반용융 성형에서 강제 표면 냉각에 의한 유도 가열 방법에 관한 연구

박준홍(Joan Hong Park),최영(Young Choi) Korean Society for Precision Engineering 2005 한국정밀공학회지 Vol.22 No.1

The procedure of semi-solid forming is composed of heating a billet, forming, compression holding and ejecting step. There are several methods to heat a billet during semi-solid forming process such as electric heating and induction heating. Usually in semi-solid forming process, induction heating has been adopted to achieve more uniform temperature of semi-solid material. Although induction heating is better method than any others, however, there is still difference of temperature between internal part and surface part of semi-solid material. Worse yet, in case of high liquid fraction of semi-solid material, liquid of the billet will flow down though solid of the billet still remains, which is very difficult to handle. In the present study, induction heating of semi-solid material with compulsive surface cooling has been performed to obtain uniform distribution of temperature. Distribution of temperature of the billets was measured and compared with that of conventional distribution of temperature. By this new induction heating method, not only temperature over the whole billet become uniform, but also control of temperature is possible.

품질경영시스템의 요구사항 활용 실태분석과 성공적 운영방안 - 경남지역 제조업체를 중심으로 -

박동준(Dong-Joan Park),강인선(In-Sean Kang) 한국산업경영시스템학회 2005 한국산업경영시스템학회지 Vol.28 No.2

ISO 9000 quality standards families were established in 1987 and have been started to implement Korean industry since early 1990s. ISO 9000 standards families of 1987 were revised in 1994 and 2000, respectively, by request of world wide certification bodies and industry quality experts. This article reviews the necessity of ISO 9001 : 2000 revision, quality management principles behind it, and benefits that ISO 9001 : 2000 could bring. We summarize responses of foreign industry that ISO 9001:2000 has been implemented. Survey questionnaire for 23 requirements of ISO 9001 : 2000 from manufacturing companies of Busan and Kyungnam provinces are collected. Research hypotheses that there is any difference in quality management system practical application due to company size and implementation motivation are tested using SPSS. Finally, recommendations are provided for operating successful quality management system.

무선 CCTV 시스템을 이용한 환자 고정 보조기술의 개발

박양균(Yang Kyun Park),하성환(Sung Whan Ha),예성준(Sung Joan Ye),조웅(Woong Cho),박종민(Jong Min Park),박석원(Suk Won Park),허순녕(Soon Nyung Huh) 대한방사선종양학회 2006 Radiation Oncology Journal Vol.24 No.4

