제약 만족 기법을 이용한 조선 산업에서의 탑재 일정 생성에 관한 연구

김기동,장용성,Kim, Ki-Dong,Jang, Yong-Sung 강원대학교 산업기술연구소 1999 産業技術硏究 Vol.19 No.-

The dock is the most important resource in shipbuilding yard. Among the shipbuilding schedules, the ship erection schedule in a dock is preferentially built. As results of it, the other schedules(machining in plants, block assembly, pre-painting, pre-rigging, painting and etc) are made. In this study, ship erection scheduling is formulated using ILOG Scheduler. This study is to develop a new problem solving method for ship erection to make an effective schedule based on Constraint Satisfaction Technique(CST).

실버 나노분말을 이용한 메탈메쉬용 페이스트의 충전 및 와이핑 특성

김기동,남현민,양상선,박이순,남수용,Kim, Gi-Dong,Nam, Hyun-Min,Yang, Sangsun,Park, Lee-Soon,Nam, Su-Yong 한국분말야금학회 2017 한국분말재료학회지 (KPMI) Vol.24 No.6

A metal mesh TCE film is fabricated using a series of processes such as UV imprinting of a transparent trench pattern (with a width of $2-5{\mu}m$) onto a PET film, filling it with silver paste, wiping of the surface, and heat-curing the silver paste. In this work nanosized (40-50 nm) silver particles are synthesized and mixed with submicron (250-300 nm)-sized silver particles to prepare silver paste for the fabrication of metal mesh-type TCE films. The filling of these silver pastes into the patterned trench layer is examined using a specially designed filling machine and the rheological testing of the silver pastes. The wiping of the trench layer surface to remove any residual silver paste or particles is tested with various mixture solvents, and ethyl cellosolve acetate (ECA):DI water = 90:10 wt% is found to give the best result. The silver paste with 40-50 nm Ag:250-300 nm Ag in a 10:90 wt% mixture gives the highest electrical conductance. The metal mesh TCE film obtained with this silver paste in an optimized process exhibits a light transmittance of 90.4% and haze at 1.2%, which is suitable for TSP application.

중앙-채널 이중게이트 MOSFET의 양자역학적 모델링 및 시뮬레이션 연구

김기동,원태영,Kim, Ki-Dong,Won, Tae-Young 대한전자공학회 2005 電子工學會論文誌-SD (Semiconductor and devices) Vol.42 No.7

본 논문에서는 결합된 슈뢰딩거-푸아송 방정식과 전류연속방정식을 셀프-컨시스턴트하게 계산함으로써, 나노-스케일 center-channel (CC) double-gate (DG) MOSFET 디바이스의 전기적 특성 및 구조해석에 관한 연구를 시행하였다. 10-80 nm 게이트 길이의 조건에서 수행한 CC-NMOS의 시뮬레이션 결과를 DG-NMOS 구조에서 시행한 시뮬레이션 결과와의 비교를 통하여 CC-NMOS 구조에서 나타나는 CC 동작특성 메커니즘과, 이로 인한 전류 및 G$_{m}$의 상승을 확인하였다. 문턱 전압 이하 기울기, 문턱 전압 롤-오프, 드레인 유기 장벽 감소의 파라미터를 통하여 단채널 효과를 최소화하기 위한 디바이스 최적화를 수행하였다. 본 나노-스케일 전계 효과 트랜지스터를 위한 2차원 양자역학적 수치해석의 관한 연구를 통하여, CC-NMOS를 포함한 DG-MOSFET 구조가 40나노미터급 이하 MOSFET 소자의 물리적 한계를 극복하기 위한 이상적인 구조이며, 이와 같은 나노-스케일 소자의 해석에 있어서 양자역학적 모델링 및 시뮬레이션이 필수적임을 알 수 있었다. The device performance of nano-scale center-channel (CC) double-gate (DG) MOSFET structure was investigated by numerically solving coupled Schr$\"{o}$dinger-Poisson and current continuity equations in a self-consistent manner. The CC operation and corresponding enhancement of current drive and transconductance of CC-NMOS are confirmed by comparing with the results of DG-NMOS which are performed under the condition of 10-80 nm gate length. Device optimization was theoretically performed in order to minimize the short-channel effects in terms of subthreshold swing, threshold voltage roll-off, and drain-induced barrier lowering. The simulation results indicate that DG-MOSFET structure including CC-NMOS is a promising candidates and quantum-mechanical modeling and simulation calculating the coupled Schr$\"{o}$dinger-Poisson and current continuity equations self-consistently are necessary for the application to sub-40 nm MOSFET technology.

