• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.409-415
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• 2018

The development of smart devices has brought about significant changes in daily life and one of the most significant changes is the virtual reality zone. Virtual reality is a technology that creates the illusion that a 3D high-resolution image has already been created using a display device just like it does in itself. Unrealized subjects are forced to rely on audiovisual materials, resulting in a decline in the concentration of practices and the quality of classes. It used virtual reality to develop effective teaching materials for radiology students. In order to produce a video clip bridge using virtual reality, a radiology clinic was selected to conduct two exposures from July to September 2017. The video was produced taking into account the radiology and work flow chart and filming was carried out in two separate locations : in the computerized tomography unit and in the LINAC room. Prior to filming the scenario and the filming route were checked in advance to facilitate editing of the video. Modeling and mapping was performed in a PC environment using the Window XP operating system. Using two leading virtual reality camera Gopro Hero, CC pixels were produced using a 4K UHD, Adobe, followed by an 8 megapixel resolution of $3,840{\times}2,160/4,096{\times}2,160$. Total regeneration time was performed in about 5 minutes during the production of using virtual reality to prevent vomiting and dizziness. Currently developed virtual reality radiation and educational contents are being used to secure the market and extend the promotion process to be used by various institutions. The researchers will investigate the satisfaction level of radiation and educational contents using virtual reality and carry out supplementary tasks depending on the results.

• Review of KIISC
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• v.20 no.3
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• pp.48-57
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• 2010

본 고는 휴먼 객체 검출 및 분류를 위한 것으로서, 입력된 동영상에서 배경 이미지와의 차분 영상을 통해 객체 영역을 검출하고, 검출된 객체 영역에서 얼굴 즉 헤드 영역을 검출하는 방법에 대해서 설명한다. 실시간으로 녹화된 동영상에서 사람이 움직이는 위치와, 크기 등이 아주 다양하며, 또한 한 사람이 아닌 여러 사람 객체를 검출하기 위하여 다중의 사람객체 검출기를 이용한 캐스케이드 사람 객체 추출 방법을 제안한다. 얼굴 크기 등을 고려하여 헤드 영역의 shape 를 기반으로 하여 1차 검출을 수행하고, 검출되지 않은 영역에 대하여 히스토그램 기반의 얼굴 영역을 검출한다. 또한 중복된 영상에 대해 베이지안 얼굴 검출기를 통해 인증함으로써 성능을 향상시킬 수 있다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.909_910
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• 2009

본 논문에서는 넓은 입/출력 변화를 가지는 비절연형 LLC 공진형 직류-직류 변환기의 제어기 설계 및 동특성에 대해서 설명한다. 먼저, 변환기의 동작 영역을 확인하고 각각의 동작점에서 변환기의 소신호 해석을 한다. 그 후에 소신호 특성을 바탕으로 적절한 보상기 회로를 구성하는 방안을 제시한다. 마지막으로 제시된 보상기 회로의 타당성을 컴퓨터를 통한 가상 실험과 실제적인 측정을 비교하며 확인한다.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.9-16
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• 2013

Long term evolution (LTE) and LTE-Advanced (LTE-A) systems adopt closed-loop multiple-input multiple-output antenna techniques. Equal gain transmission which has equal gain property is the key factor in their codebook design. In this paper, a novel differential codebook structure which maintains the codebook design requirements of LTE or LTE-A systems. Especially, eight-phase shift keying (8-PSK) constellations are used as elements of codewords, which not only maintain equal gain property but also reduce the computation complexity of precoding and decoding function blocks. The equal gain property is very important to uplink because the performance of uplink is very sensitive to the peak-to-average power ratio (PAPR). Moreover, the operation of the proposed differential codebook is explained as a rotation-lock structure. As the results of computer simulations, the steady-state throughput performance of the proposed codebook shows at least 0.9dB of SNR better than those of the conventional LTE codebook with the same amount of feedback information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6330-6339
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• 2013

