Advances in verification presented in TACAS’13

Computers are becoming increasingly ubiquitous in all aspects of our life. It is becoming more and more important to ensure that the software (and hardware) that drives them performs as expected. Verification is one approach to improve quality of software and hardware. Verification attempts to formally prove that programs or systems fulfill desired properties and lack undesirable properties. This is a thriving area of research, and much resources are invested in extending it both in academia and in industry. In this special issue, we introduce four papers on verification selected from the 19th International Conference on Tools and Algorithms for the Construction and Analysis of Systems (TACAS’13).

     

Software verification and graph similarity for automated evaluation of students’ assignments

ContextThe number of students enrolled in universities at standard and on-line programming courses is rapidly increasing. This calls for automated evaluation of students assignments.ObjectiveWe aim to develop methods and tools for objective and reliable automated grading that can also provide substantial and comprehensible feedback. Our approach targets introductory programming courses, which have a number of specific features and goals. The benefits are twofold: reducing the workload for teachers, and providing helpful feedback to students in the process of learning.MethodFor sophisticated automated evaluation of students’ programs, our grading framework combines results of three approaches (i) testing, (ii) software verification, and (iii) control flow graph similarity measurement. We present our tools for software verification and control flow graph similarity measurement, which are publicly available and open source. The tools are based on an intermediate code representation, so they could be applied to a number of programming languages.ResultsEmpirical evaluation of the proposed grading framework is performed on a corpus of programs written by university students in programming language C within an introductory programming course. Results of the evaluation show that the synergy of proposed approaches improves the quality and precision of automated grading and that automatically generated grades are highly correlated with instructor-assigned grades. Also, the results show that our approach can be trained to adapt to teacher’s grading style.ConclusionsIn this paper we integrate several techniques for evaluation of student’s assignments. The obtained results suggest that the presented tools can find real-world applications in automated grading.     

Guest editors’ introduction: Advancements and extensions of verification techniques

This special section is devoted to a selection of journal versions of papers that appeared originally in the Proceedings of the 8th International Conference on Tools and Algorithms for the Construction and Analysis of Systems (TACAS), which took place in Grenoble, France in April 2002 as a constituent event of the European joint conferences on Theory and Practice of Software (ETAPS). All papers are relevant to the field of systems validation. The first three papers advance and extend model-checking techniques, the fourth presents algorithms for run-time verification, and the last paper is about animation and test generation for formal system specifications.     

Students’ perceptions and attitudes towards asynchronous technological tools in blended-learning training to improve grammatical competence in English as a second language

The aim of our quantitative study is to explore students’ perceptions towards some asynchronous tools to acquire the objectives of the subject of English Morphosyntax. The research was based on a sample of 358 students who were recruited from a population of 451. Participants ranged in age from 20 to 58 with an average age of 29.49 and were divided into four age groups. The results showed the students’ perceptions about the efficacy of the technological tools in Blended-learning training to improve their grammatical competence in English as a second language (L2). The students highlighted the opportunity provided to have a greater autonomy to be able to set and organize their own pace of study and individual learning. They pointed out the potentiality of the VLE implemented to supply a natural environment to learn and practice English grammar in real experiences and situations, and emphasized the benefits of the e-activities to carry out a continuous assessment and the students’ self-assessment. The present study brings some light on the students’ perceptions towards the effectiveness of asynchronous tools (podcast, videocast, online tests, online glossary and forums) in teaching English grammar to foreign language learners.     

Bank employees’ internal and external perspectives on e-service quality,satisfaction and loyalty

The goal of this study is to explain how and why people alter their cognition and attitude toward e-service quality, satisfaction and loyalty, depending on their perspective. We surveyed bank employees from two perspectives: first as employees and internal users for an internal perspective and then as external customers for an external perspective. The results of the empirical analysis indicated a change in e-service quality factor significance and impact and relationships among e-service quality, satisfaction and loyalty. Context- and service-type dependency is empirically confirmed. The moderator variable is type of service. The findings are explained. Theoretical and practical implications are discussed through the lens of theory of reasoned action, the technology acceptance model and expectancy-disconfirmation theory.     

Users’ involvement may help respect social and ethical values and improve software quality

Global informatization brings potential threats. It is possible to reduce them if software developers are aware of those threats and if customers insist on eliminating them. The survey described in the paper shows that future programmers are aware of numerous threats associated with global informatization. Many threats may be reduced by users’ involvement in the software process. Software developers should learn and develop cooperation with users, as emphasized in agile methodologies. It is a task for academic teachers to promote collaboration between software authors and users, to show how to organize it, and to convince programmers that it is valuable. Users’ involvement requires changes in the software life cycle and in the set of established processes. Such changes, in the form of additionally established processes and phases in the software development cycle, are identified in the paper. One recommended process is the software product assessment intended to elicit feedback from users. Users’ involvement may help to respect ethical and social values and to produce software adapted to user expectations.     

Students’ affective content analysis in smart classroom environment using deep learning techniques

Multimedia Tools and Applications - In the era of the smart classroom environment, students’ affective content analysis plays a vital role as it helps to foster the affective states that are...     