Design of Prestressed W-Shape Beams with a Separated Prestressing Cover Plate

김기동,안효일,한기장,Dong Seong Kim 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.2

Prestressed steel beams with a prestressing cover plate (PBCP), which are expected to overcome the limitations of prestressed steel girders using tendons, were investigated in this study. Experiments and fi nite element analyses (FEA) were performed to present a design procedure. The maximum compressive force according to fl ange slenderness, which could be applied to steel beams subjected to bending moment due to ultimate load, was investigated for rolled W-shape beams. The fl exural capacity and elastic fl exural stiff ness of steel beams could be signifi cantly increased by using a cover plate attached at a fi xed distance from the bottom fl ange of a steel beam as a prestressing member. A PBCP with W920 × 1377 could achieve a maximum span of 72 m for a two-lane, single-span composite bridge with fi ve girders when the span-to-depth ratio is limited to around 38.0, whereas an ordinary composite beam with the same W-shape section, having a span-to-depth ratio of 36.0, could achieve a maximum span of around 50 m. The limitations of maximum bridge length, minimum steel amount and maximum span-to-depth ratio that rolled fl exural members can achieve were able to be effi ciently overcome by using the PBCP. The span-to-depth ratio of PBCPs was about 2.08 times larger on average than that of plate girders for bridge lengths of 50 m to 72 m. The PBCP could employ a smaller steel volume than plate girders for the same span-to-depth ratio. Therefore, it could be seen that the PBCP could be an alternative to plate girders for the limited span-to-depth ratio and even for the cost effi ciency.

National Biotechnology Innovation System in the United States

김기동,황용식,Kim, Ki-Dong,Hwang, Yong-Sik The Korean Society of Business Venturing 2010 벤처창업연구 Vol.5 No.2

Biotechnology has strategic importance related to the development of start-up companies, industries and nations in the near future. Therefore, many countries have promoted and developed biotechnology. The United States has led the world in promoting biotechnology. American biotechnology policies are diverse, and thus no comprehensive systematic studies have been done on it. In our paper, we will discuss American biotechnology policy in detail. For effective analysis, we will rely on the concept of a national innovation system, which emphasizes the institutional settings of innovation actors and their interaction. This paper deals with the American national innovation system for biotechnology. We will analyze the role of major actors, academia, public research institutes, and venture companies and their interactions. The American biotechnological innovation system is composed of diverse actors and numerous start-up companies in the biotechnology industry. In addition, there are many diverse policy programs for promoting biotechnology. Because of country-specific frame conditions, every country has different institutional settings and policies for promoting biotechnology. Our paper will render meaningful implications for various countries. We also think that this paper will be of interest for international readers.

fabrication of Zirconia Thin Films by Plasma Enhanced Metal-Organic Chemical Vapor Deposition

김기동,조영아,신동근,전진석,최동수,박종진,Kim, Gi-Dong,Jo, Yeong-A,Sin, Dong-Geun,Jeon, Jin-Seok,Choe, Dong-Su,Park, Jong-Jin Materials Research Society of Korea 1999 한국재료학회지 Vol.9 No.2

