육방정 질화붕소 나노입자 합성 및 열전도성 복합체 응용

정재용,김양도,신평우,김영국,Jung, Jae-Yong,Kim, Yang-Do,Shin, Pyung-Woo,Kim, Young-Kuk 한국분말야금학회 2016 한국분말재료학회지 (KPMI) Vol.23 No.6

Much attention has been paid to thermally conductive materials for efficient heat dissipation of electronic devices to maintain their functionality and to support lifetime span. Hexagonal boron nitride (h-BN), which has a high thermal conductivity, is one of the most suitable materials for thermally conductive composites. In this study, we synthesize h-BN nanocrystals by pyrolysis of cost-effective precursors, boric acid, and melamine. Through pyrolysis at $900^{\circ}C$ and subsequent annealing at $1500^{\circ}C$, h-BN nanoparticles with diameters of ~80 nm are synthesized. We demonstrate that the addition of small amounts of Eu-containing salts during the preparation of melamine borate precursors significantly enhanced the crystallinity of h-BN. In particular, addition of Eu assists the growth of h-BN nanoplatelets with diameters up to ~200 nm. Polymer composites containing both spherical $Al_2O_3$ (70 vol%) and Eu-doped h-BN nanoparticles (4 vol%) show an enhanced thermal conductivity (${\lambda}{\sim}1.72W/mK$), which is larger than the thermal conductivity of polymer composites containing spherical $Al_2O_3$ (70 vol%) as the sole fillers (${\lambda}{\sim}1.48W/mK$).

콜로이드 양자점 합성의 다양한 연구 개발 동향

정재용,홍종팔,김영국,Jung, Jae-Yong,Hong, Jong-Pal,Kim, Young-Kuk 한국분말야금학회 2018 한국분말재료학회지 (KPMI) Vol.25 No.4

Over the last decade, the study of the synthesis of semiconductor colloidal quantum dots has progressed at a tremendous rate. Colloidal quantum dots, which possess unique spectral-luminescent characteristics, are of great interest in the development of novel materials and devices, which are promising for use in various fields. Several studies have been carried out on hot injection synthesis methods. However, these methods have been found to be unsuitable for large-capacity synthesis. Therefore, this review paper introduces synthesis methods other than the hot injection synthesis method, to synthesize quantum dots with excellent optical properties, through continuous synthesis and large capacity synthesis. In addition, examples of the application of synthesized colloid quantum dots in displays, solar cells, and bio industries are provided.

진도 연안VTS의 성과 분석 및 기능에 관한 실증적 연구

정재용,정초영,Jeong, Jae-Yong,Jung, Cho-Young 해양환경안전학회 2012 海洋環境安全學會誌 Vol.18 No.4

2007년 태안에서 발생한 허베이 스피리트호 사건은 연안 해역 안전관리에 대한 중요성을 다시 한 번 일깨워 주었고, 이에 대한 대응방안으로 연안VTS를 우리나라 전 해역에 걸쳐 구축 운영할 계획이다. 이제까지 VTS 기능에 관한 이론적인 고찰은 있었으나, 연안VTS의 기능에 관한 실증적인 연구는 없었다. 이에 본 연구는 현재 운영되고 있는 진도 연안VTS 운영성과를 분석하고, 사고예방 사례를 조사하여 연안VTS의 기능에 관하여 조사하였다. 연안VTS는 관제구역이 넓어 해상교통 특색이 장소마다 상이하며, 집중 관제를 필요로 하는 곳이 많았고, 통항선박 중 어선과 같은 비관제 대상 선박이 다수를 차지하여 이들의 관제가 중요한 것으로 조사되었다. 그리고 선박 운항자의 집중도가 항내보다는 떨어지므로 인적과실에 의한 사고 개연성이 높은 것으로 분석되었다. 연안VTS는 항만VTS와 같이 정보제공, 항행지원, 교통관리의 역할을 주로 하고 있지만, 수색구조 지원, 해상 보안, 해상치안 업무, 해양오염 대응, 비관제 대상 선박 업무 및 수상레저 안전관리 등의 기능이 강화되는 것으로 나타났다. Hebei Spirit Oil Spill that happened in 2007 had prompted the need of revisiting the coastal safety. In response to this, Korea had made an effort to implement VTS in every coastline in the country. There are a lot of theoretical studies on VTS function nowadays, but coastal VTS are less frequently studied. In this paper, performance analysis results and accident prevention activities of Jindo Coastal VTS center were summarized and the Coastal VTS function are investigated. Jindo Coastal VTS covers relatively wide area and various places with various maritime traffic characteristics are the major navigation vessels, which means that it is important to control these vessels. Since the probability of accidents due to human error is relatively high in coastal area due to negligence tendency of crews during coastal area navigation, coastal VTS has to provide sufficient assistance to navigating vessels. Like most harbour VTS, Coastal VTS provides not only main information service, navigational assistance and traffic organization services but also various services related with advanced search-and-rescue assistance, marine national security, maritime crime prevention, oil spill response, traffic services for non-service vessel, and safety supervision for water leisure boats.

