Molecular dynamics simulation of water behavior as a function of temperatures and monomer numbers in Nafion 117

Kyungsu Oh,Seungho Park,Ohmyoung Kwon,Young Ki Choi,Joon Sik Lee 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

The proton exchange membrane plays a critical role as an electrolyte for proton transports in the PEMFC. Generally, the membrane, such as Nafion 117, consists of a polytetrafluoroethylene(PTFE) backbone and side-chains terminated with a sulfonate group(SO₃<SUP>-</SUP>).<br/> Operating the fuel cell, the membrane preferentially becomes hydrated by absorbing water. Then the hydrogen atom on the SO₃<SUP>-</SUP> part of the side-chain can detach from its own position and hop to the next SO₃<SUP>-</SUP> site.<br/> The water management is the key to the efficient operation of the fuel cell, since the water content is the one of decisive factors for membrane's lifetime and efficient operations of fuel cells as well.<br/> In this report, we made the molecule based model for hydrated Nafion 117 and simulated for various temperature and monomer numbers. Here, we analyzed the movement of water molecules and determinated the self-diffusion coefficients of water in the Nafion 117 using the mean-square displacement.

Synchronization Design of Satellite TDMA Network

Kyungsu Ko,Il-Hyuk Oh,Youn-sang Yoo,Sang Kyun Oh,Huisoo Lee 한국통신학회 2012 韓國通信學會論文誌 Vol.37 No.7

튜터링프로그램에서 튜터와 튜티의 특성에 따른 만족도와 효과의 관계분석

오경수(Oh Kyungsu),최정(Choi Jung),허지숙(Huh Jisuk) 학습자중심교과교육학회 2020 학습자중심교과교육연구 Vol.20 No.11

본 연구는 대학의 튜터링 프로그램이 학생들의 개인, 경험, 활동 특성에 따라 만족도에 유의미한 차이를 보이는지 확인하고, 튜터와 튜티의 효과를 구분하여 만족도에 미치는 영향을 확인하는데 목적이 있다. 이를 위해 A 대학교 2019학년도 2학기 튜터링 프로그램에 참여한 학생을 대상으로 2020년 2월 20일부터 23일까지 설문조사하고 분석을 진행하였다. 연구결과, 첫째, 대학 튜터링 프로그램의 만족도는 성별, 튜터링 과제 유형에 따라 유의한 차이가 있는 것으로 나타났다. 둘째, 튜터의 경우 튜터링 참여 횟수에 따라 학업성취 효과를 높게 인식하는 것으로 나타났으며 튜터의 사회정서적 효과가 만족도에 높은 영향을 주는 것으로 나타났다. 셋째, 튜티의 경우 학습과제 유형에 따라 사회정서적 효과, 학업성취 효과, 학습동기 효과에 유의한 차이를 보였다. 또한 튜티의 학업성취 효과와 학습동기 효과가 만족도에 높은 영향을 주는 것으로 나타났다. 따라서 대학 튜터링 프로그램 운영 시 효과성과 만족도를 위하여 보다 적절한 관리와 개입이 필요하며 튜터와 튜티에 따른 전략적 접근과 극대화 방안이 필요함을 확인하였다. The purpose of this study is to determine whether the tutoring program of the university shows a significant difference in satisfaction according to the individual, experience, and activity characteristics of students, and to determine the effect of student tutor and tutee on satisfaction. To this end, a survey and analysis were conducted from February 20 to 23, 2020 for students who participated in the tutoring program for the second semester of 2019 at a ‘A’ University. As a result of the research, first, the satisfaction of university tutoring programs was found to be significantly different according to gender and tutoring task type. Second, in the case of student tutors, it was found that the academic achievement effect was highly recognized according to the number of tutoring participating, and the social and emotional effects of tutors had a high effect on satisfaction. Third, in the case of tutees, there were significant differences in social emotional effects, academic achievement effects, and learning motivation effects according to the types of learning tasks. In addition, it was found that tutee s academic achievement effect and learning motivation effect had a high impact on satisfaction. Therefore, it was confirmed that more appropriate management and intervention are needed for effectiveness and satisfaction when operating a university tutoring program, and that a strategic approach and maximization plan according to tutors and tutees are needed.

