http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
겨울철 냉기를 이용한 벼의 저온저장(I) - 벼 냉각 후 저장특성 -
이재석,한충수,함택모,연광석,Lee J. S.,Han C. S.,Ham T. M.,Yon K. S. 한국농업기계학회 2005 바이오시스템공학 Vol.30 No.3
The objective of this research was to establish a domestically available cooling storage technique by cold-air in winter, using winter cool air ventilation fur determining rough rice cooling method in the storage and dry bin. The rough rice storage characteristics of two test conditions, winter cool-air ventilation storage and ambient temperature storage, were evaluated from January to July 2001, using a storage and dry bin of 300-ton capacity. Results of this research are as follows: Grain temperature was from $-5.1\~-8.5^{\circ}C$ after winter cool-air ventilation, and grain initial temperature for ambient temperature bin storage was $0.3\~1.9^{\circ}C$. Moisture content of rough rice decreased from $0.28\;to\;0.93\%$ and from $1.53\;to\;1.92\%$ to compare with original moisture contents for winter cool-air ventilation, and for ambient temperature bin storage, respectively. Broken ratio of brown rice from winter cool-air ventilation bin increased from $0.16\;to\; 0.92\%$, and brown rice broken ratio was from $2.24\;to\;2.86\%$ for ambient temperature bin storage to compare with initial broken ratio. Hardness of stored rice increased along storage period increase in alt storage methods, and cooling bin storage increased rice hardness of 0.271kgf: this increasing was lower then the other methods from 0.059 to 2.239kgf. Germination rates were decreased approximately 9.03, 3.14 and $3.20\%$ for upper, middle, and bottom of ventilating winter air bin, respectively, and germination rates of 2.70, 3.47 and $4.14\%$ were approximately decreased for upper, middle, and bottom parts of ambient temperature bin storage, respectively.
GaN 성장을 위한 기판의 Ion Implantation 전처리에 관한 연구
이재석,진정근,변동진,이재상,이재형,고의관,Lee J.,Jhin J.,Byun D.,Lee J. S.,Lee J. H.,Koh W-K. 한국재료학회 2004 한국재료학회지 Vol.14 No.7
The structural, electrical and optical properties of GaN epilayers grown on various ion-implanted sapphire(0001) substrates by MOCVD were investigated. Sapphire substrates have been widely adopted to grow high quality GaN epilayer despite the large differences of lattice constant and thermal expansion coefficient between them. So, GaN or AlN buffer layer and pre-treatment was indispensably introduced before the GaN epilayer growth. The ion-implanted substrate's surface had decreased internal free energies during the growth of the ions implanted sapphire(0001) substrates. The crystal and optical properties of GaN epilayers grown in ions implanted sapphire(0001) substrate were improved. Also, excessively roughened and modified surface by ions degraded the GaN epilyers. Not only the ionic radius but also the chemical species of implanted sapphire(0001) substrates could improve the properties of GaN epilayers grown by MOCVD. This result implies that higher quality of GaN epilayers was achieved by using ion-implanted sapphire(0001) substrate with various ions.
뚝새풀을 이용(利用)한 사과원 초생재배(草生栽培)에 관(關)한 연구(硏究)
정재식,이재석,최충돈,정종도,Jung, J.S.,Lee, J.S.,Choi, C.D.,Cheung, J.D. 한국잡초학회 1998 Weed&Turfgrass Science Vol.18 No.2
뚝새풀의 초생재배(草生栽培)에 의한 사과원 잡초(雜草) 방제(防除)의 실용화(實用化) 가능성(可能性)을 검토(檢討)하고자 뚝새풀 발생(發生) 생태(生態)에 관한 몇 가지 시험(試驗) 결과(結果)를 요약(要約)하면 다음과 같다. 1 뚝새풀 종자(種子)의 파종(播種) 시기별(時期別)출아(出芽) 소요일수(所要日數)는 9월(月) 20일(日) 파종(播種)이 일(日)로 가장 짧았고, 11월(月) 25일(日) 파종(播種)에서 111일(日)이 소요(所要)되어 가장 길었으며, 출아(出芽) 소요(所要) 적산온도(積算溫度)는 3월(月) 15일(日) 파종(播種)이 $139^{\circ}C$로 가장 적었고, 8월(月) 10일(日) 파종(播種)에서는 $988^{\circ}C$로 가장 많이 소요(所要)되었다. 2 사과원에서의 뚝새풀 생육양상(生育樣相)은 3월(月)부터 8월(月) 사이에 S자형(字型)의 생장곡선(生長曲線)을 나타내었고, 초장(長草)과 건물중(乾物重)이 3월(月) 중순(中旬)에서 4월(月) 중순(中旬)사이에 가장 많이 증가(增加)하였으며 5월(月) 중순(中旬) 이후(以後)로는 증가율(增加率)이 거의 정체(停滯)되었다. 3. 뚝새풀을 초생재배(草生栽培)한 사과원에서 뚝새풀을 제외(除外)한 초종(草種)으로는 발생량(發生量)이 망초>왕고들빼기>냉이>꽃다지 순(順)이었고, 뚝새풀의 발생(發生)이 거의 없는 포장(圃場)에서는 냉이가 가장 많이 발생(發生)하였고 왕고들빼기>망초>꽃다지 순(順)으로 발생(發生)되었다. 4. 