Recently, there is a trend on developing mobile applications based on service-oriented architecture in numerous application domains, such as telematics and smart home. Although efforts have been made on developing composite SOAP services, little emphasis has been put on invoking and composing a combination of SOAP, non-SOAP, and non-Web services into a composite process to execute complex tasks on various mobile devices. Main challenges are two-fold: one is how to invoke and compose heterogeneous Web services with various protocols and content types, including SOAP, RESTful, and OSGi services; and the other is how to integrate non-Web services, like Web contents and mobile applications, into a composite service process. In this work, we propose an approach to invoking and composing SOAP, non-SOAP, and non-Web services with two key features: an extended BPEL engine bundled with adapters to enable direct invocation and composition of SOAP, RESTful and OSGi services based on Adapter pattern; and two transformation mechanisms devised to enable conversion of Web contents and Android activities into OSGi services. In the experimental evaluations, we demonstrate network traffic and turnaround time of our approach are better than those of the traditional ones.

Aspect-oriented software development has become an important development and maintenance approach to software engineering across requirements, design and implementation phases. However, discovering early aspects from requirements for a better integration of crosscutting concerns into a target system is still not well addressed in the existing works. In this paper, we propose a Goal-driven Early Aspect approach (called GEA) to discovering early aspects by means of a clustering algorithm in which relationships among goals and use cases are utilized to explore similarity degrees of clustering goals, and total interaction degrees are devised to check the validity of the formation of each cluster. Introducing early aspects not only enhances the goal-driven requirements modeling to manage crosscutting concerns, but also provides modularity insights into the analysis and design of software development. Moreover, relationships among goals represented numerically are more informative to discover early aspects and more easily to be processed computationally than qualitative terms. The proposed approach is illustrated by using two problem domains: a meeting scheduler system and a course enrollment system. An experiment is also conducted to evaluate the benefits of the proposed approach with Mann-Whitney U-test to show that the difference between with GEA and without GEA is statistically significant.

Recently, as more and more mobile devices embedded with intelligent software become part of our daily lives, Open Services Gateway initiative (OSGi) has gained increasing attention in the development of services for such devices. However, services residing in OSGi platforms are devised specifically for the platforms' local bundles. Although several works have enhanced OSGi with various communication mechanisms that enable remote service invocations, two crucial issues pertaining to mobile computing remain to be addressed: One is limited resources of mobile devices, and the other is unstable links experienced with mobile devices. To address these two issues, we propose an itinerary-based mobile agent approach with four major features: To implement mobile agents as OSGi bundles to deliver distributed OSGi services with lower resource consumption; to extend WSDL and WS-BPEL to help developers design mobile agent itineraries; to provide an opportunistic service matchmaking mechanism allowing mobile agents to adapt to context changes at runtime; and to devise asynchronous communication mechanism to enable reliable mobile agent transmissions among mobile devices with dynamic IP addresses and intermittent connection to the Internet. Through experimental evaluations, we demonstrate that both network traffic and turnaround time of our approach are better than those of client-server ones.

Aspect-oriented approaches have resulted in a great impact on the processing of system properties during the development of software systems. However, a systematic way for eliciting early aspects from requirements is still underdeveloped to better integrate early aspects with the analysis results. As an attempt towards the investigation of the interactions among goals, scenarios, and early aspects, we proposed, in this work, a goal-driven approach to the discovery of early aspects by means of a bidding process that organizes goals into goal clusters for discovering aspectual candidates by exploring the interactions among goals and use cases. By introducing early aspects, the goal-driven approach can be further enhanced to deal with the crosscutting properties in the analysis stage of software development. The proposed approach is illustrated using the problem domains of meeting scheduler system.