목 적 본 연구에서는 선헝가속기 캔트리 헤드에 부착된 우선 CCTV 카메라를 이용한 영상처리들 동하여 환자 고 정과 지료에 있어서의 정확성과 재현성 향상 방안률 개발하고자 하였다. 대상 및 방법 선형가속기의 유사-빔 방항상 (semi-beams eye view, semi-BEV)을 얻기 위하여 무선 CCTV 모률을 자체 제작된 아크링 이흘리케이터를 이용하여 겐트리 헤드에 부착하였다 CC 미 카메라의 영상온 2.4 GHz의 고주파를 동해 치료실 벅언의 수신기로 전송된다 선헝가속기 작동시 발생하는 무선 주파수에 의한 간섭현싱 (RFinterterence) 과 누설 방사선으로 영상에 잡음이 발생하는데, 구리 호일로 카메라를 차폐하고 미디얀 필터링과 같은 영상처리 기업를 이용하여 이러한 잡음를 최소화할 수 있었다 스테레오 정합 기법과 Gauss-Newton 최적화 방법 돈툴 기반으묻 자체 제작펀 소프트웨어들 동해, 환자의 고정 상태들 나타내는 3차원적 위치, 이동, 회전 정도들 정량적으로 평가하였다 시스템의 정획도를 평가하기 위하여 팬톰 실힘을 수행하였다 또, 환자 호흥에 대한 실시간영상분석을 통해 호흠 동기 시스템 (respiratory gating system)을 구현하기 위한 방법론을 개발하였다. 결 과: 구리 호일 차페와 영상처리를 통해 잡음을 80% 이상 줄일 수 있었다 3차원 위치정보의 오차는 팬돔 실험을 통해 1.5±0.7 mm로 나타났고, 이동 및 회전랑에 대한 오자는 각각, 1 mm, 1。미만으로 나타났다 환자 호홉에 따른 호흥 동기 시스템툴 구현한 결과, 0.2초의 오차 범위 내에서 실시간 모나터링 01 가능한 것으로 나타났다. 결 론 선형가속기에 부착펀 CCTV틀 이용한 환자 고정 보조기술은 기존의 높은 비용을 필요여 하는 바 IGRT 기엄에 비하여 설치와 이용이 간펀하다 시스템이 선형가속기와 근접해 있기 때문에 야기되는 문제점은 온 연구에서 제시된 방법를 통해 해결될 수 있었다 시스템의 정확도를 평가해 볼 때 임상적으로 적용이 가능할 것으로 판단된다. Purpose: To develop a wireless CCTV system in semi-beam’'s eye view (BEV) to monitor daily patient setup in radiation therapy. Materials and Methods: In order to get patient images in semi-BEV, CCTV cameras are installed in a custom-made acrylic applicator below the treatment head of a linear accelerator. The images from the cameras are transmitted via radio frequency signal (-2.4 8Hz and 10 mW RF output). An expected problem with this system β radio frequency interference, which is solved utilizing RF shielding with Cu foils and median filtering software. The images are analyzed by our custom-made software. In the software, three anatomical landmarks In the patient surface are indicated by a user, then automaticalψ the 3 dimensional structures are obtained and registered by utilizing a localization procedure consisting mainly of stereo matching algorithm and Gauss Newton optimization. This algorithm is applied to phantom images to investigate the setup accuracy Respiratory gating system is also researched with real-time image processing. A line-laser marker projected on a patient's surface is extracted by binary image processing and the breath pattern is calculated and displayed in real-time. .Results: More than 80% of the camera noises from the linear accelerator are eliminated by wrapping the camera with copper foils. The accuracy of the localization procedure is found to be on the order of 1.5 上0 .7 mm with a point phantom and sub-millimeters and degrees with a custom-made head/neck phantom. With line-laser marker, real-time respiratory monitoring is possible in the delay time of - O. t7 sec Conclusion: The wireless CCTV camera system IS the novel tool which can monitor daily patient setups. The feasibility of respiratory gating system with the wireless CCTV is hopeful.

Skin Regeneration by Sonic Hedgehog Gene Delivery Using Amine-End Modified Polymer Nanoparticles

Joan LEE,Hyun-Ji PARK,Mun-Jung KIM,Taek Jin KANG,Yongsu JEONG,Seung-Woo CHO 한국생물공학회 2012 한국생물공학회 학술대회 Vol.2012 No.4

담석 및 편평상피 세포암이 동반된 담관 낭종 1예

박준,조철균,김현종 최신의학사 1994 最新醫學 Vol.37 No.2

협심증 환자에서 경피적 관동맥 확장술 후의 QT간격분산(QT Dispersion)의 변화

최일준,이일수,이상곤,홍명기,박성욱,박승정,김유호 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.9

Genetically Engineered Myoblast Sheet for Therapeutic Angiogenesis

Lee, Joan,Jun, Indong,Park, Hyun-Ji,Kang, Taek Jin,Shin, Heungsoo,Cho, Seung-Woo American Chemical Society 2014 Biomacromolecules Vol.15 No.1

<P>Peripheral arterial disease is a common manifestation of systemic atherosclerosis, which results in more serious consequences of ischemic events in peripheral tissues such as the lower extremities. Cell therapy has been tested as a treatment for peripheral ischemia that functions by inducing angiogenesis in the ischemic region. However, the poor survival and engraftment of transplanted cells limit the efficacy of cell therapy. In order to overcome such challenges, we applied genetically engineered cell sheets using a cell-interactive and thermosensitive hydrogel and nonviral polymer nanoparticles. C2C12 myoblast sheets were formed on Tetronic-tyramine (Tet-TA)-RGD hydrogel prepared through a highly efficient and noncytotoxic enzymatic reaction. The myoblast sheets were then transfected with vascular endothelial growth factor (VEGF) plasmids using poly(β-amino ester) nanoparticles to increase the angiogenic potential of the sheets. The transfection increased the VEGF expression and secretion from the C2C12 sheets. The enhanced angiogenic effect of the VEGF-transfected C2C12 sheets was confirmed using an in vitro capillary formation assay. More importantly, the transplantation of the VEGF-transfected C2C12 sheets promoted the formation of capillaries and arterioles in ischemic muscles, attenuated the muscle necrosis and fibrosis progressed by ischemia, and eventually prevented ischemic limb loss. In conclusion, the combination of cell sheet engineering and genetic modification can provide more effective treatment for therapeutic angiogenesis.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/bomaf6/2014/bomaf6.2014.15.issue-1/bm401605f/production/images/medium/bm-2013-01605f_0010.gif'></P>

