I-123 핵종생산장치 시스템 설계

정현우,유재준,김병일,이동훈,Jung, Hyun-Woo,You, Jae-Jun,Kim, Byung-Il,Lee, Dong-Hoon 한국정보통신학회 2014 한국정보통신학회논문지 Vol.18 No.6

30MeV 사이클로트론의 양성자가 Xe-124 기체 표적 시스템에 조사될 때 일어나는 핵반응을 적용하여 Xe 가스를 GPM으로부터 타겟으로 전송하는 시스템을 설계하였다. 시스템 설계는 크게 4파트로 구성되며 각각의 하드웨어 부분은 솔리드웍스 3-D 캐드를 이용하여 설계하였다. 타겟 시스템 중 헬륨으로 Havor foil을 냉각시키게 설계했고, 타겟 내 Xe 가스가 양성자로 조사 시 상승하는 타겟 온도를 냉각수로 냉각시켜주도록 설계하였다. 또한, 온도센서와 압력센서를 장착하여 타겟 내의 온도와 압력을 확인할 수 있도록 구성 하였다. GPM은 Xe 가스를 타겟으로 운반, 준비하는 부분이며 Xe 가스를 저장하는 부분과 불순물을 제거하는 부분으로 구성되어 있다. HCS는 헬륨을 이용하여 각 파트를 세척하고 냉각시켜 주는 부분이며, 각각의 장치들은 PLC로 제어하여 유지보수시의 편리성을 추구하였고 PC Vue 모니터링 프로그램을 사용하여 SIEMENS PLC와 인터페이스 하여 시스템을 보다 안전하고 편리하게 감시하도록 구성하였다. Xe gas is moved to target from GPM. It is used to feasible nuclear reaction from proton of 30MeV cyclotron being investigated by the Xe-124 gas target system. This system is divided into four parts. The hardware system was constructed by solidworks 3-D CAD and Helium supply is to cool the Havor foil. The Cooling water has the job of cooling down the temperature when Xe gas is being investigated in the target. Temperature and pressure gauges are attached to be checked easily. GPM has the part that prepares to transport Xe gas. There are storage vessel that stores Xe gas, the cold trap that filters humidity and impurity and lastly storage vessel that temporarily stores Xe gas. HCS using the helium is to clean and cool for each part. These parts are configured with SIEMENS PLC and PcVue monitoring program for more comfortable and easy maintenance.

마늘 및 양파 주산지 농업생산기반시설의 취약성 분석 - 전라도, 경상도를 중심으로 -

정현우,백신원,김한중,Jung, hyunwoo,Paik, sinwon,Kim, hanjoong 한국농촌계획학회 2017 농촌계획 Vol.23 No.4

In recent years, the proportion of arable land in the nation has grown from 36.2 percent in 1990 to 43.7 percent in 2013. The study first performed the vulnerability assessment of agricultural production, transportation, processing facilities, agricultural machinery leasing facilities, and water supply facilities. It was developed for the evaluation of the vulnerability of each gun of garlic and onions based on the distance from the three groups of arable bodies to the facility and the processing capacity of facilities. In view of these regional imbalances, the store, distribution and processing facilities in the main stream were found in Haenam, South Jeolla-do, and the relatively low regions of the gun were located in Goheung-gun and Hampyeong-gun. Among other regions, agricultural machinery rental facilities were high in Changnyeong-gun, Haenam, and two regions, while the water supply facilities were high in the southern area of Haenam and South Jeolla-do. The Gyeongsang-do showed relatively high levels of comparison vulnerability index compared to Jeolla-do regions. In particular, through the management plan to improve the facilities needed to improve agricultural production infrastructure, it is necessary to increase the competitiveness of agricultural productuivity through the planning of the need for additional support through the rural readjustment project.