Zirconia thin films of uniform structure were fabricated by plasma-enhanced metal-organic chemical vapor deposition. Deposition conditions such as substrate temperature were observed to have much influence on the formation of zirconia films, therefore the mechanism of decomposition of $Zr[TMHD]_4$precursor and film growth were examined by XRD, FT-IR etc., as well as the determination of the optimal deposition condition. From temperature dependence on zirconia, below the deposition temperature of 523K, the amorphous zirconia was formed while the crystalline of zirconia with preferred orientation of cubic (200) was obtained above the temperature. Deposits at low temperatures were investigated by FT-IR and the absorption band of films revealed that the zirconia thin film was in amorphous structure and has the same organic band as that of Zr precursor. In case of high temperature, it was found that Zr precursor was completely decomposed and crystalline zirconia was obtained. In addition, at 623K the higher RF power yielded the increased crystallinity of zirconia implying an increase in decomposition rate of precursor. However, it seems that RF power has nothing with the zirconia deposition process at 773K. It was found that the proper bubbler temperature of $Zr[TMHD]<_4$ precursor is needed along with high flow rate of carrier gas. Through AFM analysis it was determined that the growth mechanism of the zirconia thin film showed island model.

유한요소법에 의한 비등방성 두꺼운 원통형 쉘 및 얇은 원통형 쉘의 비교 해석

김기동,박원태,Kim, Gi-Dong,Park, Weon-Tae 한국복합신소재구조학회 2010 복합신소재구조학회논문집 Vol.1 No.3

본 연구는 비등방성 원통형 쉘의 휨문제에 대한 해석 기법을 제시하였다. 비등방성 원통형 쉘의 지배방정식을 해석하기 위해 유한요소법을 사용하였다. 두꺼운 쉘이론과 얇은 쉘이론을 사용하여 쉘의 폭-두께비 및 여러 가지 경계조건을 갖는 비등방성 원통형 쉘에 대한 해석결과를 비교 분석하였다. 본 연구의 수치해석 결과는 비등방성 원통형 쉘의 휨 거동 분석에 기여할 것으로 보인다. This paper is presented for the analysis results of the bending problems of the anisotropic cylindrical shells. In the numerical analysis of various mechanical problems involving complex partial differential equations, Finite element method is used to analyze the governing equations of anisotropic cylindrical shells. Both thin shell theory and thick shell theory are used as the basic governing equations of bending problems in the anisotropic cylindrical shells. The analysis results are compared between the anisotropic thick cylindrical shells and the anisotropic thin cylindrical shells. The results of this study will be contribute to analyze the bending behavior of anisotropic cylindrical shells.

Anneal Characteristics of LiF:Mg,Cu,Na,Si Teflon TLDs

Nam,Young-Mi,Jung,Woon-Hyuk,Lee,Dae-Won,Kim,Hyun-Ja,김기동 대한방사선 방어학회 1997 방사선방어학회지 Vol.22 No.3

열처리 특성의 연구는 열형광선량계를 재사용하는데 있어서 중요하다. 최근 개발된 디스크 형태(직경 4.5mm, 두께 약 90 ㎎/㎠)의 LiF:Mg,Cu,Na,Si Teflon TLD의 열처리 조건을 구하기 위하여 조사전 열처리, 판독과정 및 판독후 열처리의 순서로 연구하였다. Teflon TLD의 감마선 조사는 ??Co 0.1 Gy로 하였다. LiF:Mg,Cu,Na,Si Teflon TLD의 열처리 특성의 연구는 전기로와 판독장치를 이용하여 열처리 온도와 열처리 시간을 변화시키면서, 측정반복횟수에 따른 열형광강도 변화를 관찰하는 방법으로 수행하였다. LiF:Mg,Cu,Na,Si Teflon TLD의 열처리 조건은 조사전 열처리를 80℃에서 1시간 한 후 280℃까지 판독하고 판독후 열처리를 270℃에서 20초간 하는 것으로 결정되었고, 이 조건에서 10회 반복측정시 원래의 열형광강도는 5%의 감소를 보였다. The study of anneal characteristics is important for TL dosimeter to reuse. To obtain the annealing condition of the recently developed, new TL dosimeter, LiF:Mg,Cu,Na,Si Teflon TLDs in a disk type (diameter 4.5 mm, thickness about 90 ㎎/㎠), we studied for pre-irradiation annealing, readout procedure, and post-readout annealing, in order. The gamma irradiations were carried out with a ??Co, dose of 0.1 Gy. We have used the method that observe the variation of thermoluminescent(TL) intensity of these Teflon TLDs over repeated cycles by changing both anneal temperature and anneal time with the TLD reader and the oven. There is a 5% loss in sensitivity over the ten repeated readouts by the annealing condition:pre-irradiation annealing at 80℃ for one hour, readout to 280℃ and post-readout annealing at 270℃ for 20 seconds.

