A formal methodology using attributed grammars for multiprocessing-system software development. I. Design representation

With the growing complexity of multiprocessing systems and distributed computing systems, there is an increasing need to provide a formal methodology for deriving a model to represent software design for the software development of these systems. The formal methodology presented in this paper uses attributed grammars, and extends formal methods commonly used in the definition of programming languages and compiler techniques for representing the design specification of software systems and validating the implementation. This model provides a common basis in the software development phases through automated design analysis, test-case generation, and validation of the software system. This paper covers the construction of the model for the design representation using attributed grammar and the analysis of the software system design based on the model.     

基于特征模型的软件产品自动导出方法综述

在针对特定领域的软件复用中,产品导出是主要活动之一.产品导出指的是,开发人员基于领域中可复用的软件制品开发出所需的软件产品.在产品导出过程中,产品导出效率决定了软件复用的收益.在诸多影响产品导出效率的因素中,手工进行产品导出是拉低产品导出效率的主要因素之一,其最终会导致软件复用收益降低.为了提高产品的导出效率,相关研究提出了一些自动导出软件产品的方法.在这些方法中,一种普遍采用的指导思想是基于特征模型自动导出软件产品.在诸多使用该思想进行产品导出的方法中,各方法所使用的实现方式差异很大.为了给基于特征模型自动导出软件产品提供更好的支持,基于现有研究,提出了一个分类框架,并使用该框架对现有基于特征模型自动导出软件产品的方法进行了分类和比较.另外,还进一步指出了现有研究中的不足,并提出解决这些不足的设想.     

运用UML和XML构建通用远程教育系统的研究

针对目前各远程教育系统的资源描述和系统模型自成体系,无法实现教育资源的共享和系统的复用等问题,提出运用UML为系统建模,探讨用XML Schema定义描述教育资源XML文件的数据模型来实现教育资源元数据的互操作性,对远程教育系统中提高教育资源的可共享性和系统的互操作性以及可复用性具有重要的理论价值和实用性.     

基于领域特征空间的构件语义表示方法

在基于构件的软件开发范型中,构件模型是构件分类、检索和适应等关键任务的理论基础,然而构件模型中的语义表示方法一直是一个难点.提出一种以语义为核心的构件模型,采用基于领域分析的特征空间语义定义方法,从领域空间、定义空间和语境空间三个方面刻画语义结构,用描述逻辑表达语义内容及实现自动推理,尤其是文中的构件语义体概念和特征空间形式化方法,为构件复用自动化和工程化提供了一种可能的解决途径     

一个支持软件重用的信息检索系统—KDZ

软构件的有效组织与检索是软件重用技术的关键。本文介绍了一个支持软件重用的信息检索系统—KDZ。该系统以形式化方法描述软构件为基础,以重用理论为验证准则,通过项重写技术与检索技术相结合,使KDZ系统具有语义验证之功能。     

A part affordance-based approach for capturing detailed design knowledge

Design knowledge reuse is widely accepted as an effective strategy for designers to develop robust artifacts with less time and lower cost. However, there has been very little research on how to help designers capture detailed design knowledge for reuse. As a result, most detailed design knowledge still has to remain in designers’ memories as tacit knowledge, which can easily get lost due to oblivion or the mobility of designers. Therefore, this paper attempts to develop a part affordance-based approach for externalizing and capturing detailed design knowledge for effective reuse. It first introduces a part model for representing the detailed design-related information. Based on the relational theory for design, the concept, part affordance, is then employed to help designers externalize and capture various lifecycle factors that are implicit in a detailed design. Based on the affordance constraint axiom, a systematic approach is then proposed for deriving tacit design knowledge from captured part affordances through the analysis of extreme working situations. The proposed approach has been implemented as the Design Knowledge-Capturing System (DKCS). A fixture design case has been employed to illustrate the proposed approach.     

基于目标的软件可信性需求规约方法研究

高可信系统的软件规模不断扩大,其关键是分析并定义一致的可信需求描述,直接影响到需求规格说明的质量,进而影响到最终软件产品的质量。在目前公认的非功能需求规约框架的基础上,利用B抽象机理论,结合面向目标的规约方法,建立了一种可信性需求的分析与定义方法,即软件可信剖面。该方法可应用于UML,利用B抽象机理论,为可信性需求模型的定理化证明奠定了基础。     

VERTAF: an application framework for the design and verification of embedded real-time software

The growing complexity of embedded real-time software requirements calls for the design of reusable software components, the synthesis and generation of software code, and the automatic guarantee of nonfunctional properties such as performance, time constraints, reliability, and security. Available application frameworks targeted at the automatic design of embedded real-time software are poor in integrating functional and nonfunctional requirements. To bridge this gap, we reveal the design flow and the internal architecture of a newly proposed framework called verifiable embedded real-time application framework (VERTAF), which integrates software component-based reuse, formal synthesis, and formal verification. A formal UML-based embedded real-time object model is proposed for component reuse. Formal synthesis employs quasistatic and quasidynamic scheduling with automatic generation of multilayer portable efficient code. Formal verification integrates a model checker kernel from SGM, by adapting it for embedded software. The proposed architecture for VERTAF is component-based and allows plug-and-play for the scheduler and the verifier. Using VERTAF to develop application examples significantly reduced design effort and illustrated how high-level reuse of software components combined with automatic synthesis and verification can increase design productivity.     