The main purpose of this paper is to provide a snapshot of the current status of our two-phase-eight-year nation-wide effort in improving the software engineering education in Taiwan. In the first phase of this program (2004 - 2008), the number of universities that regularly offer software engineering courses grew from 63 to 92 while the number of offered courses grew from 159 to 406. The main objective of the second phase (2010 - 2014) was set to establish and implement the core competences of software engineering in our module programs. Seven capabilities are identified to form the SE core competences, including think computationally, teamwork in software development and maintenance, build abstractions and perform problem domain decompositions, analyze and model complex systems involved various domains, develop, review and verify complex systems involved various domains, create user-friendly interfaces based on user experiences, and manage and evolve large-scale design and development efforts. Multiple actions have also been taken to enhance the core competences of students in ICT-related programs in Taiwan, including developing practical course material, holding training courses for the educators, providing onsite lecturing support, and delivering industrial-oriented practical courses.

Web service discovery is the process of locating web services to meet requirements of service requesters, and is an important ingredient in building loosely-coupled SOA-based applications. In this paper, we propose a graph-based web service matchmaking approach based on WSDL without additional meta data or annotations. We divide the service matchmaking approach into two principal themes: constructing request graphs (RG) and service signature graphs (SSG) and calculating distance and similarity between a RG and an SSG. There are three main benefits in the proposed approach: (1) the structure of a service and involved data types are considered in the matching process, (2) the providers do not need to spent considerable effort annotating the service description using tags or ontology models, and (3) both the crisp similarity and fuzzy similarity can be produced automatically.

Project estimation based on function point or use case point (UCP) methods provide only fixed complexity grades which can not deal with the uncertain and imprecise conditions. This study, therefore, provides a fuzzy size estimation procedure for goal-driven use case model based on UCP using fuzzy theory. We propose a metric to calculate the unadjusted use case points of goal-driven use cases based on the relations between each use cases and goals with the fuzzy membership functions and the fuzzy rules. Furthermore, the technical and environmental factors are considered to calculate the use case points which can be used to estimate the implementation time and effort of the system under development. The proposed approach is illustrated by a benchmark problem domain of a meeting scheduler systems.

Delivering distributed telematics services has gained increasing attention in mobile computing and advanced traveler information fields. In this paper, to design and implement telematics applications, OSGi technology is exploited to support interoperability of various telematics services. Moreover, we propose a mobile agent approach to enabling the delivery of distributed OSGi services, which can gain better performance when applying it to mobile devices with limited resources and unstable connections. An application of telematics services, which assists drivers in reporting accident events when accident occurs and warns them of traffic accidents or jams on their planned routes is developed. In this application, OSGi is adopted as a service platform to manage services provided by diverse devices, while mobile agents are employed to migrate across multiple devices to access required services.

As mobile agents reside on on-board units or mobile devices and act on behalf of drivers, it imposes a strong demand to devise mechanisms for protecting the algorithms that are exclusively coded in mobile agents for different drivers. Although contactless smart cards are widely used as a means to protecting personal information, it is still a challenge to protect the whole code of a mobile agent in a limited storage. In this paper, we propose a tool, called jExtractor, by which the private or sensitive data coded in a Java-based mobile agent can be extracted and moved to a contactless smart card, and can further be read from the card and merged to be the original mobile agent. Moreover, we use 30,000 Java classes as samples to validate jExtractor. In the experimental result, 79.4% of the sample classes can successfully be extracted and moved to Mifare Standard S50 (1K) smart card with our strictest configuration level.

Recently, the growing popularity of requirements engineering attracts an increasing attention on requirements traceability and change impact analysis, which also imposes a great demand for a systematic approach in developing software systems to handling traceability relations and requirements changes in an automatic manner. In this work, a goal-driven requirements traceability approach is proposed to develop and manage requirements changes along three dimensions: (1) to develop software and manage requirements based on the goal-driven use case (GDUC) approach, (2) to establish and maintain the traceability relation with a design structure matrix (DSM) to derive the traceability tree, and (3) to analyze requirements change impacts through the partitioning of DSM into blocks to serve as a basis for calculating use case points. The proposed approach is illustrated by a benchmark problem domain of a meeting scheduler system. © 2010 Wiley Periodicals, Inc.

