Research on the Component-based Software Architecture

Computer software has been becoming more and more c om plex with the development of hardware. Thus, how to efficiently develop extensib le, maintainable and adaptable software occurs to be an urgent problem. The comp onent-based software development technique is a better method to solve the prob lem. In this paper, we first discuss the concept, description method and some fa miliar styles of software architecture, and then analyze the merits of using the software architecture to guide the software development. We also present a gene ral design method for component. Its applications are finally provided.

Moving From Traditional Software Engineering to Componentware

The field of software engineering and software technology is developing very fast. Perhaps as a consequence, there is seldom enough interest or opportunity for systematic investigation of how the underlying technology will actually perform. That is, we introduce new concepts, methods, techniques and tools – or change existing ones and emphasize their value. A major turn in software engineering leading to Componentware has dramatically changed the shape of software development and introduced interesting methods for the design and rapid development of systems which may provide cost-effective benefits. In this paper we will discuss Componentware, process model, architecture, principles and the drivers, advantages, disadvantage and reveal profound changes from the traditional software engineering approaches.

Design Mode for Component-based Virtual Plant Software

According to the morphological structure characteristics of plants, the de- velopment mode for component-based virtual plants software was put forward, and the internal structure of plant organs component under this mode were analyzed, thereby, the overall design mode for virtual plants software was given out, and its characteristics were estimated. Compared with traditional development modes of virtual plants software, component-based virtual plants software had significant advantages in code reusing, development efficiency and expansion of software functions.

A component-based back-propagation reliability model with low complexity for complex software systems

Since most of the available component-based software reliability models consume high computational cost and suffer from the evaluating complexity for the software system with complex structures,a component-based back-propagation reliability model(CBPRM)with low complexity for the complex software system reliability evaluation is presented in this paper.The proposed model is based on the artificial neural networks and the component reliability sensitivity analyses.These analyses are performed dynamically and assigned to the neurons to optimize the reliability evaluation.CBPRM has a linear increasing complexity and outperforms the state-based and the path-based reliability models.Another advantage of CBPRM over others is its robustness.CBPRM depends on the component reliabilities and the correlative sensitivities,which are independent from the software system structure.Based on the theory analysis and experiment results,it shows that the complexity of CBPRM is evidently lower than the contrast models and the reliability evaluating accuracy is acceptable when the software system structure is complex.

SOFTWARE RELIABILITY MODEL FOR COMPONENT INTERACTION MODE

With the rapid progress of component technology,the software development methodology of gathering a large number of components for designing complex software systems has matured.But,how to assess the application reliability accurately with the information of system architecture and the components reliabilities together has become a knotty problem.In this paper,the defects in formal description of software architecture and the limitations in existed model assumptions are both analyzed.Moreover,a new software reliability model called Component Interaction Mode(CIM) is proposed.With this model,the problem for existed component-based software reliability analysis models that cannot deal with the cases of component interaction with non-failure independent and non-random control transition is resolved.At last,the practice examples are presented to illustrate the effectiveness of this model.

Towards a Component Framework for Architecture-Based Self-Adaptive Applications

Self-adaptive software is an efficient way to cope with highly dynamic nature of the environment where it is situated. In this paper, from the perspective of software architecture, we propose a component framework for supporting the architecture-based design and development of self-adaptive applications. It captures some key elements of the research on software architecture and provides more flexible facilities to decouple interacting components. Based on that, a prototype is implemented to demonstrate its feasibility, and at last a case study is presented to illustrate our framework.

Survivability of Components Assembly in Architecture

Based on the in-depth analysis of the interaction patterns between the components of software system in architecture, this paper illustrates that the association among them is complex and usually changeable during the running period. So we assume the interactions between two adjacency components are grouped into a single connector, which can be used to analyze the influence of components assembly on the survivability for software architecture. The survivability of the components assembly is mapped into the connectivity of graph model. We also bring forward a simplicity method to calculate and quantify the survivability of architecture that could provide a more usable model for designers to evaluate the architecture.

