Sharif Digital Repository

Software development nowadays is heavily based on libraries, frameworks and their proposed Application Programming Interfaces (APIs). However, due to challenges such as the complexity and the lack of documentation, these APIs may introduce various obstacles for developers and common defects in software systems. To resolve these issues, developers usually utilize Question and Answer (Q&A) websites such as Stack Overflow by asking their questions and finding proper solutions for their problems on APIs. Therefore, these websites have become inevitable sources of knowledge for developers, which is also known as the crowd knowledge. However, the relation of this knowledge to the software quality... 

Developing and maintaining large software systems typically requires that developers collaborate on many tasks. During such collaborations, when multiple people work on the same chunk of code at the same time, they communicate with each other and employ safeguards in various ways. Recent studies have considered group co-development in OSS projects and found that it is an essential part of many projects. However, those studies were limited to groups of size two, i.e., pairs of developers. Here we go further and characterize co-development in larger groups. We develop an effective methodology for capturing distributed collaboration beyond groups of size two, based on synchronized commit... 

Developing and maintaining large software systems typically requires that developers collaborate on many tasks. During such collaborations, when multiple people work on the same chunk of code at the same time, they communicate with each other and employ safeguards in various ways. Recent studies have considered group co-development in OSS projects and found that it is an essential part of many projects. However, those studies were limited to groups of size two, i.e., pairs of developers. Here we go further and characterize co-development in larger groups. We develop an effective methodology for capturing distributed collaboration beyond groups of size two, based on synchronized commit... 

It remains unclear whether causal, rather than merely correlational, relationships in molecular networks can be inferred in complex biological settings. Here we describe the HPN-DREAM network inference challenge, which focused on learning causal influences in signaling networks. We used phosphoprotein data from cancer cell lines as well as in silico data from a nonlinear dynamical model. using the phosphoprotein data, we scored more than 2,000 networks submitted by challenge participants. The networks spanned 32 biological contexts and were scored in terms of causal validity with respect to unseen interventional data. A number of approaches were effective, and incorporating known biology was... 

Despite the need for change, highly available software systems cannot be stopped to perform changes because disruption in their services may consequent irrecoverable losses. Current work on runtime evolution are either too disruptive, e.g., "blackouts" in unnecessary components in the quiescence criterion approach or presume restrictive assumptions such as the "black-box design" in the tranquility approach. In this paper, an architecture-based approach, called SAFER, is proposed which provides a better timeliness by relaxing any precondition required to start reconfiguration. We demonstrate the validity of the SAFER through model checking and a realization of the approach on a component... 

Security is one of the important issues in developing and implementing software systems especially in highly critical applications. Quantification and measurement of security is one of the approaches adopted to achieve the desired degree of security. In this paper, Stochastic Activity Networks (SANs) are used to formally model the attacks on the system under investigation. To this end, the semi-Markov attack model is sketched. Having the semi-Markov model, Probability of Attack Success (PAS), Mean Time to First Breach (MTFB), and System Misuse Proportion (SMP) are measured according to the appropriate transformation of the model to a SAN model. As a case study, we have studied a high-level... 

Selecting a suitable Requirements Engineering (RE) process is usually based on personal preferences or existing company practices rather than on the characteristics of the project at hand (project situation). Feature-oriented software development is the overall process of developing software systems in terms of their features. The Software Product Line (SPL) approach is a paradigm for systematic reuse of software products, and a Software Factory is a SPL aimed at the industrialization of software development. Based on the notion that a software/RE process can be developed via an engineering process, this research aims to provide a feature-based RE process factory to develop RE processes... 

Process-centered Software Engineering Environments, or PSEEs, are intended for the definition, modification, and enactment of software process models, they thus bring software development processes into effect. Even though research efforts in process-centered software engineering abound, PSEE technology has not received the attention that it deserves. In order to create a concise but effective and practically applicable evaluation framework for PSEEs, this paper first presents a survey of PSEEs and highlights the current state of the art of the technology. The PSEEs which have been reviewed herein have been regarded as software systems, and as such, have been characterized in terms of their... 

In this paper, we present design and implementation of TCvisor, a new trusted hypervisor. To this end, TCvisor provides a secure storage with different isolated view per user by using para-passthrough and combined key. In this regard, virtualization technology of processors has been used for complete isolation from operating system. By combining TPM base key, user's password and geo function key, TCvisor provides a secure storage in an environment with split data. We have applied feature wise security analysis TCvisor's secure storage from software system layers point then we have compared performance of TCvisor to selected candidates of existing layers  

As requirements and environments become much more complex, the need for self-adaptive and self-healing software system grows. There are several existing works which present such systems by using different approaches. Using alternative solutions to provide a service or requirement is one of the most important approaches among existing works. In this paper an alternative-based approach for adding self-adaptive capabilities to software systems is proposed. In this approach a group of autonomic elements will be constructed based on different design or implementations that could be considered for a specific service or requirement. By using this approach, a highly adaptive software system could be... 

