A learning-based module extraction method for object-oriented systems

Developers apply object-oriented (OO) design principles to produce modular, reusable software. Therefore, service-specific groups of related software classes called modules arise in OO systems. Extracting the modules is critical for better software comprehension, efficient architecture recovery, determination of service candidates to migrate legacy software to a service-oriented architecture, and transportation of such services to cloud-based distributed systems. In this study, we propose a novel approach to automatic module extraction to identify services in OO software systems. In our approach, first we create a weighted and directed graph of the software system in which vertices and edges represent the classes and their relations, respectively. Then, we apply a clustering algorithm over the graph to extract the modules. We calculate the weight of an edge by considering its probability of being within a module or between modules. To estimate these positional probabilities, we propose a machine-learning-based classification system that we train with data gathered from a real-world OO reference system. We have implemented an automatic module extraction tool and evaluated the proposed approach on several open-source and industrial projects. The experimental results show that the proposed approach generates highly accurate decompositions that are close to authoritative module structures and outperforms existing methods.     

Exploring the benefits of the combination of a software architecture analysis and a usability evaluation of a mobile application

Designing easy to use mobile applications is a difficult task. In order to optimize the development of a usable mobile application, it is necessary to consider the mobile usage context for the design and the evaluation of the user-system interaction of a mobile application. In our research we designed a method that aligns the inspection method “Software ArchitecTure analysis of Usability Requirements realizatioN” SATURN and a mobile usability evaluation in the form of a user test. We propose to use mobile context factors and thus requirements as a common basis for both inspection and user test. After conducting both analysis and user test, the results described as usability problems are mapped and discussed. The mobile context factors identified define and describe the usage context of a mobile application. We exemplify and apply our approach in a case study. This allows us to show how our method can be used to identify more usability problems than with each method separately. Additionally, we could confirm the validity and identified the severity of usability problems found by both methods. Our work presents how a combination of both methods allows to address usability issues in a more holistic way. We argue that the increased quantity and quality of results can lead to a reduction of the number of iterations required in early stages of an iterative software development process.     

Why would online gamers share their innovation-conducive knowledge in the online game user community? Integrating individual motivations and social capital perspectives

The user community has been an important external source of a firm’s product or service innovation. Users’ innovation-conducive knowledge sharing enables the community to work as a vital source of innovation. But, traditional economic theories of innovation seem to provide few explanations about why such knowledge sharing takes place for free in the user community. Therefore, this study investigates what drives community users to freely share their innovation-conducive knowledge, using the theory of planned behavior. Based on an empirical analysis of the data from 1244 members of a South Korean online game user community, it reveals that intrinsic motivation, shared goals, and social trust are salient factors in promoting users’ innovation-conducive knowledge sharing. Extrinsic motivation and social tie, however, were found to affect such sharing adversely, contingent upon whether a user is an innovator or a non-innovator. The study illustrates how social capital, in addition to individual motivations, forms and influences users’ innovation-conducive knowledge sharing in the online gaming context.     

Composing enterprise mashup components and services using architecture integration patterns

Enterprise mashups leverage various source of information to compose new situational applications. The architecture of such applications must address integration issues: it needs to deal with heterogeneous local and/or public data sources, and build value-added applications on existing corporate IT systems. In this paper, we leverage enterprise architecture integration patterns to compose reusable mashup components. We present a service oriented architecture that addresses reusability and integration needs for building enterprise mashup applications. Key techniques to customize this architecture are developed for mashups with themed data on location maps. The usage of this architecture is illustrated by a property valuation application derived from a real-world scenario. We demonstrate and discuss how this state-of-the-art architecture design method can be applied to enhance the design and development of emerging enterprise mashups.     

