Ryszard Kowalczyk

A coordinated architecture for the agent-based service level agreement negotiation of Web service composition

Recent progress in the field of Web services has made it possible to integrate inter-organizational and heterogeneous services on the Web at runtime. If a user request cannot be satisfied by a single Web service, it is (or should be) possible to combine existing services in order to fulfill the request. However, there are several challenging issues that need to be addressed before this can be realized in the true sense. One of them is the ability to ensure end-to-end QoS of a Web service composition. There is a need for a SLA negotiation system which can ensure the autonomous QoS negotiation of Web service compositions irrespective of the application domain. In this paper we propose agent-based coordinated-negotiation architecture to ensure collective functionality, end-to-end QoS and the stateful coordination of complex services. We describe a prototype implementation to demonstrate how this architecture can be used in different application domains. We have also demonstrated how the negotiation system on the service providers side can be implemented both as an agent based negotiation system and as a Web service based negotiation system.

WS2JADE: integrating web service with jade agents

Web services have gained popularity today for enabling universal interoperability among applications. In many scenarios, allowing software agents to access and control Web services is important and hence the integration between these two platforms. In this paper, we focus on technical aspects of an integration framework of Web services and Jade agent platform. The mismatch of description and communication between FIPA compliant agent platforms versusWeb services are two key challenges that must be addressed. Our implementation, WS2JADE, is described and compared with WSDL2JADE - a previous implementation on the same topic, and WSIGS - a recent proposal of Web service and Agent integration architecture. In contrast to other solutions, WS2JADE provides facilities to deploy and control Web services as agent services at run time for deployment flexibility and active service discovery.

Towards Agent-Based Coalition Formation for Service Composition

The topic of agent-based service composition has been experiencing much attention recently. Researchers are applying agent technology with the aim to improve adaptiveness and flexibility of prevailing static Web service composition solutions. One major characteristic of multi-agent systems in particular is their ability of emergent behavior that allows gaining complex system behavior from small distributed sets of simple rules. This paper describes a multi-agent-based coalition formation approach for service composition that achieves emergent behavior based on a light-weight interaction protocol and decentralized decision making. The paper also presents evaluation results of first experiments to underline the validity of the approach.

e-Negotiation Systems and Software Agents: Methods, Models, and Applications

Negotiation is a decentralized decision-making process that seeks to find an agreement that will satisfy the requirements of two or more parties in the presence of limited common knowledge and conflicting preferences. Negotiation participants are agents who negotiate on their own behalf or represent the interests of their principals. When electronic negotiations enter the stage, these agents could be intelligent software entities that take part in the process of searching for an acceptable agreement. The degree of involvement of these “intelligent agents” in negotiations can range from supporting human negotiators (e. g. information search, offer evaluation) to fully automating the conduct of negotiations. Choosing the degree of involvement depends upon the characteristics of the problem in the negotiation. In this chapter, we review electronic negotiation systems and intelligent agents for negotiations. Different types of negotiation agents, their roles and requirements, and various methods for effective support or conduct of negotiations are discussed. Selected applications of intelligent negotiation agents are presented.

Dynamic analysis of multiagent Q -learning with ε-greedy exploration

The development of mechanisms to understand and model the expected behaviour of multiagent learners is becoming increasingly important as the area rapidly find application in a variety of domains. In this paper we present a framework to model the behaviour of Q-learning agents using the ε-greedy exploration mechanism. For this, we analyse a continuous-time version of the Q-learning update rule and study how the presence of other agents and the ε-greedy mechanism affect it. We then model the problem as a system of difference equations which is used to theoretically analyse the expected behaviour of the agents. The applicability of the framework is tested through experiments in typical games selected from the literature.

Service-Oriented Computing: Agents, Semantics, and Engineering

Executing Semantic Web Services with a Context-Aware Service Execution Agent.- An Effective Strategy for the Flexible Provisioning of Service Workflows.- Using Goals for Flexible Service Orchestration.- An Agent-Based Approach to User-Initiated Semantic Service Interconnection.- A Lightweight Agent Fabric for Service Autonomy.- Semantic Service Composition in Service-Oriented Multiagent Systems: A Filtering Approach.- Towards a Mapping from BPMN to Agents.- Associated Topic Extraction for Consumer Generated Media Analysis.- An MAS Infrastructure for Implementing SWSA Based Semantic Services.- A Role-Based Support Mechanism for Service Description and Discovery.- WS2JADE: Integrating Web Service with Jade Agents.- Z-Based Agents for Service Oriented Computing.

Modelling and Solving QoS Composition Problem Using Fuzzy DisCSP

Web service compositions have attracted considerable efforts in the context of supporting enterprise application integrations. For a composite service, in addition to its functional requirements, QoS requirements are important and deserve a special attention. The central question to a QoS composition problem is how to compose a service from different subcomponent services so that its overall QoS can satisfy certain requirements. In this paper, we propose an agent-based method using fuzzy distributed constraint satisfaction problem (fuzzy DisCSP) techniques to solve this problem. We show that by using the composition structures, local constraints can be constructed and used with DisCSP. We also present an a new algorithm called the fuzzy constraint satisfaction algorithm for distributed environment (FADE) to solve the problem and discuss our experiment in building a prototypical system to prove the feasibility of our approach

Policy-Based Automation of SLA Establishment for Cloud Computing Services

We propose a policy-based framework for the automated establishment of SLAs for cloud computing services. The proposed framework supports multiple interaction models for SLA establishment giving consumers and providers the flexibility to choose one that is most appropriate in a given context, while simultaneously supporting multiple concurrent SLA interactions using different interaction models. We describe the underlying policies, focussing on the key features and contributions of the framework. We also validate our framework through a real-world use-case scenario using the Amazon EC2 service.

OpenSocial: From Social Networks to Social Ecosystem

Unlike the physical world where social ecosystems are formed from the integrated and managed relationships between individuals and organisations, the online digital world consists of many independent, isolated and incompatible social networks established by organisations that have overlapping and manually managed relationships. To bring the online digital world in-line with the physical world, integration of social networks, identification of overlapping relationships in social networks, and automation of relationship management in social networks are required. OpenSocial is a framework that enables social networks to interlink and self-organise into a social ecosystem guided by the policies of individuals and organisations.

A Decentralized Service Discovery Approach on Peer-to-Peer Networks

Service-Oriented Computing (SOC) is emerging as a paradigm for developing distributed applications. A critical issue of utilizing SOC is to have a scalable, reliable, and robust service discovery mechanism. However, traditional service discovery methods using centralized registries can easily suffer from problems such as performance bottleneck and vulnerability to failures in large scalable service networks, thus functioning abnormally. To address these problems, this paper proposes a peer-to-peer-based decentralized service discovery approach named Chord4S. Chord4S utilizes the data distribution and lookup capabilities of the popular Chord to distribute and discover services in a decentralized manner. Data availability is further improved by distributing published descriptions of functionally equivalent services to different successor nodes that are organized into virtual segments in the Chord4S circle. Based on the service publication approach, Chord4S supports QoS-aware service discovery. Chord4S also supports service discovery with wildcard(s). In addition, the Chord routing protocol is extended to support efficient discovery of multiple services with a single query. This enables late negotiation of Service Level Agreements (SLAs) between service consumers and multiple candidate service providers. The experimental evaluation shows that Chord4S achieves higher data availability and provides efficient query with reasonable overhead.