Path Morphology 개념을 이용한 MIMO 채널 모델링

정원정(Won-Jeong Jeong),유지호(Ji-Ho Yoo),김태홍(Tae-Hong Kim),김명돈(Myung-Don Kim),정현규(Hyun Kyu Chung),배석희(Seok-Hee Bae),백정기(Jeong-Ki Pack) 한국전자파학회 2010 한국전자파학회논문지 Vol.21 No.2

차세대 이동 통신 시스템에서는 높은 주파수 대역, 광대역, 다중 안테나(MIMO antenna)의 사용이 예상된다. 또한 무선 통신의 급격한 수요와 이동 통신 서비스의 폭발적인 증가로 인해 차세대 이동 통신 시스템의 최적화를 위한 검증 모델 개발 연구가 필요하다. 기존 MIMO 채널 모델의 경우 도심, 부도심, 시골, 개활지 등으로 포괄적으로 전파 환경을 분류하여 연구를 수행하였으나, 이러한 접근 방법은 예를 들어 도심 환경 내에서도 다양한 morphology가 존재할 수 있기 때문에 모델링 정확도 측면에서 취약성을 가질 수 있다. 본 논문에서는 path morphology 개념을 도입하여 전파 환경을 송?수신기 사이의 건물의 높이, 밀집도 등을 고려하여 세부적으로 분류하는 방법을 제안하였다. 광선 추적(ray tracing) 기법을 이용하여 각 환경별 delay spread(DS), AoD와 AoA의 angular spread(AS)를 분석하고, 이를 바탕으로 국내 환경에 적합한 MIMO 채널 모델을 제시하였다. The use of high frequency band, broad band and MIMO antenna is expected in the next generation mobile communication system. By the rapid increase of demand for wireless communications and the explosive increase of the mobile communication services, researches for optimization of next-generation mobile communication system are required. In the existing MIMO channel models, propagation-environments are commonly classified into urban, suburban, rural area, etc. However such approaches can have drawbacks in that many different morphologies may exist even in the urban area, for example. In this paper, we introduced path morphology concept, and proposed the method of morphology classification considering the building height, density, etc. Delay spread(DS), angular spread(AS) of AoD and AoA analyzed for each environment using the ray tracing technique. Based on the analysis, a MIMO channel model appropriate in domestic environment was suggested.

터널 환경에서의 전파전파 특성 모델링 연구

정원정(Won-Jeong Jeong),김태홍(Tae-Hong Kim),한일탁(Il-Tak Han),최문영(Moon-Young Choi),류준규(Joon-Gyu Ryu),이호진(Ho-Jin Lee),백정기(Jeong-Ki Pack) 한국전자파학회 2009 한국전자파학회논문지 Vol.20 No.9

국내 환경의 경우, 산악 지형이 많은 지형적 특성상 수많은 터널이 존재한다. 터널은 무선 채널 환경 중 대표적인 음영지역으로서 실외 및 실내 환경의 무선 채널과는 다른 특성을 갖기 때문에 터널 환경에서의 안정된 서비스 품질을 확보하기 위해서는 전파 채널의 특성 연구가 필요하다. 특히 위성을 이용한 이동 서비스를 위해서는 터널에 의한 음영지역에서의 정상적인 위성 신호 수신이 필요하며, 이를 위해 Gap-Filler라고 하는 지상 중계기를 운영하게 되는데 이를 이용하기 위해서는 터널 환경에서의 전파전파 특성 분석을 바탕으로 한 Gap Filling 방법 연구가 필수적이다. 따라서 본 논문에서는 음영 지역에서의 정상적인 위성 신호 수신을 위하여 터널 환경에서의 ISM 대역의 전파전파 특성을 분석하고, 이를 바탕으로 효율적인 Gap Filling 방법에 대한 연구를 수행하였다. In the domestic environments, there are many tunnels since most of terrains have mountains. To ensure the quality of wireless network service in NLOS environment like tunnels which differ from indoor or outdoor wireless channels, researches on wave-propagation characteristics through such channel are necessary. Especially, in such environment the ground repeater called Gap-Fillers are usually used for satellite mobile services. To make sure that mobile service using satellites in tunnels is available, the research about Gap Filling method is essential. This research is focus on the characterising the wave-propagation through tunnels, to find the appropriate frequency, HPBW of the Gap-Filler antennas, the number of Gap-Fillers, etc. In this paper, we present the effective Gap Filling method in tunnels for ISM band, based on analysis of ray tracing and measurement results.

