Coping with abstraction in object orientation with a special focus on interface classes

One of the subjects that undergraduate students learning Object Oriented (OO) design find hard to apply is the construction of class hierarchies in general, and the use of interface classes in particular. The design process requires decomposition and reconstruction of problems in order to model software classes. The common attributes and behaviors are usually modeled using class inheritance except when the common behaviors do not belong to the same class hierarchy; in such case, an interface class is preferred. In order to be able to properly design, the designer has to demonstrate the abstraction abilities on various levels. In this study, we aimed at examining the students' demonstration of abstraction levels during design of class hierarchy in general, and whether or not they use interface classes in particular. The results of the study reveal that a majority of students were able to build a reasonable class hierarchy; however, many of them did not use interface classes as a tool for expressing common behaviors. Nevertheless, all of them could identify and choose the best solution for a particular problem among four different solutions, which included the use of interface class.     

MFV-Class: a multi-faceted visualization tool of object classes

INTRODUCTION The increasingly complex and large number ofsoftware products in today’s software industrymakes the tasks of software maintenance, softwarereuse and software restructuring more and moredifficult. With the popularity of the object-orientedprogramming paradigm, the ability to reverse en-gineer and understand object-oriented legacy sys-tems has become an important problem to be ad-dressed. In the object-oriented reverse engineering(OORE) research area, most researchers f…     

MFV-Class: a multi-faceted visualization tool of object classes

Classes are key software components in an object-oriented software system. In many industrial OO software systems,there are some classes that have complicated structure and relationships. So in the processes of software maintenance,testing,software reengineering,software reuse and software restructure,it is a challenge for software engineers to understand these classes thoroughly. This paper proposes a class comprehension model based on constructivist learning theory,and implements a software visualization tool(MFV-Class)to help in the comprehension of a class. The tool provides multiple views of class to uncover manifold facets of class contents. It enables visualizing three object-oriented metrics of classes to help users focus on the understanding process. A case study was conducted to evaluate our approach and the toolkit.     

层次分析法在分层教学模型建立及检验中的应用

影响分层教学的主要因素有基础知识状况、兴趣爱好、智力水平、潜在能力、学习动机（态度）、学习方法。论文借助运筹学的层次分析法和MATLAB软件求解,计算出影响数学分层教学效果（班平均成绩）的各因素所占比例,最后根据一致性检验验证模型的可行性和准确性。     

A Simplified Method Of Matrix Inversion

In this paper, the use of several measurement models for the analysis of data arising from learning hierarchies is discussed, and the results of an empirical investigation of the application of an Item Response Theory (IRT) model to a learning hierarchy in subtraction are examined. The analysis confronts the test developer’s original intentions with empirical data through the use of the IRT model, and three ways that the model can be useful in explicating the patterns of empirical results from a learning hierarchy are described.     

图式理论在英语听力教学中运用的实验研究

文章通过调查分析了听力课堂存在的问题,在英语听力教学中引入一新的教学模式—图式理论,该理论在国外二语研究中已获成效。数据分析为SPSS计算机统计软件。实验结果表明图式理论对英语听力理解有影响能促进学生英语听力水平的提高,能提高学生学习英语的兴趣。     

基于超图的软件进化模型

原型法在开发大型软件系统、理解其开发和进化过程方面是最好方法,但由于不同系统的开发环境和过程不同,很多形式模型在实现中都有技术上的困难.用基于超图的软件进化模型表示和研究有多维分层结构的复杂软件的进化过程,可以有效地帮助开发者描述、理解和控制软件的进化过程.经开发多媒体系统的实践证明,这一模型在需求多变的软件开发中进行软件进化控制效果良好.     

Formative evaluation applied to a learning hierarchy

A formative evaluation method applicable to learning hierarchies is described which simplifies data collection by employing results from a posttest. Relations among pairs of lower and higher elements of a portion of a previously formulated hierarchy for graphic skills in kinematics were tested by means of data obtained from a posttest given to 148 secondary-school students. Results were compared with those previously obtained for the same hierarchy by a rigorous validation method. Correspondence of the two sets of results was high. Examination of test responses for discrepant instances yielded further information of value. Results additionally indicate hierarchical relationships to be the same in retention as they were for learning.     

面向方面联结器的形式化及应用

目前各种主要的面向对象语言都进行了面向方面的扩展以支持AOP,由于联结器对语义和语法结构的限制,这些语言不提供对非正交方面的支持,提出了方面联结器的形式化定义,并依此实现了通用OO语言的AOP支持,该模式的归纳定义方式支持更大粒度的方面表达,能作为各种轻量级AOSD框架的基础,同时其简洁性和可扩充性适合面向对象软件的方面挖掘工程的需要。     

面向对象语言的AOP扩展

随着AOP日益广泛的应用,几乎所有的OO语言都进行了面向方面的扩展,然而这些语言无法实现对非正交方面的有效表达,方面调节模式通过一组类实现了联结器的基本任务,在该编程模式下能使用通用OO语言支持AOP,同时它的分层应用模式支持更大粒度的方面描述,能作为各种轻量级AOSD框架的基础,其简洁性和扩充性也能适应面向对象软件的方面挖掘工程的需要。     

Validation of a learning hierarchy for the mole concept

Three psychometric methods for validating learning hierarchies are applied to one data set derived from responses of grade 10 chemistry students to items representing the skills in a hypothesized hierarchy for the mole concept. Two methods which considered skills in pairs, namely the “test of inclusion” by White and Clark and the “ordering-theoretic method” by Airaisian and Bart produced generally similar results. The third method, by Dayton and Mac-ready, considered the hierarchy as a whole and produced clearer distinctions between alternative hierarchies than the first two methods. The hierarchy derived from this analysis was supported by a test for transfer of learning from subordinate to superordinate skills.     

