• Food Science and Biotechnology
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• v.14 no.2
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• pp.238-241
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• 2005

Aroma-active compounds were evaluated from salt-fermented anchovy sauce by solid phase microextraction-gas chromatography-olfactometry (SPME-GC-O) based on sample dilution analysis (SDA). SPME extract from carboxen/polydimethylsiloxane (CAR/PDMS) fiber was the most similar to the original odor of salt-fermented anchovy sauce used for this experiment, followed by divinylbenzene/CAR/PDMS (DVB/CAR/PDMS) fiber. Because salt-fermented anchovy sauce contains 23% NaCl, NaCl concentration of diluent was considered when salt-fermented anchovy sauce was serially diluted. Linear relationship between GC response and sample concentration was observed when diluted with 23% NaCl solution, whereas not observed when diluted with deodorized distilled water. Eleven and 16 aroma-active compounds were detected by SPME-GC-O based on SDA using CAR/PDMS and DVB/CAR/PDMS fibers, respectively. Butanoic acid and 3-methyl butanoic acid showed the highest ${\log}_2SD$ factors for CAR/PDMS and DVB/CAR/PDMS fibers. Dimethyl trisulfide, methional, trimethyl amine, 1-penten-3-ol, and acetic acid were also detected as potent aroma-active compounds.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1151-1153
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• 1999

3-layer polysilicon 표면미세가공공정을 이용하여 micro zone plate 렌즈와 미러 및 이를 구동하기 위한 구동기를 일체화시킨 마이크로 구동형 광학소자를 설계, 제작하였다. 650nm의 파장대역에서 초점거리가 $500{\mu}m$가 되도록 마이크로 zone plate 렌즈를 설계하였으며, 렌즈의 광학축은 실리콘 기판 상에서 $121{\mu}m$거리에 위치하도록 제작하였다. 마이크로 hinge와 스프링 latch 및 측면지지 plate를 이용하여 마이크로 렌즈와 미러가 실리콘 기판상에서 out-of-plane동작이 가능하도록 하였다. 마이크로렌즈 초점거리의 가변을 위하여 6개의 SDA(Scratch Drive Actuator)어레이를 설계, 제작하였다. 또한 빔 반사를 위한 마이크로 미러를 설계하고 $45^{\circ}$ self-assembly를 위하여 마이크로 hinge와 SDA array를 제작하였다.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.4
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• pp.115-125
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• 2014

Ground-Based Augmentation System (GBAS) is providing precision approach and landing service with aircraft around airport. FAA granted System Design Approval (SDA) of SLS-4000 to Honeywell as the first GBAS category I system on September 2009. Since then, according to their own kind of approval process including System Design Approval, Facility Approval and Operational Approval, USA, Germany, Spain and Australia have approved GBAS category I system which are installed in some airports in order to provide commercial GBAS service. Recently, KARI has also installed GBAS category I system into Gimpo international airport to establish operational technology of GBAS domestically and to validate effectiveness of GBAS system in Korea. This paper introduces overseas trends and activities regarding approval process of GBAS system and presents approval process and criteria appropriate for future commercial operation of GBAS in Korea.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.432-441
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• 2019

Objective : Few studies have reported direct comparative data of lumbar spine angles between direct lateral interbody fusion (DLIF) and oblique lateral interbody fusion (OLIF). The purpose of this study was to investigate the clinical and radiological outcomes of DLIF and OLIF, and determine influential factors. Methods : The same surgeon performed DLIF from May 2011 to August 2014 (n=201) and OLIF from September 2014 to September 2016 (n=142). Radiological parameters, cage height, cage angle (CA), cage width (CW), and cage location were assessed. We checked the cage location as the distance (mm) from the anterior margin of the disc space to the anterior metallic indicator of the cage in lateral images. Results : There were significant differences in intervertebral foramen height (FH; $22.0{\pm}2.4$ vs. $21.0{\pm}2.1mm$, p<0.001) and sagittal disc angle (SDA; $8.7{\pm}3.3$ vs. $11.3{\pm}3.2^{\circ}$, p<0.001) between the DLIF and OLIF groups at 7 days postoperatively. CA ($9.6{\pm}3.0$ vs. $8.1{\pm}2.9^{\circ}$, p<0.001) and CW ($21.2{\pm}1.6$ vs. $19.2{\pm}1.9mm$, p<0.001) were significantly larger in the OLIF group compared to the DLIF group. The cage location of the OLIF group was significantly more anterior than the DLIF group ($6.7{\pm}3.0$ vs. $9.1{\pm}3.6mm$, p<0.001). Cage subsidence at 1 year postoperatively was significantly worse in the DLIF group compared to the OLIF group ($1.0{\pm}1.5$ vs. $0.4{\pm}1.1mm$, p=0.001). Cage location was significantly correlated with postoperative FH (${\beta}=0.273$, p<0.001) and postoperative SDA (${\beta}=-0.358$, p<0.001). CA was significantly correlated with postoperative FH (${\beta}=-0.139$, p=0.044) and postoperative SDA (${\beta}=0.236$, p=0.001). Cage location (${\beta}=0.293$, p<0.001) and CW (${\beta}=-0.225$, p<0.001) were significantly correlated with cage subsidence. Conclusion : The cage location, CA, and CW seem to be important factors which result in the different-radiological outcomes between DLIF and OLIF.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1998.10a
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• pp.849-853
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• 1998