A distributed software architecture design framework based on attributed grammar

Software architectures shift the focus of developers from lines-of-code to coarser-grained architectural elements and their overall interconnection structure. There are, however, many features of the distributed software that make the developing methods of distributed software quite different from the traditional ways. Furthermore, the traditional centralized ways with fixed interfaces cannot adapt to the flexible requirements of distributed software. In this paper, the attributed grammar (AG) is extended to refine the characters of distributed software, and a distributed software architecture description language (DSADL) based on attributed grammar is introduced, and then a model of integrated environment for software architecture design is proposed. It can be demonstrated by the practice that DSADL can help the programmers to analyze and design distributed software effectively, so the efficiency of the development can be improved greatly.

SA BASED SOFTWARE DEPLOYMENT RELIABILITY ESTIMATION CONSIDERING COMPONENT DEPENDENCE

Reliability is one of the most critical properties of software system.System deployment architecture is the allocation of system software components on host nodes.Software Architecture(SA) based software deployment models help to analyze reliability of different deployments.Though many approaches for architecture-based reliability estimation exist,little work has incorporated the influence of system deployment and hardware resources into reliability estimation.There are many factors influencing system deployment.By translating the multi-dimension factors into degree matrix of component dependence,we provide the definition of component dependence and propose a method of calculating system reliability of deployments.Additionally,the parameters that influence the optimal deployment may change during system execution.The existing software deployment architecture may be ill-suited for the given environment,and the system needs to be redeployed to improve reliability.An approximate algorithm,A*_D,to increase system reliability is presented.When the number of components and host nodes is relative large,experimental results show that this algorithm can obtain better deployment than stochastic and greedy algorithms.

Representation and Adaptive Transformation of Reusable Software Components

The key ingredient for promoting software reuse in a repository base integrated development environment, is to provide support for the software developer who wants to search the repository to locate and retrieve suitable software components for reuse. This paper presents that reusable software components form a base to provide a flexible representation of component adaptability to any repository with a specific classification. As an alternative, it proposes to automatically identify and convert the component source code with all its information into a standard form, so that components can be transferred from one type of library to another.

The System for Managing Reusable Object-Oriented Software Components

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Process View of Reflection Mechanism for Reuse Software Architecture

Reflection mechanism for reuse software architecture （RMRSA） divides a software architecture into base-level architecture and meta-level architecture logically. Base-level architecture is the ordinary architecture; meta-level represents and manipulates the reusable meta-information of base-level architecture explicitly. Through reflection, the modification of meta-level architecture will result in the modification of the architecture in base-level. Then we can gain a new base-level architecture design. In this paper, we use π-calculus to define the constituents and their interaction processes of RMRSA, by these definition, we specify the business function in base-level at runtime, and illustrate the reflection mechanism between the base-level architecture and meta-level architecture.

Research on Software Architecture of the Extensible Services Router

With the rapid development of network technology, it is increasingly important to dynamically upgrade router’s software. In this paper, the authors present new software architecture to be applied to extensible services router. The novel feature of the architecture is the ability to dynamically load and configure extensible components at run time. Each component implements one function such as packets classification, packets scheduling and routing protocol. We design a simple configuration language (ESRCL) to configure and manage the router. The architecture can be configured according to the packet flows. At present, a prototype system based on highly efficient router operating system (HEROS) has been finished.

A Fuzzy Approach for Component Selection amongst Different Versions of Alternatives for a Fault Tolerant Modular Software System under Recovery Block Scheme Incorporating Build-or-Buy Strategy

Software projects generally have to deal with producing and managing large and complex software products. As the functionality of computer operations become more essential and yet more critical, there is a great need for the development of modular software system. Component-Based Software Engineering concerned with composing, selecting and designing components to satisfy a set of requirements while minimizing cost and maximizing reliability of the software system. This paper discusses the fuzzy approach for component selection using “Build-or-Buy” strategy in designing a software structure. We introduce a framework that helps developers to decide whether to buy or build components. In case a commercial off-the-shelf (COTS) component is selected then different versions are available for each alternative of a module and only one version will be selected. If a component is an in-house built component, then the alternative of a module is selected. Numerical illustrations are provided to demonstrate the model developed.

