Daniela Barreiro Claro

Web Services Composition

1. INTRODUCTION Nowadays many enterprises publish their applications functionalities on the Internet. This new generation of applications allows greater efficiency and availability for business. In fact, more and more applications make functionalities available using a web service format. However there are many services around the web, each one, taken alone, has a limited functionality. In many cases, a single service is not sufficient to respond to the users request and often services should be combined through services composition to achieve a specific goal. For example, if a user wants to travel, it is not sufficient to book a flight, but she should also take care of reserving a hotel, renting a car, getting entertained, and so on. Such composition is carried out manually today, it means that the user needs to execute all these services one by one and these tasks can be time and effort consuming. For that reason, the notion of composite services is starting to be used as a collection of services combined to achieve a users request. In other words, from a user perspective, this composition will continue to be considered as a simple service, even though it is composed of several web services. Nevertheless, prior to composing web services, candidate services should first be discovered and then selected. One difficulty is that many functionally

A Step Forward in Semi-automatic Metamodel Matching: Algorithms and Tool

In recent years the complexity of producing softwares systems has increased due the continuous evolution of the requirements, the creation of new technologies and integration with legacy systems. When complexity increases the phases of software development, maintenance and evolution become more difficult to deal with, i.e. they became more subject to error-prone factors. Recently, Model Driven Architecture (MDA) has made the management of this complexity possible thanks to models and the transformation of Platform-Independent Model (PIM) in Platform-Specific Models (PSM). However, the manual creation of transformation definitions is a programming activity which is error-prone because it is a manual task. In the MDA context, the solution is to provide semi-automatic creation of a mapping specification that can be used to generate transformation definitions in a specific transformation language. In this paper, we present an algorithm to match metamodels and enhancements in the MT4MDE and SAMT4MDE tool in order to implement this matching algorithm.

Improving Web Service Discovery by a Functional and Structural Approach

Service oriented Architecture (SOA) has been widely used in service computing applications and this fact has been encouraged the publication over the Web in a Web Service format. Whereas the number of Web services published on the Web is growing up, discovery techniques must be improved so as to retrieve more desirable services. Nowadays, the most commonly used technique is semantic filters based on ontological concepts. However, such mechanisms can leave out some important Web services of the matching process, because of their structural relationship not mentioned in an ontology. In order to overcome such problems, some authors have proposed a hybrid approach to combine traditional syntactic and semantic approaches. These proposals remain restricted especially with respect to complexity, precision and time of execution, thus making such solutions in most of cases unfeasible. In this paper, we combine semantic filters based on functional properties with a structural approach, analyzing each neighbor relationship in an ontology. The results showed a considerable improvement in terms of performance and a complexity reduction with respect to other existing techniques. Furthermore, we implement a tool called OWLS-S Discovery in order to simplify the use of our approach by developers.

A Framework for Automatic Composition of RFQ Web Services

The growth of Web service formats over the Internet is increasing. These services should often be composed to achieve a user request. We propose in this paper a framework to cope with web service composition, from discovery to optimization. This framework, called SPOC, is composed of four successive phases: discovery, planning, quote execution and optimization. Only RFQ (Request for Quote) web services are treated in this first version of SPOC. The Discovery phase aims to search for web services in a repository. The Planning phase determines which services satisfy the user request. The Quote Execution phase involves processing a Request For Quote (RFQ) by calling web services. The last phase optimizes these results giving tradeoff compositions. As a proof-of-concept example, we applied SPOC to public competition processes in Public Markets.

Inference Approach to Enhance a Portuguese Open Information Extraction.

Open Information Extraction (Open IE) enables the extraction of facts in large quantities of texts written in natural language. Despite the fact that almost research has been doing in English texts, methods and techniques for other languages have been less frequent. However, those languages other than English correspond to 48% of content available on websites around the world. In this work, we propose a method for extracting facts in Portuguese without pre-determining the types of the facts. Additionally, we increased the quantity of those extracted facts by the use of an inference approach. Our inference method is composed of two issues: a transitive and a symmetric mechanism. To the best of our knowledge, this is the first time that inference approach is used to extract facts in Portuguese texts. Our proposal allowed an increase of 36% in quantity of valid facts extracted in a Portuguese Open IE system, and it is compatible in the quality of facts with English approaches.

