Jingjun Zhang

Research on Reusability of Software Connector Based on AOP

With the increasing complexity of software system, the reusable design and implementation of connector are becoming more and more significant for software architecture. However, some non-functional concerns (e.g. safety and quality etc.) provided by connector have crosscutting attributes, and which often cause connector hard to reuse. Therefore this paper presents an aspect-oriented approach to improve reusability of connector at architectural level. By introducing aspect to connector, we extend the basic elements of connector by two means: 1) taken non-functional concern as a new entity, and 2) encapsulated with advice. Then we set up the model of aspect connector, and describe it in ADL extension. Furthermore, we also give the reusable process of connector. Finally, with a case, we prove that our proposal can provide an effective solution to enhance the reusability of connector.

Mapping Features to Architectural Components in Aspect-Oriented Software Product Lines

Software product lines (SPLs) based development aims at saving development cost as well as reducing time-to-market by structured reuse of base assets for a group of similar products. Requirements of a product line are organized into features in feature-oriented analysis (FOA) approach. Commonalities and variabilities among products in a product line are showed in the features. The effectiveness of a SPL approach depends on how well features variabilities are implemented and managed. Because there is cross-cutting among the features, it is difficult to implement these features into architectural components. In recent years some papers introduced aspect-oriented techniques into SPLs to modularized the variable features. In this paper we describe the role of aspects in software product lines. According to the role of aspects, we classify the features and propose a process to map features to architectural components in an aspect-oriented product line engineering (AOPLE).

Optimal design of fuzzy logic controller for multi-body model of semi-active suspension based on genetic algorithm

This paper presents a novel control scheme for the multi-body semi-active suspension system. The proposed scheme is composed of two parts: a multi-body model of the semi-active suspension system and a genetic algorithm-based fuzzy logic controller. With the fast development of computers, multi-body model and multi-body systems dynamics are applied to a broad variety of engineering problems. In this work, ADAMS software is utilized to complete the multi-body model of a full car semi-active suspension system. In order to control the suspension system efficiently, a fuzzy logic controller is developed in MATLAB/Simulink environment. The kernel of the fuzzy logic controller is a set of linguistic control rules. The conventional fuzzy control rules are established by the knowledge and experience of expertise or skilled operator. In other words, the rules are dependent on the knowledge and the experience of expertise, and may not be optimal. So, in this paper, a fuzzy logic controller is developed to generate the rule table automatically based on the improved genetic algorithm. To verify the performance of the genetic algorithm-based controller, simulations were simulated with random road profile at two different speeds, 25m/sec and 35m/sec, to demonstrate the effectiveness of the proposed control system in comparison with the passive suspension response. It was shown that this developed fuzzy logic controller based on genetic algorithm enhances the performance of the full car suspension system significantly. This control system is suitable for the multi-body model and can be extended to other applications of the mechanical systems.

A joint optimization method of genetic algorithm and numerical algorithm based on MATLAB

The mathematic model of a two-bar truss is built in MATLAB and the analysis is carried out by the genetic algorithm toolbox. In order to compare with each other, the parametric model of the planar truss is also established by the ANSYS Parametric Design Language and solutions are obtained using the first-order method native to ANSYS. The comparison of the results shows that genetic algorithms do not always display better properties than other algorithms for some problems. Finally, a joint optimization method which combines MATLAB genetic algorithm toolbox and the numerical algorithm based on the quasi-Newton method is proposed. Then the method is identified through the numerical example of the two-bar truss. The simulation results indicate that the joint optimization method can always converge to the global optimal solution.

An Improved Method of Structural Optimization Based on ANSYS

Because of the deficiency existing in both zero-order algorithm and first-order algorithm of ANSYS, this paper presents an improved method combining with both algorithms. Firstly, the zero-order algorithm is adopted to confirm the approximate location of the optimal solution, which will not be trapped into local optimum solutions. Secondly, the first-order algorithm is applied to determine the best solution by executing restart of optimization design. Finally, the improved method is examined through a numerical example by virtue of ANSYS10.0 and MATLAB7.0. The simulation results indicate that this method is more effective than traditional methods and advantages of it are much more remarkable when it is applied to complicated engineering structures.

