전자빔 조사가 ZnO 박막의 전기적 특성 변화에 미치는 영향

최준혁,조인환,김찬중,전병혁,Choi, Jun Hyuk,Cho, In Hwan,Kim, Chan-Joong,Jun, Byung-Hyuk 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.1

The effect of low temperature ($250^{\circ}C$) heat treatment after electron irradiation (irradiation time = 30, 180, 300s) on the chemical bonding and electrical properties of ZnO thin films prepared using a sol-gel process were examined. XPS (X-ray photoelectron spectroscopy) analysis showed that the electron beam irradiation decreased the concentration of M-O bonding and increased the OH bonding. As a result of the electron beam irradiation, the carrier concentration of ZnO films increased. The on/off ratio was maintained at ${\sim}10^5$ and the $V_{TH}$ values shifted negatively from 11 to 1 V. As the irradiation time increased from 0 to 300s, the calculated S. S. (subthreshold swing) of ZnO TFTs increased from 1.03 to 3.69 V/decade. These values are superior when compared the sample heat-treated at $400^{\circ}C$ representing on/off ratio of ${\sim}10^2$ and S. S. value of 10.40 V/decade.

휨응력을 받는 바닥강판의 피로균열진전해석

최준혁,경갑수,최동호,장동일,Choi, Jun Hyeok,Kyung, Kab Soo,Choi, Dong Ho,Chang, Dong Il 한국강구조학회 1999 韓國鋼構造學會 論文集 Vol.11 No.4

반복하중을 받는 용접구조물의 피로수명 추정에 있어서 파괴역학을 이용한 피로균열 진전해석방법은 매우 유용하다. 휨응력을 받는 바닥강판의 피로균열 진전해석 문제에서는 균일한 축하중 하에서의 피로균열 진전해석 절차를 동일하게 적용할 수 있다. 본 연구에서는 휨응력하에서 피로균열 진전수명을 계산하는 방법을 제시하고 2차원 균열 문제에서의 피로균열 진전을 다루었다. 수치적으로 계산된 균열진전은 균열길이가 증가함에 따라 피로균열의 진전속도가 점차 감소하고 실험결과와 잘 일치하였다. 피로 수명은 초기균열길이와 균열형상에 따라 달라짐을 알 수 있었다. The fatigue crack growth analysis based on the fracture mechanics is useful to the estimation of the fatigue life on welded structures under cyclic loading. The analysis procedure in fatigue crack growth under uniform axial loading is applicable to bending fatigue problem as well. The intent of the present study is to show the procedure for calculating the fatigue crack propagation lifetimes of deckplates under bending stress and to explain the crack growth rates for the two dimensional crack problems. It is shown that the fatigue crack grows at a decreasing rate and the fatigue life depends on the initial crack length and the crack shape. The numerically predicted crack growth agree with the experimental data.

팟캐스트를 활용한 PR교육 활용 사례

최준혁(Choi, June Hyock) 한국전시산업융합연구원 2015 한국과학예술융합학회 Vol.19 No.-

팟캐스트를 활용하는 공공기관, 민간기업, 언론사, 개인 등이 점차 늘고 있다. 팟캐스트의 교육적 효과를 실증하는 다양한 연구들이 발표되는 가운데, 교육기관에서도 재학생 및 일반 시민을 대상으로 하는 팟캐스트를 제공하고 있다. PR에 관심이 있거나 PR을 직업으로 삼고자 하는 대학생들에게 PR에 관한 컨텐츠를 제공하기 위해 2011년 10월 26일부터 “최준혁의 PR토크”라는 팟캐스트를 제작 및 배포하고 있다. 107개의 에피소드들은 PR강의, 인터뷰, PR사례, 쟁점 분석 등으로 분류할 수 있는데, 각각의 유형을 정규 강의의 보조재, 간접적 직업 체험 지원, 졸업생 사후관리의 수단 등에 활용할 수 있는 방안을 제시했다. 마지막으로 팟캐스트 제작의 구체적인 방법과 절차도 설명했다. Many government bodies, private companies, media, and individuals are gradually creating and distributing podcasts for their own purposes. As empirical studies about the effect of podcasts on education have been conducted frequently, many educational institutions are making podcasts for teaching their students and citizens. I also have been creating 107 podacasts entitled as Junehyock Choi"s PR Talk as of October 2014. The Talk was made for college students in PR major or preparing for PR jobs. The Talk"s episodes can be classified into categories such as public relations lectures, interviews, public relations cases, and issues management. This article suggests how to utilize podcasts for undergraduate public relations education: utilizing podcasts for supplemental to regular courses, providing indirect experience about public relations fields, updating new public relations cases and trends for graduates. This article shows how to create podcasts at home and free.