The aims of this study were to identify the significant predictors of the sexual behavior of middle school students. The subjects consisted of 603 middle school students (male 344, female 259). The data was collected through self-report questionnaires, which were constructed to include the attitudes to sexual behavior, sexual permissiveness, perceived behavioral control, sexual behavioral intention, father's child-rearing attitudes, mother's child-rearing attitudes, friends' attitudes to sex, exposure to pornography, and sexual behavior. The data was analyzed using the SPSS 19.0 program. The significant predictors of sexual behavior of middle school students that explained 51.0% of the variance in sexual behavior were the friends' attitudes to sex, alcohol drinking experience, experience of sexual abuse, sexual permissiveness, exposure to pornography, sexual behavioral intention, perceived behavioral control, father's child-rearing attitudes, and mother's child-rearing attitudes. These findings suggest that the approach to a sexual education promotion program for middle school students should consider multisystemic predictors.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.07a
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• pp.98-101
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• 2015

최근, 텔레비전을 시청하지 않는 대기 상태에서의 셋톱박스의 대기 전력이 여타 가전기기의 대기 전력보다 10 배 이상을 상회하고 있어, 셋톱박스의 대기전력 저감은 국가적으로도 관심을 받고 있다. 셋톱박스의 대기전력 저감을 위해 대기상태의 셋톱박스의 최소전력 동작 모드인 수동대기모드가 제안되었지만, 셋톱박스가 수동대기모드에서는 셋톱박스의 업데이트 및 제어가 어려우므로, 셋톱박스의 수동대기모드 활용은 어려울 것이다. 본 논문은 수동대기모드에 가까운 대기전력을 소모하면서도 대기상태에서도 셋톱박스의 업데이트를 제공할 수 있는 망연동수동대기 모드를 정의하고, 망연동수동대기모드를 이용한 셋톱박스의 업데이트를 위한 셋톱박스 제어기법을 제안하고, 이 제어 기법을 위한 셋톱박스와 네트워크의 구조, 기능, 시그널링에 대해 설명한다. 본 논문의 망연동수동대기모드와 제어 방안은 셋톱박스 사업자 측면에서 활용성이 높으므로, 낮은 대기전력을 소모하는 셋톱박스 시장을 활성화하여 국가 및 세계적인 전력 감소에 큰 기여를 할 것이다.

• Journal of The Korean Association For Science Education
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• v.40 no.6
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• pp.595-609
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• 2020

The purpose of this study is to analyze the experiences of teachers who participated in the development of online science class videos in the context of covid-19, their perception of online science class, and the characteristics of the online science class content developed by teachers. A survey and interviews were conducted with ten elementary school teachers who made online science class videos themselves. Also the characteristics of the online science class were investigated by analyzing the online science class video produced by the participants. As a result, participants in the study recognized the lack of production time, difficulty in filming and editing, concerns over misconceptions, the problem of solving copyrights for existing materials, and the burden of external disclosure. Although it was a teacher who had experience producing online science class video contents, no research participants actively answered the merits of online science class. On the other hand, the study participants cited that the shortcomings of online science classes were that students had fewer opportunities for inquiry and lack of communication or interaction. In particular, these shortcomings were thought to have a great influence on the quality of online science classes, especially in making inquiry classes difficult. Some teachers took a negative view that online science classes could not completely replace face-to-face classes. However, if multiple teachers are presented with supplementary teaching activities that complement the content-based online teaching method, the method of combining online science classes and face-to-face classes is not. Through the analysis of the contents of the online science class, the introduction and arrangement steps of the online science class were similar to the process of the face-to-face science class, but the inquiry step and the conceptual explanation step showed a big difference from the face-to-face science class.

• Clean Technology
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• v.17 no.2
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• pp.103-109
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• 2011

The process optimization was carried out to improve the throwing power (TP) and the thickness uniformity of the electroless copper (Cu) plating, which plays a seed layer for the subsequent electroplating. The DOE (design of experiment) was employed to screen key factors out of all available operation parameters to influence the TP and thickness uniformity the most. It turned out that higher Cu ion concentration and lower plating temperature are advantageous to accomplish uniform via filling and they are accounted for based on the surface reactivity. To visualize what occurred experimentally and evaluate the phenomena qualitatively, the kinetic Monte Carlo (MC) simulation was introduced. The combination of neatly designed experiments by DOE and supporting theoretical simulation is believed to be inspiring in solving similar kinds of problems in the relevant field.