리드 솔로몬 복호화기의 성능 향상 기법에 관한 연구

고경수(Kyungsu Ko),오일혁(Ilhyuk Oh),고동국(Dongkuk Ko),Nguyen Minh Viet,이황수(Hwang Soo Lee) 한국통신학회 2010 한국통신학회 학술대회논문집 Vol.2010 No.6

A Novel Topoisomerase Inhibitor, Daurinol, Suppresses Growth of HCT116 Cells with Low Hematological Toxicity Compared to Etoposide

Kang, Kyungsu,Oh, Seung Hyun,Yun, Ji Ho,Jho, Eun Hye,Kang, Ju-Hee,Batsuren, Dulamjav,Tunsag, Jigjidsuren,Park, Kwang Hwa,Kim, Minkyun,Nho, Chu Won Elsevier 2011 Neoplasia Vol.13 No.11

<P>We report that daurinol, a novel arylnaphthalene lignan, is a promising potential anticancer agent with adverse effects that are less severe than those of etoposide, a clinical anticancer agent. Despite its potent antitumor activity, clinical use of etoposide is limited because of its adverse effects, including myelosuppression and the development of secondary leukemia. Here, we comprehensively compared the mechanistic differences between daurinol and etoposide because they have similar chemical structures. Etoposide, a topoisomerase II poison, is known to attenuate cancer cell proliferation through the inhibition of DNA synthesis. Etoposide treatment induces G(2)/M arrest, severe DNA damage, and the formation of giant nuclei in HCT116 cells. We hypothesized that the induction of DNA damage and nuclear enlargement due to abnormal chromosomal conditions could give rise to genomic instability in both tumor cells and in actively dividing normal cells, resulting in the toxic adverse effects of etoposide. We found that daurinol is a catalytic inhibitor of human topoisomerase Il alpha, and it induces S-phase arrest through the enhanced expression of cyclins E and A and by activation of the ATM/Chk/Cdc25A pathway in HCT116 cells. However, daurinol treatment did not cause DNA damage or nuclear enlargement in vitro. Finally, we confirmed the in vivo antitumor effects and adverse effects of daurinol and etoposide in nude mice xenograft models. Daurinol displayed potent antitumor effects without any significant loss of body weight or changes in hematological parameters, whereas etoposide treatment led to decreased body weight and white blood cell, red blood cell, and hemoglobin concentration.</P>

목도나루학교 전환기교육 학습자의 자아 성장 사례연구

오연주(Yeonju Oh),박경수(Kyungsu Park),김영인(Youngin Kim) 학습자중심교과교육학회 2024 학습자중심교과교육연구 Vol.24 No.7

목적 본 연구는 학교 교육 환경에서 학생의 자아 성장 과정을 심층적으로 이해하기 위하여 전환기교육 기관인 ‘목도나루학교(충북소재)’에 재학하고 있는 연구참여자 4명의 자아 성장 과정을 탐구하고자 하였다. 방법 재학생 전체를 대상으로 예비조사, 전체 교사를 대상으로 기초조사를 실시하여 4명의 연구참여자를 선정하였다. 연구참여자에게 반구조화된 심층면접을 실시하고 전사하여 자료를 수집하였다. 수집된 자료는 Nvivo(ver. 14)를 활용하여 개방코딩, 축코딩, 선택코딩의 과정을 순환적으로 거쳐 분석하였다. 결과 목도나루학교의 전환기교육에 참여한 연구참여자들은 개인차가 있는 성장 과정을 드러냈다. 이들은 다양한 계기와 요소를 자신의 자아 성장의 배경으로 인식하고 있으며, 개별 성장은 독립적이라기보다는 자아정체성⋅사회적 정체성⋅진로정체성의 영역에서 상호 영향을 주고받거나 전환되는 총체적인 특성을 나타낸다. 결론 이러한 결과는 중등교육에서 개별 학습자의 자아 성장 과정에 대한 개인차를 더욱 심층적으로 이해하고, 교수활동 중심의 협소한 접근을 넘어 학교를 둘러싼 다양한 생활공간과 관계적 측면을 포함하는 총체적 접근의 필요성을 제안한다. Objectives This study aims to deeply understand the process of self-growth in students within the school educational environment. It explores the self-growth process of four participants who are enrolled in a transitional educational institution, ‘Mokdonaru School’ located in Chungcheongbuk-do. Methods Preliminary surveys were conducted among all enrolled students, and foundational surveys were carried out with all teachers to select four research participants. Semi-structured, in-depth interviews were conducted with these participants, and the data was collected through transcription. The gathered data was analyzed using Nvivo (version 14), processing a cyclical process of open coding, axial coding, and selective coding. Results The participants in this study revealed a growth process characterized by individual differences. They recognize various triggers and elements as the background of their self-growth, and their individual growth is not so much independent as it is holistic, affecting and transforming across the areas of self-identity, social identity, and career identity. Conclusions These findings suggest the need for a deeper understanding of individual differences in students' self-growth processes in secondary education, and for a holistic approach that goes beyond a narrow focus on teaching activities to include the diverse living spaces and relational aspects surrounding the school.

