• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.51.1-51.1
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• 2010

본 논문에서는 wavelet 변환을 이용하여 태양광 발전 시스템의 계통 전원 고조파를 측정하는 방법을 연구하였다. PCS(Power Conditioning System)는 태양전지의 전력을 교류로 변환하여 계통에 연계시키는 장치이다. 직류에서 교류로 변환할 때 스위칭 노이즈가 발생하고, 전력품질이 약화되게 된다. Wavelet 이론은 시간 파형을 주파수 성분으로 분해할 수 있는 기술이다. 이중에서 MLD(Multi-evel Decomposition)기법은, 계산량이 적으면서도 빠른 시간 내에 고조파 성분들을 알아낼 수 있다. 시스템 모델링과 wavelet 이론 소개, 그리고 컴퓨터 모의실험과 DSP 제어기를 이용한 실험 결과로서 본 연구의 타당성을 입증하였다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.417-418
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• 2003

2002년 10월과 11월에는 가을 추수 후 소각이 대기질에 미치는 영향을 조사하고자 광주과학기술원 내에서 에어로졸과 대기 복사 집중 측정 기간을 가졌다. 12시간 또는 일평균 자료만을 제공하는 에어로졸 화학적 특성의 측정과 달리 자외선 영역의 다파장 회전차폐판 복사계 (Ultraviolet Multi-filter Rotating Shadowband Radiometer)를 이용한 에어로졸 광학 깊이(aerosol optical depth)는 1분 간격의 직달 일사량 자료로부터 에어로졸 복사적 특성을 시간에 따른 변화를 볼 수 있다는 장점을 가진다. (중략)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.11a
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• pp.14-14
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• 1997

추진제의 노화 못지 않게 점화제의 노화도 추진 기관 성능에 큰 영향을 미칠 것으로 예측된다. 따라서 10년 이상 경과된 활성 모터에서 점화기를 분해하여 노화에 의한 점화제의 성능 변화를 알아보았다. 분석에 사용한 점화제는 II-D Bi-Convex형상의 B-KNO$_3$ 펠렛으로 열량, 자동 점화온도, 기계적 물성의 변화를 관찰하였고, 밀폐 용기(Closed bomb)에서 연소시험을 통하여 노화에 따른 점화알약의 압력변화를 측정하고 이론 값과 비교하였다. 또한 비활성 모타를 이용한 연소시험으로 점화기의 점화지연시간, 최대 압력, 최대 압력 도달시간 등을 측정하고 이론식과 비교하여 노화에 의한 변화를 관찰하였다.

• Culinary science and hospitality research
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• v.18 no.5
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• pp.267-278
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• 2012

The purpose of this study was to investigate the quality characteristics of Sulgidduck made with commercial dry rice powder, providing an optimal milk ratio and soaking time for dry powder in water to make Sulgidduck using dry rice powder. The Sulgidduk samples with dry rice powder were prepared with two soaking times (0, 30 min) and different amounts of milk (0, 20, 40, 60%), and analyzed for moisture content, Hunter's color value, texture characteristics and sensory evaluation. The moisture content of the samples ranged from 36.37% to 39.80% and the highest moisture quantity was showed in the group with 20% of milk and 30min of soaking time(SM20). The L-value was the highest in the group with 20% of milk and 0min of soaking time(M20). The b-value was increased with the amount of milk and soaking time increased, showing the highest in the group with 60% of milk and 30min of soaking time(SM60). TPA showed that SM20 had the lowest hardness and the highest adhesiveness. Chewiness, gumminess and cohesiveness were the highest in the group with 60% of milk and 0min of soaking time(M60). Based on quantitative descriptive sensory evaluations, the score of white color and moistness was showed high in the group with 0% of milk and 0min of soaking time(M0), and white powder on the surface was shown the most in the group with 20% of milk and 30min of soaking time(SM20). The score of moistness, springiness and chewiness were highest in the group with 20% of milk and 0min of soaking time(M20). Sulgidduk made with 20% of milk and 0min of soaking time(M20) was the most preferable in color, flavor, taste, and overall acceptability.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.35-43
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• 2017