직접 수열 확산 방식 기반 다중 밴드 FSK 신호의 성능 분석 및 실험 결과

정현우,신지은,정지원,Jeong, Hyun-Woo,Shin, Ji-Eun,Jung, Ji-Won 한국음향학회 2021 韓國音響學會誌 Vol.40 No.4

본 논문에서는 수중 통신에서 은밀성과 성능 향상을 위해 직접 수열 확산 방식 기반 다중 밴드 기법을 사용한 부 대역 Frequency Shift Keying(FSK) 신호의 효율적인 송수신 구조를 제시하였다. 은밀성적인 측면에서는 Pseudo Noise(PN) 부호의 chip을 직접 곱하는 직접 수열 대역 확산 방식을 적용하였으며, 성능적인 측면에서는 다중 경로 특성, 도플러 확산 등으로 인한 성능 감쇠를 극복하기 위해 다중 밴드, 터보 등화, 각 밴드별 가중치 알고리즘을 적용하였다. 시뮬레이션 결과를 바탕으로, 송수신기 사이의 거리가 약 300 m ~ 500 m인 호수에서 기동 실험을 하여 대역확산 신호의 chip 수를 8개, 32개로, 다중 밴드 수는 4개 일 때의 성능을 분석하였으며, chip 수가 증가할수록, 터보 등화 기법 적용 시 반복횟수가 증가할수록 성능이 향상되었고, 다중 밴드에서 프리엠블 오류율을 분석하여 밴드 별 가중치를 적용 시 더 많은 패킷 전송 성공률을 나타냈다.

수중 음향 통신에서 주파수 편이 변조 신호의 프리엠블 오류율을 이용한 주파수 이득 조절 연구

정현우,정지원,김완진,Jeong, Hyun-Woo,Jung, Ji-Won,Kim, Wan-Jin 한국음향학회 2022 韓國音響學會誌 Vol.41 No.2

The main characteristics of the underwater acoustic channel have varying multipath and fast fading. Especially, Frequency Shift Keying (FSK) signals with multiple frequency bands caused loss of information bits allocated on the specific frequencies due to selective fading phenomenon. Therefore, this paper proposes frequency gain control algorithm based on preamble error rates. The proposed algorithm estimates optimal gain value in the range of preamble error rate with less than 10 % for specific faded frequency. By employing turbo equalized FSK signals with rate of 1/3, the experiment was conducted on a lake in Munkyeong city with distance of 300 m to 500 m. The result confirms that packets are decoded successfully by applying proposed algorithm as increasing number of iterations.

구강건강지표를 활용한 건강수명 연구경향 분석: 최근 10년간의 논문분석(2010-2020)

정현우,양정연,박희정,Jung, Hyunwoo,Yang, Jungyeon,Park, Hee-Jung 한국학교ㆍ지역보건교육학회 2021 한국학교지역보건교육학회지 Vol.22 No.2

Purpose: The purpose of this article is to clearly describe research trends on health life expectancy using oral health indicators that have been published from 2010 to 2020 then suggest the direction of future research. Methods: Online academic databases in English (PubMed, Web of Science and Embase) were used to find those articles by applying a variety of keywords, including terms (adjusted life year, adjusted life expectancy, dental and oral). We identified relevant articles based on the following classification method of Mathers: (1) health gaps, (2) health expectancies. Results: Among 1,728 articles from the online databases, the final 13 studies satisfied the inclusion criteria and were selected for analysis. Health life expectancy studies indicate that research growth was recently achieved overseas. Among the literature collected in this study, 10 studies using health gap indicators yielded seven Disability-Adjusted Life Year (DALY), and three calculated Quality-Adjusted Life Year (QALY), which differed in the nature of the survey data used in the study measuring DALY and QALY. There are only three health expectancies and the number of papers were smaller than the health gap study. Conclusion: Establishing a foundation to calculate health life expectancy indicators through the development and improvement of oral health level are needed. More studies in the area of health life expectancy estimation research is based on actual prevalence and oral health-related quality of life are also needed.