A study on factors that affect users’ behavioral intention to transfer usage from the offline to the online channel

Increasingly more service providers offer both offline and online services simultaneously, but consumers still seem to prefer using offline services rather than online ones. Our research focuses on factors that influence users’ intention to transfer their usage from the offline to the online channel that offer similar services. Drawing on the valence framework and prior research related to habit, innovativeness, and Internet experience, we propose a research model that incorporates motivators and inhibitors of usage transfer from both the offline and online channels. Using banking services in China as the research context, our study reveals that innovativeness in new technology and relative benefit have positive effects on users’ intention to transfer usage. Conversely, habits that consumers form in the offline channel have a negative effect on the intention to transfer usage. Moreover, our findings indicate that Internet experience moderates the relationship between relative benefit and consumers’ intention to transfer usage from offline to online services. These results provide a better understanding of consumers’ usage-transfer behavior and offer suggestions to providers in boosting their consumers’ use of online services.     

Context-aware intelligent service system for coal mine industry

In coal mine industry, the context-aware intelligent service system can be used to provide the most appropriate information services to miners according to their real-time situation. As a result, the information resources can be taken full advantage of so as to help miners to improve their safety condition, which are not just accessible to the management staff. However, there is not a detailed discussion or an in-depth research on the implementation of service system at present. In order to bridge the gap between the theory and the practice in the field, three critical problems need to be solved: (1) How to model the served miners’ context? (2) How to provide the information services to meet miners’ customized demands? (3) How to verify the availability of service invocation? According to the characteristics and practical needs of coal mine, this paper first proposes the Coal Mine Semantic Sensor Network Ontology (CMSSN) to build miner's context model, which can facilitate reusing the context resources in different coal mines. Then, the configuration model connecting context information and business services is constructed to realize the customized service invocation. Thirdly, the method of computational experiment is proposed to verify the availability and validity of service system, i.e. whether the service system can provide the suitable service on time in various virtual accident experiments. A case study is given to explain how to implement the computational experiment on a virtual coal mine simulation platform. Finally, the potential problems in realizing the system are discussed, which will be our research focus in future.     

Combining service-orientation and software product line engineering: A systematic mapping study

ContextService-Orientation (SO) is a rapidly emerging paradigm for the design and development of adaptive and dynamic software systems. Software Product Line Engineering (SPLE) has also gained attention as a promising and successful software reuse development paradigm over the last decade and proven to provide effective solutions to deal with managing the growing complexity of software systems.ObjectiveThis study aims at characterizing and identifying the existing research on employing and leveraging SO and SPLE.MethodWe conducted a systematic mapping study to identify and analyze related literature. We identified 81 primary studies, dated from 2000–2011 and classified them with respect to research focus, types of research and contribution.ResultThe mapping synthesizes the available evidence about combining the synergy points and integration of SO and SPLE. The analysis shows that the majority of studies focus on service variability modeling and adaptive systems by employing SPLE principles and approaches.In particular, SPLE approaches, especially feature-oriented approaches for variability modeling, have been applied to the design and development of service-oriented systems. While SO is employed in software product line contexts for the realization of product lines to reconcile the flexibility, scalability and dynamism in product derivations thereby creating dynamic software product lines.ConclusionOur study summarizes and characterizes the SO and SPLE topics researchers have investigated over the past decade and identifies promising research directions as due to the synergy generated by integrating methods and techniques from these two areas.     

A new model for context-aware transactions in mobile services

With the ubiquity of handheld devices (such as smart phones and PDAs) and the availability of a wide range of mobile services (such as mobile banking, road traffic updates, and weather forecast), people can nowadays access information and conduct online transactions virtually anywhere and anytime. In such flexible, dynamic but less reliable environment, transaction management technology is believed to provide service reliability and data consistency. Indeed, in mobile and ubiquitous environments where devices as well as services can seamlessly join and leave the ubiquitous network; transaction management can be very helpful during the recovery of services from failure. Current transaction models and commit protocols do not take into account context information. However, in mobile environments, it is imperative to consider context information in the commit of a transaction—i.e., a transaction can be successfully completed if it meets the required context. In this paper, we propose a new model for context-aware transactions and their performance management in mobile environments. Unlike conventional transactions, context-aware transactions adapt to the required context. By context, we mean the service’s context as well as the users’ context that includes users’ needs and preferences. This paper designs and develops the proposed transaction model and evaluates its performance in terms of time and message complexities as well as transaction’s throughput.     