Recently, aspect-oriented approaches have resulted in a tremendous impact on the processing of broadly scoped properties during the development of software systems. However, the weaving mechanism of these crosscutting concerns cannot be easily represented with the extant unified modeling language (UML) notation at the early stage of software development life cycle. As an attempt toward the investigation of how the crosscutting behavior takes place, we proposed, in this work, an aspect-enhanced goal-driven approach to modeling the aspectual behavior in UML state transition diagrams and sequence diagrams with the proposed interaction operators based on the aspectual weaving semantics. By introducing the proposed interaction operations in the UML combined fragment, UML sequence diagrams can be further enhanced to support the modeling of the interactions between aspectual and base behavior in the analysis and design stage of software development. To further exemplify our points, the meeting scheduler system is chosen as a vehicle to illustrate the proposed approach. © 2010 Wiley Periodicals, Inc.

Recently, a trend to use reputation model for selecting service providers becomes evident in the area of electronic commerce. Most of the effort have been made on providing a reliability value associated with the predicted reputation to interpret how reliable is the reputation. However, the predicted reputation will become ineffective with a low reliability value. Rather than providing a reliability of a reputation, in this paper, we propose a reputation model, called Risk-Enabled reputAtion modeL (REAL), by introducing the notion of risks to better interpret the recent performance of a service provider in e-commerce. The proposed approach has been validated as a better model to reflect a service provider's recent performance than given by the extant on-line auctions sites or the models using the technique of adopting mean values.

As open multi-agents systems are getting increasing attentions in building large-scale software systems, the study on agent organizations - a building block of multi-agents systems, becomes a promising research track. Roles as a first class citizen in agent organizations impose an imperious demand for dealing with the major challenge: how agents bind roles in the formation of agent organizations in which agents can dynamically enter or leave the organizations. This challenge can be further decomposed into four issues: how to discover agents distributed over various organizations, how to select reliable agents to bind roles, how to enable agents to cooperate in roles binding, and how to unbind roles as agents leave an organization. The focus of this paper is on an extension to Contract Net protocol with reputation model to address these four issues related to the life cycle of dynamic role binding, called Agent-centric Contract Net Protocol (ACNP), as a negotiation mechanism that agents can adopt to establish agent organizations at run time through roles binding.

Service-Orientated Computing (SOC) has become a main trend in software engineering that promotes the construction of applications based on the notion of services. SOC has recently attracted the researchers' attention and has been adopted industry-wide. However, service composition that enables one to aggregate existing services into a new composite service is still a highly complex and critical task in service-oriented technology. To enhance availability of composite services, we propose a discovery-based service composition framework to better integrate component services in both static and dynamic manner, including (1) to devise a notion of service availability especially for composition; (2) to develop a dynamic service composition (DSC) pattern for addressing the issues of service availability; and (3) to extend Contract Net Protocol (ECNP) to coordinate service discovery, composition and invocation based on the composite pattern. The main benefit of the proposed approach is better availability through attaching multiple candidate services for future binding.

In recent years, the influence of design patterns on software quality has attracted an increasing attention in the area of software engineering, as design patterns encapsulate valuable knowledge to resolve design problems, and more importantly to improve design quality. Basically, a design pattern is composed of an intent description and a solution model. When the problem in the intent is a quality problem, the structure model should provide a solution to improve the relevant quality. In this work we provide an approach to verify if a design pattern is well-designed, i.e. it answers the question of the proposed structural model really resolves the quality problems described in the intent. Our approach is based on a generic object-oriented quality model.

As the number of agents increases rapidly on the Internet, discovering appropriate service agents with required capabilities for request agents becomes a crucial issue in multi-agent systems. Two major discovering approaches have been developed: centralized matchmaking approaches and distributed bidding approaches. However, the former approaches may suffer the problem of middle agent overload and can not reflect the dynamic characteristic of agent capabilities, while the later has the problems of the overhead for maintaining contact lists of service agents in each request agent and sending ineffective CFP messages to non-qualified service agents. To address the above problems, in this paper, we propose a CNP-based bidding mechanism based on Possibilistic Petri Nets that facilitates request agents to find preferred service agents. Moreover, our mechanism provides more flexible match that not only supports exact match but also takes the degree of satisfaction into account.