ARIFS:: an Environment for Incomplete and Formal Specifications

The selection of appropriate components for satisfying a given equirement is a key problem in software reuse. Although this problem is remarkable in the reuse of software within same domain or application area, which is known as vertical reuse, it is more pronounced in horizontal reuse, that is, the reuse of software elements in different application areas. This paper describes how ARIFS tool (Approximate Retrieval of Incomplete and Formal Specifications) provides a suitable reusing environment to classify, retrieve and adapt formal and incomplete requirements specifications. Both classification and retrieval tasks are based on functional similarities according to structural closeness, which provides a suitable basis for horizontal reuse; and semantic closeness, which is more appropriated for vertical reuse. To this effect, we define four partial ordering relations among reusable components and different measures to quantify functional differences among them. By using these measures we are able to offer an approximate and efficient retrieval, without formal proofs, and to predict adaptation efforts to satisfy the required functional specification.     

Assessing the cost-effectiveness of software reuse: A model for planned reuse

Information systems development is typically acknowledged as an expensive and lengthy process, often producing code that is of uneven quality and difficult to maintain. Software reuse has been advocated as a means of revolutionizing this process. The claimed benefits from software reuse are reduction in development cost and time, improvement in software quality, increase in programmer productivity, and improvement in maintainability. Software reuse entails undeniable costs of creating, populating, and maintaining a library of reusable components. There is anecdotal evidence to suggest that some organizations benefit from reuse. However, many software developers practicing reuse claim these benefits without formal demonstration thereof. There is little research to suggest when the benefits are expected and to what extent they will be realized. For example, does a larger library of reusable components lead to increased savings? What is the impact of component size on the effectiveness of reuse? This research seeks to address some of these questions. It represents the first step in a series wherein the effects of software reuse on overall development effort and costs are modeled with a view to understanding when it is most effective.     

基于本体的领域分析

软件复用被认为是改善软件质量和提高软件生产力最有希望的技术。为了支持复用,软件开发过程必须考虑两个方面的问题:为复用开发和用复用开发。本体逐渐成为构建信息系统、提供知识共享和复用的重要机制。领域分析是软件复用工程中最重要的工作。本课题利用本体的概念,讨论了领域分析技术中的领域本体的概念、领域本体的形式化描述,本体模型的UML表达,并给出基于本体的领域分析过程,以期对软件复用工程的领域分析过程有所改进。     

Automatic synthesis and verification of real-time embedded software for mobile and ubiquitous systems

Currently available application frameworks that target the automatic design of real-time embedded software are poor in integrating functional and non-functional requirements for mobile and ubiquitous systems. In this work, we present the internal architecture and design flow of a newly proposed framework called Verifiable Embedded Real-Time Application Framework (VERTAF), which integrates three techniques namely software component-based reuse, formal synthesis, and formal verification. Component reuse is based on a formal unified modeling language (UML) real-time embedded object model. Formal synthesis employs quasi-static and quasi-dynamic scheduling with multi-layer portable efficient code generation, which can output either real-time operating systems (RTOS)-specific application code or automatically generated real-time executive with application code. Formal verification integrates a model checker kernel from state graph manipulators (SGM), by adapting it for embedded software. The proposed architecture for VERTAF is component-based which allows plug-and-play for the scheduler and the verifier. The architecture is also easily extensible because reusable hardware and software design components can be added. Application examples developed using VERTAF demonstrate significantly reduced relative design effort as compared to design without VERTAF, which also shows how high-level reuse of software components combined with automatic synthesis and verification increases design productivity.     

提高SoC设计效率的基于组件方法综述

片上系统本身的异构性和并发性导致了对系统进行统一建模的困难,从而阻碍了设计效率的提高.对现有系统级方法的分析表明:这类方法不能对不同设计之间更加细节的共同特性进行抽象,限制了复用的范围,不能带来设计效率的进一步提高.因此,通过对面向对象设计、软件工程、形式化语义和系统级EDA这4种基于组件方法描述模型及其对复用影响的讨论,确定了系统的刻画特征,采用这些特征来描述片上系统将带来设计效率的提高.     

