INTELSAT 구조개편 현황과 전망

김영관,Kim, Yeong-Gwan 한국위성정보통신학회 1998 위성통신과 우주산업 Vol.6 No.1

조종 숙련도 변화에 따른 심리적 리스크 이미지의 변화에 대한 평가

김영관,임현교,Kim, Yeong-Gwan,Im, Hyeon-Gyo 대한인간공학회 2003 大韓人間工學會誌 Vol.22 No.1

The resonance behaviour needs be understood to identify the mechanisms responsible for the dynamic characteristics of human body, to allow for the non-linearity when predicting the influence of seating dynamics. and to predict the adverse effects caused by various magnitudes of vibration. However, there are currently no known studies on the effect of vibration magnitude on the transmissibility to thoracic or lumbar spine of the seated person. despite low back pain(LBP) being the most common ailment associated with whole-body vibration. The objective of this paper is to develop a proper mathematical human model for LBP and musculoskeletal injury of the crew in a maritime vehicle. In this study, 7 degree-of-freedom including 2 non-rigid mass representing wobbling visceral and intestine mass, is proposed. Also. when compared with previously published experimental results, the model response was found to be well-matching. When exposed to various of vertical vibration, the human model shows appreciable non-linearity in its biodynamic responses. The relationships of resonance for LBP and musculoskeletal injury during whole-body vibration are also explained.

정현파로 구동되는 PZT 광경로 지연기를 이용한 광 간섭 단층촬영시스템

김영관,김용평,Kim, Young-Kwan,Kim, Yong-Pyung 한국광학회 2007 한국광학회지 Vol.18 No.4

We fabricated and characterized an optical delay line for optical coherence tomography (OCT). The delay line was composed of a cylindrical piezoelectric transduce (PZT) and a single mode optical fiber. The OCT system used a duplex scanning optical delay line which was symmetrically driven in the reference and sample arms. We showed that the sinusoidal-wave was superior to a triangular-wave for driving the optical delay line for scanning depth and repeatability. 광간섭 단층촬영(OCT)용으로 원통형 압전소자(PZT)와 단일모드 광섬유를 이용한 광경로 지연기를 제작하여 정현파로 구동하고 특성을 분석하였다. 제작한 OCT 시스템은 검침단과 기준단을 대칭 구동하는 이중 광경로 지연방식을 사용하였다. 정현파 구동을 통한 PZT 광경로 지연 방식은 삼각파 구동과 비교하여 입력파형의 첨두 부분에서의 비선형현상을 제거하여 높은 반복성을 나타냄을 보였고, 삼각파 구동으로는 불가능했던 부분을 영상화 할 수 있었다.

식물기반 치료용 항체생산

김영관,소양강,박다영,김현순,전재흥,추영국,고기성,Kim, Young-Kwan,So, Yang-Kang,Park, Da-Young,Kim, Hyun-Soon,Jeon, Jae-Heung,Choo, Young-Kug,Ko, Ki-Sung 한국식물생명공학회 2010 식물생명공학회지 Vol.37 No.3

Antibodies are powerful and versatile tools to play a critical role in the diagnosis and treatment of many diseases. Their application has been enhanced significantly with the advanced recombinant DNA and heterologonous expression technologies, allowing to produce immunotherapeutic proteins with improved biofunctional properties. However, with currently available technologies, mammalian cell-based therapeutic antibody production, as an alternative for production in humans and animals, is often not plentiful for passive immunotherapeutics in treatment of many diseases. Recently, plant expression systems for therapeutic antibodies have become well-established. Thus, plants have been considered to provide an attractive alternative production system for therapeutic antibodies, as plants have several advantages such as the lack of human pathogens, and low cost of upstream production and flexible scale-up of highly valuable recombinant glycoproteins. Recent advances in modification of posttranslational processing for human-like glycosylation in transgenic plants will make it possible that plant can become a suitable protein expression system over the animal cellbased current production system. This review will discuss recent advances in plant expression technology and issues for their application to therapeutic antibody production.

TiO₂ 박막을 이용한 광촉매반응의 응용

김영관,김성호,김동현,Kim, Yeong-Kwan,Kim, Sung-Ho,Kim, Dong-Hyun 강원대학교 산업기술연구소 1997 産業技術硏究 Vol.17 No.-

Photocatalytic reaction using $TiO_2$ thin film was applied for the inactivation of coliform bacteria and the degradation of formic acid. UV processes coupled with and without $TiO_2$ were tested for the river water samples. It took 5 and 15 minutes, respectively, to obtain 99% destruction of coliform bacteria in the total coliform test, which demonstrated the effectiveness of the photocatalytic reaction. Complete degradation of formic acid determined by TOC analysis was observed in 20 minutes by ozone/photocatalysis, while formic acid was degraded as little as about 20% during the first 100 minutes by ozone treatment alone. When ozone was supplied to the $TiO_2/UV$ system, however, it provided a synergetic effect for the degradation of formic acid.