해상교통흐름을 고려한 방파제 배치에 관한 연구

정재용(Jae-Yong Jung),박영수(Young-Soo Park),고재용(Jae-Yong Ko) 한국항해항만학회 2005 한국항해항만학회지 Vol.29 No.3

선박 조종자는 방파제를 통항할 경우 조선 부담감 느낀다. 방파제를 배치할 때 아직까지 선박 조종자의 조선 부담감을 고려한 적은 없다. 이 연구는 해상교통류 시뮬레이션을 이용하여 조선 부담감이 발생하는 상황을 재현하여 선박 조종자의 조선 부담감을 정량적으로 표현한 모델인 환경스트레스모델을 그 재현된 상황에 적용하였다. 주요한 결과는 다음과 같다. (1) 방파제 배치 변화에 의한 조선 부담감의 차이는 그다지 크지 않다. (2) 방파제 사이의 항로 폭이 동일하면 선박의 속력에 따라 조선 부담감의 크기가 다르다. (3) 방파제 사이의 항로 폭이 넓어지면 조선 부담감은 감소한다. A mariner feels the shiphandling difficulty when the vessel onboard passes through breakwater. Until now, the shiphandling difficulty of the mariner has not been taken into account in the layout of a pair of breakwater. This paper reproduced such a situation that shiphandling is difficult enough by using marine traffic flow simulation, it is assessed by using ES Model which is a quantitative model for evaluating the difficulty of shiphandling arising from maneuvering a ship in the restricted or congested waters. The results are as follows. (1) The change in the layout of a pair of breakwaters has little influence on the shiphandling difficulty. (2) If the width between breakwaters is the same, the speed of a ship affects the shiphandling difficulty. (3) The increase of the width decreases the shiphandling difficulty.

만성 누공 및 치근단부 치석이 존재하는 상악 제1소구치의 치험례

정재용(Jae-Yong Jung),정일영(Il-Young Jung),김의성(Euiseong Kim) 대한치과의사협회 2003 대한치과의사협회지 Vol.41 No.9

구조선의 도착시간 산출을 위한 실험 데이터 구축

정재용(Jae-Yong Jeong),정초영(Cho-Young Jung) 한국마린엔지니어링학회 2017 한국마린엔지니어링학회지 Vol.41 No.1

연골판 주위 결절종으로 의심되었던 관절 외 연골판 주위 활액막 연골종 - 1례 보고 -

전재균,선두훈,정현석,김영우,정재용,Chon, Je-Gyun,Sun, Doo-Hoon,Jeong, Hyeon-Seok,Kim, Young-Woo,Jung, Jae-Yong 대한관절경학회 2009 대한관절경학회지 Vol.13 No.3

활액막 연골종이 관절 외에서 발생하는 경우는 매우 드물다. 손 발 및 손목 등에서 주로 발생하며, 대 관절 가운데 주로 슬 관절에 발생하며, 건막, 관절막, 및 점액낭에서 발생하는 것으로 알려져 있다. 발생 원인은 특발성이며, 활막 세포가 연골 세포로 화성(metaplasia)에 의한다. 연골 단괴는 석회화가 진행되어 골화가 이루어지는데, 석회화 또는 골화가 이루어지기 전 단계에서는 단순 방사선 소견으로 진단이 어려워 MRI등의 검사가 필요하다. 저자는 크기가 크고 MRI 소견에서도 낭종과 유사한 소견을 보여 결절종으로 의심하여 수술하였던 관절 외 연골판 주위 활액막 연골종을 보고 한다. Extraarticular synovial chondromatosis is a very rare disease which affects the hands, feet, and wrists most commonly. In cases of involvement around large joints, the tissues around knee are usually involved. It arises from tendon sheath, capsular tissue and bursae. It is an idiopathic process in which the synovial cells undergo the metaplasia into cartilage cells. Chondroid matrix of the cartilaginous nodules calcify and ossify to be the osteochondroma. On simple radiograms before calcification and/or ossification of the chondroid tissues the cartilaginous nodules look normal on radiograms. Therefore MRI is needed to establish the diagnosis. We report a case of extraarticular pan-peri-meniscal synovial chondroma around right knee, initially suspected as a ganglion cyst which clinically mimicked a large rounded lesion or a cystic lesion on MRI.