Nanosilver particles-based conductive patterns developed by direct soft imprint lithography

최준혁,S.W. Lee,K.D. Kim,D.G. Choi,J.H. Jeong,E.S. Lee 한국물리학회 2009 Current Applied Physics Vol.9 No.11

For the direct patterning of electronic device structures, the present work explored an idea of using UV imprint based on nanosilver particles-dispersed UV (ultraviolet) curable resin. In current work, asreceived Ag solution was applied to HEMA (hydroxyethyl methacrylate) as an ultraviolet (UV) curable precursor with the addition of photoinitiator (~3 wt%) to formulate electrically conductive resin mixtures with the Ag contents of 40–60 wt%. The UV exposed imprinted patterns with PDMS (polydimethylsiloxane) stamp become electrically conductive after properly optimized heat treatment. Those are, then, wetetched to remove imprint residue, which lead to the formation of the isolated current transfer media. This imprint scheme can contribute to substantially reduced process steps and corresponding costs associated with additional metal processes.

인체사료의 처분에 관한 법률문제 - 독일의 논어를 중심으로 -

최준혁,Choi, Jun-Hyouk 대한의료법학회 2007 의료법학 Vol.8 No.1

Hier zu behandelndes Thema ist ein altes Problem beim Recht, das seinen Ursprung sogar im romischen Recht finden kann. Aber wegen der medizinischen und naturwissenschaftlichen Entwicklung $t\ddot{a}ucht$ es wieder mit anderen Konstellationen auf. Dabei geht es besonders darum, ob sich die Patienten an der kommerziellen Nutzung seiner $K\ddot{o}rpersubstanzen$ von anderen-z. B. $\ddot{A}rzten$ oder Forschern-beteiligen $k\ddot{o}nnen$. $Daf\ddot{u}r$ gibt es in Bezug auf Gesetz keine besonderen Regelungen in Deutschland. Und nach zivilrechtlicher Theorie stellt Nutzung menschlicher $K\ddot{o}rpersubstanzen$ eine Personlichkeitsverletzung des fruheren $Tr\ddot{a}gers$ und/oder eine Verletzung des Arzt-Patienten-Vertrages dar. $Au{\beta}erdem$ ist Anspruch des $fr\ddot{u}heren\;Tr\ddot{a}gers$ debkbar, der auf dessen Einwilligung basiert. Dabei sind diese Probleme $zun\ddot{a}chst$ unter $Pers\ddot{o}nlichkeitsverletzung$ zu subsumieren und damit zu $l\ddot{o}sen$.

거제도 해양의 여름 및 겨울철 환경에서 거리에 따른 대기투과도를 고려한 함정의 적외선 신호 특성 분석

최준혁,김정호,정인화,이필호,김태국,Choi, Jun-Hyuk,Kim, Jung-Ho,Jung, In-Hwa,Lee, Phil-Ho,Kim, Tae-Kuk 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.2

The IR signature data of a ship is mainly affected by location, meteorological conditions(atmosphere temperature, wind direction and velocity, humidity etc.), atmospheric transmittance, solar position and ship surface temperature etc. The IR signatures received by a remote sensor at a given temperature and wavelength region is consisted of the self-emitted component directly from the object surface, the reflected component of the solar irradiation at the object surface, and the scattered component by the atmosphere without ever reaching the object surface. Computer simulations for prediction of the IR signatures of ships are very useful to examine the effects of various sensor positions. In this paper, we have acquired the IR signature for different sensor positions by using computer program for prediction of the IR signatures. The numerical results show that the IR signature contrast as compared to the background sea considering the meteorological conditions, solar and sky irradiations.

