• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.361-363
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• 2016

전 세계적으로 프로그래밍 교육에 대한 관심이 증가에 따라 프로그래밍 교육에 대한 중요도와 평가도 중요해졌다. ACM-ICPC 프로그래밍 대회 같은 여러 프로그래밍 대회가 있고 대회 출전을 돕기 위한 온라인 평가 시스템이 전형적인 예이다. 이런 온라인 평가 시스템들을 참고하여 중등학교 학생의 프로그래밍 언어 학습에 도움을 줄 수 있는 프로그램을 설계하기 위한 오류분석 지원 시스템을 제안한다. 본 연구에서는 오류분석 지원 시스템을 통하여 프로그래밍 언어 학습을 함에 있어서 발생할 수 있는 오류들을 분석하여 실제 프로그래밍 교육 환경에 도움을 주고자 한다.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.2
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• pp.48-55
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• 2010

This paper proposes a realtime tracking algorithm of mobile object in indoor or outdoor environment. For this purpose the proposed system selects location data closer to mobile objects in real time using Triangulation method and DCM (Database Correlation Method). Also, this system utilizes the adjusted location data selected by using Kalman filter to improve the location accuracy of transfer object. Be studied in existing the Kalman filter have unstable location data until its settlement because of it extracts current values by using the past the information. However, proposed location tracking system don't apply existent Kalman filter to this system and it permits precisional tracking location by using more effective methods.

• The KIPS Transactions:PartA
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• v.16A no.6
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• pp.453-462
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• 2009

Studies on software plagiarism detection, prevention and judgement have become widespread due to the growing of interest and importance for the protection and authentication of software intellectual property. Many previous studies focused on comparing all pairs of submitted codes by using attribute counting, token pattern, program parse tree, and similarity measuring algorithm. It is important to provide a clear-cut model for distinguishing plagiarism and collaboration. This paper proposes a source code clustering algorithm using a probability model on extreme value distribution. First, we propose an asymmetric distance measure pdist($P_a$, $P_b$) to measure the similarity of $P_a$ and $P_b$ Then, we construct the Plagiarism Direction Graph (PDG) for a given program set using pdist($P_a$, $P_b$) as edge weights. And, we transform the PDG into a Gumbel Distance Graph (GDG) model, since we found that the pdist($P_a$, $P_b$) score distribution is similar to a well-known Gumbel distribution. Second, we newly define pseudo-plagiarism which is a sort of virtual plagiarism forced by a very strong functional requirement in the specification. We conducted experiments with 18 groups of programs (more than 700 source codes) collected from the ICPC (International Collegiate Programming Contest) and KOI (Korean Olympiad for Informatics) programming contests. The experiments showed that most plagiarized codes could be detected with high sensitivity and that our algorithm successfully separated real plagiarism from pseudo plagiarism.

• International Journal of Control, Automation, and Systems
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• v.6 no.6
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• pp.809-817
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• 2008

Program plagiarism is widespread due to intelligent software and the global Internet environment. Consequently the detection of plagiarized source code and software is becoming important especially in academic field. Though numerous studies have been reported for detecting plagiarized pairs of codes, we cannot find any profound work on understanding the underlying mechanisms of plagiarism. In this paper, we study the evolutionary process of source codes regarding that the plagiarism procedure can be considered as evolutionary steps of source codes. The final goal of our paper is to reconstruct a tree depicting the evolution process in the source code. To this end, we extend the well-known bioinformatics approach, a local alignment approach, to detect a region of similar code with an adaptive scoring matrix. The asymmetric code similarity based on the local alignment can be considered as one of the main contribution of this paper. The phylogenetic tree or evolution tree of source codes can be reconstructed using this asymmetric measure. To show the effectiveness and efficiency of the phylogeny construction algorithm, we conducted experiments with more than 100 real source codes which were obtained from East-Asia ICPC(International Collegiate Programming Contest). Our experiments showed that the proposed algorithm is quite successful in reconstructing the evolutionary direction, which enables us to identify plagiarized codes more accurately and reliably. Also, the phylogeny construction algorithm is successfully implemented on top of the plagiarism detection system of an automatic program evaluation system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.167-174
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• 2012

The circuits including with Optical transceiver and clock data recovery, in this paper, SERDES (SERializer-DESerializer) are implemented to construct a GE-PON burst-mode transceiver supporting IEEE 802.3ah and a jig for measuring the burst-mode characteristics, that is to say, PON upstream optical transmission environment are manufactured to evaluate the performance of transceiver. we verified that the limiting amplifier compensated the gap of max. 26dB optical power by experiments. The startup acquisition lock time is 670ns in case of using VSC7123 and 2300ns in case of S2060 and the data acquisition lock time were measured to be 400ns and 600ns, respectively, in the upstream channel transmission in this work. While on the other, VSC7123 is satisfied with IEEE802.3ah recommendations.