• International Journal of Control, Automation, and Systems
• /
• 제6권6호
• /
• pp.809-817
• /
• 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.

• Journal of Electrical Engineering and Technology
• /
• 제13권6호
• /
• pp.2212-2219
• /
• 2018

This paper describes extended fault location algorithm using estimated remote source impedance. The method uses data only at the local end and the sequence current distribution factors for more accurate estimation. The proposed algorithm can respond to variation of the local and remote source impedance. Therefore, this method is especially useful for transmission lines interconnected to a wind farm that the source impedance varies continuously. The proposed algorithm is very insensitive to the variation in fault distance and fault resistance. The simulation results have shown the accuracy and effectiveness of the proposed algorithm.

• 설비공학논문집
• /
• 제3권3호
• /
• pp.197-205
• /
• 1991

A numerical study has been performed to investigate two dimensional natural convection heat transfer in a rectangular enclosure with heat sources of constant temperature at the bottom. Calculations were made for various dimensionless heat source lengths, W/L=0.1-0.5, and positions of heat sources at $Gr=2.57{\times}10^6$, Pr=0.71 and Ks/Kf=28.98. For various positions of heat sources, the maximum local Nusselt numbers generally show X=0.81-0.85 at the bottom and X=0.23 at the top. For various dimensionless heat source lengths, the maximum local Nusselt numbers at the bottom show W/L=0.4 for one heat source, W/L=0.2 for two heat sources with fixed centers, W/L=0.5 for two heat sources with moved centers. Finally the maximum heat transfer at the bottom exhibits in condition of W/L=0.4 for two heat sources with moved centers.

• Nuclear Engineering and Technology
• /
• 제54권10호
• /
• pp.3803-3810
• /
• 2022

OpenMC is a community-driven open-source Monte Carlo neutron and photon transport simulation code. The Weight Window Mesh (WWM) function and an automatic Global Variance Reduction (GVR) method was recently developed and implemented in a developmental branch of OpenMC. This WWM function and GVR method broaden OpenMC's usage in general purposes deep penetration shielding calculations. However, the Local Variance Reduction (LVR) method, which suits the source-detector problem, is still missing in OpenMC. In this work, the Weight Window Generator (WWG) function has been developed and benchmarked for the same branch. This WWG function allows OpenMC to generate the WWM for the source-detector problem on its own. Single-material cases with varying shielding and sources were used to benchmark the WWG function and investigate how to set up the particle histories utilized in WWG-run and WWM-run. Results show that there is a maximum improvement of WWM generated by WWG. Based on the above results, instructions on determining the particle histories utilized in WWG-run and WWM-run for optimal computation efficiency are given and tested with a few multi-material cases. These benchmarks demonstrate the ability of the OpenMC WWG function and the above instructions for the source-detector problem. This developmental branch will be released and merged into the main distribution in the future.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (3)
• /
• pp.199-201
• /
• 2003

Ad hoc network은 stationary infrastructure의 도움 없이 이동 노드들이 필요 시 network 형태을 구성하여 통신이 이루어지게 하는 network으로 ad hoc network 환경에 맞는 다양한 라우팅 프로토콜들이 개발되었고 크게는 table­driven, on­demand 방식으로 나눌 수 있는데 on­demand 방식의 AODV 프로토콜은 routing overhead가 적다는 장점이 있는 반면 single path로 data forwarding을 진행하여 중간노드의 이동에 의한 path가 broken되는 경우 local routing을 하거나 새로이 source­initialed route rediscovery을 수행하여 전송 delay 및 control traffic overhead 등을 높이는 결과를 발생 시켰다. 본 논문은 single path로 구성되는 AODV 프로토콜의 route failures시 문제점을 보완한 Associativity Based Redundancy path Routing(ABRR) 및 Alternate Redundancy path Routing(ARR) schemes을 제안한다. 첫째, ABRR은 main path상에 있는 각 노드들은 associativity based stable node 정보를 이용하여 path broken 이전에 local redundancy path을 구성하여 path broken시 local routing없이 route을 복구할 수 있게 하고 둘째, ARR은 source­initialed route discovery에 의해 alternate path을 구성하여 ABRR 그리고 local routing에 의해 main route recovery 실패 시 alternate path을 main path로 전환하여 control traffic overhead 및 전송 delay을 줄이게 한다.

• 한국컴퓨터정보학회논문지
• /
• 제10권6호
• /
• pp.287-298
• /
• 2005

지방자치시대를 맞이하여 진정한 지방분권화를 이루기 위해서는 일정 행정 수준의 자주재정 확립이 보장되어야 한다. 현재 우리나라에서는 지방정부가 안고 있는 수직적 $\cdot$ 수평적 재정불균형 문제를 해소하며, 국가차원의 지역균형발전 및 행정의 효율성 및 효과성을 확보하기 위한 수단으로 지방재정조정제도를 시행하고 있다. 지방재정조정제도는 지역 간의 세원편재와 재정불균형의 시정을 통한 지방자치단체의 일정 행정 수준(national minimum standard)을 확보할 수 있도록 재원을 보장해주며 합리적이고 효율적인 제도 운영이 중요하다. 본 연구에서는 지방재정조정제도의 두 가지 수단인 지방교부세와 국고보조금에 대하여 알아보고 재정력이 취약한 자치단체의 재정형평성에 기여할 수 있는 개선방안을 제시하였다. 지방교부세와 국고보조금의 배분방식과 운영형태 등을 조정하여 형평성 원칙에 맞게 운영해 나가야 할 것이다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제6권6호
• /
• pp.1627-1648
• /
• 2012