Software architecture review by association

During the process of software design, software architects have their reasons to choose certain software components to address particular software requirements and constraints. However, existing software architecture review techniques often rely on the design reviewers’ knowledge and experience, and perhaps using some checklists, to identify design gaps and issues, without questioning the reasoning behind the decisions made by the architects. In this paper, we approach design reviews from a design reasoning perspective. We propose to use an association-based review procedure to identify design issues by first associating all the relevant design concerns, problems and solutions systematically; and then verifying if the causal relationships between these design elements are valid. Using this procedure, we discovered new design issues in all three industrial cases, despite their internal architecture reviews and one of the three systems being operational. With the newly found design issues, we derive eight general design reasoning failure scenarios.     

Component-based development of Web-enabled eHome services

In this paper we will take a look at the inside of connected homes, which build up complex IT systems. The building blocks of such systems are electronic devices, networks, and services, which empower the user to interact with his environment. Web-enabled eHome services offer functionality to the user by abstracting from devices and realize connectivity in three dimensions: (1) inner connectivity, (2) outer connectivity, and (3) integrative connectivity. Generations of Web-enabled eHome services have been developed based on proprietary hard- and software. Today, an extensible and modular platform is required for forward-looking design and implementation of such services. We describe a new view on component-based development of Web-enabled eHome services. While there is an adequate framework (open service gateway initiative) for the development of state-of-the-art Web-enabled eHome services, there is no knowledge about the system and service structure and its architecture in detail. We propose an 3-layer system structure (called PowerArchitecture), which incorporates several established design ideas and show how this cookbook makes system architects and developers life easier.     

An empirical study of the factors affecting social network service use

Social network services are emerging as a promising IT-based business, with some services already being provided commercially such as Facebook, Cyworld and Xiaonei. However, it is not yet clear which potential audience groups will be key social network service participants. Moreover, the process showing how an individual actually decides to start using a social network service may be somewhat different from current web-based community services. Hence, the aims of this paper are twofold. First, we empirically examine how individual characteristics affect actual user acceptance of social network services. To examine these individual characteristics, we apply a Technology Acceptance Model (TAM) to construct an amended model that focuses on three individual differences: social identity, altruism and telepresence, and one perceived construct: the perceived encouragement, imported from psychology-based research. Next, we examine if the users’ perception to see a target social network service as human relationship-oriented service or as a task-oriented service could be a moderator between perceived constructs and actual use. As a result, we discover that the perceived encouragement and perceived orientation are significant constructs that affect actual use of social network services.     

Dynamic multiple-frame bandwidth provisioning with fairness and revenue considerations for Broadband Wireless Access Systems

The increasing demand for wireless heterogeneous multimedia services presents a real challenge to mobile network operators. Even with the substantial increase in the supported bandwidth in emerging Broadband Wireless Access Systems (BWASs) such as 3.5G High Speed Downlink Packet Access (HSDPA) and the Worldwide Interoperability for Microwave Access (WiMAX), satisfying the bandwidth requirements of mobile users while increasing the revenues of network operators is still one of the major issues in these systems. Therefore, bandwidth provisioning will certainly play a decisive role in the success of such BWASs. In this paper, we propose a novel dynamic multiple-frame bandwidth provisioning scheme for BWASs. The proposed scheme spans multiple time frames and optimally allocates them to the different classes of traffic depending on their weights, the real-time bandwidth requirements of their users’ connections, their channel quality conditions and the expected obtained revenues. To maximize fairness and still maintain service differentiation between classes, we provide a unique formulation for dynamically computing the class weights. Simulation results are provided to show the potential and effectiveness of our scheme.     

An empirical investigation of end-users’ switching toward cloud computing: A two factor theory perspective

With the diffusion of cloud services, they are becoming an alternative to traditional information technology (IT). Despite the importance of cloud services, relatively few studies have been devoted to an empirical examination of the switching behavior from traditional IT to cloud services at the individual level. Therefore, this study attempts to explore the switching factors (i.e. switching enablers and switching inhibitors) and to empirically examine the relationships between those and users’ intention to switch to cloud services, based on the two-factor theoretic perspective. This study uses a longitudinal design to get survey data from undergraduate students at two universities in Korea in the context of IT switching to Google Apps settings. According to our findings, this study found that users’ switching intention to cloud services was not only positively influenced by expected switching benefits whose antecedents are omnipresence of cloud services and collaboration support, but also negatively influenced by expected switching costs whose antecedents are satisfaction with incumbent IT and breath use of inclement IT. The impacts of switching benefits and costs on switching intention were also positively moderated by end users’ personal innovativeness.     

