• 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.

• Analytical Science and Technology
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• v.27 no.3
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• pp.147-152
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• 2014

RUVIS(Reflective Ultraviolet Imaging System) is an effective equipment that detects the location of latent fingerprint at crime scene using short wavelength ultraviolet of 254 nm. In this study, the degree of DNA damage in biological samples was compared depending on the distance and time of processing using four commonly used RUVIS. 50% of DNA was damaged by treating 10 seconds at 10 cm distance in 3 types of RUVIS such as Police RUVIS, SIRCHIE mini light and SIRCHIE RUVIS. In addition, the degree of DNA damage was increased as the distance was closer and the treatment time was longer. It showed that short wavelength UV could cause DNA damage when used close to the samples at crime scene. Therefore, it was suggested to use RUVIS at a distance of at least 1 m. The degree of DNA damage was not significant by Polilight which used long wavelength ultraviolet of 350 nm. As a result, the choice and usage of which UV light and RUVIS were critical for detection of fingerprint and successful DNA typing.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.7
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• pp.685-691
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• 2011

The aim of this study is to point out the uniqueness of Doppler optical coherence tomography (DOCT) for use in a probe station for (in vivo) visualization of microscale flow and structure and to maximize the effectiveness of DOCT by overcoming its limitations. Conventional DOCT produces images of only one of the velocity components that is parallel to the incident light. In this study, a multi-angle DOCT to quantify a velocity vector field is proposed; this is an extension from a velocity scalar field to a vector field. Quantifying an instantaneous three-dimensional velocity field in a pulsating flow is another challenge because of its limited frame rate. The in-vivo pulsating blood flow is measured by using an electrocardiogram-gated multi-angle DOCT in a hamster cheek pouch model. It is shown that the aliasing problem caused by a relatively low frame rate is resolved by using this method of measurement.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.254.1-254.1
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• 2013

현재의 나노기술 및 부품은 나노미터 이하의 초고분해능을 요구하면서도 나노미터 이하의 정확도로 가공할 수 있는 기술을 요구하고 있다. 이온현미경은 위 두 요구조건을 만족하는 차세대 현미경으로써 초고분해능 이미징과 함께 기존의 갈륨이온을 사용하는 집속이온빔 장치보다 네온가스등을 이용하여 더 정밀하게 에칭 및 스퍼터링을 할 수 있다. 이온현미경은 전자현미경에 비해 더 깊은 초점심도를 갖으며, 색수차와 구면수차에 비교적 둔감하고 전자에 비해 무거운 이온의 무게 때문에 짧은 파장을 갖는 특징을 가지고 있다. 이와 같은 특징을 이용하면 전자현미경과 다른 여러 특징과 장점을 갖는 고분해능의 현미경을 제작할 수 있다. 이와 같이 차세대 현미경으로 주목받는 이온현미경의 중요한 부분인 이온총은 현재 가스장 이온 소스 방법으로 대부분 개발되고 있다. 가스장 이온 소스는 1950년대에 E. W. Muller에 의해 개발된 전계 이온 현미경(Field Ion Microscope)에서 응용된 방법으로 뾰족한 탐침에서의 가스 이온화를 기반으로 한다. 가장 보편적으로 사용되는 재질은 텅스텐으로 수십 nm 정도의 곡률 반경을 갖도록 제작하고 초고진공에 설치하여 강한 양전압을 인가함과 동시에 가스를 팁 주변에 넣어주면 팁표면에서 이온빔이 발생하게 된다. 본 연구에서는 위와 같이 차세대 나노장비로써 주목받는 이온현미경의 특징에 대해 소개하고, 특히 이온현미경의 이온총 원천기술 개발을 위해 연구하고 있는 가스장 이온 소스의 특성에 대해 소개한다. 수소, 네온, 헬륨의 전계 이온현미경과 함께 생성된 이온빔의 안정도 및 각전류 밀도를 계산하여 실제 이온총으로의 적용 가능성에 대해 보여준다.

• The Journal of Society for e-Business Studies
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• v.22 no.1
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• pp.107-122
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• 2017

Nowadays, digital forensic experts are not only computer experts who restore and find deleted files, but also general experts who posses various capabilities including knowledge about processes/laws, communication skills, and ethics. However, there have been few studies about qualifications or competencies required for digital forensic experts comparing with their importance. Therefore, in this study, AHP questionnaires were distributed to digital forensic experts and analyzed to derive priorities of competencies; the first-tier questions which consisted of knowledge, technology, and attitude, and the second-tier ones which have 20 items. Research findings showed that the most important competency was knowledge, followed by technology and attitude but no significant difference was found. Among 20 items of the second-tier competencies, the most important competency was "digital forensics equipment/tool program utilization skill" and it was followed by "data extraction and imaging skill from storage devices." Attitude such as "judgment," "morality," "communication skill," "concentration" were subsequently followed. The least critical one was "substantial law related to actual cases." Previous studies on training/education for digital forensics experts focused on law, IT knowledge, and usage of analytic tools while attitude-related competencies have not given proper attention. We hope this study can provide helpful implications to design curriculum and qualifying exam to foster digital forensic experts.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.1-17
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• 2020

Three-dimensional microscopic approaches in histopathology display multiplex properties that present puzzling questions for specimens as related to their comprehensive volumetric information. This information includes spatial distribution of molecules, three-dimensional co-localization, structural formation and whole data set that cannot be determined by two-dimensional section slides due to the inevitable loss of spatial information. Advancement of optical instruments such as two-photon microscopy and high performance objectives with motorized correction collars have narrowed the gap between optical theories and the actual reality of deep tissue imaging. However, the benefits gained by a prolonged working distance, two-photon laser and optimized beam alignment are inevitably diminished because of the light scattering phenomenon that is deeply related to the refractive index mismatch between each cellular component and the surrounding medium. From the first approaches with simple crude refractive index matching techniques to the recent cutting-edge integrated tissue clearing methods, an achievement of transparency without morphological denaturation and eradication of natural and fixation-induced nonspecific autofluorescence out of real signal are key factors to determine the perfection of tissue clearing and the immunofluorescent staining for high contrast images. When performing integrated laboratory workflow of tissue for processing frozen and formalin-fixed tissues, clear lipid-exchanged acrylamide-hybridized rigid imaging/immunostaining/in situ hybridization-compatible tissue hydrogel (CLARITY), an equipment-based tissue clearing method, is compatible with routine procedures in a histopathology laboratory.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.29-37
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• 2019

Textile quality management targets the physical properties of fabrics and the subjective discriminations of color and fitting. Color is the most representative quality factor that consumers can use to evaluate quality levels without any instruments. For this reason, quantification using a color discrimination device has been used for statistical quality management in the textile industry. However, small and medium-sized domestic textile manufacturers use only visual inspection for color discrimination. As a result, color discrimination is different based on the inspectors' individual tendencies and work procedures. In this research, we want to develop a textile industry-friendly quality management method, evaluating the possibility of rapid color discrimination using a digital imaging device, which is one of the office-automation instruments. The results show that an imaging process-based color discrimination method is highly correlated with conventional color discrimination instruments ($R^2=0.969$), and is also applicable to field discrimination of the manufacturing process, or for different lots. Moreover, it is possible to recognize quality management factors by analyzing color components, ${\Delta}L$, ${\Delta}a$, ${\Delta}b$. We hope that our rapid discrimination method will be a substitute technique for conventional color discrimination instruments via elaboration and optimization.