César J. Acuña

Modeling semantic web services: a case study

Nowadays, there is an enormous amount of study about the semantic Web, especially regarding one specific technology: semantic Web services. However, to be widely adopted by users and to succeed in real-world applications, semantic Web services development must catch up with mainstream software trends. As has already occurred with traditional Web services, Web development should be adapted to support the systematic development of the new components required by applications involving semantic Web services. In this paper we present, through a case study, an approach for developing semantic Web services. This approach is based on the extension of MIDAS, a model-driven methodology for Web Information Systems development.

Integrating software architecture into a MDA framework

Model Driven Development (MDD) is one of the main trends in Software Engineering nowadays. Its main feature is to consider models as first-class concepts. Model Driven Architecture (MDA), the MDD proposal by the OMG, defines an infrastructure which considers models at three different levels of abstraction, namely Computer-Independent Model (CIM), Platform-Independent Model (PIM) and Platform-Specific Model (PSM). Although it is becoming ever more important, the MDA approach has still some gaps. In our opinion, the lack of an adequate support for architectural design has been, ironically, one of its main drawbacks. MIDAS is an specific Model Driven Architecture for Web Information Systems (WIS) Development. It proposes to model a WIS by considering three different viewpoints, namely Content, Hypertext and Behaviour Viewpoints, which are orthogonal to MDA abstraction levels. In this paper, we propose to extend MIDAS by integrating architectural design aspects. Software architecture is therefore conceived as an crosscutting perspective, which is in turn orthogonal to those three viewpoints. MDA abstraction levels are still considered, and therefore both Platform-Independent Architecture and Platform-Specific Architecture models are defined. This approach, named Architecture-Centric Model-Driven Architecture (ACMDA), has several advantages, as it allows architectural design to benefit from the adaptability and flexibility of an MDD process; and on the other hand it extends MDA philosophy by integrating true architectural concerns, effectively turning it into an Architecture-Centric Model-Driven Development (ACMDD) process.

A Model Driven Approach for XML Database Development

In this paper we propose a methodological approach for the development of XML databases. Our proposal is framed in MIDAS, a model driven methodology for the development of Web Information Systems (WISs) based on the Model Driven Architecture (MDA) proposed by the Object Management Group (OMG). So, in this framework, the proposed data Platform Independent Model (PIM) is the conceptual data model and the data Platform Specific Model (PSM) is the XML Schema model. Both of them will be represented in UML, therefore we also summarize in this work an extension to UML for XML Schema. Moreover, we define the mappings to transform the data PIM into the data PSM, which will be the XML database schema. The development process of the XML database will be shown by means of a case study: a WIS for the management of medical images stored in the XML DB of Oracle.

Defining Service-Oriented Software Architecture Models for a MDA-based Development Process at the PIM level

Although the development of service-based software has evolved greatly in the last years, there is still a lack of accurate development methodologies applied to service orientation. To solve this, we focus on the model- driven development approach, and more specifically in MDA, the proposal by the OMG, as it is one of the main trends in nowadays software engineering. Accordingly, we propose to define a service-oriented software architecture (SOSA) model within a model-driven methodological framework called MIDAS, for the adaptable and flexible development of modern systems. In the present work we study the concepts and elements that need to be defined at a platform independent and neutral abstraction level. This paper reflects our proposal of PIM-level architecture model for service-oriented software architectures within MIDAS.

UML Profile for the Platform Independent Modelling of Service-Oriented Architectures

The vast diversity of implementation and support platforms for service-oriented architectures (such as Web, Grid or even CORBA) increases the complexity of the development process of service-based systems. To reduce it, both the architectural properties of the SOC paradigm and a development approach based on the MDA proposal can be studied. This work describes a UML profile for the PIM-level service-oriented architectural modelling, as well as the correspondent metamodel. PIM (Platform Independent Model) level is chosen because it does not reflect constraints about any specific platform or implementation technology. The proposal sketched in this article is part of our research of a service-oriented development method (SOD-M) called MIDAS.

A Web Information System for Medical Image Management

In the last years, the use of digital images for medical diagnosis and research has increased considerably. For this reason, it is necessary to develop new and better applications for managing in an effective way a large amounts of medical information. DICOM is the standard for the Digital Imaging and COmmunications in Medicine. However, DICOM information is difficult to interchange and integrate out of the scope of medical specialized equipment. This drawback make difficult its use and its integration in a wide context as the Web. XML is the standard for the information exchange and data transportation between multiple applications. As the XML databases are emerging like the best alternative to storage and manage XML documents, in this work we present a Web Information System to store, in an integrated way, DICOM and Analyze 7.5 files in an XML Database. For its development, the XML schemas for both DICOM and Analyze 7.5 formats have been obtained and the architecture for the integration of XML documents in the XML DB has been defined.

Toward Web portals integration through semantic Web services

Nowadays Web users have a vast amount of information resources at their disposal. These information resources include not only the data on the Web but also Web portals which offer users services such as flight ticket booking. Internet users demand integrated access to all information resources available on the Web; so both the services and the Web data have to be incorporated in integration efforts. Most of the known integration approaches ignore the services and operational aspects offered by Web portals, moreover, they are mostly ad hoc and hardly customized solutions. This paper tries to tackle the above problem proposing a service-oriented architecture for Web data and service integration. Firstly, it proposes a service-oriented platform-independent architecture, and, secondly, it presents a specific deployment of such architecture for data and service integration on the Web using semantic Web services implemented with the WSMO (Web services modeling ontology).

Toward UML-Compliant Semantic Web Services Development

The emerging Semantic Web and, in particular, Semantic Web services SWS, demands the inclusion of new components in applications involving this technology. Therefore, Web development methodologies must be tailored to support the systematic development of such new components. In previous works we presented a UML profile, which extends the SOD-M method for service oriented Web Information System development of the MIDAS model-driven framework, to address the development of Semantic Web Services using WSMO Web Service Modeling Ontology. The UML profile allows for the modeling of the new elements required by WSMO Web Services. This article focuses on studying the possibility of improving the proposed UML profile, including the OCL Object Constraint Language, for the representation of WSMO logical axioms through three case studies. This would allow developers, whose knowledge does not extend beyond UML, to develop applications that use Semantic Web services.

Integrating Web Portals with Semantic Web Services: A Case Study

Several systems integration proposals have been suggested over the years. However these proposals have mainly focused on data integration, not allowing users to take advantage of services offered by Web portals. Most of the mentioned proposals only provide a set of design principles to build integrated systems and lack in suggesting a systematic way of how to develop systems based on the integration architecture they propose. In previous work we have developed PISA Web Portal Integration Architecture-a Web portal integration architecture for data and services-and MIDAS-S, a methodological approach for the development of integrated Web portals, built according to PISA. This work shows, by means of a case study, how both proposals fit together integrating Web portals.

Using an Architecture-Centric Model-Driven Approach for Developing Service-Oriented Solutions: A Case Study

As services continue achieving more importance in the development of software solutions for the Internet, software developers and researchers turn their attention to strategies based on the SOC (Service-Oriented Computing ) paradigm. One of these development approaches is SOD-M specifically designed for building service-oriented solutions. In this article we present the results of redesigning a real-world Web-based Information System, called MEDiWIS, using SOD-M. The main goal of the redesigned MEDiWIS system is to support the storage and management of digital medical images and related information by presenting its functionalities as software services. We analyze in detail the main challenges we have found using an ACMDA (Architecture-Centric Model-Driven Architecture) approach to achieve this goal.