An Experimental and Computational Study of Environmental Loads on a Fixed Substructure for Offshore Wind Turnbine

Wu-Joan Kim(김우전),Yeon-Seok Park(박연석),Chang-Yong Song(송창용),Jae-Hoon Yoo(유재훈),Dae-Yong Lee(이대용) 한국해양환경·에너지학회 2013 한국해양환경공학회 학술대회논문집 Vol.2013 No.11

본 논문에서는 해상풍력터빈 설치를 위한 지지구조물에 작용하는 파도와 조류에 의한 환경하중에 대하여 조사하였다. 다중 파일로 이루어진 고정식 해상풍력 지지구조물에 대하여 조파수조 시험과 CFD 유동해석이 수행되었다. 먼저 하부구조물 모형에 대하여 조파수조에서 파랑하중을 계측하였다. 또한 수치조파수조를 이용한 CFD 유동해석과 구조물의 동적구조응답해석을 위한 FEM 해석이 이루어졌다. 다음으로 모형 구조물을 예인수조에서 끌면서 조류하중을 계측하였다. 그리고 해저면에 형성되는 조류 점성경계층에 의해 구조물의 다리와 해저면이 만나는 지점에서 발생하는 horse-shoe 보오텍스에 대한 수치모사와 그로 인한 해저면 침식 현상인 scouring에 대한 시뮬레이션을 수행하였다. Environmental loads acting on an offshore structure for wind turbine by waves and current flow were investigated. Both wave tank measurement and CFD simulation were performed with a fixed type offshore wind turbine substructure having multi-piles. In the first, measurement of wave load on the model substructure was carried out at the wave tank. CFD simulation using the numerical wave tank was also done with the design wave condition and FEM analysis for dynamic load response of substructure was calculated. Next, current load was measured by towing the model substructure in the towing tank. Finally the formation of horse-shoe vortices around the juncture of substructure legs and seabed, due to bottom boundary layer, and the resulting scouring phenomena were simulated.

다이오드 정류기와 인버터를 이용한 순간 전압 강하 보상기

이준기(Joan-Gee Lee),박덕희(Duk-Hee Park),김희중(Hee-joong Kim),한병문(Byung-Moon Han),소용철(Yong-Chul Soh) 전력전자학회 1999 전력전자학술대회 논문집 Vol.1999 No.7

This paper describes controller development for a dynamic voltage compensator using a shunt diode converter and series inverter. The control system was designed using 1/4 period integrator and vector relationship between the supply voltage and load voltage. A simulation model and scaled hardware model were developed for analyzing performance of the controller and the whole system Both results confirm that the dynamic compensator can restore the load voltage under the fault of the distribution system

New Naming Service Architecture for Limited Resource System within CORBA - based Network Management

권준협(Joan H. Kwon),정문상(Moon S. Jeong),박종태(Jong T. Park) 한국정보과학회 2000 한국정보과학회 학술발표논문집 Vol.27 No.1A

Nowadays, efforts are in progress for the standardization of CORB Abased telecommunication network management framework. To implement a network management system based on the framework completely, CORBA ORB and some of CORBA services should be installed in the element. And then, there must be the naming tee, which corresponds to the containment relationships between components in the network element. If we use conventional OMG naming service to form the naming tree, an MOs, a software fragmenthat corresponds to each component in a system, should be instantiated. However, the network element is usually a kind of limited resource system, which cannot provide sufficient resources for applications run on it. Hence, instantiatingall MOs can cause problems for that kind of system. This paper presents Smart Naming Service architecture as a solution to the problem.