가시설 H-pile의 유동화 채움재 개발

정원정(Jeong Won-Jeong),임종철(Im Jong-Chul),김태효(Kim Tae-Hyo),주인곤(Joo In-Gon),강현우(Kang Hyun-Woo) 한국지반환경공학회 2011 한국지반환경공학회논문집 Vol.12 No.8

흙막이 가시설 공사에 사용되는 H-pile은 철거의 어려움으로 공사 완료 후 그대로 지중에 사장되거나 사용 후 인발된다. 이때 H-pile 외부에 공동이 있을 경우 지반 변형을 일으키게 된다. 본 연구의 목적은 H-pile을 이용한 흙막이 구조물 조성 시 천공후 공동 충진을 용이하게 할 수 있고, H-pile 회수 시 마찰을 최소화하는 채움재 개발에 있다. 일차시험에서는 연구 목적을 만족하는 배합비를 선정하기 위해 수행되었고, 이차시험에서는 사용재료와 철판의 전단시험으로 인발 시 적용성을, 압밀시험을 통해 공동 충진 시 적용성을 평가하였다. 시험결과 유동화 채움재로서 우수한 성질을 보이는 배합은 벤토나이트를 기준으로 물 350%~450%, 시멘트 70%~100%, 모래 70%~100%가 포함된 배합으로 나타났다. Nowadays, H-piles are usually used as temporary retaining walls, and sometimes buried in the ground after construction. The purpose of this study is the development of flowable fill materials that are easy to fill holes of retaining wall structure and minimize friction during pulling out H-pile. The first test was performed to decide mix proportion that is reasonable for purpose, in the second test, direct shear test was performed to get pullout resistance between flowable fills material and H-pile, and one dimensional consolidation test was performed to analyze the compressibility. In the test result, it showed that flowable fill material mix proportion is 350-450% of water, 70-100% of cement and 70-100% of sand based on the bentonite weight.

교양체육 참여 대학생들의 진로통제소재가 진로포부와 진로자기효능감에 미치는 영향

정원정(Won, Chung-chung),윤미정(Yoon, Mee-Cheong),김희진(Kim, Hee-Jin),이수정(Lee, Soo-Jeong),김도연(Kim, Do-yeon),황미숙(Hwang, Mi-Sook) 한국사회체육학회 2021 한국사회체육학회지 Vol.- No.83

Purpose: The purpose of this study is to analyze the effects and correlation among the career locus of control, career aspirations, and careers self-efficacy. Methods: The data were collected from 8 universities by nonprobability sampling. The total subjects were 287 (male=128 and female=159). αset was .05. Multiple Regression Analysis was used for the hypothesis confirmation. Results: First, ‘internal factor’ in career locus of control affected ‘leadership’ in career aspiration factor. ‘Influence from others’ and ‘lethargy" in career locus of control affected ‘professionalism’ factor in career aspiration. And ‘internal control’& ‘influence from others’ in career locus of control factor affected career aspiration factor ‘job satisfaction’. Second, in career locus of control factor ‘internal control’, ‘influence from others’, ‘fortune’, and ‘lethargy’ did not affect ‘information setting’, ‘career planning’, ‘solution’ and ‘self-evaluation’ in career self-efficacy factor. Third, in career aspiration factor ‘leadership’, ‘professionalism’, and ‘job satisfaction’ did not affect career self-efficacy factor ‘information setting’,‘ career planning’, ‘solution’, and ‘self-evaluation’. Conclusion: In summary, the university students’ career decision behavior like career locus of control affects career aspiration to promote as an important variables for the career development promotion after the graduation for a career decision.

동아무용콩쿠르 심사자 신뢰도

김명주 ( Myung Ju Kim ),이윤혜 ( Yun Hye Lee ),차수정 ( Soo Jeong Cha ),유지영 ( Ji Young Yoo ),정원정 ( Won Jeong Jeong ) 한국무용연구학회 2013 한국무용연구회 국제학술발표논문집 Vol.2013 No.-

This study has a purpose to ensure the number of judges to satisfy the estimated reliability among the judges of Dong-A. The number of final candidates of Dong-A concours Korean dance part was 40(the number of traditional dance =21,the number of creative dance =19). The reliability of scores from 7judges was produced with intraclass correlation coefficient and reliability was set at 0.80. The result of reliability showed that traditional dance was 0.55, the reliability was 0.75. To suffice the standard 0.80, traditional dance part needs 16 judges and creative dance part needs 10 judges. Thus, we need to develop the way of applying analytic evaluation and diverse evaluating standards to solve this problem more than holistic evaluation.

^(155,156)Gd 동의원소의 keV 영역 중성자 포획단면적 측정

정원정,황정훈,김현,노태익 東亞大學校 2004 東亞論叢 Vol.41 No.-

The Neutron Capture Cross-Section of ^(155,156)Gd were measured in a neutron energy region from 15 to 85 keV using the 3MV Pelletron accelerator of Tokyo Institute of Technology. Pulsed neutrons were produced from the ^(7Li)(p,n)^(7)Be reaction. The incident neutron spectrum on a capture sample was measured by means of a TOF method with a ^(6)Li-glass detector. The capture γ-ray were detected with a large anti-Compton NaI(TI) spectrometer. A pulse-height weighting technique was applied to measured capture γ-ray pulse-height spectra to derive capture yields. The capture cross sections were obtained by using the standard capture cross-section of ^(197)Au. The present results are corrected for isotope impurities of sample because the samples contain various isotope Godolinium. The present results are compared with the previous measurements and the evaluated data of ENDF/B-VI.