The notion of organizations is getting increasing attentions for building open multi-agent systems by mimicking the collaboration of human beings for achieving the organization objectives. However, there is little support in the existing approaches to dealing with the issues of dynamic role binding towards building an agent organization in which roles and agents are designed by different designers. The main challenge is how to determine that an agent is capable of assuming a role and to build the relation between the role and the agent. As an attempt towards the investigation of the relationship between agents and roles, we propose an approach, called AgentJ a Java-based agent platform, to dealing with the issues by extending object-oriented programming with the following main features: (1) a role specification and a role matching mechanism are devised to determine whether an incoming agent is capable of assuming a role; and (2) the binding relation between agent and role is established through a role binding mechanism.

A number of approaches have been proposed in tackling the timetabling problem, such as operational research, human-machine interaction, constraint programming, expert systems, and neural networks. However, there are still several key challenges to be addressed: easily reformulated to support changes, a generalized framework to handle various timetabling problems, and ability to incorporate knowledge in the timetabling system. In this article, we propose an automatic software engineering approach, called task-based conceptual graphs, to addressing the challenges in the timetabling problem. Task-based conceptual graphs provide the automation of software development processes including specification, verification, and automatic programming. Maintenance can be directly performed on the specifications rather than on the source code; moreover, hard and soft constraints can be easily inserted or removed. A university timetabling system in the Department of Computer Science and Information Engineering at National Central University is used as an illustrative example for the proposed approach. © 2005 Wiley Periodicals, Inc. Int J Int Syst 20: 1137–1160, 2005.

This work presents a fuzzy mental model to address evolution of intelligent agents in virtual market. Agent fitness and fuzzy multi-criteria decision-making are proposed as evolution mechanisms, and fuzzy soft goals are introduced to facilitate the evolution process. Genetic programming operators are employed to restructure agents in the proposed multi-agent evolution cycle. We conduct a series of experiments to determine the most successful strategies and to see how and when these strategies evolve based on the context and the bidding stance of the agent's opponent.

Fuzzy theory is suitable to capture and analyze the informal requirements that are imprecise in nature, meanwhile, XML is emerging as one of the dominant data formats for data processing on the Internet. In this paper, we attempt to markup the fuzzy objects with XML, and provide conversion rules to define the mapping from fuzzy objects model and fuzzy objects specification into XML schema and XML documents, respectively.

In this paper, we have attempted a study of current approaches carried out in the confluence of the two technologies: fuzzy set theory and software engineering, that could provide a powerful tool for requirements engineering, formal specifications, software quality prediction, object-oriented modeling, and etc. Various requirements analysis and specifications modeling technologies that utilize fuzzy theory are identified, and works related to the use of fuzzy logic for predicting software quality are also outlined.

In this study, we have attempted a survey of current approaches carried out in the confluence of the two technologies, fuzzy set theory and object-oriented technology, that could provide a powerful tool for enhancing database management systems, software modeling, and knowledge representation in artificial intelligence (AI) systems. Possible types of fuzziness are discussed and key features related to different kinds of fuzzy software systems are also pinpointed. In a nutshell, fuzzy theory, as a modeling mechanism, is especially useful in tackling real world applications whose complexity demands are growing intensively. © 2001 John Wiley & Sons, Inc.

The focus of the paper is on the use of time Petri nets to serve as the verification mechanism for acquired scenarios. Use cases are used to elicit the user needs and to derive the scenarios. After specifying all possible scenarios, each of them can be transformed into its corresponding time Petri nets model (TPN). Through the analysis of these TPN models, wrong information and missing information in scenarios can be detected. The proposed approach is illustrated by a course registration problem domain.

