Abstract Object‐oriented component engineering is increasingly used for system development, partly because it emphasizes portability and reusability. Each time a component is used, it must be retested in the new environment. Unfortunately, the data abstraction that components usually use results in low testability. First, internal variables cannot be directly set. Second, even though a test input may trigger a fault, the failure does not propagate to the output. This paper presents a technique to increase object‐oriented component testability, thereby making it easier to detect faults. Components are often sealed so that source code is not available. The program analysis is performed at the Java component bytecode level. A component's bytecode is analysed to create acontrol and data flow graph, which is then used to increase component testability by increasing both controllability and observability. We have implemented this technique and applied it to several components. Experimental results reveal that fault detection can be increased by using our increasing testability process. Copyright © 2008 John Wiley & Sons, Ltd.

There is a lack of published studies on software development in Southeast Asia, which is fast becoming an IT outsourcing haven. This paper presents exploratory survey and case study results on software practices of some software firms in five ASEAN countries (Malaysia, Philippines, Singapore, Thailand and Vietnam), and provides directions for further research on software practices in the ASEAN/Southeast Asian region.

Signature technique that is proposed for multikey indexing is used for flexible searching in the area of databases. In this article, we present a new signature technique called Virtual Path Signature for supporting query processing of aggregation hierarchy as a tree in object-oriented databases (OODBs). We derive cost formulas for its storage overhead as well as the retrieval cost. Comparing with the Tree Signature Scheme, the Virtual Path Signature shows significant improvement in the retrieval operation, especially when the target distance between the target class and the predicate class is high. © 2004 Wiley Periodicals, Inc.

This article proposes an automatic scheme for synthesizing formal specification from the definitions of the relational data model—entity relationship diagram (ERD), and their data dictionaries. The formal specification of both structural and behavioral properties of the relational database model is generated in Z schemas. In our approach, the mandatory structural constraints—the uniqueness of primary key, foreign keys, and referential integrity constraints among the relations in the method—are preserved. We propose a set of transformation rules to exhaustively produce Z schemas of the states and primitive operations—cascade insertion, deletion, and updating. Moreover, in this article we focus on a composition technique of constructing the composite operations using the primitive composition tree. The revision of the formal specification can be conducted easily with the mathematical proofs of the properties of the data model using the Z prover tool. © 2004 Wiley Periodicals, Inc.

The problem of extending binary support vector machines (SVMs) for multiclass classification is still an ongoing research issue. Ussivakul and Kijsirikul proposed the adaptive directed acyclic graph (ADAG) approach that provides accuracy comparable to that of the standard algorithm - Max Wins and requires low computation. However, different sequences of nodes in the ADAG may provide different accuracy. In this paper we present a new method for multiclass classification, reordering ADAG, which is the modification of the original ADAG method. We show examples to exemplify that the margin (or 2/|w| value) between two classes of each binary SVM classifier affects the accuracy of classification, and this margin indicates the magnitude of confusion between the two classes. In this paper, we propose an algorithm to choose an optimal sequence of nodes in the ADAG by considering the |w| values of all classifiers to be used in data classification. We apply minimum-weight perfect matching with the reordering algorithm in order to select the best sequence of nodes in polynomial time. We then compare the performance of our method with previous methods including the ADAG and the Max Wins algorithm. Experiments denote that our method gives the higher accuracy, and runs faster than Max Wins.

Web applications are becoming more complex and the way to manage the complexity is to model them. This paper presents a methodology to model Web applications directly from the object-oriented fashion on the top of the event-driven programming concept. Our approach, WebForm-based Web application modeling methodology (WWM), provides guidelines to model Web application architectures from higher point-of-view than the Web element perspective. We employ the Unified Modeling Language (UML) and a subset of use case maps (UCM) for our methodology. The case study is developed to present how a Web application can be modeled, built and integrated with the business objects. A set of components is developed in order to use in the case study. Connection of the presentation to business layer shows that it could be done transparently via the components. The various issues are discussed to further extend our work.