• Applied Microscopy
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• v.36 no.spc1
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• pp.1-7
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• 2006

The three-dimensional structure of an inorganic crystal, $SmZn_{0.67}Sb_2$ (space group $P4/nmm,\;a=4.30(3){\AA}\;and\;c= 10.27(1){\AA}$), was refined by electron crystallography utilizing high voltage electron microscopy (HVEM). Effects of instrumental resolution, image quality, beam damage and specimen tilting on the structure refinement have been evaluated. The instrumental resolution and image quality were the most important factors on the final results in the structure refinement, while the beam damage and specimen tilting effects could be experimentally minimized or controlled. The average phase errors $({\Phi}_{res})$ for the [001], [100] and [110] HVEM images of $SmZn_{0.67}Sb_2$ were $10.1^{\circ},\;9.6^{\circ}\;and\;6.8^{\circ}$, respectively. The atomic coordinates of $SmZn_{0.67}Sb_2$ were consistent within $0.0013{\AA}{\sim}0.0088{\AA}$, compared to the X-ray crystallography data for the same sample.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.580-582
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• 2005

거리가 상당히 먼 곳에서 고가의 장비를 사용하기 위해서는 사용할 연구 인력이 직접 와야 하는 많은 시간적 비용적 문제가 발생한다. 특히 본원에 장비되어 있는 초고전압 투과전자현미경(High Voltage Electron Microscopy - 이하 HVEM)의 경우 고가의 장비로 지역마다 기기를 구비할 수 없어 사용자는 직접 장비가 있는 연구실까지 와서 사용해야 한다. HVEM은 1천만 배율의 성능을 가진 국내 유일은 물론 전 세계적으로도 손꼽히는 고성능의 투과전자현미경으로 NT(Nano Technology), BT(Bio Technology) 연구에 있어서 핵심적인 역할을 하는 청단 연구기기이다. 따라서 본 논문에서는 그리드 컴퓨터 기술을 이용하여 HVEM을 원격제어 하는 시스템을 구축하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.583-585
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• 2005

바이오 및 재료 분야 등 NT(Nano Technology), BT(Bio Technology)에 관련된 연구를 보다 더 수월하게 하기 위해 본원에 설치되어 있는 초고전압 투과전자현미경(High Voltage Electron Microscopy - 이하 HVEM)을 이용한다. HVEM을 통해 획득한 이미지의 정보는 매우 방대하여 하나의 시료를 관찰하는데 있어서 수백 메가 이상의 용량을 차지하고, 연구를 수행하는데 있어서 데이터를 여러 형태로 관찰 분석하기 때문에 수월한 지원을 위해 체계적으로 관리할 수 있는 데이터베이스 시스템이 필요하다. 그러나 일반적인 범용 데이터베이스로는 이러한 대규모의 데이터를 저장할 수 없다. 따라서 본 논문에서는 이러한 용량 데이터를 체계적으로 관리할 수 있도록, 데이터 그리드와 연구 데이터의 정보를 갖는 metadata 테이블을 통해 서로 먼 거리에 있는 연구원들이 데이터를 접근하고 대규모 저장 공간을 갖는 데이터베이스 시스템을 제안한다.

• Journal of Korean Library and Information Science Society
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• v.38 no.3
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• pp.117-138
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• 2007

The purpose of this study is to building e-Science environment based on HVEM, remote control system of HVEM and the data portal, which is made by HVEM for efficiently management and sharing of data are needed. Furthermore, specialized metadata is required as well for the structuralization, storage, management search and share of the data created from the data portal. In this research paper, we propose the specialized metadata model, only suitable for HVEM, for more efficient management and share of data created by HVEM under the e-Science environment.

• Applied Microscopy
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• v.35 no.4
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• pp.98-104
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• 2005

A FOV (field-of-view) of the HV-MSC (high voltage multi-scan CCD, $1024{\times}1024$ pixels) camera mounted in the post-column HV-GIF (high voltage gatan image filter) has been drastically enlarged by the projection lens current adjustment. An imaging area of the HV-MSC camera obtained at the lowest magnification (2,000x) is $112{\mu}m^2$ which corresponds to the recording area of the film at the magnification of 8,800x, while the achievable recording area is only $0.43{\mu}m^2$ at the same magnification without this technique. Ignoring the image distortion of less than 5%, we have designed an on-site reference graph to estimate projection lens currents for microscope magnifications above 8,800x, where the recording area on the HVMSC is same as that on the film.