LC/MS법 및 LC/UVD(EPA-631)를 이용한 수계 중 Benomyl의 분석법 평가

김기동,최원규,서용찬,박병황,최혜경,Kim, Kee D.,Choi, Won Gyu,Seo, Yong Chan,Park, Byung Hwang,Choi, Hye Kyung 대한화학회 2001 대한화학회지 Vol.45 No.1

내분비계 장애물질 중의 하나인 농약 benomyl의 환경잔류실태를 조사하기 위해 수질중의 benomyl 농도를 정량 하였다. 일반적으로 benomyl은 가수분해하여 carbendazim으로 변하며 본 분석법은 carbendazim을 정량 하는 간접법이다. 수질중의 잔여 benomyl은 가수분??후 적절한 용매로 추출하여 농축, 정제되었다. 농축된 시료의 carbendazim 농도를 LC/MS (TOF)로 분석하였으며 그 결과 방해물질에 의해 발생할 수 있는 오차를 제거할 수 있었다. 검출한계는 LC/UVD법(EPA-631)에 비하여 약 1,600배 낮았으며 spike의 회수율도 약 80~118%로 양호하였다. Benomyl, one of the known endocrine disrupting chemicals, was analyzed to understand the its fate in water. Benomyl analysis process in water sample include the following sequential steps. Hydrolysis of benomyl into carbendazim, solvent extraction, concentration, and the concentration of final carbendazim solution was determined by LC/MS (TOF). Recoveries of the spiked samples were good with the range of 80.6 to 118.6% and the MDL was 1,600 times lower than that of LC/UVD method. The use of LC/MS (TOF) successfully eliminated the positive error incurred by interferencing materials in the matrix.

낙석방지울타리의 성능평가 I: 성능평가기준

김기동,고만기,김달성,문병갑,Kim, Kee Dong,Ko, Man Gi,Kim, Dal Sung,Moon, Byung Gab 대한토목학회 2015 대한토목학회논문집 Vol.35 No.1

The purpose of this study is to suggest performance levels, a test method, and assessment criteria for the performance assessment to allow standardized tests for rockfall protection systems. The range of rockfall impact energy was determined by using domestic rockfall data and a total of 9 performance levels from 50kJ to 1500kJ were suggested. The performance assessment is implemented by two types of full-scale free-fall impact tests to investigate the serviceability and the maximum capacity as in European and American standards. It was considered to be reasonable that the specimens of rockfall protection systems consist of 3 spans and the concrete block of a polyhedron with 26 faces, similar to spheres, impacts at the center of a center span. Assessment criteria were constructed to investigate whether a rockfall penetrated rockfall protection systems and whether the deformed specimen encroached on the roadway or obstructed the vehicle traffic. 본 연구에서는 낙석방지울타리에 대한 표준화된 시험이 가능하도록 성능평가에 필요한 성능등급, 시험방법, 평가기준을 제안하고자 하였다. 국내 낙석자료를 이용하여 낙석에너지의 범위를 결정하고 50kJ에서 1500kJ까지 총 9등급의 성능등급을 제시하였다. 성능평가는 유럽과 미국의 기준과 같이 사용성과 최대성능을 조사하기 위한 2종류의 실물 자유낙하 충격시험으로 이루어진다. 낙석방지울타리의 시험체는 3경간으로 구성되고 구형에 가까운 26면체 콘크리트 블록이 중앙 경간의 중앙에 충돌하는 것이 합리적인 것으로 판단되었다. 시험의 평가기준은 낙석의 관통여부와 변형을 겪은 낙석방지울타리가 도로를 침범하거나 차량통행을 방해할 가능성이 있는지를 검토하도록 구성되었다.