라인 해석법(Method of Line), MOL과 파수 영역 해석법(Space Domain Approach), SDA를 결합한 공간-파수 영역 해석법(SSDA)를 이용하여 MIC/MMIC 회로에서 임의 입체 구조를 갖는 공진기를 해석한다. SSDA는 상대 수렴(relative convergence)특성을 갖지 않으며, 반 해석적 (semianalytical )특성으로 수치적 효율이 높다. 경계치 문제로부터 씨스팀 행렬방정식 형태로 유도된그린 함수에 갤러킨법을 적용한다. 삼각, 사각 및 불연속 구조를 갖는 스트립 패치의 폭, 위치와 기판의 두께 변화에 따른 공진 주파수를 계산하였다.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.905-908
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• 1999

In this paper, we present a polysilicon actuator on silicon wafer using surface micromachining technology which employs an electrostatic stepwise driven Scratch Drive Actuator to generate a force that can move an external object. For optical applications, we propose wavelength selector using distributed feedback structures and this micro actuator.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.8
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• pp.1111-1120
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• 1998

Spray Drying Absorber(SDA) system, where the combustion product gas is mixed with atomized limestone-slurry droplets and then the chemical reaction of $SO_2$ with alkaline components of the liquid droplets forms sulfates, has been widely used to eliminate $SO_2$ gas from coal fired power plants and waste incinerators. Liquid atomization is necessary because it can maximize the reaction efficiency by increasing the total surface area and dispersion angle of the alkaline components. First, numerical calculations using FLUENT are carried out to investigate $SO_2$ concentration distribution and thus to calculate $SO_2$ removal efficiency. So to attain the optimized spray conditions, then an electrostatic spraying system is set up and spray visualization is performed to show the effect of an electric field on overall droplet size. Next, the effect of an electric field on the concentrations of $SO_2$ is experimentally examined. Field strength is varied from -10 kV to 10 kV and configurations of conduction charging and induction charging are utilized. Consequently, the electrostatic removal efficiency of 501 increases about 30% with the applied voltage of ${\pm}10kV$ but is independent of polarity of the applied voltage. It Is also found that the conduction charging configuration results in higher efficiency of $SO_2$ removal that the induction charging configuration. Finally, the effect of slurry temperature on $SO_2$ removal is studied. The temperature influences on the electrostatic removal efficiency of $SO_2$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.1
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• pp.37-46
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• 2003

The transient responses on arbitrarily interconnected digital transmission lines are analyzed by an efficient node discretization technique. Since the proposed node discretization technique offers an efficient means to discretize transmission lines, the transient waveform at any position on the arbitrarily interconnected lines is easily predicted. Dispersive microstrip multiconductor transmission lines arbitrarily connected are analized for generality. The derivation of frequency-dependent equivalent circuit elements of coupled transmission lines have been carried out by the spectral domain approach(SDA). The effects of variations of excited pulse width on the crosstalks of the high-speed microstrip coupled-lines are also investigated. It has been well known that the crosstalk spike level is monotonously increased when the coupling length and effective permittivity of substrate are increased. In this paper, it is found that the variations of crosstalk level are not further monotonous as shortening the exciting pulse width toward several picosecond. The results are verified by the generalized S-parameter technique.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.191-203
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• 2012

Mycelial growth of ectomycorrhizal fungi (27 strains of 8 species) collected from Korean forests was observed on various culture conditions (media, temperature, pHs). After 60 days of incubation, all strains grown on potato dextrose agar (PDA) and modified Melin-Norkran's agar (MMNA), whereas no mycelial growth was observed on malt extract agar (MEA) or sabouraud dextrose agar (SDA) in some strains including Tricholoma matsutake. Mycelial growth on PDA was poor at high temperature ($30^{\circ}C$) than the low temperature ($10^{\circ}C$). The optimal temperature on PDA and pH in potato dextrose broth (PDB) for mycelial growth in most strains were $20-25^{\circ}C$ and pH 4-5, respectively. All strains tested showed the carboxymethyl cellulase (CM-cellulase) activity and the maximal cellullase activity was expressed by the mycelium of T. matsutake (KFRI 1266) on the CMC agar plate with pH 5.0.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.11
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• pp.952-960
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• 2018

Recently, lots of remote sensing satellite require agility to collect more images within the limited time frame. To satisfy this kind of mission requirement, high torque actuator such as CMG is an essential element. In this study, 5Nm class small CMG developed by KARI is introduced to implement for an agile small satellite design. One of the singularity escape CMG steering law, Designated Direction Escape (DDE) method, which is a sort of modified version of Singular Direction Avoidance (SDA) method is summarized for its application on the numerical simulation of agile attitude control system design result. The performance of DDE method is demonstrated properly by escaping well known elliptic internal singularity successfully. 5Nm class small CMG cluster in a pyramid type as well as a roof type configuration is utilized to perform the numerical simulation and to demonstrate its agility design result for a small satellite. Simulation result shows the properness of 5Nm small CMG to a small agile satellite system. Also, the simulation result provides some valuable information that is important to CMG hardware design and manufacturing.