Sharif Digital Repository

Object-oriented frameworks are widely used to develop new applications. They provide reusable concepts that are instantiated in application code through potentially complex implementation steps such as subclassing, implementing interfaces, and calling framework operations. Unfortunately, many modern frameworks are difficult to use because of their large and complex APIs and frequently incomplete user documentation. To cope with these problems, developers often use existing framework applications as a guide. However, locating concept implementations in those sample applications is typically challenging due to code tangling and scattering. To address this challenge, we introduce the notion of... 

Nano-micro grippers are able to pick-transport-place the micro or nanometer -sized materials, such as manipulation of biological cells or DNA molecules in a liquid medium. This paper proposes a novel monolithic nano-micro gripper structure with two axis piezoresistive force sensor which its resolution is under nanoNewton. The results of the study have been obtained by the simulation of the proposed gripper structure in Matlab software. Motion of the gripper arm is produced by a voice coil actuator. The behavior of the cell has been derived using the assumptions in the literatures. Moreover, two simple PID controllers, one for control of the gripper motion and another for control of the force... 

A nonlinear inverse finite element method is developed for estimation of initial blank shape and strain distribution in final shape. This method often based on implicit static algorithms, causes sometimes convergence problems because of strong nonlinearities. In order to avoid the converging problems, especially in the quasi vertical walls, an appropriate initial guess is introduced. By using this initial guess, the number of iterations in the nonlinear numerical solution is decreased, solution speed is significantly increased and complicated geometries can be analyzed by this method with good accuracy. Application to a Srail part shows good agreement between commercially available finite... 

This paper presents an event-driven simulation-based optimization method for solving the train timetabling problem to minimize the total traveling time in the hybrid single and double track railway networks. The simulation approach is well applied for solving the train timetabling problems. In present simulation model, the stations and block sections of the railway network are respectively considered as the nodes and edges of the network model. The developed software named SIMARAIL has the capability of scheduling trains in large scale networks respecting the capacity constraints and infrastructure characteristics. This simulation model for railway timetabling is based on a detailed... 

This paper proposes a control strategy for the autonomous (islanded) operation of a four-wire, electronically-coupled distributed generation (DG) unit which can feed a highly unbalanced load, e.g., due to the presence of single-phase loads. In the grid-connected mode, the power-electronic interface of the DG unit enables the exchange of real and reactive power with the distribution network, based on the conventional dq-frame current control strategy. The current control scheme is disabled subsequent to the detection of an islanding event, and the proposed controller is activated. The proposed control strategy utilizes: i) an internal oscillator to maintain the island frequency and ii) a... 

The increase in complexity and rate of technological changes in modern software development has led to a demand for systematic methods that raise the abstraction level for system maintenance and regression testing. Model-driven development (MDD) has promised to reduce extra coding efforts in software maintenance activities using traceable change management. The research described in this paper presents a Z-notation-based framework, called delta-based regression testing (DbRT), for formal modeling of regression testing in the context of MDD. The framework proposes to propagate the changes from a software specification to testing artifacts in order to preserve consistency after system... 

Exceptions are an indispensable part of the software development process. However, developers usually rely on imprecise results from a web search to resolve exceptions. More specifically, they should personally take into account the context of an exception, then, choose and adapt a relevant solution to solve the problem. In this paper, we present Exception Tracer, an Eclipse plug in that helps developers to resolve exceptions with respect to the stack trace in Java programs. In particular, Exception Tracer automatically provides candidate solutions to an exception by mining software systems in the Source Forge, as well as listing relevant discussions about the problem from the Stack Overflow... 

Nowadays, knowledge is the key to success in all software engineering processes. This valuable knowledge, obtained through analysis, design, development, and maintenance processes of the system, should be saved and reused in designing and developing current and similar systems. Using pre-existing knowledge is a practical approach which reduces design complexity, improves software architecture design and manages software quality. In this paper, we describe an approach to create architecture design knowledge using a hierarchical structure of architectural styles based on quality attributes. Knowledge is most importance asset of our approach that reuses similar domains, correlates architectures... 

In this study nickel ferrite magnetic nanoparticles were applied as an efficient and reusable catalyst in the four-component synthesis of substituted pyrroles under neat conditions. The reaction was conducted using various amounts of catalyst at different temperatures and finally, application of 5 mol% of catalyst at 100 °C was determined as the optimum reaction condition. Results showed that nickel ferrite nanoparticles could catalyze the reaction at relatively short times (3-4 h) with high to excellent yields (70-96%). The catalyst could be recovered easily using an external magnetic field and reused nine times without any significant activity lost  

Experimental and theoretical results of a two-stage beam shaping system based on a flexible plastic fiber-bundle and a prism duct are described in this study. An imaging technique is used to investigate the divergence effect on the output beam images and intensity profiles. Photograph pictures of the output beam at different axial distances are taken by a digital camera and the image data is converted into a response curve and presented in this study. According to the experimental results, the propagation in the free space transforms a square beam with a hat-top intensity distribution into a rectangular beam with a conical intensity distribution. For theoretical investigations, using VOB... 

