• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.6
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• pp.491-496
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• 2002

Multi-objective Optimization Problems(MOPs) are occur more frequently than generally thought when we try to solve engineering problems. In the real world, the majority cases of optimization problems are the problems composed of several competitive objective functions. In this paper, we introduce the definition of MOPs and several approaches to solve these problems. In the introduction, established optimization algorithms based on the concept of Pareto optimal solution are introduced. And contrary these algorithms, we introduce theoretical backgrounds of Nash Genetic Algorithm(Nash GA) and Evolutionary Stable Strategy(ESS), which is the basis of Co-evolutionary algorithm proposed in this paper. In the next chapter, we introduce the definitions of MOPs and Pareto optimal solution. And the architecture of Nash GA and Co-evolutionary algorithm for solving MOPs are following. Finally from the experimental results we confirm that two algorithms based on Evolutionary Game Theory(EGT) which are Nash GA and Co-evolutionary algorithm can search optimal solutions of MOPs.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.129-147
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• 2002

This paper presents a variational equality formulation by Providing new dynamic route choice condition for a link-based dynamic traffic assignment model. The concepts of used paths, used links, used departure times are employed to derive a new link-based dynamic route choice condition. The route choice condition is formulated as a time-dependent variational equality problem and necessity and sufficiency conditions are provided to prove equivalence of the variational equality model. A solution algorithm is proposed based on physical network approach and diagonalization technique. An asymmetric network computational study shows that ideal dynamic-user optimal route condition is satisfied when the length of each time interval is shortened. The I-394 corridor study shows that more than 93% of computational speed improved compared to conventional variational inequality approach, and furthermore as the larger network size, the more computational performance can be expected. This paper concludes that the variational equality could be a promising approach for real-time application of a dynamic traffic assignment model based on fast computational performance.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.409-416
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• 2017

In this paper, we consider a framework of compressed sensing over finite fields. One measurement sample is obtained by an inner product of a row of a sensing matrix and a sparse signal vector. A recovery algorithm proposed in this study for sparse signals based probabilistic decoding is used to find a solution of compressed sensing. Until now compressed sensing theory has dealt with real-valued or complex-valued systems, but for the processing of the original real or complex signals, the loss of the information occurs from the discretization. The motivation of this work can be found in efforts to solve inverse problems for discrete signals. The framework proposed in this paper uses a parity-check matrix of low-density parity-check (LDPC) codes developed in coding theory as a sensing matrix. We develop a stochastic algorithm to reconstruct sparse signals over finite field. Unlike LDPC decoding, which is published in existing coding theory, we design an iterative algorithm using probability distribution of sparse signals. Through the proposed recovery algorithm, we achieve better reconstruction performance as the size of finite fields increases. Since the sensing matrix of compressed sensing shows good performance even in the low density matrix such as the parity-check matrix, it is expected to be actively used in applications considering discrete signals.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.677-680
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• 2010