자궁동정맥 기형 1 예

정현우(Hyun Woo Jung),이현주(Hyun Ju Lee),신현찬(Hyun Chan Shin),정철권(Chul Gyun Jung),정정은(Jung Eun Chung),정기성(Ki Sung Chung) 대한산부인과학회 2001 Obstetrics & Gynecology Science Vol.44 No.6

Arteriovenous malformation of uterus is a rare disease in gynecology, and its etiology, diagnosis, classification is not definitely established. We have experienced a patient, 22-year-old woman with a uterine arteriovenous malformation presenting with vaginal bleeding, no other symptom. Diagnosis was established by pelvic ultrasonography and angiography, and the treatment was done by embolization of arteriovenous malformation of uterus. We report a case of uterine arteriovenous malformation with a brief review of the literatures.

가스터빈 블레이드 내부 냉각 유로 요철이 열전달 특성에 미치는 영향

정현우(Hyunwoo Jung),유재영(Jaiyoung Ryu) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11

The rib turbulator plays important role to remove the heat by enhancing heat transfer of coolant passage wall. Various author investigated the configuration of the rib turbulator by experiment and computational methods, however, their investigations were confined to low Reynolds number and very high rotation number while the present gas turbine in land-based power plant have been developing to achieve higher temperature and Reynolds number close to 500000. Therefore, we investigated the characteristics of fluid behavior and thermal transfer in rib turbulated coolant passage with high Reynolds number and rotating speed of 3600RPM using computational fluid dynamics (CFD) methods. The Nusselt number and friction factor were quantified for evaluating thermal characteristics and pressure drop. The averaged Nusselt number was almost equal in first passage but showed significant differences in second passage according to increase of Reynolds number. Moreover, smaller rib spacing induces better heat transfer but larger pressure loss.

초등 체육과 교육과정의 움직임 역량 국제비교 연구

정현우(Hyunwoo Jung),손지훈(Jihoon Son) 한국스포츠교육학회 2021 한국스포츠교육학회지 Vol.28 No.4

본 연구는 체육과 교육과정 국제비교 연구를 통해, 교육과정에서 움직임 역량의 특징과 차이점을 분석하고, 향후 체육과 교육과정 개정 방향에 필요한 시사점을 탐색하였다. 이를 위해 한국, 홍콩, 캐나다 온타리오주를 선정하여 교육목표, 교육내용, 교수·학습에서 움직임 역량의 반영 수준과 양상을 비교·분석하였다. 교육목표에서는 홍콩과 온타리오가 움직임 역량을 포함하고 있었다. 교육내용에서는 한국이 표현활동의 일부로만 움직임 요소를 반영한 것에 반해, 홍콩은 움직임 기술을, 온타리오는 움직임 역량을 핵심 교육내용으로 설정하였다. 또한, 한국과 홍콩은 일반적인 교수·학습 방향을 제시한 것에 비해, 온타리오는 움직임 역량 요소별로 구체적인 교수·학습 방안을 안내하였다. 연구 결과를 종합해 볼 때, 향후 체육과 교육과정 개정 시, 기본 움직임 기술에 기반을 두고 의도적으로 움직임 역량을 교육해야 하며, 발달단계와 기술의 전이를 고려하여 교육내용과 교수·학습을 설계할 필요가 있다. 마지막으로 초등학교 교육과정과 움직임 역량에 대한 연구 활성화의 필요성과 초등학교 교사의 움직임 역량 전문성 함양 필요성을 제언하였다. This study analyzed the characteristics and differences of movement competency in the curriculum through an international comparative study of national curriculum elementary school physical education, and explored implications for the future direction of curriculum revision. For this, Korea, Hong Kong, and Ontario were selected, and the level and pattern of reflection of movement competency in educational goals, educational contents, and teaching and learning were compared and analyzed. In the educational goal, Hong Kong and Ontario included movement competency. In the educational content, while Korea reflected movement elements as part of expression activities, Hong Kong set movement skills and Ontario set movement competency as the core educational content. In addition, while Korea and Hong Kong presented general teaching and learning directions, Ontario provided specific teaching/learning methods for each movement competency element. Accordingly, it is necessary to intentionally educate the movement competency, and to design the educational content and teaching and learning methods considering the developmental stage and movement skills transfer. Lastly, the necessity of revitalizing research on movement competency that can be used in the elementary curriculum and fostering the movement competency expertise of elementary school teachers was suggested.