In this paper the Contour Integral (CI) method is applied to the design and analysis of substrate integrated waveguide (SIW) filters. This method is used for planar structures and is based upon the discretization of the boundary of the structure and needs less memory than full wave methods. For decreasing the computation time, circular vias replaced by square ones. A four pole Chebyshev X band dual inductive post substrate integrated waveguide filter is designed using this technique and the results are compared with measurements and simulation software Ansoft HFSS. Good agreement is seen between the results  

Reusing the programs which have already been developed can shorten the production time and reduce costs and expenses. One of the important issues in software reuse is finding a program or a program component in a program library which has been already developed and using it in the new program. In view of precision and automation that formal methods can provide, we can use formal methods in retrieval appropriate components from the software libraries. In this paper, some of the works done in the field of retrieval of the components from the libraries by the help of formal methods have been surveyed and reviewed  

It has become essential to scrutinize and evaluate software development methodologies, mainly because of their increasing number and variety. Evaluation is required to gain a better understanding of the features, strengths, and weaknesses of the methodologies. The results of such evaluations can be leveraged to identify the methodology most appropriate for a specific context. Moreover, methodology improvement and evolution can be accelerated using these results. However, despite extensive research, there is still a need for a feature/criterion set that is general enough to allow methodologies to be evaluated regardless of their types. We propose a general evaluation framework which addresses... 

One of the major challenge and time-consuming work is optimum test data generation to assure software quality. Researchers have proposed several methods over years to generate automatically solution which have different drawbacks. In this paper, we propose Genetic Algorithm (GA) based tester with different parameters to automate the structural-oriented test data generation on the basis of internal program structure. Our proposed fitness function is intended to traverse paths of the program as more as possible. This integration improves the GA performance in search space exploration and exploitation fields with faster convergence. At last, we present some results according to our experiment... 

This paper introduces a new framework included mathematical model and a new software package interfacing two powerful softwares (MATLAB and GAMS) for obtaining the optimal distributed generation (DG) capacity sizing and sitting investments with capability to simulate large distribution system planning. The proposed optimization model allows minimizing total system planning costs for DG investment, DG operation and maintenance, purchase of power by the distribution companies (DISCOs) from transmission companies (TRANSCOs) and system power losses. The proposed model provides not only the DG size and site but also the new market price as well. Three different cases depending on system... 

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... 

Focusing on aspects during early stages of the software development lifecycle has received special attention by many researchers, leading to the advent of numerous Aspect-Oriented Software Development (AOSD) methods. This has consequently given a relatively high level of maturity to aspect-oriented processes. Process patterns, on the other hand, have been adopted as suitable mechanisms for defining or tailoring processes to fit specific organizational/project requirements. Process patterns, which essentially are reusable process components extracted from successful processes and practices, can be used to engineer new software development methodologies or to enhance existing ones. We propose... 

During the past decade, Electro-Hydraulic system has performed a significant role in industrial engineering as an actuator for high performance and precision positioning applications. In this case, many control methods have been developed for an electro-hydraulic actuated clutch. In this paper a Linear Quadratic Regulators (LQR) is proposed to trajectory control of a wet clutch actuated by a hydraulic servo valve mechanism. Simulation study was performed using linearized mathematical model of the system implemented in MATLAB software. Based on the simulation results performance of the proposed controller was evaluated and discussed  

Context constructing bespoke software development methodologies for specific project situations has become a crucial need, giving rise to Situational Method Engineering (SME). Compared with Software Engineering, SME has a long way to go yet; SME approaches are especially deficient as to support for modeling, portability, and automation. Model-Driven Development (MDD) has been effectively used for addressing these issues in Software Engineering, and is also considered a promising approach for resolving them in SME. Objective This paper aims to address the shortcomings of existing SME approaches by introducing a novel MDD approach, specifically intended for SME purposes, that uses a... 

A great amount of effort has been made in order to reach a more precise understanding of the adhesion phenomenon that happens as a vital component of several biological systems. Therefore, a firm understanding of the important factors that influence this phenomenon is of special importance in triggering the adhesive characteristics of different biological, bio-inspired and synthetic materials in fields such as tissue engineering. In this study the adhesive characteristics of a multi-material system consisting of the frequently used synthetic material, graphene, in the form of armchair-configuration sheets, and an important biological filament which is type 1 Collagen consisting of 3 alpha...