• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.995-1006
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• 2022

The purpose of this study was to investigate the current status of practical course operation in a non-face-to-face online environment, learning effects, and students' experiences and perceptions for radiology major students using a survey. The questionnaire consisted of a total of 34 items in 5 areas: general characteristics of subjects, current learning participation in non-face-to-face environments, learning satisfaction, learning outcomes, improvement and requirements. For the analysis of the questionnaire responses, frequency analysis was performed on the response frequency, ratio, and scale for each item. Based on the general characteristics of the survey respondents, cross-analysis was performed using the chi-square test for participation in non-face-to-face learning, learning performance, and learning satisfaction. implemented. Improvements and requirements were qualitatively analyzed for the repetition frequency of words with the same meaning. Through the results of analyzing the responses of a total of 397 questionnaires, the direction of design and development of practical classes in a non-face-to-face environment in the future and basic information and implications for efficient operation were confirmed. Based on this, it is necessary to continue to think and make efforts for the efficient operation of non-face-to-face practice classes in the post-corona era.

• Journal of the Korean Geotechnical Society
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• v.17 no.1
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• pp.85-97
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• 2001

Tse와 Cruden(1979)에 의해 암석 절리면 거칠기 정량화에 대한 연구가 시작된 이후 통계적인 정량화방법, 프랙탈 차원을 이용하는 방법 그리고 스펙트럼 분석을 이용하는 방법이 제안되었다. 이러한 통계적 정량화방법은 치수의존적이라는 단점이 있으며, 프랙탈 차원을 이용하는 방법은 크로스오버 차원이라는 문제점이 있는 것으로 평가되고 있다. 이 문제점들을 보완하는 방법으로 스펙트럼 분석법이 제시되어 많은 연구가 이루어졌다. 본 연구에서는 Barton과 Choubey(1977)가 제안한 10개의 절리면 프로파일을 수치화하고 통계적 분석, 프랙탈 차원 분석 그리고 스펙트럼 분석을 실시하여 이들 문제점을 살펴보고 스펙트럼 분석법이 위상이 변조된 프로파일에 대하여 문제가 있음을 확인하였다. 이들 문제점을 해결하기 위하여 측정간격과 프로파일의 기울기를 의미하는 통계적 파라미터의 관계를 선형으로 회귀분석하였다. 이렇게 구한 10개의 1차식의 기울기와 절편은 JRC와 매우 상관성이 높게 나타났다. 이 기울기와 절편을 거칠기 정량화의 변수로 사용함으로서 통계적 분석법에서의 치수의존적인 문제와 스펙트럼 분석에서의 위상변조의 문제를 해결하였다.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.159-167
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• 2010

The purpose of this study was to identify patterns of caries in the dentition of preschool children using cluster analysis and multidimensional scaling. 815 preschool children aged 36-71 months old were examined for caries experience. The first four clusters in the cluster analysis were (1) molars, (2) upper incisors, (3) lower 1st molars, and (4) upper 1st molars in teeth, (1) occlusal surfaces of lower molars and upper 2nd molars, (2) mesial surfaces of upper central incisors, (3) occlusal surfaces of lower 1st molars, and (4) separation between occlusal surfaces of upper and lower 2nd molars in tooth surfaces, and (1) proximal surfaces of upper anterior teeth, (2) occlusal surfaces of lower molars, (3) buccolingual surfaces of upper anterior teeth and (4) buccolingual, proximal, and occlusal surfaces of upper molars and buccolingual and proximal surfaces of lower molars in tooth surfaces groups. In the multidimensional scaling analysis, teeth could be divided into lower 1st molars, upper 1st molars, upper central incisors, upper lateral incisors, lower 2nd molars, upper 2nd molars, and the rest(canines, lower incisors), tooth surfaces could be divided into occlusal surfaces of lower molars, mesial surfaces of upper central incisors, occlusal surfaces of upper molars, and the rest, and tooth surface groups could be divided into proximal surfaces of upper anterior teeth, buccolingual surfaces of upper anteiror teeth, occlusal surfaces of lower molars, and the rest in the order of the distance from others. In the cluster analysis and the multidimensional scaling analysis, caries patterns were different according to the age.

• Journal of Venture Innovation
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• v.4 no.1
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• pp.23-38
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• 2021

This paper will examine the service quality of online education on service value, learning immersion, major satisfaction. The result structural equation model show that service quality of online education had a positive impact on service value. First, system convenience, system quality, interaction had a positive impact on service value. Second, System convenience, system quality, interaction had a positive impact on learning immersion Third, Online education on service value had a positive impact on Major Satisfaction. Fourth, Learning immersion had a positive impact on Major Satisfaction.