We propose an adaptive method for detecting plagiarized pairs from a large set of source code. This method is adaptive in that it uses an adaptive algorithm and it provides an adaptive threshold for determining plagiarism. Conventional algorithms are based on greedy string tiling or on local alignments of two code strings. However, most of them are not adaptive; they do not consider the characteristics of the program set, thereby causing a problem for a program set in which all the programs are inherently similar. We propose adaptive local alignment-a variant of local alignment that uses an adaptive similarity matrix. Each entry of this matrix is the logarithm of the probabilities of the keywords based on their frequency in a given program set. We also propose an adaptive threshold based on the local outlier factor (LOF), which represents the likelihood of an entity being an outlier. Experimental results indicate that our method is more sensitive than JPlag, which uses greedy string tiling for detecting plagiarism-suspected code pairs. Further, the adaptive threshold based on the LOF is shown to be effective, and the detection performance shows high sensitivity with negligible loss of specificity, compared with that using a fixed threshold.

• Asian Journal of Atmospheric Environment
• /
• 제8권3호
• /
• pp.115-125
• /
• 2014

In this study, particle composition data for $PM_{10}$ samples were collected every 3 days at Seoul, Korea from August 2006 to November 2007, and were analyzed to provide source identification and apportionment. A total of 164 samples were collected and 21 species (15 inorganic species, 4 ionic species, OC, and EC) were analyzed by particle-induced x-ray emission, ion chromatography, and thermal optical transmittance methods. Positive matrix factorization (PMF) was used to develop source profiles and to estimate their mass contributions. The PMF modeling identified nine sources and the average mass was apportioned to secondary nitrate (9.3%), motor vehicle (16.6%), road salt (5.8%), industry (4.9%), airborne soil (17.2 %), aged sea salt (6.2%), field burning (6.0%), secondary sulfate (16.2%), and road dust (17.7%), respectively. The nonparametric regression (NPR) analysis was used to help identify local source in the vicinity of the sampling area. These results suggest the possible strategy to maintain and manage the ambient air quality of Seoul.

• 한국환경과학회지
• /
• 제20권1호
• /
• pp.137-146
• /
• 2011

In this research, food waste source reduction model for apartment was investigated. In spite of prohibition of direct landfill of food waste and continuous efforts made by government and local government, food waste production increases steadily. Recycling ratio of the food waste increases every year, but its products have many problems like low quality, stability, salt, odor etc. Household occupies 63.3% of whole food waste production and this is subject to be a key factor to control food waste. We surveyed S apartment in Kwangju city as a model case, in which administrative office and women's association adopted clean plate eating, separation of raw food waste and earth worm composting as a series of method for source reduction and recycling inside the apartment. With the help of residents' participation and practice, food waste production decreased 15.6% from 0.31 g/capita/day in 2007 to 0.26 g/capita/day in 2009 (domestic average 0.30 g/capita/day). Separation of raw food waste and its composting using earth worm were very effective, and were subject to resolve the problems of present food waste treatment technologies. And earth worm composting was very useful in environmental, economical, societal and educational aspects. Instead of economical incentive, educational programs about food value, environmental problem and critical method for food waste separation were more effective for promotion of source reduction. From the analyses on the process and success factors in this model, we could conclude that leader's role was one of the key factors for the settlement of source reduction, and that was to understand the seriousness of the food waste and to seek solution, to test techniques, and to practice by oneself. Furthermore, networking and collaboration among residents, local government, NGO and local press promoted residents' participation, and it was through various education and investigation. Finally, source reduction and self recycling model of food waste in the apartment, that applies separating raw food waste and earth worm composting based on the collaboration among residents, local government, NGO, and local press, should be disseminated, and environmental policy also should be changed to make it possible.

• 한국정보통신학회논문지
• /
• 제22권2호
• /
• pp.221-226
• /
• 2018

오픈소스는 소스 코드를 볼 수 있고 수정할 수 있다는 점에서 기존 코드의 버그 수정이나 새로운 아이디어의 추가가 가능하다. 오픈소스는 이를 이용한 상업용 소프트웨어 개발은 물론 교육용으로도 그 활용 범위가 매우 넓다. 교육용 블록 프로그래밍 환경의 하나인 앱인벤터는 앱인벤터 오픈소스를 통해 자체 로컬 서버의 구축은 물론 플랫폼 자체도 수정할 수 있다. 본 논문에서는 앱인벤터 오픈소스를 로컬 서버에 구현한다. 특히 교육기관의 특성을 반영한 로컬 서버 구축을 위해 앱인벤터 오픈소스 플랫폼을 수정하고 그 과정에 대하여 기술한다. 이를 통해 학생들에게 보다 친숙한 교육 환경을 제공할 수 있고 나아가 학생들의 요구를 반영한 나만의 프로그래밍 블록 추가와 같은 능동적인 대처를 통해 교육 만족도도 높일 수 있다.