This study was to research the relationships between rice straw degradation and changes of fibrolytic bacteria population during the in vitro rumen fermentation. Dry matter(DM) digestion of rice straw and population of fibrolytic bacteria were measured at the 0. 4, 8, 12 and 48 hours during the incubation. The populations of F. succinogenes. R. albus and R. flavefaciens were defined as log copy number of 16S rDNA by technical method of Quantitative real-time PCR. Total population of F. succinogenes, R. flavefaciens and R. albus was sum of bactera attached on rice straw and suspended in medium. It's population was increased with incubation, reached top level of 29.0 Log copy No at the 24 hour and then decreased. In the meantime, DM digestion of rice straw showed the higher increasement from the 8 hour to the 24 hour than from the 0 hour to the 8 hour, and then a slowdown in increasing trend of digestibility. Attachments of F. succinogenes, R. flavefaciens and R. albus were detected immediately after start of in vitro rumen incubation. At the same time, the colonized bacterial share were respectively 34.5%, 84.4% and 67.9% in total population. All of them was reached the highest colonized bacterial share above 94.7% at the 4 hour incubation. However population of attached bacteria was shown the highest level at the 12 hour or the 24 hour incubation. Kinetics of colonization were formed area of top speed from the 12 hour to the 24 hour and respectively reached 10.33, 9.28 및 8.30 Log copy No/h/g DM at the 24 hour by F. succinogenes, R. flavefaciens and R. albus. The kinetics of rice straw degradation was formed top level of 0.95% DM/h at the 24 hour. The present results gave clear evidence that degradation of rice straw was increased with the development of total fibrolytic bacteria in process of rumen fermentation. Also, their attachment was largely occurred immediately after insertion of rice straw, the colonized bacteria was actively proliferated, and then degradation of rice straw was maximized.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.201-201
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• 2011

컷오프 진단법은 프로브 형태로 제작된 마이크로 웨이브 진단법으로, 간단한 수식을 통해 전자밀도, 전자온도 등의 측정이 가능하며, 장치나 분석방법이 매우 간단한 장점을 지닌다. 또한, 측정에 약 1 mW 정도의 적은 파워를 사용하여 플라즈마 상태를 거의 변화시키지 않으며, 공정 플라즈마에서도 사용이 가능하다. 그러나 컷오프 진단법을 사용한 측정은 다른 종류의 프로브와 마찬가지로, 약 1초 정도의 긴 시간이 필요로 하는 단점이 있다. 따라서 기존의 컷오프 진단법은 펄스 플라즈마나 토카막과 같이 빠르게 변하는 플라즈마를 측정하기에는 무리가 있다. 본 발표에서는 컷오프 진단법을 새로운 방법으로 구현하여 더욱 빠르게 측정할 수 있는 방법을 소개하고자 한다. 컷오프 프로브는 방사 안테나, 측정 안테나와 네트워크 분석기로 구성되어 있다. 네트워크 분석기는 두 안테나 사이의 플라즈마 투과 스펙트럼을 만드는데 쓰이며, 주파수 스캔 방법을 사용하여 스펙트럼을 만든다. 컷오프 진단법의 측정시간은 주파수 스캔에 걸리는 시간에 의해 결정된다. 본 발표에서는 측정을 빠르게 하고자 전혀 새로운 방법을 도입하였다. 펄스 형태의 단일신호를 플라즈마 투과 특성을 살피는데 이용하면 측정을 매우 빠르게 할 수 있다. 그래서 펄스제조기와 오실로스코프를 이용하여 스펙트럼을 얻는데 사용하였다. 이론적으로는 이 방법을 통해 측정시간을 수 nano second 수준으로 줄일 수 있다. 실험적으로는 micro second 정도의 시간으로 측정을 할 수가 있었으며, 동일한 스펙트럼 및 측정결과를 얻을 수 있었다. 또한 이 방법을 펄스플라즈마에 적용할 경우 수십 nano second 수준의 시간분해능으로 측정을 할 수가 있었다. 이 방법을 응용하면 토카막 언저리와 같이 매우 빠르게 변하며 반복되지 않는 플라즈마의 측정도 가능할 것으로 예상된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.268-270
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• 2007

