpg)
Phase3 - Composition
• Step1: Creation of a Trader Agent responsible for the request.
• Step2: Migrate to a place, where information for composition exist.
• Step3: Create Adaptive Service Offers (ASO) for requesting users/actors.
• Step4: Getting the (next) Service Offers.• Step5: Do composition
(repeat step 4, if necessary).
![Page 14: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/14.jpg)
Phase3 – Non-directed Composition
Communication via a gateway
User 1 Connection
User 2 Connection
Service A
mode 1
Connection
H320-Standard
Service B
mode 1
Connection
H323-Standard
Gateway
mode 1
H323-Standard
H320-Standard
Connection is a Request Characteristic
H320-Standard, H323-Standard are Compatibility Characteristics.
![Page 15: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/15.jpg)
Phase3 – Directed Composition
Booking of a Flight: (User is a Adaptive Service Offer (ASO), which can take over a new
mode/role)
User
mode/role 1Flight – OUT
New rolePayment – IN(Checks with PAIf necessary, new request forDraft-Payment)
Draft-Payment – OUT
ASO
Travel Agency
mode 1
Flight – IN
Payment – OUT(condition: has to be done by Actor of Flight – IN)
Bank
mode xDraft-Payment - IN
Personal Agent
(PA)
![Page 16: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/16.jpg)
Possibilities for the Composition
Multiple Connections with one service (non-directed composition)
Servicemode
AAA
Servicemode
AConnection
Servicemode
AConnection
Servicemode
AConnection
User2mode
Connection
User1mode
Connection User3mode
Connection
![Page 17: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/17.jpg)
Possibilities for the Composition
Workflow like Connections (directed composition)
ServicemodeA-INA-OUTA-IN
Servicemode
A-OUT
Servicemode
A-OUTE-OUT
Servicemode
A-INB-OUTC-OUTD-OUT
Servicemode
D-INE-IN
Servicemode
C-IN
Servicemode
B-IN
combining
splitting
![Page 18: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/18.jpg)
Possibilities for the CompositionUse of Capability Specifications
• Property Types could be specified, which uses specifications for capabilities of agents, which are providing Software Services. (e.g. LARKS (Klusch, Sycara), HyperType (Zapf)).
• A Characteristic could hold a Property of this Property Type and another Property in order to keep necessary ontology information (necessary for LARKS).
• This Characteristic could be used as a General Characteristic of the Service Mode of the Service Offer, describing this special capability of the agent.
• Special Compatibility Characteristics, held by the Service Sockets of such a Service Mode or by a User-Request, could describe the compatibility constraints and allow the composition.
![Page 19: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/19.jpg)
Constraints
• Several kinds and locations of constraints exist:– In the ontological repository:
Property Type, Characteristic, Service Template.
– In the Request (phase 3).– In the collecting federated traders (phase 2).
• During the composition, constraints of a property a in characteristic A will be combined with the constraints of property b in characteristic B, if a service mode, used in the composition, has sockets with these characteristics and has a rule that these properties mean the same.
![Page 20: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/20.jpg)
Phase4 – Checking Constraints
• During the Composition process (phase3) only relevant Service Offers (step4) were selected and used.
• The collected constraints for composition have to be checked in phase4, using methods of the properties.
• Available resources for the service have to be checked and reserved, using the interface methods to the Facility Agent (FA).
![Page 21: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/21.jpg)
Phase4 - Transaction Control for Resource Management
• In order to check the availability of resources for the composite services and in order to reserve these resource, a trader agent must perform a transaction control.
• For every service, which is part of the composite service, the trader has to communicate with the Facility Agent.
• The Facility Agent must be able to reserve resources for one trader agent, distinguishing between the different composite services.
![Page 22: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/22.jpg)
Phase4 – Selection of Composite Service
• Only Composite Services, fulfilling all constraints and having enough resources, can be selected.
• If preferences of users were learnt, then these could be used for selection.
• The request could name Properties, which are relevant for selection. They could be compared with methods defined in their Property Types.
• Composite Services, fulfilling more constraints better than others, could be preferred.
![Page 23: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/23.jpg)
Phase5 – Scheduling of Composite Service
• A Service Offer contains the interface information for its Facility Agent (FA). This information get their information from the Service, Service Mode, and Service Sockets with their Characteristics and Properties.
• A schedule of an Adaptive Service Offer (ASO), which stands for a requesting user, can be a negotiation with the user (e.g. payment). It can lead to a new service request (e.g. draft-payment).
• If necessary, repeat of trading process (phase3).
![Page 24: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/24.jpg)
Learning of Preferences
• The Trader waits for a feedback for learning of user preferences.
• Since ACTAS uses Request Characteristics for a User-Request, Properties defined in a fixed semantic context can be used for learning. This allows e.g. table-learning.
• It is up to the Agent system to give further information of the context of the user.
![Page 25: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/25.jpg)
Security Aspects
• The Personal Agent (PA) should know the location of its user and his/her security rights.
• General Characteristics with Properties holding security information and methods could be defined.
• These Characteristics would allow pre-selecting of Service Offers and checking of constraints.
![Page 26: Adaptive, Composite Trading based on Agents ACTAS](https://reader035.fdocuments.in/reader035/viewer/2022062308/56813344550346895d9a3b90/html5/thumbnails/26.jpg)
What Is ACTAS?• ACTAS allows non-directed and directed service composition.
• Flexible ontological contexts with Characteristics
• Simple compatibility operator
• Local definition of compatibility with different Service Modes for Service Templates and Service Offers.
• Adaptable for different trading applications with the use of Service Sockets.
• Using of federated traders for pre-selecting of Service Offers.
• Allows learning of user preferences.
• ACTAS is based on a Agent System
• Having several features and their constraints in a Property Type allows the composition and handling of simultaneous features.