Aspect-oriented modeling and mapping driven by Model Driven Architecture

Model Driven Architecture (MDA) is a development methodology taking model as center, which is initiated by the Object Manage Group. Based on UML and other standard etc, MDA can create highly abstract model that will be understood by computer. These models are independent of concrete platform technology and stored in a standard way. Based on Object-Oriented, Aspect-Oriented Programming (AOP) went further on the principle of Concern Separation. It separates the crosscutting concerns in the independent aspect modular. AOP has now matured to become a complete methodology, hoping to present its benefits in the whole development cycle. Aspect-Oriented Modeling in the Framework of MDA needs extend the UML meta-model, establish aspect oriented meta-model and AspectJ meta-model, in order to define aspect Platform-Independent Models (PIM) and Platform-Specific Models (PSM). In this paper, we give a method of aspect-oriented modeling, some rules to transform aspect PIM to aspect PSM to support aspect-oriented software development in the framework of MDA.

The Role of Aspects in Software Product Lines

Software product lines (SPLs) based development aims at saving development cost as well as reducing time-to-market by structured reuse of base assets for a group of similar products. Requirements of product line are organized into features in FOA (Feature-Oriented Analysis) approach. Commonalities and variabilities among products in a product line are showed in the features. The effectiveness of a SPL approach depends on how well feature variability is implemented and managed. Because there is crosscutting among the features, it is difficult to implement these features into architectural components. In recent years some papers introduce aspect-oriented techniques into SPL to modularize the variable features. In this paper we describe the role of aspects in software product lines from 3 phases, showing their ability for encapsulating variable features into architectural components, and demonstrating how software product lines benefit from adopting aspect-oriented software development concepts.

A Management Information System based on AOP

Since the object oriented programming (OOP) approach can solve the problems of the procedural language efficiently, a majority of software projects adopt this programming paradigm which is used popularly nowadays, however, it cannot efficiently solve the problem that arise from the cross-cutting concerns such as scattered codes and tangled codes with poor readability and low reuse of the codes. So we introduce a new programming paradigm called aspect-oriented programming (AOP), a new promising method that can resolve the problem putting forward above, which makes developer separate the task such as cross-cutting concerns which should not be tangled together. At this issue, we introduce a mature language realizing the technology AOP called AspectJ, and some relating concepts we will use. We show the advantage of this new programming method through a management information system which using AOP method in the authentication and authorization, analyzing the direction of the software development.

Studying of fuzzy logic control semi-active suspension based on improved genetic algorithm

Establishing a 2-DOFs of 1/4 semi-active suspension system model, Using genetic algorithm approach, fuzzy logic controller of the semi-active suspension was designed, simulated in the environment of Matlab/Simulink. The results of compared with the passive suspension demonstrate that this developed fuzzy logic controller based on genetic algorithm enhances the performance of the full car suspension system significantly.

The application of co-simulation technology of ANSYS and MSC.ADAMS in structural engineering

The combination of ANSYS and ADAMS can improve the precision of system simulation. In this paper, first, a cable-stayed space truss, consisting of stay cables, columns, and the space truss, is built in ANSYS. Second, the modal neutral file (mnf) needed in ADAMS is generated by executing the macro command “ADAMS” and then imported into ADAMS software. Third, the flexible body in the mnf file is connected to the rigid body built in ADAMS through the external nodes specified in ANSYS, and then the dynamic analysis can be carried out. Subsequently, the load file needed by ANSYS could be obtained by clicking on the menu “File Export”. Finally, the load file is imported into ANSYS software by the APDL language and the static analyses corresponding to different load steps are carried out. The simulation analysis shows a good performance and some results we are interested in are obtained.