基于支持向量机的酵母重组热点和冷点的预测

使用基于统计学习理论的支持向量机(SVM)方法,提出了针对重组热点和冷点分类预测的新方法.对酵母基因组的303个重组热点开放阅读框(hot ORF)以及48个重组冷点开放阅读框(cold ORF),提取了序列的一般二联碱基丰度特征,以及基于密码子使用偏性的二联碱基丰度特征,然后使用二倍交叉验证方法,选择不同的核函数和对应参数,对数据集进行了训练和分类预测.研究结果表明,当使用径向基核函数,并采用基于密码子使用偏性的二联碱基丰度特征时,预测准确率为87·47%.     

基于“雨课堂”的混合式教学模式在大学英语教学中的应用研究

大学英语学习推崇引导性和多样性,以应用型本科院校一年级162名学生为研究对象,在大学英语教学中推进基于"雨课堂"的混合式教学模式,以SPSS分析问卷调查的定量研究和随机半结构访谈的定性研究发现,学生对于这种教学模式的接受程度较高。在教学效果上,学生从自身角度对这种教学模式给与了较好的评价,认为能提高自身的语言应用能力,尤其是写作和阅读能力。学生对于该模式的接受程度和其英语能力提升程度成一定的在正比。在大学英语教育中推进基于"雨课堂"的混合式教学模式,对提升传统教学模式具有一定的指导意义。     

类规模对面向对象度量与易维护性关联关系潜在混和效果元分析

用在设计阶段可以收集到的3个规模度量分析类规模对面向对象度量与易维护性之间关联关系的混和效果.为得到尽可能通用的结论,在127个C＋＋系统和113个Java系统上分析类规模的混和效果.首先,对每个面向对象度量,在单个系统上计算代表由类规模造成的关联扭曲的间接效果和它的方差.然后,利用统计的元分析方法计算这些系统上的平均间接效果并判断它是否显著地区别于零.实验结果表明,不论使用哪个类规模度量进行分析,类规模对面向对象度量与易维护性之间关联关系的混和效果通常是存在的.因此,验证面向对象度量与易维护性之间关系的实验研究应将类规模视为一个混和变量.     

基于UML行为模型的高速公路收费系统的设计

统一建模语言(UML)是一种可视化的面向对象的建模语言，具有强大的行为建模能力，我们将UML行为模型应用到高速公路收费系统的设计中，根据这种思路设计的长潭高速公路收费系统运行安全可靠，结构严谨。     

Instructional Design Paradigms: Is Object-Oriented Design Next?

The current systematic approaches taught to. and perhaps used by, instructional designer's share much in common with structured computer software design approaches. The computing field is currently undergoing major changes fostered by the growth of object-oriented (OO) analysis, design, and programming methods. The OO paradigm may also offer a revised focus for ID research. Several instructional design (ID) researchers are already adopting OO computing terminology. The suggested cross-over of OO from computing to instructional design is tied to design trends and ongoing research in II).     

在线课程学习评价的RFM-DS模型

为了更好地对学生在线学习的自主性和交互性进行全方位的考察,文章在传统的RFM模型的基础上,提出了一种改进的RFM-DS模型,对学生在线课程学习进行评价。在权重系数设置方面,集成主观赋权的层次分析法和客观赋权的主成分分析法,兼顾评价主体的主观偏好性及评价客体的客观真实性,采用“高等数学”在线开放课程的学习行为数据对模型进行应用,得到了在线学习的综合评分数据公式,提高了评价的科学性和有效性。     

基于SVM技术的文本分类研究

SVM(Support Vector Machine,支持向量机)是由Vapnik等人提出的一种新的机器学习方法。以结构误差理论、条件二次优化理论与核空间理论作为理论基础,能够较地的解决机器学习的问题,如模型选择、过学习、非线性问题和灾难维数等,很适合应用在文本分类领域。针对文本分类技术的新问题,研究了已有的主动学习方法并对其进行改进,提出了一种新的主动学习算法,很好地解决了小规模标注样本集的分类问题。该方法尤其在难以获得大量类标签或者标注样本耗费较大的领域,更能显示出它的优越性,适合日新月异的互联网的应用。     

基于RBF核的SVM分类应用研究

支持向量机(Support Vector Machine,SVM)在解决小样本、非线性及高维模式识别中具有优势,但核函数的选取没有定论,且其参数对SVM模型的性能起重要作用。针对这些问题,文章建立了基于SVM的分类模型,并通过UCI数据集验证了径向基核函数(Radial Basis Function,RBF)较其他核函数的有效性,其中核参数的选取采用改进的网格搜索法进行寻优。分类实验结果表明,选择RBF核函数的分类准确度较其他核函数提高了2.5%到35%。