움직이는 물체의 개수에 비례하는 시간을 가지는 전역조명 알고리즘

정호욱(Zheng, Haoxu),오경수(Oh, Kyungsu),백두원(Paik, Doowon) 한국게임학회 2016 한국게임학회 논문지 Vol.16 No.2

간접조명은 실제감에 많은 도움을 주지만 많은 계산량이 필요하기 때문에 실시간 전역조명에서는 적용되기 힘들었다. 특히 2차광원에서의 가시성을 계산하기위해서는 각 광원에 대해서 모든 물체들을 처리해야 하기 때문에 계산량이 많다. 본 논문에서는 움직이지 않는 물체들의 가시성을 재활용하여 움직이는 물체가 많지 않을 경우 효율적이면서도 2차광원의 가시성을 활용하는 간접조명 알고리즘을 제안한다. 기존 방법에 비해서 정확하면서도 효율적인 2차광원 가시성을 바탕으로 보다 복잡한 장면에서 사실적인 간접조명을 실시간에 가능하게 한다. Global illumination is key factor for realistic image but it is not common in realtime rendering due to its complexity. Visibility of 2^nd lights is hard to determine because we should process all object for each 2^nd light. In this paper, we reuse visibility of static objects. We present an indirect illumination algorithm which shows good performance and provides exact 2^nd light visibility when the scene has small number of moving objects. Our method renders correct image while showing good performance.

회수 물류 네트워크 디자인

송병덕(Byung Duk Song),오용희(Yong Hui Oh),박경수(Kyungsu Park) 한국SCM학회 2016 한국SCM학회지 Vol.16 No.2

With legislations and customers’increased attention to environment issues, interests on reverse logistics have been increased. In this paper, we address a design issue of reverse logistics network with the objectives of minimizing total establishment cost of collection centers and transportation cost of collected end-of-used product by determining the locations of centers, reverse logistics network and minimum quality of end-of-used product to be collected. We propose mathematical model and genetic algorithm to support such decisions. Validity of the proposed genetic algorithm was tested via numerical experiments with various distributions on the quality of end-of-products.

컬러감자 홍영, 자영으로부터 항산화 화합물의 정량 및 간세포 보호 효과 탐색

김상민 ( Sang Min Kim ),강경수 ( Kyungsu Kang ),하인수 ( In Su Ha ),노주원 ( Chu Won Nho ),남정환 ( Jung Hwan Nam ),조지홍 ( Ji Hong Cho ),권오근 ( Oh Keun Kwon ),정진철 ( Jin Cheol Jeong ),이재권 ( Jae Kwon Lee ),판철호 ( Cheol H 충북대학교 과학교육연구소 2014 과학교육연구논총 Vol.29 No.1

The colored Potatoes, ‘Hongyoung’ and ‘Jayoung’ cultivars bred in Rural Development Administration (Korea) contain antioxidant compounds such as chlorogenic acids and anthocyanin compounds in the tuber. In this study, main antioxidant compounds in both cultivars were identified by LC-MS analysis and quantified by HPLC analysis. The result showed that three compounds (petunidin-3-O-coumaroyl-rutinoside-5-O-glucoside, pelargonidin-3-Ocoumaroyl- rutinoside-5-O-glucoside and peonidin-3-O-coumaroyl-rutinoside -5-O-glucoside) were identified as main anthocyanins in ‘Jayoung’ cultivar while only pelargonidin-3-O-coumaroyl-rutinoside-5-O-glucoside was presented as a major anthocyanin in ‘Hongyoung’ cultivar. Among chlorogenic acids, 5-O-caffeoylquinic acid was the most abundant in both cultivars. In order to evaluate hepatoprotective activity of these potatoes, the methanol extracts and their serial solvent fractions were prepared by solvent partition and XAD-7 column chromatography method and treated on hepatoma HepG2 cells of which cytotoxicity was induced by tert-butyl hydroperoxide. Among the tested samples, anthocyanin-rich fractions from both cultivars contained the strongest hepatoprotective effect on HepG2 cells. This result indicates that hepatoprotective effect of these fractions can be occurred from anthocyanin.

Development of Fe distribution analysis method in brain tissue of patients with multiple sclerosis using fsLA-ICP-MS

Sunghwa Choi,yuri Lee,Jihae Oh,jaejong Jin,hyeong-geol Shin,jongho Lee,kyungsu Park 한국분석과학회 2022 학술대회논문집 Vol.2022 No.5