Mihhail Matskin

Logic-based Web services composition: from service description to process model

This paper introduces a method for automatic composition of semantic Web services using Linear Logic (LL) theorem proving. The method uses semantic Web service language (DAML-S) for external presentation of Web services, while, internally, the services are presented by extralogical axioms and proofs in LL. We use a process calculus to present the composite service formally. The process calculus is attached to the LL inference rules in the style of type theory. Thus the process model for a composite service can be generated directly from the proof. The subtyping rules that are used for semantic reasoning are presented with LL inference figures. We propose a system architecture where the DAML-S translator, the LL theorem prover and the semantic reasoner can operate together to fulfill the task. This architecture has been implemented in Java.

Composition of Semantic Web services using Linear Logic theorem proving

This paper introduces a method for automatic composition of Semantic Web services using Linear Logic (LL) theorem proving. The method uses a Semantic Web service language (DAML-S) for external presentation of Web services, while, internally, the services are presented by extralogical axioms and proofs in LL. LL, as a resource conscious logic, enables us to capture the concurrent features of Web services formally (including parameters, states and non-functional attributes). We use a process calculus to present the process model of the composite service. The process calculus is attached to the LL inference rules in the style of type theory. Thus, the process model for a composite service can be generated directly from the complete proof. We introduce a set of subtyping rules that defines a valid dataflow for composite services. The subtyping rules that are used for semantic reasoning are presented with LL inference figures. We propose a system architecture where the DAML-S Translator, LL Theorem Prover and Semantic Reasoner can operate together. This architecture has been implemented in Java.

An agent-based approach to modelling virtual enterprises

This paper describes how virtual enterprises (VEs) can be modelled using the AGORA multi-agent architecture, designed for modelling and supporting cooperative work among distributed entities. The model consists of a structure of AGORAs and agents, where AGORAs are facilitators of cooperative work for agents and the agents represent the partners of the VE, the cooperative mechanisms and the service providers. The distributed and goal-oriented nature of the VE provides a strong motivation for the use of agents to model VEs. The main advantages of this approach are that the structure of AGORAs provides a homogeneous modelling environment throughout the life cycle of the VE, traceability of the VE activities and a history of the VE. In addition to these, it is important to point out that, agents being computational entities, the resulting model provides an easy and efficient passage from the model to the computational support that is required by the VE.

Value-Added Web Services Composition Using Automatic Program Synthesis

The number of products and services available over the Internet increases dramatically during the last years and it is already beyond the human ability to analyze and combine them efficiently. At the same time if we consider works in software engineering (and, in particular, in component-based system development) then we can find quite strong similarity in problem description. The web services can be treated in a way similar to software components and service composition can be considered as problem of software synthesis and composition. Basic idea of our approach is applying the software synthesis and composition methods to value added web services composition. We also describe some technical details within the approach, in particular, a web service description language and a program synthesis method.

Agora: An Infrastructure for Cooperative Work Support in Multi-Agent Systems

In this paper, we describe an infrastructure for cooperative work support in Multi-Agent Systems (MAS). The infrastructure is based on a concept of Agora which can be considered as a facilitator of cooperative work. Basic features of the Agora based system as well as some implementation details (including communication adapter, message wrapper, proxy and default agent) are presented. An example of Virtual Shopping Mall as a general framework for modeling agent-based intelligent software services in mobile communications is used for illustration of the approach.

Social Trust-Aware Recommendation System: A T-Index Approach

Collaborative Filtering based on similarity suffers from a variety of problems such as sparsity and scalability. In this paper, we propose an ontological model of trust between users on a social network to address the limitations of similarity measure in Collaborative Filtering algorithms. For enhancing the constructed network of users based on trust, we introduce an estimate of a user’s trustworthiness called T-index to identify and select neighbors in an effective manner. We employ T-index to store raters of an item in a so-called TopTrustee list which provides information about users who might not be accessible within a predefined maximum path length. An empirical evaluation shows that our solution improves both prediction accuracy and coverage of recommendations collected along few edges that connect users on a social network by exploiting T-index. We also analyze effect of T-index on structure of trust network to justify the results.

Semantic web service composition through a p2p-based multi-agent environment

This paper describes a multi agent system (MAS) for distributed composition of Semantic Web services. Since our system is intended to function in highly dynamic environments, where heterogeneous agents rapidly join and leave the system, we consider P2P approach as most suitable for facilitating agent and service discovery. The MAS is based on Chord P2P network, which allows the MAS to dynamically publish and locate available Semantic Web services, which are specified with OWL-S. In order to compose new Web services from existing ones, agents apply symbolic reasoning in a cooperative problem solving manner.

Symbolic Agent Negotiation for Semantic Web Service Exploitation

This paper presents an architecture and a methodology for agent-based Web service discovery and composition. We assume that Web services are described with declarative specifications like DAML-S. Based on the declarative information about services, symbolic reasoning can be applied while searching for or composing automatically new services. We propose that symbolic agent negotiation could be used for dynamic Web service discovery and composition. Symbolic negotiation, as we consider it here, is a mixture of distributed planning and information exchange. Therefore, by using symbolic negotiation for automated service composition, we support information collection and integration during service composition. The latter aspect has been largely neglected in automated service composition until now.

Agent interaction protocols for the selection of partners for virtual enterprises

A Virtual Enterprise can be described as an organisational form that emerges when individual entities form a team to achieve a specific goal. The ability to assemble the best team is key to the success of the Virtual Enterprise and this imposes strong demands on its formation. In this paper, we present an agent-based model of a Virtual Enterprise, where the partners of a Virtual Enterprise are represented by software agents. We show how this model can support the different processes that are used in selecting the partners. We do this by analysing the agent interaction protocols for the different partner selection processes and by adapting it to provide the necessary agent-based support. We also describe the contents of the knowledge base of a single agent and how it can be used in the selection processes.

Mobile Commerce Agents in WAP-Based Services

With the increasing number of e-commerce services for mobile devices, there are challenges in making these services more personalized and to take into account the severely constrained bandwidth and restricted user interface these devices currently provide. In this paper we consider an agent-based platform for support of mobile commerce using wireless (WAP-based) devices. Agents represent mobile device customers in the network by implementing highly personalized customer profiles. The platform allows customization and adaptation of mobile commerce services as well as pro-active processing and notification of important events. Information to the customers is delivered both via WML-decks and SMS messages. Usage of the platform is illustrated by examples of valued customer membership services and subscription services support. Some details of a prototype platform implementation are briefly considered.