• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.146-153
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• 2008

Due to the extremely short pulse in the Ultra-Wideband (UWB) technology, the accurate synchronization acquisition method is very important for both high data-rate WPAN and low data-rate WPAN. In this paper, we propose the synchronization acquisition algorithm based on two-step signal search method to acquire the synchronization in the UWB multi-path channel. At the first step, the search window is divided by two and the window that has higher power is chosen as a next search window. This operation is repeated until the measure power of the search window is smaller than the threshold value. At the second step, we employ Linear Search algorithm to the search window obtained at the first step for fine search. The proposed algorithm is proved that the synchronization acquisition is faster than the parallel search algorithm and it shows good performance in environment of the SNR extreme changes by the simulation.

• Fire Science and Engineering
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• v.12 no.2
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• pp.29-42
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• 1998

The use of computer supported fire safety engineering calculations has grown significantly in recent years and will be increased rapidly. In this study, in order to examine for fire dynamics of the enclosed compartment with window glass(3mm, 4mm thickness) when the window glass breaks, we conducted numerical computer simulations about foam sofa fire with the zone type computer mode, FASTLite package(version 1.1.2) and the Berkeley algorithm for breaking window glass in a compartment fire, BREAK1 program (version 1.0). The analysis of the results in this paper shows that there are differences of fire dynamics between open-or enclosed-state compartment fire and the enclosed compartment fire with window glass breaking. It is also shown in this study that backdraft phenomenum occurs due to accumulated unburned combustible fuel when the glass of 4mm thickness breaks, and that temperature differences between the inner-and outer-surfaces of 3mm and 4mm thick glasses are appreciable. This study will help fire fighter to establish fire suppression or occupant's refuge strategies and fire safety engineer to enhance simulation techniques about the five dynamics of compartment fire.

• Fire Science and Engineering
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• v.12 no.3
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• pp.21-30
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• 1998

This is a study on the relation of window glass breaking time, shape, and vent condition in a compartment fire through the experiment. We recognize the phenomenon that window glass breakage in a compartment fire be arose from the thermal stresses due to the temperature temperature difference was 233.4$^{\circ}C$ for test 1-3, 138$^{\circ}C$ for text 2-1, 83.6$^{\circ}C$ for test 2-2. The interior test 2-2, 400.9$^{\circ}C$ for test 2-3. so if the flame didn't reach at the surface of window glass, the breakage of glass occure at 40$0^{\circ}C$~50$0^{\circ}C$. when the fire size reached to 1541.14kW, the window might be broken by thermal stress. But window glass was not collapsed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.663-668
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• 2000

To develop natural intermediate flavoring substances, optimal processing conditions and qualities for two stage enzyme hydrolysate (TSEH) from low-utilized small longfinned squid were investigated. The optimal conditions for TSEH method were found as digestion with Alcalase (0.2% w/w-sample, pH 8.0) at 55$^{\circ}C$ 3 hours at the 1st stage and with Neutrase (exo-peptidase, 0.2% w/w-sample, pH 6.0) at 45$^{\circ}C$ for 2~3 hours at the 2nd stage. Among the method of water extract, autolytic extract and various kinds yields, transparency and organoleptic taste. From the results of chemical experiments and sensory evaluation, longfinned squid TSEH is flavorable as the natural intermediate taste-active substances for fisheries products such as soup base, squid-taste pasty and snacks.

• The Korean Journal of Zoology
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• v.38 no.1
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• pp.20-25
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• 1995