A perceptual evaluation of grating frequencies and velocities in the analysis of dynamic images

Dynamic images that possess beauty and are user-friendly can increase the use of digital technology. In addition to information conveyance, dynamic images also act as a communication bridge in the human–machine interface. Dynamic images are widely used in the application of digital media. Therefore, understanding the visual effects of dynamic images on viewers is a very important issue. From a visual communication design perspective, dynamic images influence not only image quality, but also the viewers’ perception and impression of the displayed image. In the contemporary age characterized by universal usage of dynamic images, designers should attain synchronized knowledge and understanding of relevant media technology so as to present preferred design quality in the management of digital design such as animation design, Web page design, multimedia design, and so on. The current study noted that psychological effects such as viewers’ visual attention, preferences, and understanding were more important than image quality. Therefore, this study adopted the viewpoint of “visual design” and conducted a perceptual evaluation of grating frequency and grating velocity. The pair-comparison method and scale method were adopted in the research methodology to simplify perceptual evaluations and enhance their validity. The purpose of this study was: (1) To propose recommendations for displaying dynamic images and improving image performance using perceptual evaluation methods. (2) To examine the influence of psychological factors on viewer’s comfort when they experience dynamic images. (3) To identify the best grating feature combinations that meet viewer’s psychological characteristics and propose recommendations for dynamic images design. The study concludes that it is useful to establish criteria for evaluating users’ perception and to, develop perceptual evaluations of dynamic images. It is recommended that designers find a balance between watching a moving imaging display “clearly” and watching it “comfortably” for successful reception by the viewer.     

可变粒度及面向过程的软件配置管理系统

软件配置管理（SCM）贯穿于整个软件生命周期，足软件开发过程中质量管理的精髓所在。该文在研究了现有的软件配置管理技术成果的基础上，分析了新的软件开发技术的发展所提出的问题和爰求以及目前软件配置管理系统的不足，提出了一个支持可变粒度的、面向过程的软件配置管理系统——FDSCM，并依次详细介绍了该系统在配置项的分类、组织、描述和版本管理方面对可变粒度配置管理的支持，以及在支持迭代开发的过程管理方面的具体设计和实现策略。     

A systematic review of software architecture visualization techniques

ContextGiven the increased interest in using visualization techniques (VTs) to help communicate and understand software architecture (SA) of large scale complex systems, several VTs and tools have been reported to represent architectural elements (such as architecture design, architectural patterns, and architectural design decisions). However, there is no attempt to systematically review and classify the VTs and associated tools reported for SA, and how they have been assessed and applied.ObjectiveThis work aimed at systematically reviewing the literature on software architecture visualization to develop a classification of VTs in SA, analyze the level of reported evidence and the use of different VTs for representing SA in different application domains, and identify the gaps for future research in the area.MethodWe used systematic literature review (SLR) method of the evidence-based software engineering (EBSE) for reviewing the literature on VTs for SA. We used both manual and automatic search strategies for searching the relevant papers published between 1 February 1999 and 1 July 2011.ResultsWe selected 53 papers from the initially retrieved 23,056 articles for data extraction, analysis, and synthesis based on pre-defined inclusion and exclusion criteria. The results from the data analysis enabled us to classify the identified VTs into four types based on the usage popularity: graph-based, notation-based, matrix-based, and metaphor-based VTs. The VTs in SA are mostly used for architecture recovery and architectural evolution activities. We have also identified ten purposes of using VTs in SA. Our results also revealed that VTs in SA have been applied to a wide range of application domains, among which “graphics software” and “distributed system” have received the most attention.ConclusionSA visualization has gained significant importance in understanding and evolving software-intensive systems. However, only a few VTs have been employed in industrial practice. This review has enabled us to identify the following areas for further research and improvement: (i) it is necessary to perform more research on applying visualization techniques in architectural analysis, architectural synthesis, architectural implementation, and architecture reuse activities; (ii) it is essential to pay more attention to use more objective evaluation methods (e.g., controlled experiment) for providing more convincing evidence to support the promised benefits of using VTs in SA; (iii) it is important to conduct industrial surveys for investigating how software architecture practitioners actually employ VTs in architecting process and what are the issues that hinder and prevent them from adopting VTs in SA.     