It is widely recognized that requirements engineering is a knowledge-intensive process and cannot be dealt with using only a few general principles. Since knowledge plays a crucial role in software development, software engineers have to describe and organize various aspects of knowledge before the program can be written. A recent work by Robillard reveals that software development can be further improved by recognizing the relevant knowledge structures. In this paper, we propose the use of a task-based conceptual graphs (TBCB) framework as a basis for automating software development. By structuring and operationalizing conceptual graphs, TBCG specifications can be transformed into executable programs automatically. To construct a conceptual model, task-based specification methodology is used as the mechanism to structure the knowledge captured in conceptual models, whereas conceptual graphs are adopted as the formalism to express task-based specifications and to provide a reasoning capability for the purpose of automation. Once task-based graphs have been constructed and verified, a blackboard system will automatically transform TBCG specifications into a software system composed of database schemas, knowledge base, and user interfaces. A meeting scheduling system is used as an illustrative example to demonstrate our approach. © 2000 John Wiley & Sons, Inc.

One of the foci of the recent developments in requirements engineering has been the study of conflicting requirements. However, there is no systematic way in the existing approaches to handling the interactions among requirements and their impact on the structuring of requirement specifications. In this paper, a new approach is proposed to formulate the requirement specifications based on goal interactions (i.e., cooperative, conflicting, counterbalanced and irrelevant).

In this paper, we propose an approach to reusing requirements specification, called task-based specifications in conceptual graphs (TBCG). In TBCG, task-based specification methodology is used to serve as the mechanism to structure the knowledge captured in conceptual models, and conceptual graphs are adopted as the formalism to express requirements specification. TBCG provides several mechanisms to facilitate the reuse of formal specifications: a contextual retrieval mechanism to support context-sensitive specifications retrieval and incremental context acquisition, a graph matching mechanism to compute the similarity between two graphs based on the semantic match and fuzzy logic, and a paraphraser to serve as an explanation mechanism for the retrieval specifications. ©1999 John Wiley & Sons, Inc.

This paper presents our reachability tree logic (RTL) and its integration with time Petri nets to specify and verify the temporal behavior of high assurance systems. The specification phase begins with a system modeling to model system requirements into a time Petri net N and construct a reachability tree RT of N. We then use RTL to specify the desired temporal behavior as formula F. The verification phase uses a model-checking algorithm to check whether RT can satisfy F, that is to find firing sequences to satisfy F. If F is not satisfied, we then modify N into N′ and obtain a RT′ of the modified N′. The modification (refinement) continues until the modified RT′ can satisfy F. In addition, we will demonstrate how to reduce the complexity of model-checking by using our RTL-based algorithm. We have implemented a specification and verification toolkit called NCUPN (National Central University Petri Nets toolkit) using Java. NCUPN is now available on the Internet via

A framework of integrated expert systems based on fuzzy Petri net, called fuzzy Petri net based expert system (FPNES) are proposed for bridge damage assessment. Major features of FPNES include: reasoning for uncertain and imprecise information; knowledge representation through the use of hierarchical fuzzy Petri nets; reasoning mechanism based on fuzzy Petri nets; and explanation of reasoning process through the use of hierarchical fuzzy Petri nets. FPNES offer several important benefits: (1) providing reasoning mechanism for uncertain and fuzzy information, (2) improving the efficiency of rule based reasoning by constructing relationship of concurrency among rule activation, and (3) explaining how to reach conclusions through the movements of tokens in fuzzy Petri nets. An application to the damage assessment of the Da-Shi bridge in Taiwan is used as an illustrative example of FPNES.

The paper presents a mechanism for normalizing fuzzy rules of a rule-based system, transforming the rules into a fuzzy Petri net, and answering queries based on the net with imprecise information. In addition, the authors present an algorithm utilizing the formalism of Petri nets to compute the degree of truth of the resulting answers to the queries. The degree of truth is computed in algebraic form based on the state equation which can be implemented in matrix computation in Petri nets.