Autonomic Software Component QoS Matchmaking Algorithm Based on Fidelity Factor in Agent-Based Autonomic Computing System

Autonomic software component (ASC) QoS matchmaking problem for autonomic element has been taken as one of the most important issue in field of autonomic computing based on agent. Aimed at overcoming drawbacks such as subjec-tiveness and unfairness, and improving the self-configuration capability for autonomic element, we introduce evalua-tion mechanism of confidence of individual QoS attributes during ASC QoS matchmaking, i.e., fidelity factor for each attribute, and propose an ASC QoS matchmaking algorithm based on fidelity factor. Simulation experiments demon-strate that our proposed algorithm performs best performance in terms of QoS than other existing algorithms, and has better compromise between attribute quality and users’ evaluation when selecting ASC.

Component-Based Software Trustworthiness Fuzzy Analytic Hierarchy Process Model

For a more accurate and comprehensive assessment of the trustworthiness of component-based soft- ware system, the fuzzy analytic hierarchy process is introduced to establish the analysis model. Combine qualitative and quantitative analyses, the impacts to overall trustworthiness by the different types of components are distinguished. Considering the coupling relationship between components, dividing the system into several layers from target layer to scheme layer, evaluating the scheme advantages disadvantages by group decision-making, the trustworthiness of a typical J2EE structured component-based software is assessed. The trustworthiness asses model of the software components provides an effective methods of operation.

Testing Component-Based Software: What It has to do with Design and Component Selection

In a component-based software development life cycle, selection of preexisting components is an important task. Every component that has to be reused has an associated risk of failure of not meeting the functional and non-functional requirements. A component's failure would lead a developer to look for some other alternative of combinations of COTS, in-house and engineered components among possible candidate combinations. This means design itself can readily change. The very process of design of a software system and component selection seems to be heavily dependent on testing results. Instability of design, further, becomes more severe due to requirements change requests. Therefore, this instability of design has to be essentially mitigated by using proper design and testing approaches, otherwise, it may lead to exorbitantly high testing cost due to the repeated testing of various alternatives. How these three activities: Component-based software design, component selection and component-based software testing are interrelated? What process model is most suited to address this concern? This work explores the above questions and their implication in terms of nature of a process model that can be convincing in case of component-based software development.

3D Digital Design of Cranes' Structures Based on Hybrid Software Architecture

3D digital design for cranes’ structures based on hybrid software architecture of Client/Server and Browser/Server is introduced in this paper. Based on Pro/ENGINEER platform,3D parametric model family is built to allow generation of feasible configurations of cranes’ structures in Client/Server framework. Taking use of Visual C++,the second exploiting software kit provided by Pro/ENGINEER and ANSYS GUI/APDL modeling patterns,an integration method of 3D CAD and CAE is achieved,which includes regeneration of 3D parametric model,synchronous updating and analysis of FEA model. As in Browser/Server framework,the 3D CAD models of parts,components and the whole structure could also be displayed in the customer’s browser in VRML format.

Retrieving reuse component based on semantic

According to the current research status of component retrieval, the component description model based on facet classification is improved by adding semantic features. Furthermore, the component retrieval process model is put forward by combining the domain ontology with the relative concept match algorithm. A detailed illustration of a component reasoning engine and a component classification engine is given and the component classification algorithm is provided by using the Naive Bayes algorithm based on domain ontology. The experimental results show that the recall ratio and the precision ratio are obviously improved by using the method based on semantics, and demonstrate the feasibility and effectiveness of the proposed method.

Component-Based Software Reuseon the World Wide Web

Component-based software reuse (CBSR) has been widely used in software developing practice and has an even more brilliant future with the rapid extension of the Internet, because World Wide Web (WWW) makes the large scale of component resources from different vendors become available to software developers. In this paper, an abstract component model suitable for representing components on WWW is proposed, which plays important roles both in achieving interoperability among components and among reusable component libraries (RCLs). Some necessary changes to many aspects of component management brought by WWW are also discussed, such as the classification of components and the corresponding searching methods, and the certification of components.