위성산업 활성화를 위한 정책방향

김영관,Kim, Yeong-Gwan 한국위성정보통신학회 1999 위성통신과 우주산업 Vol.7 No.2

밀폐공간내 복사에 의한 고체연료 점화의 실험적 연구

김영관,백승욱,Kim, Yeong-Gwan,Baek, Seung-Uk 대한기계학회 1996 大韓機械學會論文集B Vol.20 No.11

An experimental study has been conducted to explore the behaviors of the radiative ignition of polymethylmetacrylate(PMMA) in a confined enclosure such as the ignition delay time, PMMA surface temperature, the ignition location and the ignition process. In addition, the effects of hot wall orientation on the ignition delay and PMMA surface temperature were studied. When the hot wall is located at the bottom, ignition delay time is the shortest. Ignition surface temperature becomes the lowest for the hot top wall case. These are due to buoyancy effect. Since the radiative heat flux of hot wall is rather lower than laser source, the ignition is considered to be controlled by the mixing process. Therefore, the ignition location, where appropriate mixture of fuel and oxygen exists, occurs near the hot wall. The flame propagates along the hot wall where there exists sufficient oxygen.

Two possible ways of lowering the production cost of crystalline silicon wafers for solar cells

김영관,Jung Min Kim 한양대학교 세라믹연구소 2004 Journal of Ceramic Processing Research Vol.5 No.3

Making a thinner wafer is a simple way of reducing the production costs of silicon solar cells. However, supporting this thin wafer in some way is necessary to protect the solar cell from breakage. A cheap substrate needs to be developed and attached to the thin silicon solar cell with aluminum paste. Silicon solar cells of 150 µm thickness with a sintered substrate on the back side show a 5.4% conversion efficiency as a solar cell. Compared to commercial silicon cells, a lower short circuit current (Jsc) is obtained. This might be due to the poor conduction in the back layer of aluminum which is absorbed into the supporting substrate during the annealing for bonding. Another way of lowering wafer costs is to apply the extrinsic gettering method to the silicon wafers made from cheap silicon raw materials which possibly contain metal impurities. Damage induced during the slicing process of the silicon wafers with wire saws is found to generate dislocations after the oxidation process which may contribute to the gettering. Therefore, without any additional process, cheaper raw materials are expected to be used for the cost reduction of the silicon wafers.

시간영역 광 간섭 단층촬영 시스템의 소형 엔도스코프 제작 및 영상구현

김영관,이성헌,김용평,Kim, Young-Kwan,Lee, Sung-Hun,Kim, Yong-Pyung 한국광학회 2010 한국광학회지 Vol.21 No.5

We fabricated and characterized a compact endoscopic catheter for optical coherence tomography. The optical delay line (ODL), composed of a cylindrical piezoelectric transducer (PZT) and an optical fiber, was operated with a 1 kHz sinusoidal driving wave in the time-domain. When the ODL was driven with a sinusoidal wave function, the axial scanning speed was 6 m/s and the axial acquisition rate was 2000 line/s at a depth of about 3 mm. Endoscopic OCT images of a human finger and earhole were successfully obtained with an image rate of ten frames per second. 광 간섭 단층촬영 시스템(OCT)을 위한 소형의 광섬유 도관형 주사장치인 엔도스코프(endoscope catheter)를 제작하였다. 깊이방향 주사장치인 원통형 압전소자(PZT)를 이용한 광경로 지연기는 정현파 1 kHz로 구동하여 시간영역에서 엔도스코프 OCT 영상을 구현하였다. 정현파로 구동한 광경로 지연기의 속도는 6 m/s 이고, 깊이방향 스캐닝의 데이터 획득은 3 mm 기준에서 초당 2000 라인이다. 제작한 엔도스코프로 사람의 손가락 및 귀에 대한 초당 10프레임의 OCT 영상을 성공적으로 획득하였다.

광간섭 단층촬영(OCT)용 PZT 광경로 지연기에서의 편광모드 분산 및 열요동 보상

김영관,박성진,김용평,Kim, Young-Kwan,Park, Sung-Jin,Kim, Yong-Pyung 한국광학회 2005 한국광학회지 Vol.16 No.6

광간섭 단층촬영(OCT)용으로 원통형 압전소자(PZT)와 단일모드 광섬유를 이용한 광경로 지연기를 제작하여 그 특성을 분석하였다. 광경로 지연기에서 발생하는 편광모드 분산은 편광조절기로 조절하였고, 열요동을 2중 광경로 지연기를 구성하여 최소화하였다. 이중 광경로 지연기는 단일 광경로 지연기에 비해 2배의 측정 깊이와 속도를 구현하여 $18.6\pm0.5{\mu}m$의 해상도. 측정 깊이 1.68 mm, 측정 녹도 360.4 mm/s를 각각 얻었다. We have fabricated and characterized optical delay lines for optical coherence tomography, which is composed of cylindrical PZT(piezoelectric transducer) and single mode optical fiber. The polarization mode dispersion from the optical delay lines was compensated by the polarization controllers. By applying the duplex optical delay line, we minimized the thermal drift due to optical delay lines and obtained the scan range of 2 times that of a single optical delay line. The OCT system showed resolution of $18.6\pm0.5{\mu}m$, scanning range of 1.68mm, and scanning speed of 360.4mm/s.