소프트웨어 기반 정도관리 시스템을 이용한 부피세기조절회전치료 환자 별 정도관리의 유용성 평가

강동진(Dong-Jin Kang),정재용(Jae-Yong Jung),신영주(Young-Joo Shin),민정환(Jung-Whan Min),김연래(Yon-Lae Kim),권경태(Kyung-Tae Kwon) 대한방사선과학회(구 대한방사선기술학회) 2018 방사선기술과학 Vol.41 No.1

The purpose of this study is to evaluate the usefulness of a software-based quality assurance system based on Volumetric Modulated Arc Therapy treatment plan. Evaluate treatment plan through the D VH analysis, PTV mean dose (   ) and PTV 95% dose(   ) compare the MFX based on original treatment plan, Average error rate was 0.9±0.6%, 1.0±0.8%, respectively. Measuring point dose using phantom and ion chamber, the average error rate between the ionization chamber and MFX was 0.9±0.7%, 1.1±0.7% (high dose region), 1.1±0.9%, 1.2±0.7% (low dose region). The average gamma though of MFX and Delta 4PT is 98.7±1.2%, 98.4±1.3%, respectively. Through this study, A software based QA system that simplifies hardware based QA procedures that involve a lot of time and effort. It can be used as a simple and useful tool in clinical practice.

시계열 분석을 통한 해상교통량 예측 방안

유상록,박영수,정중식,김철승,정재용,Yoo, Sang-Rok,Park, Young-Soo,Jeong, Jung-Sik,Kim, Chul-Seong,Jeong, Jae-Yong 해양환경안전학회 2013 해양환경안전학회지 Vol.19 No.6

In this study, time series analysis was tried, which is widely applied to demand forecast of diverse fields such as finance, economy, trade, and so on, different from previous regression analysis. Future marine traffic volume was forecasted on the basis of data of the number of ships entering Incheon port from January 1996 to June 2013, through courses of stationarity verification, model identification, coefficient estimation, and diagnostic checking. As a result of prediction January 2014 to December 2015, February has less traffic volume than other months, but January has more traffic volume than other months. Also, it was found out that Incheon port was more proper to ARIMA model than exponential smoothing method and there was a difference of monthly traffic volume according to seasons. The study has a meaning in that future traffic volume was forecasted per month with time series model. Also, it is judged that forecast of future marine traffic volume through time series model will be the more suitable model than prediction of marine traffic volume with previous regression analysis. 본 연구는 기존의 회귀분석과는 달리 금융, 경제, 무역 등 다양한 분야의 수요 예측에 널리 적용되고 있는 시계열 분석 방법을 시도하였다. 인천항의 1996년 1월부터 2013년 6월까지 입항 척수 자료를 바탕으로 정상성 검증, 모형의 식별, 모수의 추정, 진단 과정을 거쳐 장래 해상교통량을 예측하였다. 2014년 1월부터 2015년 12월까지 예측한 결과 2월달의 교통량이 다른 달 보다 적게 예측된 반면, 1월달의 교통량은 다른 달 보다 많을 것으로 나타났다. 또한 인천항은 지수평활법 보다 ARIMA 모형이 적합하며, 계절에 따라 월별 교통량의 차이를 보이는 것을 알 수 있다. 본 연구는 시계열 분석으로 장래 교통량을 월별로 예측하였다는 점에서 의의가 있다. 또한 기존의 회귀분석으로 예측한 장래 해상교통량보다 시계열 분석으로 예측한 장래 해상교통량이 더 적합한 모형인 것으로 판단된다.

무지 외반증 재발의 한 원인으로 생각되는 종자골 정복에 영향을 주는 인자

윤영필,이철형,정현윤,김영우,정재용,Yune, Young-Phil,Lee, Chul-Hyung,Jeong, Hyun-Yoon,Kim, Young-Woo,Jung, Jae-Yong 대한족부족관절학회 2010 대한족부족관절학회지 Vol.14 No.1

Purpose: The incomplete reduction of the sesamoid has lately been issued as cause for recurrence. In this study, we analysed factors that may influence reduction of sesamoid. Materials and Methods: The study consists of 50 cases operated by single surgeon. Eighteen cases were done by proximal chevron osteotomy, and 32 cases were done by scarf osteotomy. Hallux valgus (HV) angle and intermetatarsal (IM) angle were measured before and three months after the surgery. Sesamoid position (SP) was classified according to Hardy and Clapham grade system. Results: After the proximal chevron osteotomy, the correction of the mean HV angle was $19.5^{\circ}$, and IM angle was $6.2^{\circ}$. SP was changed from 5.6 to 3.4 grade. After the Scarf osteotomy, the correction of the mean HV angle was 25 degree, and IM angle was $9^{\circ}$. SP was changed from 5.5 to 2.8 grade. There was difference of sesamoid's correction between two different method of surgery (p=0.127). However, better correction of sesamoid was witnessed with bigger correction angle regardless of method of surgery (p=0.002, 0.001). Conclusion: We believe surgical method do not effect sesamoid's correction but more correction angle can result in better correction of sesamoid position.