Research and Implementation of Program Plagiarism Detection System
|School||Sun Yat-sen University|
|Keywords||Source code plagiarism detection Abstract syntax tree Normalized operator Design and Implementation|
Higher education at home and abroad , the homework phenomenon is generally more serious , especially in computer courses , source code plagiarism . Therefore, the study of the source code plagiarism detection technology is of great significance . In this paper, the existing systems as well as the existing detection algorithms , and found that there is lack of these algorithms and systems . For example , most systems only provide a detection algorithm , and the applicable range of a different detection algorithm is different , the user can not according to its own need to select a suitable detection algorithm . The actual testing , we also found that a number of factors that leads to detection noise , affecting the calculation of similarity . For example , a large number of duplicate variable declaration statement , as well as copycat changes to the source code . This article is designed and implemented a source code plagiarism detection system PlagiarismChecker contains four detection algorithm . The user can choose different algorithms and combination of these algorithms to detect and filter the results , you can set the similarity threshold can also be provided by PlagiarismChecker system interface to facilitate the implementation and application of new detection algorithm . This article provides a Web application source code Catcher provides online testing services , test results returned by mail . Through experiments proved PlagiarismChecker effective than the existing system , it is able to detect plagiarism operations on . Noise problems exist in the actual testing , detection algorithm based on the abstract syntax tree , we propose using normalized operator to solve this problem . The paper designs and implements a five operators , operator in this way can be normalized effective to eliminate noise . The article also improved PlagiarismChecker system , allows the system to easily add a new operator, can cope with the new found plagiarism practices .