본 연구는 경기도 구리시의 2개 초등학교 5, 6학년 학생을 대상으로 시력 저하 실태 및 그와 관련된 요인들을 알아보고 시력 저하 예방교육의 기초자료로 활용하고자 시도 된 연구이다. 자료의 수집은 2009년 11월 1일부터 12월 10일까지 초등학교 5학년, 6학년 학생 793명(남 417명, 여 376명)이었고 2009학년도의 시력검사자료 분석과 문헌 및 기존의 조사도구를 토대로 개발한 자가 보고식 설문지를 이용하여 조사하였다. 자료 분석은 SPSS WIN 12.0(한글판)프로그램을 이용하여 빈도, 백분율, $x^2$-test 및 로지스틱 회귀분석의 통계적 방법으로 분석하였다. 시력저하에 유의한 영향요인으로 좌측시력을 종속변수로 한 경우 중 일반특성에 따른 변수인 부모 및 형제와 자매가 안경 및 렌즈 착용하는 경우, 경제적으로 어려울수록 시력 저하 자가 많았고, 환경특성에 따른 변수인 거실 및 방안밝기가 어두울수록, 컴퓨터 사용 시 실내밝기가 어두울수록, TV의 눈높이 및 컴퓨터 모니터의 눈높이가 높을수록 시력 저하 자가 많았다. 우측시력을 종속변수로 한 경우 중 일반특성에 따른 변수인 부모가 안경 및 렌즈를 착용할수록, 형제 와 자매가 안경 및 렌즈를 착용할수록, 경제적으로 어려울수록 시력 저하 자가 많았고, 환경특성에 따른 변수인 거실 및 방안밝기가 어두울수록, 컴퓨터 사용 시 실내밝기가 어두울수록, TV의 눈높이 및 컴퓨터 모니터의 눈높이가 높을수록 시력 저하 자가 많았다. 안경 및 렌즈를 종속변수로 한 경우 중 일반특성에 따른 변수인 부모 및 형제와 자매가 안경 및 렌즈를 착용할수록, 경제적으로 어려울수록 시력 저하 자가 많았으며, 환경특성에 따른 변수인 거실 및 방안밝기의 실내밝기가 어두울수록, TV의 눈높이 및 컴퓨터 모니터의 눈높이가 높을수록 시력 저하 자가 많았다. 눈 건강상태를 종속변수로 한 경우 중 일반특성에 따른 변수인 경제적으로 어려울수록 시력 저하 자가 많았고, 건강행동특성에 따른 변수인 주관적인 건강상태가 나쁠수록, 눈 피로감이 있을수록 시력 저하 자가 많았으며 환경특성에 따른 변수인 거실 및 방안밝기의 실내 밝기가 어두울수록 시력 저하 자가 많았다. 시력저하관련 요인을 연구한 결과 학생들의 시력 저하 자가 매년 증가하고 있다는 것을 알 수 있었고, 유전적 요인에 의한 시력저하는 개인의 노력에 의하여 사전예방이 어렵지만 환경적 요인에 의한 시력저하는 노력과 관심으로 사전예방이 가능하므로 학생들의 시력건강증진을 위하여 학부모와 학교 및 전문 의료기관이 서로 연계적인 협조 하에 학생들 개개인에 맞는 효율적인 시력증진관리프로그램 개발하는 것이 필요하고, 현행학교시력검사의 정확성을 기하기 위하여 표준화된 시력검사 지침을 개발하여 사용할 필요가 있으며, 지역 및 환경적 배경이 다르다 보니 연구결과가 다르게 나타나는 경우가 있는데 객관적인 결과를 도출하기 위하여 여러 지역의 학생을 대상으로 다양하고 체계적인 연구를 해야 할 필요성이 있다고 생각한다.

• The Journal of the Korea Contents Association
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• v.14 no.7
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• pp.93-102
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• 2014

Recently, various types of dramas have been broadcasted in Korea. Especially, historical dramas having backgrounds about historical events or characters have been recorded high ratings of the viewing audience, as well as a lot of influence on many parts of Korean society. Besides, the historical drama like raised a craze for popular Korean cultures in many Asian countries. The subjects and characters of historical drama are diversifying in recent years. For example, is a royal cook, is a story about running away slaves and their chaser, is a story about a very well-known painter of the Joseon Dynasty era, and is a veterinarian. At this point, in celebration of the officially appointed "year of mathematics", it is very meaningful to demonstrate the importance of mathematics with a historical drama about mathematics and mathematicians of the Joseon Dynasty. In this article, the reasons for production of historical dramas about mathematics and mathematicians in the Joseon Dynasty was presented in two ways. First, modern mathematics has high level of abstractness as its nature, and therefore many students and the public can not understand what except for some areas. Second, it is possible the easier and various approaches can be used to deal with contents about real-life in the view of popularization of mathematics. Also, this article would aim to explore the main character and episodes about mathematics and mathematicians in Joseon Dynasty. For example, the anecdote of Hong Jung Ha, the works of mathematics in the King Sejong's periods, the study of Hong Gil Ju, the joint researches between Nam Byung Gil and Lee Sang Hyuk, the story of Lee Seung Hun, and the mathematics study of middle class people.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.8
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• pp.2780-2792
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• 2010

In this study, we examine what components of e-learning environment affect e-learners' satisfaction. We focus on the task based approach to perceived website complexity(PWC). We study about the role of e-tutor using the internet, telephone, text message and e-mail etc. To test our model, we collected 235 data from online learners of Korea Culture & Content Agency using survey method. The research was conducted by SPSS15.0. Our results show that the relationship between PWC and e-learner satisfaction was negative. The rules of e-tutor are supporting e-learning service and facilitating recommendation intention. This study provides implications to design future e-learning service, understand user's herd behavior and evaluate learning process developed.