동면종의 압착도말 세포소견 -1예 보고-

최준혁,신덕섭,Choi, Joon-Hyuk,Shin, Duk-Seop The Korean Society for Cytopathology 2008 대한세포병리학회지 Vol.19 No.2

Hibernoma is a rare, benign adipose tumor composed of brown fat cells with eosinophilic granular or multivacuolated cytoplasm. The cytologic features of hibernoma have been rarely reported and may mimic other polygonal cell neoplasms. We report the imprint cytologic features of a case of hibernoma in the left thigh of a 68-year-old woman. Microscopic examination showed large, round, or polygonal brown fat cells. The cells were arranged in fragments or clusters. The nuclei were uniformly round with finely granular chrornatin. The cytoplasm was multivacuolated or univacuolated. The abundant eosinophilic granular cytoplasm was also present. No nuclear atypia were present. Immunohistochemical staining showed that cells were positive for S-100 protein.

A Diffusion-based Model Theory of Passive-Targeted Drug Delivery in Solid Tumors

최준혁,강남룡,최상돈,Choi, Joon-Hyuck,Kang, Nam-Lyong,Choi, Sang-Don Korean Society of Medical Physics 2007 의학물리 Vol.18 No.3

A model theory of passive-targeted drug delivery in sphere-shaped solid tumors is introduced on the basis of Fick's law of diffusion, with appropriate boundary and initial conditions. For a uniform initial concentration inside the tumor, the concentration is obtained as a function of time and radial position. The concentration is shown to approach the equilibrium distribution as the time elapses, as is expected by the Gedanken Experiment. The time-evolution rate is found to be determined by the diffusion coefficient of the drug in the tissue, the size of the tumor, the volume of the drug-injected region, and the concentration gradient at the boundary. 공모양의 단단한 종양안에서 수동조준된 약물의 전달에 관한 모델이론이 적절한 경계조건과 초기조건하에서 픽의 확산법칙으로부터 유도된다. 종양안의 농도는 초기값이 일정하면 시간과 지름의 함수로 나타난다. 생각실험(사고실험)으로부터 예측되는 바와 같이, 농도는 시간이 경과함에 따라 평형값에 접근한다. 시간에 따른 농도의 변화는 조직안의 약물의 확산계수, 종양의 크기, 주입된 약물의 양, 경계면에서의 농도의 물매(gradient)에 의해 결정된다.

콘크리트 슬래브 궤도 교량의 사용성 검토를 위한 레일 지지점에서의 작용력 해석

최준혁,Choi, Jun-Hyeok 대한토목학회 2013 대한토목학회논문집 Vol.33 No.4

본 연구에서는 콘크리트 슬래브 궤도를 가지는 교량의 사용성 검토에 있어 단위 축하중, 단위 수직 단차, 단위 회전에 의해 발생되는 레일 지지점의 작용력에 대한 기준 값을 구하였다. 해석방법에 있어서는 레일이 탄성 스프링에 의해 연속적으로 지지되는 모델과 이산적으로 지지되는 모델이 이용되었다. 해석결과 얻어진 레일 지지점에서의 작용력은 콘크리트 궤도의 사용성 검토에서 참조되고 있는 DS 804 기준에 제시된 값과 비교되였으며, 그 결과는 잘 일치하였다. 또한, 레일 지지점의 간격과 체결장치의 강성이 레일 지지점에서의 작용력에 미치는 영향을 분석하였다. In this study, the reference values for the internal forces of the rail supports caused by a wheel load, a unit vertical displacement, a unit end rotation in examination of the serviceability of concrete slab track bridge were obtained. In analysis, the analysis models of which the rail was continuously and discretely supported by elastic springs were used. The internal forces of the rail supports from the analysis were compared with the results provided in the DS 804 regulations and agreed with well. In addition, the effects of the space between the rail supports and the stiffness of fastener on the internal forces of the rail supports were investigated.

측정된 기상 조건 데이터를 이용한 지상물체의 표면온도 특성 연구

최준혁,박태원,김태국,Choi, Jun-Hyuk,Park, Tae-Won,Kim, Tae-Kuk 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.3

This paper is a part of developing a program that predicts the surface temperature and the IR images of ground objects by considering solar irradiation and atmospheric convection. The thermal modeling is essential for identifying objects on the scenes obtained from the remote sensing. And the temperature distribution on the objects is necessary to obtain their infrared images in contrast to the background. We considered the composite heat transfer modes including conduction, convection and spectral solar radiation incident on the objects within a scene to calculate the surface temperature distribution. The surface temperatures obtained by using the S/W developed in this study(Silhouette) and a commercial S/W(SE-Workbench-IR) are computed and compared each other. Results obtained by using the S/W developed in this study(Silhouette) show fairly good agreement with those obtained by the SE-Workbench-IR.