We investigated characteristics of meat quality using by spectroscopic methods in visible region. Characteristics of beef muscle quality was measured by using spectrum analysis. We take the 3 samples of meat, and each sample has 3 measuring point. Also each measured samples has alternate thawing time(the state of frozen meat, thawing 20 minute and thawing 40 minute in the room temperature). As a results of experiments, measured intensity has changed by distributions of Myoglobin in meat muscles. And we can distinction the and characteristics of meat quality by distributions of lean meat and fat.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.2
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• pp.139-147
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• 1998

This study has been performed to evaluate the relationship between the remained mineral components in a decalcified bone matrix and an ectopic bone formation efficiency. The freezed rat diaphyseal cortical bones measuring 0.5cm in length were demineralized in heated 0.6N HCl at $60^{\circ}C$ for 5, 10, 15, 20, 25, 30, 35, 40 minutes, respectively, using a controlled heat ultrasonic cleaner. Each 1cc of decalcifying solution taken during decalcification procedure was used to calculate calcium content using calcium dignostics kit under 600nm of spectrophotomer. After decalcification, each specimen was also weighed. Then each prepared specimen was implanted into the dorsal pouch of 24 Sprague-Dawley rats divided into 8 groups by time course. The implants were harvested at 1, 2, and 3 weeks and prepared for routine H-E stain specimens to evaluate osteogenic activity. The results are as follows: 1. There was statistical significant difference in change of calcium concentration up to demineralization of 30 minutes and each allogenic bones decalcifed up to 20 minutes revealed 99.65% of decalcification in average. 2. There was statistical significant difference in change of weight in demineralized allogenic bone up to 20 minutes treatment but, no significant change was noted after that time. 3. The histologic analysis revealed active ectopic bone formation in the implanted allografts demineralized for 20, 25, 30 minutes, respectively. However, the other groups of allografts showed relatively poor osteoinductive activity. These findings suggest that complete decalcification with a minimized degeneration of collagen matrix is necessary to induce maximal osteogenesis by decalcified bone allograft.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.11A
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• pp.1613-1619
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• 2000

이 논문에서는 전파재널 측정 시스템을 이용하여 건물내 무선 채널의 전파특성인 실효 시간지연 확산과 경로손실을 측정하고 분석한 결과를 제시한다. 구성된 측정 시스템은 미끄럼 상관기를 이용한 대역확산 채널 측정 시스템에서 2 GHz에서 동작하며 3 m 의 분해능을 갖는다. 건물내 무선 채널 특성의 측정환경은 송신 안테나와 수신 안테나가 같은 층에 있을때, 서로 다른 층에 있을때, 그리고 사무실 안에 같이 위치할 때의환경으로구분하여 실험한다.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.291-297
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• 2007

The hydrolysis reaction of sulfur mustard(HD, bis 2-chloroethylsulfide), one type of the blister agents was studied in water to find the operation conditions which can convert HD into less toxic compounds. The reaction was proceeded into two steps. First, 10~20 wt% of HD was hydrolyzed in water at $90^{\circ}C$ for 2 hr and aqueous sodium hydroxide solution(2.1 eq) was subsequently added to the reaction mixture at room temperature. The efficiency of HD hydrolysis at this experimental conditions was greater than 99.99% and the final degradation products of HD were 68 wt% of thiodiglycol, 8 wt% of 1,2-bis(2-hydroxyethylthio)ethane and 24 wt% of bis(2-hydroxyethylthioethyl)ether.