• Journal of KIISE
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• v.41 no.9
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• pp.666-673
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• 2014

This paper proposes a scalable face recognition method for unconstrained face databases, and shows a simple experimental result. Existing face recognition research usually has focused on improving the recognition rate in a constrained environment where illumination, face alignment, facial expression, and background is controlled. Therefore, it cannot be applied in unconstrained face databases. The proposed system is face feature extraction algorithm for unconstrained face recognition. First of all, we extract the area that represent the important features(landmarks) in the face, like the eyes, nose, and mouth. Each landmark is represented by a high-dimensional LBP(Local Binary Pattern) histogram feature vector. The multi-scale LBP histogram vector corresponding to a single landmark, becomes a low-dimensional face feature vector through the feature reduction process, PCA(Principal Component Analysis) and LDA(Linear Discriminant Analysis). We use the Rank acquisition method and Precision at k(p@k) performance verification method for verifying the face recognition performance of the low-dimensional face feature by the proposed algorithm. To generate the experimental results of face recognition we used the FERET, LFW and PubFig83 database. The face recognition system using the proposed algorithm showed a better classification performance over the existing methods.

• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.167-174
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• 2020

The social statistic was used to top 250 Korean and Japanese YouTube channels based on the number of subscribers examine its channel type (private/corporations/others), distribution of contents and private YouTube channels' date of registration. The channel examination was also used to provide practical hint to create new Youtube contents. According to the statistics, Korean channels were mainly managed by K-Culture related companies for the promotional purpose, whereas Japanese channels were mainly managed by individuals with a variety of contents. It is presumed that Japanese individuals have been engaged in creating individual video content since the early period through video uploading platforms other than YouTube such as Niconico Douga. Since the expansion of the YouTube market will continue, it is important not only to reinforce corporations' marketing on YouTube but also to promote the uniqueness and the diversity of YouTube content for the individuals to improve the economical, sentimental, and informational contents in order to create socially effective personal contents that can be competitive in the global market.

• Journal of The Korean Association of Information Education
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• v.10 no.1
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• pp.47-57
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• 2006

As teenagers' Internet use increases and Internet takes an important part in their everyday lives, many people become concerned with Internet addiction. In this study, I attempt to analyze the current status of teenagers' Internet addiction using an evaluation tool developed for students, and to compare elementary students' Internet addiction level with secondary students. Also I analyze factors affecting Internet addiction. For the analysis, 18 variables are selected from the areas such as demographic background, the experience of Internet use, family-related traits and social activities. A survey was conducted to 1,155 elementary students and 1,822 secondary students selected from nationwide schools. The main finding of this study is that among the elementary students 5.0% of the sample students are in the stage of serious addiction, and 19.7% in the stage of early addiction. In addition, the level of elementary students' Internet addiction is significantly higher than the level of secondary students. Also, the degree of elementary students' Internet addiction is significantly affected by some factors such as gender, surfing time, surfing purpose, satisfaction with parental relationship, parents' interference in Internet use, conversation frequency among family members, and satisfaction with school life.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.44-54
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• 2015

The purpose of this study is to analyze the images of children and adults that is reflected in TV commercial advertisements. For this purpose, 241 public TV advertisements were collected from the domestic ads information sites. The analysis criteria used for this study was the one modified from the ads analysis tool developed by Young-hee Ha(2011). The results showed that the number of ads employing the child model was varied according to the product item. The child model appeared the most in the ads for food/beverage and secondly, the ones for computer/electric home appliances. Furthermore, the child model behaved very similarly to the adults in the ads, especially in the aspect of positive communication. And both adult and a child models tended to have the main role in ads. Regarding the relationships among model characters, cooperative relationship between an adult and a child appeared the most and there were lots of family relationships. The results imply that a child in our society is becoming a considerable family member referred for making decision in purchasing commercial products. In addition, it is discussed that the child's image reflected in the ads would have influence on a child viewer's self image.