New members’ online socialization in online communities: The effects of content quality and feedback on new members’ content-sharing intentions

Online communities’ viability and success are dependent on current members’ active participation and content contribution, as well as on the sustainable community registration of new members. Based on the member-life cycle perspective, this study attempted to discover mechanisms that might be employed to increase new members’ community participation. This study focused on user-generated content (UGC) sharing. The results of this study suggest that UGC quality gaps that exist between current and new members are important factors that might affect new members’ socialization. In addition, the results demonstrated that feedback provided by members can affect new members’ participation when UGC quality gaps exist. The results revealed that new members preferred an equivalent UGC community to either a superior or inferior community when they were unable to derive benefits from those communities. However, an investigation of the types of feedback provided revealed that new members expressed preferences for superior UGC communities to obtain learning opportunities and expressed preferences for inferior UGC communities to develop social relationships. This study can help researchers better understand how UGC communities’ elements can affect new members’ behaviors. In addition, the results can help community managers devise differentiated approaches.     

Differential effects of formal and self-control in mobile platform ecosystems: Multi-method findings on third-party developers’ continuance intentions and application quality

Although control modes have been studied extensively in traditional IS contexts, minimal attention has been directed toward understanding how different control modes operate in platform ecosystems. Drawing on the IS control and self-determination literatures, we examined the differential effects of formal and self-control on third-party developers’ continuance intentions and application quality on mobile software platforms. Two studies from a laboratory experiment (N = 138) and a follow-up field survey with Android app developers (N = 230) show that self-control is superior to formal control because it allows for higher perceived autonomy that in turn promotes continuance intentions and application quality.     

Technical, legal and ethical dilemmas: distinguishing risks arising from malware and cyber-attack tools in the ‘cloud’—a forensic computing perspective

While hype around the benefits of ‘cloud computing’increase, challenges in maintaining data security and data privacy have also been recognised as significant vulnerabilities (Ristenpart et al. in Proceedings of the 14th ACM conference on computer and communications security, pp 103–115, 2009; Pearson in CLOUD’09, pp 44–52, 2009; Vouk in J Comput Inf Technol 4:235–246, 2008). These vulnerabilities generate a range of questions relating to the capacity of organisations relying on cloud solutions to effectively manage risk. This has become particularly the case as the threats faced by organisations have moved increasingly away from indiscriminate malware to more targeted cyber-attack tools. From forensic computing perspective it has also been recognised that ‘cloud solutions’ pose additional challenges for forensic computing specialists including discoverability and chain of evidence (Ruan et al. in Adv Digital Forensics VII:35–46, 2011; Reilly et al. in Int J Multimedia Image Process 1:26–34, 2011). However, to date there has been little consideration of how the differences between indiscriminate malware and targeted cyber-attack tools further problematize the capacity of organisations to manage risk. This paper also considers these risks and differentiates between technical, legal and ethical dilemmas posed. The paper also highlights the need for organisations to be aware of these issues when deciding to move to cloud solutions.     

Modeling and estimating the subjects’ diversity of opinions in video quality assessment: a neural network based approach

Subjective experiments are considered the most reliable way to assess the perceived visual quality. However, observers’ opinions are characterized by large diversity: in fact, even the same observer is often not able to exactly repeat his first opinion when rating again a given stimulus. This makes the Mean Opinion Score (MOS) alone, in many cases, not sufficient to get accurate information about the perceived visual quality. To this aim, it is important to have a measure characterizing to what extent the observed or predicted MOS value is reliable and stable. For instance, the Standard deviation of the Opinions of the Subjects (SOS) could be considered as a measure of reliability when evaluating the quality subjectively. However, we are not aware of the existence of models or algorithms that allow to objectively predict how much diversity would be observed in subjects’ opinions in terms of SOS. In this work we observe, on the basis of a statistical analysis made on several subjective experiments, that the disagreement between the quality as measured by means of different objective video quality metrics (VQMs) can provide information on the diversity of the observers’ ratings on a given processed video sequence (PVS). In light of this observation we: i) propose and validate a model for the SOS observed in a subjective experiment; ii) design and train Neural Networks (NNs) that predict the average diversity that would be observed among the subjects’ ratings for a PVS starting from a set of VQMs values computed on such a PVS; iii) give insights into how the same NN based approach can be used to identify potential anomalies in the data collected in subjective experiments.

     

Peat resource mapping in Lewis using remote sensing techniques and automated cartography†

Abstract

The application of methodology developed for peat resource survey has illustrated the usefulness of multi-level and multi-band aerial photography in classifying Landsat multispectral imagery. Ground truthing to characterize the thematic maps plotted from the aerial photography and Landsat imagery was based primarily on vegetation surveys. The results of this work are illustrated with a series of maps and photographs and the usefulness of the approach is assessed.     

IT investments disclosure,information quality,and factors influencing managers’ choices

We explored how IT disclosure affects information quality in the market and identified the factors that influence managers’ choices in IT disclosure quality. Adopting a comprehensive view of IT investments disclosure mechanisms, we found that IT disclosure quality was positively associated with information quality. Specifically, our results showed that an increase in quantitative information in IT disclosure could improve the information environment in the market, thereby reducing the perception of information risk among market participants. We also found that managers’ disclosures were less quantitative when the IT investment was more asset-specific in relation to higher agency costs.