The Semantic Web should enable greater access not only to content but also to services on the Web. Users and software agents should be able to discover, invoke, compose, and monitor Web resources offering particular services and having particular properties. As part of the DARPA Agent Markup Language program, we have begun to develop an ontology of services, called DAML-S, that will make these functionalities possible. In this paper we describe the overall structure of the ontology, the service profile for advertising services, and the process model for the detailed description of the operation of services. We also compare DAML-S with several industry efforts to define standards for characterizing services on the Web.

/pdf/daml-s-semantic-markup-for-web-services-2bz2kpfwet.pdf

DAML-S: semantic markup for web services

The paradigmatic shift from a Web of manual interactions to a Web of programmatic interactions driven by Web services is creating unprecedented opportunities for the formation of online business-to-business (B2B) collaborations. In particular, the creation of value-added services by composition of existing ones is gaining a significant momentum. Since many available Web services provide overlapping or identical functionality, albeit with different quality of service (QoS), a choice needs to be made to determine which services are to participate in a given composite service. This paper presents a middleware platform which addresses the issue of selecting Web services for the purpose of their composition in a way that maximizes user satisfaction expressed as utility functions over QoS attributes, while satisfying the constraints set by the user and by the structure of the composite service. Two selection approaches are described and compared: one based on local (task-level) selection of services and the other based on global allocation of tasks to services using integer programming.

/pdf/qos-aware-middleware-for-web-services-composition-x57gs4mhme.pdf

QoS-aware middleware for Web services composition

The Web is moving from being a collection of pages toward a collection of services that interoperate through the Internet. The first step toward this interoperation is the location of other services that can help toward the solution of a problem. In this paper we claim that location of web services should be based on the semantic match between a declarative description of the service being sought, and a description of the service being offered. Furthermore, we claim that this match is outside the representation capabilities of registries such as UDDI and languages such as WSDL.We propose a solution based on DAML-S, a DAML-based language for service description, and we show how service capabilities are presented in the Profile section of a DAML-S description and how a semantic match between advertisements and requests is performed.

https://www.cmpe.boun.edu.tr/~pyolum/cmpe596/papers/matchmaking.pdf

Semantic Matching of Web Services Capabilities

JADE (Java Agent Development Framework) is a software framework to make easy the development of multi-agent applications in compliance with the FIPA specifications. JADE can then be considered a middle-ware that implements an efficient agent platform and supports the development of multi agent systems. JADE agent platform tries to keep high the performance of a distributed agent system implemented with the Java language. In particular, its communication architecture tries to offer flexible and efficient messaging, transparently choosing the best transport available and leveraging state-of-the-art distributed object technology embedded within Java runtime environment. JADE uses an agent model and Java implementation that allow good runtime efficiency, software reuse, agent mobility and the realization of different agent architectures.

Developing Multi-Agent Systems with JADE

Service-oriented architectures (SOA) is an emerging approach that addresses the requirements of loosely coupled, standards-based, and protocol- independent distributed computing. Typically business operations running in an SOA comprise a number of invocations of these different components, often in an event-driven or asynchronous fashion that reflects the underlying business process needs. To build an SOA a highly distributable communications and integration backbone is required. This functionality is provided by the Enterprise Service Bus (ESB) that is an integration platform that utilizes Web services standards to support a wide variety of communications patterns over multiple transport protocols and deliver value-added capabilities for SOA applications. This paper reviews technologies and approaches that unify the principles and concepts of SOA with those of event-based programing. The paper also focuses on the ESB and describes a range of functions that are designed to offer a manageable, standards-based SOA backbone that extends middleware functionality throughout by connecting heterogeneous components and systems and offers integration services. Finally, the paper proposes an approach to extend the conventional SOA to cater for essential ESB requirements that include capabilities such as service orchestration, "intelligent" routing, provisioning, integrity and security of message as well as service management. The layers in this extended SOA, in short xSOA, are used to classify research issues and current research activities.