부품단종에 대한 조사·분석 및 관리방안

정현우(Hyun-Woo Jung),심보현(Bo-Hyun Shim) 한국산학기술학회 2020 한국산학기술학회논문지 Vol.21 No.5

무기체계를 구성하는 원자재 또는 부품이 수요에 따라 개발이 되어 생산되다가 기술의 발전 또는 시장 상황의 변화에 따라 노후화가 진행되어 생산이 중단되는 경우를 부품단종이라 한다. 현재 우리 군이 사용 중인 무기체계의 장비들은 부품단종으로 인해 조달, 정비, 운용 등에 어려움을 겪고 있다. 무기체계의 수명주기 기간 중 발생하는 부품단종 문제는 소요군 뿐만 아니라 장비, 부품, 원자재의 제조자 및 공급자에게 경제적인 손실과 무기체계 전투태세 준비에 영향을 미친다. 그러나 첨단기술의 발전으로 무기체계를 구성하는 전자부품의 수명은 점점 단축되고 있다. 또한 무기체계의 특성상 개발부터 폐기에 이르기까지 수십 년이 소요됨에 따라 부품단종이 발생하게 되고, 이는 무기체계 장비의 전투준비태세와 수명주기 비용에 심각한 악영향을 미친다. 따라서 무기체계 장비의 개발에서부터 폐기까지의 총 수명주기에 부품단종을 체계적으로 관리하는 것이 필요하다. 본 연구에서는 선진국의 부품단종 관리 제도를 분석하여 국내 실정에 맞는 부품단종 관리방안을 제시하고, 나아가 부품단종 관리의 조기 정착을 위한 발전 방안을 제시하고자 한다. Parts obsolescence is a component type, in which raw materials or parts that make up a weapons system, are developed and produced according to demand, but they age due to changes in technology or market conditions. The weapon system equipment currently being used by the military is having difficulty in procurement, maintenance, and operation because of the obsolescence of parts. Parts obsolescence during the life cycle of a weapons system affects not only the combat readiness of the military but also the economic loss of material, parts, and equipment manufacturers and suppliers. On the other hand, advanced technology has reduced the life span of electronic components that make up the weapons system. In addition, because of the nature of the weapons system, the obsolescence of components takes decades from development to disposal, which has a serious adverse effect on equipment readiness and life cycle costs. Therefore, it is necessary to manage systematically the parts obsolescence from development until the disposal of the weapons system equipment. This study examined the system of component control in developed countries to present a proper management plan for local situations and propose development plans for the early settlement of component control.

주사전자 현미경의 전자렌즈 설계 및 해석

정현우(H. U. Jung),박만진(M. J. Park),박근(K. Park),김동환(D. H. Kim),장동영(D. Y. Jang) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11

The scanning electron microscope (SEM) is one of the most popular instruments available for the measurement and analysis of the micro/nano structures. It is equipped with an electron optical system that consists of an electron beam source, magnetic lenses, apertures, deflection coils, and a detector. The magnetic lenses play a role in refracting electron beams to obtain a focused spot using the magnetic field driven by an electric current from a coil. A SEM column usually contains two condenser lenses and an objective lens. The condenser lenses generate a magnetic field that forces the electron beams to form crossovers at desired locations. The objective lens then focuses the electron beams on the specimen. The present work concerns finite element analysis for the electron magnetic lenses so as to analyze their magnetic characteristics. To improve the performance of the magnetic lenses, the effect of the excitation current and polepiece design on the amount of resulting magnetic fields and their peak locations are analyzed through the finite element analysis.