뚝새풀의 생육(生育) 재생기(再生期)인 3월(月) 중순(中旬)에 뚝새풀의 우점도(優點度)가 90%정도(程度)가 되면 생육(生育) 후기(後期)까지 문제(問題) 잡초(草種)인 망초 왕고들빼기 냉이 등(等)을 효과적(效果的)으로 방제(防除)할 수 있었으나 생육(生育) 재생기(再生期)에 우점도(優點度)가 20%미만(未滿)이면 뚝새풀의 생육(生育) 성기(盛期)인 5월(月) 까지는 다른 잡초(雜草)의 발생(發生)이 경감(輕減)되었으나 이후(以後) 점차(漸次) 증가(增加)하였다. 5. 이상(以上)의 결과(結果)에서 사과원에서의 뚝새풀 초생재배(草生栽培)는 다른 잡초(雜草)들의 발생(發生)을 억제(抑制)시켜 잡초방제(雜草防除)의 성력화(省力化)와 하절기(夏節期)의 과다(過多)한 지온상승(地溫上昇)을 방지(防止)하여 과수(果樹)의 생육(生育)을 양호(良好)하게 할 것으로 기대(期待)된다. The experiment was carried out to obtain basic informations on sod culture using water foxtail in apple orchard at Kyeongbuk Provincial RDA in 1996 to 1997. Period of seedling emergence varied with sowing time and accumulative temperature. Sowing at Nov. 25 required longer than 100 days, while it needed only 8 days when water foxtail was sowed at Sep. 20. In a view of accumulative temperature, sowing at March 15 needed $139^{\circ}C$ but it required about $1,000^{\circ}C$ at August 10. This result showed that the seed of water foxtail has strong summer-dormancy in natural condition. Water foxtail had s-shape growth curve during growing season, and growth rate was the highest from March to May in this period. Plant height increased 2 times and 4 times for dry weight from March 20 to April 20. However, growth was decreased by summer depression after May. Major weeds in apple orchard were horseweed, akino-nogeshi and shepherd's-purse. These species were suppressed by the dominance of water foxtail. Water foxtail as a cover plant could be used for a method of weed control instead of herbicide in apple orchard.
탄성 힌지 타입 레버 메커니즘을 이용한 자동 초점 조절 미세구동장치에 대한 연구
이재석(J. S. Lee),홍석인(S. I. Hong),김호상(H. S. Kim),장한기(H. K. Jang),이경돈(K. D. Lee) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월
In precision laser microfabrication, focusing is essential to acquire good machining precision and uniform machining quality. If it does not perform, laser machining cannot be realized. So, confocal scanning method with high depth resolution is used for focus detection technique. This paper is concerned with a procedure for design, analysis and performance test of an autofocus fine actuating stage, which is composed of flexure-hinge type lever mechanism and piezoelectric actuator. Through series of analytical design, the stage is simplified as a rigid bodies(lever and main body) and springs(flexure hinges). The simplified model was applied to determine the dimension of flexure hinges and lever. After structural analysis confirmed design requirement, an actual stage was made and verified through an experiment on the static and dynamic characteristics(maximum stroke and 1st natural frequency). The fabricated stage was satisfied with the design requirement.
굴삭기 냉각시스템 설계 평가를 위한 엔진룸 열유동 해석 검증
이재석(J.S. Lee),서영민(Y.M. Seo),정찬혁(C.H. Jeong),박용갑(Y.G. Park),하만영(M.Y. Ha) 한국전산유체공학회 2019 한국전산유체공학회지 Vol.24 No.2
Basically, excavators perform high-load operation in a fixed place on the construction site and the cooling performance of an excavator is determined by a cooling system consisting of heat exchangers and a single fan which are located inside engine room. Therefore, during development of an excavator, it is really important to stably design the cooling system by estimating the heat sources of the excavator. In this study, CFD analysis of the engine room was carried out on four different types of excavators and the results of each CFD analysis were compared with those of the heat balance test. Based on the cooling performance index, which is defined by using the design reference temperature of each heat exchanger, the analysis error rate is up to approximately 10%. As these results, CFD analysis can be used to virtually evaluate excavator cooling performance and to perform design evaluation and verification of the cooling system.