/pdf/service-oriented-architectures-approaches-technologies-and-1m0bcwz0fm.pdf

Service oriented architectures: approaches, technologies and research issues

Putting Web Services in Context

The current practice housing policies of Malaysia and Nigeria did not highlight on the affordability of formal low cost houses. There are no laws, sections or guidelines regulating the affairs of formal low cost housing. The current policies did not consider the beneficiaries of the formal low cost housing in their design; the design reflects the western culture which is not tantamount to that of the beneficiaries. It did not conform to their culture, family background and size. The current practice policies of Malaysia and Nigeria did not consider the family issues of the low income earners and did not provide for public participation in their deliberations contrary to the need of the beneficiaries. This study establishes that participation in policy deliberations will make them feel self-worth. The beneficiaries want incentives to improve their earnings. This study shows that formal low cost houses in Batu Pahat, are affordable while those in Bauchi, are not affordable. Formal low cost houses are located in the same neighborhood with medium and high cost houses in Batu Pahat and enjoy all facilities, utilities and services there. The situation is not the same in Bauchi, where formal low cost houses are located separate at the peripheries of the town outside trekking distances which repel beneficiaries because of the awkward location. The residents of the formal low cost houses Batu Pahat, have higher qualification, higher earnings, less number of defendants, while those at Bauchi, have higher number of defendants, lower income, lower qualification. This study further ascertained that the interplay of these three intangible socio economic elements is the major impediment that blocks affordability. The policy makers and the residents submit that these affordability elements should be upheld in other to ensure formal low cost housing possession by the low income earners. This article further ascertained that the intangible socio economic elements play more role than the physical or tangible elements.

http://www.aessweb.com/pdf-files/aefr%203(7),%20923-947.pdf

Comparative study between malaysia and nigeria formal low cost housing policy issues

Residential segregation, the spatial separation of population sub-groups within a given geographical area, is a phenomenon which is prevalent in both developed and developing countries like Nigeria. This study sought to contribute to existing knowledge by reviewing the existing patterns of residential segregation and housing quality in Nigeria, and developing a framework for the existing patterns of residential segregation and housing quality. The study established that the existing residential segregation patterns are based mainly on religion, ethnicity, age and income; and the factors responsible for residential segregation in the study area are individual and aggregate socioeconomic characteristics, individual preference/taste/choice of neighbourhood and political/institutional factors. While the indicators of housing quality in the study area are building design, type of roofing and wall materials, condition and age of buildings, the type of internal facilities and the source of lighting. And the framework showed that there is a relationship between the factors responsible for residential segregation and housing quality in the study area. Keywords: Framework, Patterns, Residential Segregation, Housing Quality, Bauchi

/pdf/framework-of-the-existing-patterns-of-residential-4s59y8sk1r.pdf

Framework of the Existing Patterns of Residential Segregation and Housing Quality in Nigeria

We describe a novel approach by which software can assess the ability of a confederation of heterogeneous systems to interoperate to achieve a given purpose. The approach uses ontologies and knowledge bases (KBs) to capture the salient characteristics of systems, on the one hand, and of tasks for which these systems will be employed, on the other. Rules are used to represent the conditions under which the capabilities provided by systems can fulfill the capabilities needed to support the roles and interactions that make up each task. An Analyzer component employs these KBs and rules to determine if a given confederation will be adequate, to generate suitable confederations from a collection of available systems, to pre-diagnose potential interoperability problems that might arise, and to suggest system configuration options that will help to make interoperability possible. We have demonstrated the feasibility of this approach using a prototype Analyzer and KBs.

/pdf/purpose-aware-reasoning-about-interoperability-of-13ublfy0y4.pdf

Purpose-aware reasoning about interoperability of heterogeneous training systems

Sometimes one does not want all the solutions to a query but instead only those that are most desirable according to user-specified preferences. If a user-specified preference relation is acyclic then its specification and meaning are straightforward. In many settings, however, it is valuable to support preference relations that are not acyclic and that might not even be transitive, in which case though their handling involves some open questions. We discuss a definition of desired solutions for arbitrary preference relations and show its desirable properties. We modify a previous extension to SPARQL for simple preferences to correctly handle any preference relation and provide translations of this extension back into SPARQL that can compute the desired solutions for all preference relations that are acyclic or transitive. We also propose an additional extension that returns solutions at multiple levels of desirability, which adds additional expressiveness over prior work. However, for the latter we conjecture that an effective translation to a single (non-recursive) SPARQL query is not possible.

David Martin

Papers

Putting Web Services in Context

Comparative study between malaysia and nigeria formal low cost housing policy issues

Framework of the Existing Patterns of Residential Segregation and Housing Quality in Nigeria

Purpose-aware reasoning about interoperability of heterogeneous training systems

Comparative Preferences in SPARQL