Improving service matching and selection in ubiquitous computing environments: a user study

In large ubiquitous computing environments it is hard for users to identify and activate the electronic services that match their needs. This user study compares the newly developed service matcher system with a conventional system for identifying and selecting appropriate services. The study addresses human factors issues such as usability, trust and service awareness. With the conventional system users have to browse a hierarchical list of currently available services and activate the service that they think satisfies their current needs. With the service matcher users just enter their current need using natural language, after which a wizard, emulating an existing service matcher algorithm, searches for and activates a matching service based on the given need and the users’ location and gaze direction. This study shows that with the hierarchical list, only 66% of the tasks are solved correctly, and females score significantly worse than males. With the service matcher, the performance increases significantly to 84% correctly performed tasks and the gender difference disappears.     

User adoption of social networking sites: Eliciting uses and gratifications through a means–end approach

This research examines users’ motives for adopting and using social networking sites (SNSs), with the aim of providing a better understanding of the fundamental reasons behind SNS adoption behavior. To uncover the relationship between the attributes of SNSs and users’ perceptions of their consequences and values, this study integrates a means–end approach with uses and gratifications theory and thereby extends the technique to a communication media selection context. Laddering interviews identify users’ perceptions of five attributes, 10 consequences, and four values associated with SNS adoption (i.e., Facebook). The results show that belonging, hedonism, self-esteem, and reciprocity are the four main values users attain through SNS adoption. Furthermore, the chains associated with SNS adoption can be represented in a hierarchical value map. This study should help practitioners design online communication platforms that more closely fit their users’ needs and provide users with safer, more friendly, and thus more attractive environments.     

User‐Centric Service Map for Identifying New Service Opportunities from Potential Needs: A Case of App Store Applications

Today, service innovation is just as important as product innovation. The ideation of service innovation, vis‐à‐vis product innovation, is user‐oriented, rather than maker‐oriented. Thus, capturing and understanding user context is key to being able to offer personalized and relevant services, and further identify new service opportunities. Therefore, a user‐centric approach is needed in new service development, especially in the era of ubiquitous service. There exists a rich literature on how to incorporate customers into new service development, but most has focused only on their expressed needs, and failed to identify potential needs. In response, this paper proposes a ‘user‐centric service map’, which first visualizes the portfolio of existing services based on the dictionary of potential needs and then helps to investigate vacuums that can provide a concrete shape for new service opportunities. The suggested approach is composed of three parts: first, constructing a potential needs dictionary, second, developing a service map, and finally, identifying new service opportunities. A case study of Apple's App Store services is conducted to verify the feasibility and utility of the proposed approach and offer strategic implications.     

Implementing adaptive mobile GI services based on ontologies: Examples from pedestrian navigation support

As we are facing the dawn of ubiquitous computing (UbiComp) by emerging mobile devices and distributed applications, personalization is leaving the desktop domain, because adaptation and context-awareness play a major role in UbiComp in order to realize the user friendliness postulated for UbiComp applications. Adaptation is a relatively new concept for GI services. Therefore we introduce the related research areas. The two most important factors for adaptation are (a) context as the representation of the current situation and (b) the user itself. In particular how to dynamically derive information on the users’ properties is a research area applying learning strategies introduced shortly. We see these two concepts not isolated but propose an integrated situation model including several types of context as well as user parameters. After this introduction we present several approaches to realizing adaptive mobile GI services in the domain of pedestrian navigation and tourist information – representing first steps towards UbiGIS (www.ubigis.org). These include context and user-aware proactive tips, personalized tour planning and adaptive maps. Implementations and new concepts for extensions of these are presented. The paper closes by an outlook on open research issues related to adaptive GI services.