Classification model analysis for the prediction of leptospirosis cases

Leptospirosis is a disease that affects mainly low-income populations, with an incidence of 500,000 cases per year worldwide[1]. The disease has symptoms often confused with other febrile syndromes, such as dengue, influenza and viral hepatitis. Improved diagnosis of patients with leptospirosis is very important for health professionals, epidemiological surveillance and primarily for rapid evaluation and appropriate treatment of patients. In this work, an analysis of the data mining techniques classification was performed, evaluating algorithms of the methods of Decision Tree, Classification Rules and Bayesian Classification. Of these, JRip was the model with the best performance, yielding 85% sensitivity and 81% specificity. The algorithms successfully predicted the disease and may represent a new tool to assist health professionals in the daily hospital routine, especially in endemic areas for leptospirosis, accelerating targeted treatment, and minimizing disease exacerbation and mortality.

Model Driven Testing for Cloud Computing

In this paper, the authors present a proposal to support the creation of test cases for software systems under cloud computing environments. This approach is based on Model Driven Engineering (MDE). A Methodology and metamodels are proposed to support the generation of test cases. Specific metamodels for cloud computing environments are provided. Business models are created conform to UML (including profiles) and test cases are created conform to a metamodel that is independent testing platform. Both models are manipulated by model transformation that generates test cases for cloud computing environments. These metamodels are used in conjunction with the tool MT4MDE and SAMT4MDE for developing testing models. An illustrative example helps to understand the proposed approach.

Building Test Cases through Model Driven Engineering

Recently, Model Driven Engineering (MDE) has been proposed to face the complexity in the development, maintenance and evolution of large and distributed software systems. Model Driven Architecture (MDA) is an example of MDE. In this context, model transformations enable a large reuse of software systems through the transformation of a Platform Independent Model into a Platform Specific Model. Although source code can be generated from models, defects can be injected during the modeling or transformation process. In order to delivery software systems without defects that cause errors and fails, the source code must be submitted to test. In this paper, we present an approach that takes care of test in the whole software life cycle, i.e. it starts in the modeling level and finishes in the test of source code of software systems. We provide an example to illustrate our approach.

A systematic mapping study on open information extraction

Abstract Open information extraction (Open IE) is a task for extracting relationship triples in plain texts without previously determining these relationships. The Open IE systems are generally applied to solutions on the web-scale such improving question answering systems, ontology constructions, document filtering and clustering. Since 2007, within the first Open IE system TEXTRUNNER, other related works have been proposed in this area. Despite other secondary studies on Open IE, useful information available to initiate new research in the area is limited. Thus, we propose a review of the literature in Open IE by a systematic mapping study. We have retrieved 2484 articles about Open IE in Science Direct, IEEE Xplore, ACM Digital Library, Scopus and Google Scholar databases. Among them, 2411 were filtered by exclusion criteria proposed in our systematic mapping protocol. The remaining 73 papers represent the state-of-the-art from the past seven years. Different researchers have proposed important contributions and have pointed out some open problems for Open IE. As a result, we summarized these contributions and identified significant gaps that could be envisioned as future works.

Generating correct compositions of semantic web services with respect to temporal constraints

Services are being widely published over the Web and many services may be composed to attend a users need. A composition of services can demand complex requirements to get an executable composition. Temporal restrictions are one of these requirements. As compositions are dynamically composed, model checking can be applied to verify if compositions are correct in relation to the temporal restrictions required. In this work we propose an algorithm that creates semantic web service compositions and verifies the correctness of a composition checking the temporal restrictions of each iteration. Experiments were carried out and the precision of retrieved services and their execution time were analyzed.