계배 limb bud 간충직 연골원성 세포로부터 연골세포로의 분화에 미치는 transforming growth factor-f2(TGF-$\beta$2)의 영향을 알아보기 위하여, Hamburger-Hamilton stages 23/24의 간충직 세포들을 미세배양법으로 배양하면서. TGF-$\beta$2의 농도 및 처리시간에 따른 연골세포의 분화에 미치는 영향을 조사하였다 그 결과 TGF-$\beta$2는 배양 첫 24시간 동안 1-2 ng/ml의 농도로 처리하였을 때 가장 효과적으로 연골세포의 분화를 촉진하였으며, 또한 TGF-$\beta$2의 처리군에서 배양 3일째에 tsss) sulfate의 glycosaminoglvcan으로의 유입량이 현저히 증가함을 보였다 한편. 배양 48시간내에TGF-$\beta$2를 처리한 경우 분화를 촉진 유도한 반면, 배양 48시간 이후에 처리하였을 때에는 분화 촉진 효과가 나타나지 않았다. 이상의 결과로부터 TGF-$\beta$2는 연골원 세포의 분화 초기단계에 세포외기질의 합성을 촉진시켜 세포응축을 유발하고. 세포-세포 및 세포-세포외기질의 상호작용을 증대시킴으로써 연골세포로의 분화를 촉진시킬 것으로 추정되었다.

• 대한공업교육학회지
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• v.41 no.1
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• pp.128-146
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• 2016

The purpose of this study was to provide a basic research data for increasing the quality of 'creative engineering design' lesson and the teaching learning capability of high school teachers by analyzing the teaching learning management status and improvement plan of 'technology home economics subject' lesson for high school teachers. In order to investigate the teaching learning management status, the survey questionnaires from 63 teachers were collected from high school teachers who teach technology home economics subject currently and analyzed by statistical program SPSS 20. The main results of this study were as follows: First, for the contents of 'creative engineering design' lesson, the highest mean of response was 'creative thinking method'(M=4.22). In the learning activities, the teachers perceived the importance of the 'idea concept' highly. Second, in the management of 'creative engineering design' lesson, the teachers perceived the importance of the secure of tool, material budget, and practice space for the lesson highly. In the teaching capabilities, the teacher perceived the importance of the preparing teaching learning strategy most($$M{\frac{._-}{.}}4.14$$). Third, the teachers preferred to product for making uncomfortable things better in life and the other production outside from the content of textbook. Fourth, in the ratio of practice:theory lesson, they perceived the ratio of 3:7(36.5%), 4:6(25.4%), and 2:8(23.8%) are appropriate. In the assessment, the combination of production, portfolio, and presentation was preferred most. Fifth, there were statistically significant difference in teachers' interest and satisfaction and contents about 'creative engineering design' lesson between groups divided by the existence of practice space, certification held(technology teacher, non technology teacher), etc. Therefore, in order to improve the interest and satisfaction about the 'creative engineering design' lesson, the secure of space for technology practice and material budget were required. In addition, training and seminars program for improving the teaching capability for 'creative engineering design' lesson were required.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.67-72
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• 2010