Evaluating architectures and choosing the correct one is a critical issue in software engineering domain, in accordance with extremely extension of architecturedriven designs. In the first years of defining architecture styles, some special quality attributes were introduced as their basic attributes. After a moment, by utilizing them in practice, some results were obtained confirming some of attributes; some others meanwhile were not witnessed. As software architecture construction process is dependent on and addressed by both usage conditions and quality attributes, in this paper a framework has been proposed to provide an environment and a platform that can cover evaluation of... 

High availability of software systems is an essential requirement for pervasive computing environments. In such systems self-adaptation, using dynamic reconfiguration is also a key feature. However, dynamic reconfiguration potentially decreases the system availability by making parts of the system temporary frozen, especially during incomplete or faulty execution of the reconfiguration process. In this paper, we propose Assured Dynamic Reconfiguration Framework (ADRF), consisting of run-time analysis phases, assuring the desired correctness and completeness of dynamic reconfiguration process. We also specify factors that affect availability of reconfigurable software in pervasive computing... 

New Advances in mobile computer technology and the rapid growth of wireless networks in quality and quantity has introduced new applications and concerns in computer science and industry. The unique requirements and constraints associated with mobile systems have brought new challenges to software development for such environments, as it demands extensive improvements to traditional systems development methodologies in order to fulfill the special needs of this field. We examine the challenges of developing software for mobile systems, starting by reviewing mobile systems' characteristics and investigating the status quo of mobile software development methods. It has been shown that Agile... 

New Advances in mobile computer technology, along with rapid growth of quality and quantity of wireless networks, introduce new capabilities, applications, and concerns to computer science and industry. Unique requirements and constraints of mobile systems bring new challenges to software development for such environments. It demands reconsidering the traditional approaches of information access, software design, and performance evaluation. Despite the various constraints and problems, research endeavors aimed at ameliorating the status quo through enhancing/devising software design and performance evaluation techniques for mobile software systems have been relatively few and far in between.... 

None of the processing models in the software development has explained the software systems performance evaluation and modeling; likewise, there exist uncertainty in the information systems because of the natural essence of requirements and this may cause other challenges in the processing of software development. By the definition of UML extended version (Fuzzy UML), software functionality requirements that are stated in an uncertain way are supported; moreover, the concrete model is converted to formal model for modeling and performance evaluation of the software systems. This paper describes a methodology to develop a fuzzy coloured Petri net (F-CPN) model of a system. The F-CPN model... 

Due to the enlargement and complexity of software systems and the need for maintenance and update, success of systems depends strongly on their architecture. Software architecture has been a key element in software development process in two past decades. Therefore, choosing the correct architecture is a critical issue in software engineering domain, with respect to the extremely extension of architecturedriven designs. Moreover, software architecture selection is a multi-criteria decision-making problem in which different goals and objectives should be considered. In this paper, a Decision Support System (DSS) has been designed which provides software architects with more precise and... 

Constraint automata have been proposed as the operational semantics of Reo, a glue-code language for the exogenous composition and orchestration of components in a software system. In this paper we recast the theory of constraint automata into that of Büchi automata on infinite strings of records. We use records to express simultaneity constraints of I/O operations and show that every constraint automaton can be expressed as a Büchi automaton on an appropriate alphabet of records. Further, we give examples of component compositions that are expressible as Büchi automata but not as constraint automata. Finally, we show that the join composition operator for constraint automata and its... 

The continuing process of software systems enlargement in size and complexity becomes system design extremely important for software production. In this way, the role of software architecture is significantly important in software development. It serves as an evaluation and implementation plan for software development and software evaluation. Consequently, choosing the correct architecture is a critical issue in software engineering domain. Moreover, software architecture selection is a multicriteria decision-making problem in which different goals and objectives must be taken into consideration. In this paper, more precise and suitable decisions in selection of architecture styles have been... 

In the last two decades, a number of architecture-based software development notations, methods, techniques, and tools were formulated. Of particular interest to the software architecture researchers and practitioners were the notations and languages for modeling software architectures, known as ADLs. Object Stochastic Activity Network (OSAN) is a new model which inherits useful features from Petri nets, stochastic activity networks and queue networks, which made it a powerful and flexible tool to model concurrent systems and evaluate and verify them. This paper introduces OSAN as a new analyzable architecture description language, which can be used both for modeling architectural aspects of... 

Model-driven approaches to software engineering have expanded their influence in recent years, with Object Management Group's Model-Driven Architecture (MDA) being the major force behind this boost. However, despite its merits, MDA remains insufficient for software system development, in the sense that it does not provide a concrete and comprehensive process for governing software development activities. There is therefore a strongly felt need for new model-driven software development methodologies. In this paper we review a number of existing model-driven methodologies, and propose a general framework for Model-Driven Development (MDD) based on MDA. The framework can be used for assessing...