Chisu Wu

Genetic-algorithm-based real-time task scheduling with multiple goals

This paper presents and evaluates a new method for real-time task scheduling in multiprocessor systems. Its objectives are to minimize the number of processors required and the total tardiness of tasks. The minimization is carried out through a multiobjective genetic algorithm (GA), because the problem has non-commensurable and competing objectives to be optimized. The experimental results showed that when compared to five methods used previously, such as list-scheduling algorithms and a specific GA, the performance of our algorithm was comparable or better for 178 out of 180 randomly generated task graphs. Also shown is the impact of the sparsity of a task graph on the performance of our algorithm.

A unified model for the implementation of both ISO 9001

ISO 9001 is a standard for quality management systems and CMMI is a model for process improvement. If an ISO-certified organization wishes to improve its processes continuously, implementing CMMI would be a good choice, as it provides more detailed practices for process improvement than the ISO standards. However, there are two issues that need to be resolved when an ISO-certified organization implements CMMI. First, it is not easy to identify any reusable parts of the ISO standards, and it would be advantageous to be able to reuse selected portions of the ISO standards during CMMI adoption in order to use existing resources to their best advantage. Second, it is difficult for an ISO-certified organization to implement CMMI in a straightforward, easy manner because of the differences in the language, structure, and details of the two sets of documents. In this paper, we present our unified model for ISO 9001:2000 and CMMI that resolves these two issues. Our model would be an extremely useful tool for ISO-certified organizations that plan to implement CMMI.

Complexity measures for object-oriented program based on the entropy

Software metrics are widely advocated as fundamental elements of an engineering approach to planning and controlling software development. They are especially important in object-oriented programming. We propose a new software complexity model which consists of class complexity, inter-object complexity, and the total complexity for the object-oriented program. We measure the complexities based on the entropy concept. The class complexity for a class measures the information flows in a class based on the information passing relationship among member data and member functions. The inter-object complexity for a program measures the information flows between objects. The total complexity for a program is measured by the class complexity and the inter-object complexity. We evaluate the proposed metrics using the complexity properties proposed by Weyuker (1988). Experimental results of C++ classes show the effectiveness of the proposed metrics. We assert that the class complexity and the inter-object complexity are correlated to other metrics for object-oriented concepts.

An efficient version model of software diagrams

Various types of diagrams are used to represent the design of software systems. During the design phase, versions of a diagram may be created like other design documents and source code, and it is necessary to manage them efficiently. However, traditional configuration management systems and some object-oriented database management systems that provide object versioning are not suitable for managing versions of a diagram. In this paper, we propose an efficient version model of software diagrams. This model reflects the common characteristics and structure of software diagrams, and revisions of a diagram are managed by operation delta and object visibility. A merge model for versions of a diagram is also presented at the end of this paper.

An integrated model of ISO 9001:2000 and CMMI for ISO registered organizations

ISO 9001 is a standard for quality management systems while CMMI is a model for process improvement. If an organization that has achieved ISO registration wishes to improve processes continuously, CMMI can be a strong candidate because it provides a more detailed roadmap for process improvement. However, with respect to adopting CMMI in organizations that are familiar with ISO 9001, there are some issues that need to be resolved. For example, ISO 9001 and CMMI have different targets, intent, and quantity of detail. In this paper, we present an integrated model of ISO 9001:2000 and CMMI, which would resolve the above problems. We expect that this model will be a useful tool for ISO registered organizations aim to attain higher CMMI levels.

A reengineering process for migrating from an object-oriented legacy system to a component-based system

Computing environments are evolving from mainframe systems to distributed systems. Stand-alone programs that have been developed using object-oriented technology are not suitable for these new environments. However, programs that have been developed using a component-based technology have proven to be more suitable for the new environments due to their granularity and reusability. In this paper, we present a reengineering process for migrating from an object-oriented legacy system to a component-based system. This process consists of two steps: first, to create basic components with the relationship of their constituent classes, second, to refine components using the metrics we propose.

Automatic Discovery of Web Services Based on Dynamic Black-Box Testing

Most current approaches to Web Service discovery exploit description logic-based matchmaking algorithms. Until now, these Semantic Web Service technologies have not substituted for traditional search methods, because higher modeling costs, such as representing Service Annotation Ontologies and Domain Ontologies, are required. In this paper, we present an automatic testing-based approach to the discovery of Web Services. Through the automatic generation and execution of test cases based on a small amount of semantic information, Web Services are simultaneously evaluated and a decision is made on which Web Services the requestor needs. The experimental results show our technique reduces modeling costs significantly, whilst outperforming existing approaches in terms of precision. Furthermore, reliable QoS attribute values are obtained as by-products.

Mock Object Models for Test Driven Development

Test driven development uses unit tests for driving the design of the code. Mock object is an object that imitates the behavior of an object with which class under test has an association to assist the unit testing. Although many tools for mock object are used in practice, there has been few research on defining the mock object model. For the comparisons of the testing capability of the tools, it is important to define the models. In this paper we represent the models of the existing mock object tools and indicate the limitations of them. In addition we propose a new model to overcome the limitations of the existing tools. With this model, more general behavior of the class under test related to the mock object can be expressed and tested

Intelligent search agent for software components

Component software is one of the most promising methods for software reuse. The tremendous increase in the use of the World Wide Web (WWW) has accelerated the opening of reuse repositories on the Internet. However, existing document search engines are not usable for software components on the WWW because they usually conduct HTML-based keyword searches. In this paper, we describe an intelligent search agent system for components on the WWW. The agent has intelligence features such as preference, reasoning and learning. In order to improve the search performance and the user convenience, we adopted several progressive technologies and XML with rich semantics.

Extracting Development Organization from Open Source Software

The increasing demand for open source software in various fields of computer science is obvious. Many developers adopt open source software in their development process, organization culture, and products. Hence, there are many cases where developers who are new to open source software should maintain and continue to develop the software. This paper suggests a methodology to evaluate unseen organizational effort for open source software. It proposes ways to coordinate developers to maintain it.