Retrieving and classifying instances of source code plagiarism

Automatic detection of source code plagiarism is an important research field for both the commercial software industry and within the research community. Existing methods of plagiarism detection primarily involve exhaustive pairwise document comparison, which does not scale well for large software collections. To achieve scalability, we approach the problem from an information retrieval (IR) perspective. We retrieve a ranked list of candidate documents in response to a pseudo-query representation constructed from each source code document in the collection. The challenge in source code document retrieval is that the standard bag-of-words (BoW) representation model for such documents is likely to result in many false positives being retrieved, because of the use of identical programming language specific constructs and keywords. To address this problem, we make use of an abstract syntax tree (AST) representation of the source code documents. While the IR approach is efficient, it is essentially unsupervised in nature. To further improve its effectiveness, we apply a supervised classifier (pre-trained with features extracted from sample plagiarized source code pairs) on the top ranked retrieved documents. We report experiments on the SOCO-2014 dataset comprising 12K Java source files with almost 1M lines of code. Our experiments confirm that the AST based approach produces significantly better retrieval effectiveness than a standard BoW representation, i.e., the AST based approach is able to identify a higher number of plagiarized source code documents at top ranks in response to a query source code document. The supervised classifier, trained on features extracted from sample plagiarized source code pairs, is shown to effectively filter and thus further improve the ranked list of retrieved candidate plagiarized documents.     

黔北俗语的包容与超越

黔北俗语数量大,品种多,层次和内容非常丰富,它们充分表现出黔北民间对各种关系诸如社会关系、人际关系和文化关系复杂多面的认识。黔北是一方四汇之地,四方移民及其风俗,通过其对立矛盾俗语的联结、济泄、转化、融合,最终完成其艰难的超越。     

智慧城市信息安全风险评估模型构建与实证研究

[目的/意义] 面对智慧城市日益突出的信息安全问题,提出一个科学的风险评估模型,以快速对智慧城市进行风险分类并分析风险因素。[方法/过程] 从智慧城市信息安全的5个层次和风险评估的4个主要因素出发,构建智慧城市信息安全风险指标框架,对智慧城市实例进行ward系统聚类形成分类属性,选择C4.5算法的决策树方法建立风险评估模型,并验证模型的科学性。[结果/结论] 结果发现:安全管理制度、数据泄露与损坏威胁、安全意识薄弱性和设备安全漏洞是智慧城市之间差距最显著的风险因素,根据评估结果提出保障智慧城市信息安全的建议。     

艺术类专业大学英语教学模式探究

本文重点讨论了如何针对艺术类专业大学生的特点:独特个性和接受能力,构建既能体现现代教育理念又有利于学生英语学习的特有模式.我们在教学中尝试了通过课程中的任务设计和小组合作的学习方式,开展互动,突出了教学设计的个性化和实用性,实现特色化教学,变枯燥的知识讲述为鲜活的、真实的学习体验和实践.     

中欧体育健康项目“健康儿童?健康社会”研究

“健康儿童?健康社会”（HCSC）是在欧盟体育健康发展准则下,构建由家庭、学校、体育组织、地区政府等诸多部门组成的复合体系,通过降低BMI值减少超重,改善运动能力,进而提高个人生活质量。主要通过对HCSC项目的历史发展进行论述,对HCSC的核心理念、组织构架、运作模式3方面进行剖析,并以中国实验学校为例,对实验干预前后学生的身体健康指标进行对比分析,旨为国内相关领域研究抛砖引玉。     

提升网络学术期刊传播能力的实践与思考

为提升网络学术期刊的传播能力,提高网络学术期刊的发行质量,针对网络学术期刊的特点,围绕其发行与传播环境,并结合对2015年我国SCI收录期刊的实证分析,提出提升网络学术期刊传播能力的对策。网络学术期刊传播能力的提升,需要编辑树立互联网思维,需要建立健全多渠道的发行途径,重视标识符的使用以及重视挖掘语义出版等新出版模式。学术期刊的发展应顺应时代潮流,新元素和新出版模式的使用将成为网络学术期刊发展的必然趋势。     

The impact of collaborative online reading on summarizing skills

The aim of this study was to determine whether, as a result of collaborative-online reading of a chapter from a book of an academic nature, the quality of the collaborative summary that the readers would write would be higher than that written by readers who would both read the same chapter and write a summary in a face-to-face setting. In this study we examined the difference between the summaries written by participants from two groups, each group was divided into subgroups of 3 participants who had read collaboratively a chapter of a book, and collaborated on writing a summary. The participants of the experimental group read the chapter as it appeared in a website for collaborative reading built especially for this study and the participants were asked to summarize the chapter on a shared online digital document. The participants of the control group were asked to read the chapter face-to-face and to collaboratively summarize it in hand writing. The quality of the summaries was evaluated with a tool developed by Rivard (2001). This tool was developed to measure the quality of the summaries. In our study the main and secondary ideas that were supposed to be included in the participants’ summaries were identified by three literature teachers using ten different criteria and the summaries were analyzed by two other judges based on these criteria. The findings indicated that there were significant differences in the majority of the writing indicators being measured with the tool. The findings indicated that collaborative-online reading and writing produce a summary of a higher quality than one read and hand written collaboratively face-to-face.     

Parents of Traditionally Aged Community College Students: Communications and Choice

Five suburban community colleges in a metropolitan area collaborated on a survey to parents of high school graduates of the class of 2002 who attended the colleges in fall 2002. The study was undertaken to learn more about parents roles in their students selection of community colleges, to give insights and information about this important community college constituency, and to assist community colleges to shape more effective ways to foster positive and supportive opinions among parents of potential students. Parents want the community college to provide students with credits and grade point averages enabling transfer, overestimate their students academic skills as measured by course placement tests, engaged in a number of college-choice activities, and indicate that factors associated with lifestyle and money were major reasons for selecting the community college. Associations between parents social capital and perceptions of their students academic abilities were found for a number of dependent variables examined. The study also revealed important differences in how participating institutions record and calculate key measures such as credits earned and grade point averages.