Sharif Digital Repository

Update of software usually equates disruption to a program's execution. However, such disruptions in the execution of applications that provide round-the-clock services is not desirable. Examples of such applications include multi-tier enterprise systems with which users may interact via distinct presentation tiers at the same time. Existing software updating systems do not operate in the enterprise applications, or they need most of the redeployment tasks to be performed manually. In this paper, we present a framework capable of Automatically Redeploying Enterprise Software Applications (ARESA). This system combines the idea of incremental and integral updates to preserve the consistency of... 

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... 

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  

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... 

Stochastic activity networks (SANs) are a stochastic generalization of Petri nets. SAN models have been used to evaluate a wide range of systems and are supported by several modeling tools. We have introduced object stochastic activity networks (OSANs) to overcome some restrictions of these models. OSANs integrate the concepts of object-orientation into SAN models. Elements of OSANs and their submodels are defined as classes. OSANs are more appropriate that most other objectoriented or high-level extensions of Petri nets for application on software systems. In this paper, we will present the definitions, behavior and an example of OSAN models. The objectorientation of OSANs and the... 

Reo is a connector language for the exogenous composition and orchestration of components in a software system. An operational semantics of Reo connectors can be given in terms of Büchi automata over a suitable alphabet of records, capturing both synchronization and context dependency requirements. In this paper, we define an action based linear time temporal logic for expressing properties of Reo connectors. Formulas can be synthesized into Büchi automata representing Reo connectors, thus leading to an automata based model checking algorithm. By generalizing standard automata based model checking algorithms for linear time temporal logic, we give an efficient on-the-fly algorithm for the... 

It is now a common approach pursued by programmers to develop new software systems using Object-Oriented Application Frameworks such as Spring, Struts and, Eclipse. This improves the quality and the maintainability of the code. Furthermore, it reduces development cost and time. However, the main problem is that these frameworks usually have a complicated Application Programming Interface (API), and typically suffer from the lack of enough documentation and appropriate user manuals. To solve these problems, programmers often refer to existing sample applications of those frameworks to learn how to implement the desired functionality in their own code. This is called the Monkey See, Monkey Do... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

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... 

In software systems development lifecycle making use of software architecture, especially by taking advantage of architecture styles and patterns, is an essential part which increases product's quality. Nowadays, in order to cover complexity of systems, combination of different architecture styles should be used; therefore ambiguous behaviors might occur. Hence, due to the critical need for toolsets capable of selecting suitable styles and patterns, an environment is proposed in this paper which can perfectly cover different aspects of the implementation of decision support system (DSS). The designed environment obviates data implementation concepts and security considerations. Moreover, it... 

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...