Purpose: In Asan Medical Center we perform myocardial perfusion SPECT to evaluate cardiac event risk level for non-cardiac surgery patients. In case of patients with cancer, we check tumor metastasis using whole body bone scan and whole body PET scan and then perform myocardial perfusion SPECT to reduce unnecessary exam. In case of short term in patients, we perform $^{201}Tl$ myocardial perfusion SPECT after whole body bone scan a minimum 16 hours in order to reduce hospitalization period but it is still the actual condition in which the evaluation about the affect of the crosstalk contamination due to the each other dissimilar isotope administration doesn't properly realize. So in our experiments, we try to evaluate crosstalk contamination influence on $^{201}Tl$ myocardial perfusion SPECT using anthropomorphic torso phantom and patient's data. Materials and Methods: From 2009 August to September, we analyzed 87 patients with $^{201}Tl$ myocardial perfusion SPECT. According to $^{201}Tl$ myocardial perfusion SPECT yesterday whole body bone scan possibility of carrying out, a patient was classified. The image data are obtained by using the dual energy window in $^{201}Tl$ myocardial perfusion SPECT. We analyzed $^{201}Tl$ and $^{99m}Tc$ counts ratio in each patients groups obtained image data. We utilized anthropomorphic torso phantom in our experiment and administrated $^{201}Tl$ 14.8 MBq (0.4 mCi) at myocardium and $^{99m}Tc$ 44.4 MBq (1.2 mCi) at extracardiac region. We obtained image by $^{201}Tl$ myocardial perfusion SPECT without gate method application and analyzed spatial resolution using Xeleris ver 2.0551. Results: In case of $^{201}Tl$ window and the counts rate comparison result yesterday whole body bone scan of being counted in $^{99m}Tc$ window, the difference in which a rate to 24 hours exponential-functionally notes in 1:0.114 with Ventri (GE Healthcare, Wisconsin, USA), 1:0.249 after the bone tracer injection in 12 hours in 1:0.411 with 1:0.79 with Infinia (GE healthcare, Wisconsin, USA) according to a reduction a time-out was shown (Ventri p=0.001, Infinia p=0.001). Moreover, the rate of the case in which it doesn't perform the whole body bone scan showed up as the average 1:$0.067{\pm}0.6$ of Ventri, and 1:$0.063{\pm}0.7$ of Infinia. According to the phantom after experiment spatial resolution measurement result, and an addition or no and time-out of $^{99m}Tc$ administrated, it doesn't note any change of FWHM (p=0.134). Conclusion: Through the experiments using anthropomorphic torso phantom and patients data, we found that $^{201}Tl$ myocardium perfusion SPECT image later carried out after the bone tracer injection with 16 hours this confirmed that it doesn't receive notable influence in spatial resolution by $^{99m}Tc$. But this investigation is only aimed to image quality, so it needs more investigation in patient's radiation dose and exam accuracy and precision. The exact guideline presentation about the exam interval should be made of the validation test which is exact and in which it is standardized about the affect of the crosstalk contamination according to the isotope use in which it is different later on.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.109-113
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• 1998

압력조정기란 저장탱크와 용기로 부터 연소기에 공급되는 가스압력을 연소기의 압력에 맞게 조절하여 정상연소가 되도록 돕는 장치로써, 용기 및 저장탱크내의 압력변화에 대응하여 공급압력을 일정하게 유지하고, 가스의 조성, 온도, 소비량, 소비시간, 잔류가스량 등의 변화에 따라 감압작용과 정압작용을 동시에 하는 장치이다. LPG용 압력조정기는 일반가정용이나 업소에서 주로 사용하는 조정기로써 용량 4kg/h부터 집단공급용인 수백 키로까지의 제품이 있으며 일반적으로 감압작용, 정압작용, 폐쇄작용을 한다. (중략)

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.101-103
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• 2003

일상생활에서 컴퓨터 사용은 많은 시간을 차지하고 있다. 다한 증상의 사용자나 환자가 장시간 컴퓨터 마우스를 사용하게 되면 손의 땀으로 작업 중 불편함을 겪게 된다. 본 연구에서는 땀 발생으로 변화되는 피부 전도도 (저항)의 변화를 전압의 변화로 측정하여, 측정된 전압 값이 지정된 번호에 포함되면 자동으로 송풍 팬이 구동되는 컴퓨터용 마우스를 개발하였다. 사용자의 땀 분비와 관련된 피부 전도도의 변화는 마우스에 부착된 금속 전극을 이용하여 측정하였고, DAQ 보드를 통해 컴퓨터(PC)에 전달하고 user interface 창에 디스플레이 시키도록 하였다. 마우스 패드 아래에 부착된 송풍 팬의 구동 제어는 LabVIEW Program을 이용하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.10a
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• pp.167-171
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• 1995

본 연구에서는 광픽업 액츄에이터의 동적특성과 관련한 주요 설계 변수를 도출하였고, 이 결과를 이용하여 초기설계를 용이하게 하는 방안을 제시하였다. 이러한 연구결과를 바탕으로 많은 시간과 노력을 들이지 않아도 주요한 설계변수만을 사용하여 초기 설계단계에서 핵심적인 부분에 대한 사양을 결정할 수 있을 것이며, 이를 바탕으로 상세 설계단계에서 보다 창의 적인 설계를 수행할 수 있을 것이다.