Electron microscopy analysis of soft materials with freeze-fracture techniques

김완태,윤동기 대한화학회 2023 Bulletin of the Korean Chemical Society Vol.44 No.2

Electron microscopy (EM) is a technique that observes the complexmicrostructure of a sample with a resolution of several Å using high-energyelectrons with a short wavelength. It is very effective for visualizing nanostruc-tures that would not be observed with an optical microscope. However, thereare limitations in that the observation must be carried out with a very thin filmin a vacuum, and the electron beam may damage the samples. The samplemay be out of the desired state or damaged, and the image may be distorted.As a solution to these problems, a freeze-fracture technique can be proposed.Freeze-fracture method is a process of rapidly freezing a sample and then frac-turing it to produce a metal replica of the morphology of the bulk of the sur-face. This article includes an overview and principles of freeze-fracturetechniques and examples of analysis of various soft structures

개에서 실험적으로 유발한 척추압박에 대한 적외선 체열촬영술의 적용

김완태,김민수,김순영,서강문,남치주 한국임상수의학회 2005 한국임상수의학회지 Vol.22 No.4

This study was performed to examine the absolute skin temperature and temperature difference () between the left and the right, the upper and the lower parts on the back of dog and to investigate the clinical usefulness of infrared thermography as diagnostic or prognostic aid on experimental spinal cord compression by using Digital Infrared Imaging System. In normal dogs, symmetrical and contouring patterns were observed in thermogram. The skin temperature difference was not significant between the left and the right, the upper and the lower parts on the back. In spinal cord compressed dog, there was symmetrical temperature reduction pattern around lesion. Patterns of between thoracic and lumbar portions were remarkable and showed the tendency to return to normal after 4 weeks of operation. It is considered that infrared thermography is a useful diagnostic and prognostic aid for spinal cord injury in dogs.

M68020C CROSS COMPILER SYSTEM의 3B20S에의 이식 ( Porting of M68020C Cross Compiler System Onto 3B20S Computer )

김완태,정상현,최영철,유근호,여재홍 대한전자공학회 1988 대한전자공학회 학술대회 Vol.1988 No.7

안전한 ESS 사용을 위한 System 구조와 GUI 구현에 관한 연구

김완태,김현식,박병준,Kim, Wantae,Kim, Hyunsik,Park, Byungjoon 디지털산업정보학회 2019 디지털산업정보학회논문지 Vol.15 No.2

As interest in the efficiency use of energy has been recently rising, studies have been performed in utilizing various types of eco-friendly green energy and natural energy. Especially there has been rapidly increase in the fields using ESS (Energy Storage System), which is the technology for storing the energy from nature. The application fields of ESS is continuously growing and expanding to various types of technologies. However, in recent years there have been continuing problems with the safety of ESS. And related researches are going on. In this paper, we has proposed a system structure to utilize more secure ESS and has monitored the system status of ESS in real time by using smart phone app. This paper has also proposed a new method to configure secure ESS by implementing GUI (Graphical User Interface) to control the system. And then explain experimental results to investigate the efficiency of the proposed ESS.

火傷을 입은 흰쥐의 赤血球 壽命

金完泰 명지대학교 1968 明大論文集 Vol.2 No.-

Dept of food technology and Nutrition, Myong-ji College The rates of disappearance of Cr^51 tagged erythrocytes were measured in rats with a 20% body area scald. Radio-actvites were decreased exponentally with time showing straight lines on the Semi-logarhythmic paper. On the basis of SA of Cr^51 VS time curve, half survival time(t½) were calculated in normal and scald group in normal rats (6 rats), mean half survival time was 5.4 days and 2.1 day's in the scald rats consisted nine rats, Mechanisms of decrease in mean half survival time in the scald rats were briefly discussed.

스마트 자동차의 BSD 검지를 위한 추적알고리즘에 관한 연구

김완태 (사)디지털산업정보학회 2023 디지털산업정보학회논문지 Vol.19 No.2

Recently, Sensor technologies are emerging to prevent traffic accidents and support safe driving in complex environments where human perception may be limited. The UWS is a technology that uses an ultrasonic sensor to detect objects at short distances. While it has the advantage of being simple to use, it also has the disadvantage of having a limited detection distance. The LDWS, on the other hand, is a technology that uses front image processing to detect lane departure and ensure the safety of the driving path. However, it may not be sufficient for determining the driving environment around the vehicle. To overcome these limitations, a system that utilizes FMCW radar is being used. The BSD radar system using FMCW continuously emits signals while driving, and the emitted signals bounce off nearby objects and return to the radar. The key technologies involved in designing the BSD radar system are tracking algorithms for detecting the surrounding situation of the vehicle. This paper presents a tracking algorithm for designing a BSD radar system, while explaining the principles of FMCW radar technology and signal types. Additionally, this paper presents the target tracking procedure and target filter to design an accurate tracking system and performance is verified through simulation.