• Applied Microscopy
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• v.37 no.2
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• pp.111-121
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• 2007

Coefficient of spherical aberration of the objective lens in the KBSI-HVEM was evaluated by diffractogram method. Instrumental resolution was also discussed with this method. In order to improve the accuracy, digital processing and graphical curve fitting for intensity profile of diffractogram were employed. Experimental concerns where the optimal procedure of the measurement con be accomplished for this study were discussed. The spherical aberration coefficient $(C_s)$ was estimated to be $2.628{\pm}0.04\;mm$ from this study, which was almost coincident with the value of the manufacture's suggestion $(C_s=2.65\;mm)$.

• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.197-202
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• 2017

Three-dimensional melanin granules of mummy's hair analyzed using high voltage electron microscopy at 1250kV. The melanin granules in the cortex of mummy's hair located in close proximity to the outer of cortex in the adjacent place of the cuticles. A lot of melanin granule performed in this area. It is a distinguished difference from modern human. While it rotated up to 60 degree counter-clockwise and taken a photo per one degree using high voltage electron microscopy. The melanin granule displayed with long elliptical and variable at the size. The size of granule is measured from $0.3{\sim}0.6{\mu}m$ in minimum diameter and $0.5{\sim}1{\mu}m$ in maximum diameter. Conclusionally, high voltage electron microscope has higher resolution and penetration power than conventional transmission electron microscope that could be load biological thick specimen.

• 한국전자현미경학회:학술대회논문집
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• 2005.05a
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• pp.127-129
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• 2005

• Applied Microscopy
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• v.34 no.1
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• pp.13-21
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• 2004

The high voltage electron microscope (HVEM) newly installed in KBSI is an advanced transmission electron microscope capable of atomic resolution (${\leq}1.2{\AA}$ point-to-point resolution) together with high titling function (${\pm}60^{\circ}$), which are suitable to do 3-dimensional atomic imaging of a specimen. In addition, the instrument can be controlled by remote operation system, named as 'FasTEM' for the HVEM, which is favorable to overcome some environmental obstacles resulting from the direct operation. The FasTEM remote operation system has been established between the headquarter of KBSI in Daejeon and the Seoul branch. The server system in the headquarter has been connected with a portable client console system in the Seoul branch using an advanced internet resource, 'KOREN' of 155 Mbps grade. Most of the HVEM functions essential to do remote operation are available on the portable client console. The experiment to acquire the high resolution image of [001] Au has been achieved by excellent transmission of control signals and communication with the HVEM. Real-time reaction like direct operation, such as controls of the illumination and projection parameters, acquisition and adjustment of each detector signal, and electrical steering of each motor-driven system has been realized in remote site. It is positively anticipated that the first remote operation of HVEM in conjunction with IT infraengineering plays a important role in constructing the network based e-Science Grid in Korea for national user s facilities.

• Applied Microscopy
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• v.42 no.2
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• pp.105-109
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• 2012

Electron tomography (ET) of biological specimens is performed from a series of images obtained over a range of tilt angles in a transmission electron microscope. When using the high voltage electron microscope (HVEM), various noises appear in EM images acquired from thick sections by high voltage electron beam. In order to obtain an adequate result in electron tomograms that allow visualization of rather complex and mega-cellular structure such as brain tissue, it is necessary to remove the noise in each original tilt images of thick section. Using band-pass filtering of original tilt images, the filtered images are obtained and used to assemble a reconstructed tomogram. The qualified 3D tomogram from filtered images results in a considerable reduction of the noises compared to conventional tomogram. In conclusion, this study suggests that band-pass filtering is effective to improve the brightness and intensity of HVEM produced tomograms acquired from micron-thick sections of biological specimens.