形式化描述语言B的面向对象机制研究

在分析B语言和面向对象方法的基础上,提出一种具有面向对象特性的形式化描述语言B ,该语言克服原有B语言没有机制形式描述一系列实例变量和不确定的行为的缺点。     

An object-oriented software life cycle of an intelligent tutoring system

Abstract  This paper describes the application of an object-oriented model of life cycle in the development of an intelligent tutoring system for secondary students in the domain of algebraic powers. The system is called EasyMath and has been developed using the Rational Unified Process, which is an object-oriented process proposed for use with the Unified Modelling Language. The Rational Unified Process supports multiple recursions of the phases of the software life cycle. This has been enriched to include empirical studies and formative evaluations appropriate for knowledge-based educational software.     

面向对象技术的机器翻译系统的设计与实现

在分析以往机器翻译系统的基础上,针对以信息提取为目的的机器翻译系统在行业内的应用提出了一个基于面向对象技术（OOT）的机器翻译系统的模型,并在文中给出了该模型的面向对象描述,利用该模型可以快速建立灵活的机器翻译系统。     

Design-code traceability recovery: selecting the basic linkage properties

Traceability ensures that software artifacts of subsequent phases of the development cycle are consistent. Few works have so far addressed the problem of automatically recovering traceability links between object-oriented (OO) design and code entities. Such a recovery process is required whenever there is no explicit support of traceability from the development process. The recovered information can drive the evolution of the available design so that it corresponds to the code, thus providing a still useful and updated high-level view of the system.

Automatic recovery of traceability links can be achieved by determining the similarity of paired elements from design and code. The choice of the properties involved in the similarity computation is crucial for the success of the recovery process. In fact, design and code objects are complex artifacts with several properties attached. The basic anchors of the recovered traceability links should be chosen as those properties (or property combinations) which are expected to be maintained during the transformation of design into code. This may depend on specific practices and/or the development environment, which should therefore be properly accounted for.

In this paper different categories of basic properties of design and code entities will be analyzed with respect to the contribution they give to traceability recovery. Several industrial software components will be employed as a benchmark on which the performances of the alternatives are measured.     

The transformation and analysis of networks by means of computer algorithms

This paper describes the analysis of networks, using digital computers. If the nodes of the network are assigned alpha-numeric symbols, the network is said to be alpha-numerical. The paper describes transforma-tions of non-directed alpha-numeric networks: edges are separated and rearranged so as to form new networks. The results of these investiga-tions lead to the formulation of algorithms, which have been programmed and solved on a ZUSEZ 22 digital computer. Networks are stored as incidence matrices and transformed by matrix operations. Transforma-tions which are effected by separation and rejoining of at most two edges, are called elementary transformations. It will be shown that every struc-tural transformation can be represented as a logical consequence of elementary transformations. Our investigations permit the following ex-positions:

Alpha-numerical networks can be interpreted as chemical structure formulae; transformations can be interpreted as chemical reactions.     

An ontology of slums for image-based classification

Information about rapidly changing slum areas may support the development of appropriate interventions by concerned authorities. Often, however, traditional data collection methods lack information on the spatial distribution of slum-dwellers. Remote sensing based methods could be used for a rapid inventory of the location and physical composition of slums. (Semi-)automatic detection of slums in image data is challenging, owing to the high variability in appearance and definitions across different contexts. This paper develops an ontological framework to conceptualize slums using input from 50 domain-experts covering 16 different countries. This generic slum ontology (GSO) comprises concepts identified at three levels that refer to the morphology of the built environment: the environs level, the settlement level and the object level. It serves as a comprehensive basis for image-based classification of slums, in particular, using object-oriented image analysis (OOA) techniques. This is demonstrated by with an example of local adaptation of GSO and OOA parameterization for a study area in Kisumu, Kenya. At the object level, building and road characteristics are major components of the ontology. At the settlement level, texture measures can be potentially used to represent the contrast between planned and unplanned settlements. At the environs level, factors which extend beyond the site itself are important indicators, e.g. hazards due to floods plains and marshy conditions. The GSO provides a comprehensive framework that includes all potentially relevant indicators that can be used for image-based slum identification. These characteristics may be different for other study areas, but show the applicability of the developed framework.     

Fault prediction and the discriminative powers of connectivity-based object-oriented class cohesion metrics

Context

Several metrics have been proposed to measure the extent to which class members are related. Connectivity-based class cohesion metrics measure the degree of connectivity among the class members.

Objective

We propose a new class cohesion metric that has higher discriminative power than any of the existing cohesion metrics. In addition, we empirically compare the connectivity and non-connectivity-based cohesion metrics.

Method

The proposed class cohesion metric is based on counting the number of possible paths in a graph that represents the connectivity pattern of the class members. We theoretically and empirically validate this path connectivity class cohesion (PCCC) metric. The empirical validation compares seven connectivity-based metrics, including PCCC, and 11 non-connectivity-based metrics in terms of discriminative and fault detection powers. The discriminative-power study explores the probability that a cohesion metric will incorrectly determine classes to be cohesively equal when they have different connectivity patterns. The fault detection study investigates whether connectivity-based metrics, including PCCC, better explain the presence of faults from a statistical standpoint in comparison to other non-connectivity-based cohesion metrics, considered individually or in combination.

Results

The theoretical validation demonstrates that PCCC satisfies the key cohesion properties. The results of the empirical studies indicate that, in contrast to other connectivity-based cohesion metrics, PCCC is much better than any comparable cohesion metric in terms of its discriminative power. In addition, the results also indicate that PCCC measures cohesion aspects that are not captured by other metrics, wherein it is considerably better than other connectivity-based metrics but slightly worse than some other non-connectivity-based cohesion metrics in terms of its ability to predict faulty classes.

Conclusion

PCCC is more useful in practice for the applications in which practitioners need to distinguish between the quality of different classes or the quality of different implementations of the same class.     

基于图像核心库的SAR图像处理平台的开发模式

设计了一个基于二维矩阵类的图像核心库，巧妙地将图像处理的各个流程进行了封装，实现界面与图像核心过程分离的面向对象的开发模式，然后在算法模式设计上引入动态插件式DLL的技术，通过设计统一形式的DLL算法模块和算法接口，借助独特的文本解析机制使得仅仅更新一个hii文本文件就可以动态地将算法加入平台，实现预期算法与平台分离的目标。     

UML在流程工业优化调度工艺描述系统中的应用

结合建模工具Rational Rosc说明如何在系统开发过程中运用UML建模。通过流程工业优化调度工艺描述系统的实际建模，对UML建模应用作了进一步说明。