• Journal of Satellite, Information and Communications
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• v.7 no.2
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• pp.67-71
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• 2012

This paper represents the impact analysis results of antenna reflector for the UHF-band antenna of Space Launch Vehicle. Three types of UHF-band antenna reflector model have been proposed and simulated to compare their characteristics such as resonance frequency, reflection loss and radiation pattern etc. Simulation results showed that resonance frequency and return loss of each reflector models were rarely affected even if reflector sizes are changed. The antenna gain and 3dB bandwidth were slightly changed to the worse directions as the reflector sizes are smaller.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.2
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• pp.365-370
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• 2000

In this dissertation, in order to analyze the ground plane size which will affect the antenna characteristic, the appropriate antenna was designed and produced in compliance with the needs that the existing antenna should be improved, and then the optimum ground plane size was calculated. It was proved it affected the radiation characteristic greatly but didn't affect the impedance characteristic nearly when ground plane size of the existing folded slot antenna was enlarged with using the copper e cut in some size. Though it require the complicate procedure by the strict design in order to calculate exactly, if it is made of the antenna of the appropriate size that the effect of ground plane can be taken no account, it can be made easily.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.651-652
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• 2023

코로나 팬더믹으로 인해 시작된 비대면 수업의 도입은 대학교육시스템에 변화를 가져왔다. 대학은 비대면 수업 운영에 대한 경험 및 학습자 만족도를 기반으로 비대면 수업을 대학 학사 운영에 활용하는 방안을 모색하기 시작하였다. 본 논문은 비대면과 대면이 혼합된 하이브리드 수업 운영에서 학습자들이 다양한 특성의 과목에서 만족한 수업방식과 의견을 조사·분석함으로써 비대면과 대면 수업을 혼합 활용하는 효과적 방안을 모색하는데 필요한 학습자 의견 도출에 그 목적이 있다. 조사 결과, 학습자들은 전반적으로 하이브리드 수업에 만족하고 있고, 과목 특성에 따라 비대면과 대면 수업의 장점을 혼합한 수업에 대한 학습효과를 올바르게 인식하고 있음을 알 수 있고, 수업 맞춤형 하이브리드 수업 운영을 선호하는 것으로 나타났다. 향후 대학은 학습자의 만족도를 높일 수 있는 하이브리드 수업 운영을 위한 제도 등을 마련하여 효과적인 수업 운영 및 활성화를 지원할 필요가 있다고 사료된다.

• Proceedings of the KSEG Conference
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• 2002.04a
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• pp.75-83
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• 2002

국내 절개면은 대개 절개면의 구성물질에 패한 지질공학적인 특성과 구성물질내의 지질구조 등에 대한 충분한 고려가 수행되지 않은 상태에서 구성물질의 강도에만 의존하여 설계·시공되었다. 따라서 매년 강우기와 해빙기에 반복적인 붕괴사고가 발생하고 있으며 이로 인한 인명피해와 재산손실이 매년 발생하고 있다. 따라서 절개면의 붕괴를 방지할 수 있는 근본적인 대책안의 제시와 함께 절개면에서 발생하는 붕괴를 예방하고 붕괴특성 및 붕괴 원인 규명을 위한 기초 연구로서 국내의 절개면에 대한 지질공학적인 특성 연구가 절실한 실정이다. 본 연구는 2001년 한국건설기술연구원에서 수행한 362개소의 절개면을 대상으로 절개면의 구성물질 및 지질구조에 대한 지질공학적 특성을 분석하였다. 본 연구는 국내에 분포하는 절개면의 붕괴 특성과 붕괴 인자에 대한 기초 연구로 차후 국내 절개면에 대한 설계기준을 재정립하고 절개면에 대한 효율적인 관리를 수행하기 위한 기초 자료로 사용될 수 있을 것으로 판단된다.

• Journal of the Korea Convergence Society
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• v.12 no.9
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• pp.215-227
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• 2021

The purpose of this study was to propose an efficient management strategy for untact real-time early childhood physical education(ECPE). The studay method was used in-depth interview, non-participant observation. The results of the study ar as follows. First, factors to be considered for untact real-time ECPE are 'location', 'communication', 'program', facilities' and 'equipment.' Second, for the effective untact real-time ECPE management, 'class design', 'class preparation', 'remote manager', and 'teaching ability.' are the sub-factors. The more of research on untact real-time ECPE are needed. Based on this study, it is hoped that an effective operation plan for untact real-time ECPE classes will be prepared.

• Korean Journal of Optics and Photonics
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• v.31 no.6
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• pp.328-333
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• 2020

In this paper, we study the analysis method for the aspherical tolerance of a Korsch telescope using a Q polynomial. It is important to analyze the tolerances for evaluating quality in high-precision fabrication of aspherical reflectors for high-resolution satellites. Thus we express the aspheric surface in terms of a Q polynomial in which each coefficient term is composed independently, and analyze the tolerance of a Korsch telescope. We also analyze the tolerance using Zernike fringe sag, which expresses the shape error of an aspherical mirror. By comparing the two results, we confirm that the Q-polynomial method can be used to analyze an aspherical mirror.