Clipping 구조를 개선한 OFDM 전송시스템의 PAPR 감소에 관한 연구

김완태,조성준,Kim, Wan-Tae,Cho, Sung-Joon 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.8

Recently many communication systems ate adapting the OFDM(Orthogonal Frequency Division Multiplexing) for multimedia data services. However, OFDM has some problems that PAPR is increased when sub-carries are summed up with same phases. This problem causes severe signal distortions while the signal is passing through non-linear system such as power amplifier resulting in performance degradation of transmission system. In this paper, we use IF-Clipping method to solve PAPR problem and the signal distortion caused by clipping is limited by use of SAW (Surface Acoustic Wave) filter and power amplifier(TWTA). And we derive the optimal parameter(PAPR, Backoff) values to meet the spectrum mask of WiBro system. 현재의 통신 시스템은 멀티미디어 서비스를 제공하기 위하여 OFDM(Orthogonal Frequency Division Multiplexing) 방식이 주로 쓰이고 있다. 그러나 OFDM 방식은 다수의 부반송파를 사용하므로 부반송파들이 동일위상으로 더해질 때 놀아지는 PAPR(Peak-to-Average Power Ratio)이 문제가 되고 있다. PAPR의 문제는 신호가 전력증폭기와 같은 비선형 소자를 통과할 때 심각한 왜곡을 받게 되므로 전송시스템 성능이 저하된다. 본 논문에서는 PAPR 문제를 해결하기 위해 IF-Clipping 기법을 제안하고, 신호의 clipping에 의해 발생되는 신호의 왜곡을 SAW(Solace Acoustic Wave) 필터와 전력증폭기를 사용하여 제한하였다. 또한 clipping 기법 이용 후 SAW Filter와 전력증폭기를 사용하여 WiBro 시스템의 Spectrum Mask를 만족하는 이상적인 파라메터 값(PAPR, Backoff)을 찾았다.

둔장지역 해안사로부터 일메나이트 및 저어콘의 회수를 위한 연구

김완태,전호석,장세원,정강섭,신희영 한국자원공학회 2006 한국자원공학회지 Vol.43 No.6

In order to establish the optimized recovery process for ilmenite and zircon from beach sand of Dunjang area, Chonnam Province, the physical beneficiation and subsequent mineralogical characterization of the separated minerals were conducted. There was a clear relationship between particle size and heavy mineral content that the heavy minerals were mostly concentrated in the particles sized below 150μm. Gravity separation using spiral separator and shaking table separator made it possible to pre-concentrate the heavy minerals by rejecting light and coarse particles consist mainly of quartz. High-intensity magnetic separator and induced magnetic separator were used to separate the magnetic particles from non-magnetic particles of gravity concentrate and subsequently to fractionate the magnetic particles into three fractions, high susceptible, less susceptible and magnetic-others according to their magnetic susceptibility. Most of ilmenite and ilmenite-rich particles was finally concentrated in the high susceptible magnetic fraction and the content of TiO2 was 43.9wt.%. On the other hand, zircon and zircon-rich particles were concentrated in the non-magnetic fraction and magnetic-others showing ZrO2 contents of 6.8wt.% and 3.1wt.%, respectively. The zircon and zircon-rich particles were further beneficiated by screening that most of them could be recovered. 전라남도 둔장지역의 해안사로부터 일메나이트 및 저어콘의 회수를 위한 최적공정의 확립을 위해 물리적 선별 및 분리된 산물의 광물학적 평가를 수행하였다. 시료의 입자크기와 중광물의 함량과는 밀접한 관련이 있었으며 중광물은 대부분 150㎛ 이하의 입자에 분포하고 있음을 알 수 있었다. 중광물의 농축을 위해 스파이럴 및 요동테이블을 이용한 비중선별을 행하였으며 주로 석영으로 이루어진 경광물 및 조립광물을 제거함으로써 중광물이 농축된 정광을 얻을 수 있었다. 이 비중정광으로부터 자성입자를 분리하기 위해 고밀도 자력선별기를 사용하였으며 분리된 자성입자는 유도자력선별기를 이용하여 자성입자들이 가지는 자력감응도에 따라 고감응, 저감응 및 미감응 자성입자를 각각 분리하였다. 그 결과 일메나이트 및 함 일메나이트 광물은 대부분 고감응 자성입자로 농축되었으며 이때 산물의 TiO2 함량은 43.9wt.%로 나타났다. 반면 저어콘 및 함 저어콘 광물은 비자성 입자 및 미감응 입자로 분리되었으며 ZrO2 함량은 각각 6.8wt.% 및 3.1wt.%로 나타났으며 대부분 체질을 통해 회수할 수 있었다.

Evaporation of Torus-Shaped Droplets Formed by Smectic Liquid Crystal

김완태,윤동기,김대석 한국고분자학회 2023 한국고분자학회 학술대회 연구논문 초록집 Vol.48 No.2

초등학교 실과 재배 실습지도에 관한 실태 조사연구

김완태,김형균 한국실과교육연구학회 2008 實科敎育硏究 Vol.14 No.2