基于Rebeca模型的硬件设计形式化验证

形式化验证是对传统验证方法的补充,是数字电路验证的一条有效途径,对于并发系统,行为建模是一种非常合适的建模方法;Rebeca是由Sirjani和Movaghar提出的一种基于行为的建模语言,支持形式化,一方面,Rebeca是一种类Java的语言,软件工程师很容易使用,另一方面,它是一种支持形式化验证及其相关理论的模型语言,可以为不精通于形式化方法的开发人员和研究人员提供方便的验证过程;在深入研究Rebeca的基础上,采用Rebeca对硬件设计进行建模,然后Modere形式化验证工具对AES密码芯片进行形式化验证。     

MiRA—Mixed Reality Agents

In recent years, an increasing number of Mixed Reality (MR) applications have been developed using agent technology — both for the underlying software and as an interface metaphor. However, no unifying field or theory currently exists that can act as a common frame of reference for these varied works. As a result, much duplication of research is evidenced in the literature. This paper seeks to fill this important gap by outlining “for the first time” a formal field of research that has hitherto gone unacknowledged, namely the field of Mixed Reality Agents (MiRAs), which are defined as agents embodied in a Mixed Reality environment.Based on this definition, a taxonomy is offered that classifies MiRAs along three axes: agency, based on the weak and strong notions outlined by Wooldridge and Jennings (1995); corporeal presence, which describes the degree of virtual or physical representation (body) of a MiRA; and interactive capacity, which characterises its ability to sense and act on the virtual and physical environment.Furthermore, this paper offers the first comprehensive survey of the state-of-the-art of MiRA research and places each project within the proposed taxonomy. Finally, common trends and future directions for MiRA research are discussed.By defining Mixed Reality Agents as a formal field, establishing a common taxonomy, and retrospectively placing existing MiRA projects within it, future researchers can effectively position their research within this landscape, thereby avoiding duplication and fostering reuse and interoperability.     

ON ANALOGY FOR SOFTWARE REUSE: A PERSPECTIVE FROM CYBERNETICS

Principles developed in cybernetics and systems theory can offer meaningful hindsight to research and development in computer science and may also provide some kind of guidance to the future study of computer science. In this paper we provide some comments on the role of analogy in software reuse from the perspective of cybernetics. Our purpose is to encourage a dialogue between researchers in software engineering and those in the study of cybernetics and systems. Three aspects of cybernetics are examined: the two-dimensional nature of cybernetics and systems theory, software reuse as a form of self-adaptation that originated from the abstract schema implied by analogy, and the nonrational cognitive process involved in using analogy for software reuse. We hope that cybernetics can provide meaningful insight related to analogy in software reuse; we also hope this kind of study will benefit cybernetics itself.     

基于刻面描述的构件检索

随着软件复用实践的深入和软件构件库规模的扩大,对软件构件的表示与检索的研究正受到越来越多的重视.针对基于刻面描述的软件构件,结合模式分析中的树匹配思想,根据构件刻面描述的特点,提出了一种基于树包含(tree inclusion)的构件检索方法,并进行了理论上的分析与实验上的检验.实验结果证明了它的可行性与有效性.     

DSSRE：基于WWW的分布式软件重用支撑环境

软件重用被视为解决软件危机、提高软件生产率和质量的有效途径。传统的软件重用的活动仅限于机构或企业的内部,随着Internet应用的逐渐普及,WWW已经发展成为一个巨大的分布式信息空间,为用户提供了一个极具价值的信息源,也对软件重用技术产生了重大的影响。其跨平台、分布式的特点为软件重用的应用实践活动开辟了广阔的前景。文中提出了在WWW上开发软件重用环境的思想,并由此设计了DSSRE系统。该系统基于SSRE,并了一个分布式、面向对象的支持软件重用的开发环境。     

The impact of software evolution and reuse on software quality

This paper presents a case study of a software project in the maintenance phase. The case study was based on a sample of modules, representing about 1.3 million lines of code, from a very large telecommunications system. Software quality models were developed to predict the number of faults expected from the coding through operations phases. Since modules from the prior release were often reused to develop a new release, one model incorporated reuse data as additional independent variables. We compare this model's performance to a similar model without reuse data.Software quality models often have product metrics as the only input data for predicting quality. There is an implicit assumption that all the modules have had a similar development history, so that product attributes are the primary drivers of different quality levels. Reuse of software as components and software evolution do not fit this assumption very well, and consequently, traditional models for such environments may not have adequate accuracy. Focusing on the software maintenance phase, this study demonstrated that reuse data can significantly improve the predictive accuracy of software quality models.