• 한국공작기계학회논문집
• /
• 제15권4호
• /
• pp.44-48
• /
• 2006

Recently, demand the ultra precision product which is increasing rapidly is used extensively frontier industry field such as semi-conductor, computer, aerospace, precision machine. Ultra precision processing is the portion that is very needed to NT in the field of mechanical engineering. The latest date, together with radical advancement of electronic and photonics industry, necessity of ultra precision processing is on the increase for the manufacture of various kernel parts those are connected with these industrial fields. Specially, require motion accuracy of high resolution of nm order in stroke of hundreds millimeters according as diameter of processing object great and processing accuracy rises. In this case ,the response speed absolute delay because inertial mass of moving part is very large. Therefore, real time motion error compensation becomes very hardly. In this paper, we used ultra precision cutting unit(UPCU) to cope such problem. a UPCU is designed and tested to obtain sub-micrometer from accuracy in diamond turning of flat surfaces. The thermal growth spindle error is compensated for real time using a UPCU driven by piezoelectric actuator along with a laser encoder displacement sensor.

• Journal of Animal Science and Technology
• /
• 제64권2호
• /
• pp.262-273
• /
• 2022

Under the four-cut system, low-lignin alfalfa (Medicago sativa L.) may extend harvesting intervals improving harvest management flexibility and producing forage products with higher nutritive values. The objective of this study was to compare forage yield and nutritive values of low-lignin and conventional alfalfa varieties when applied to six different harvest schedules in the first (2016) and second (2017) production years. There were 12 treatments of two alfalfa varieties as whole plots and six harvest schedules as subplots. Across harvest schedules, there were four cuttings in two production years. Three harvest intervals including "Standard" (high quality, HQ), "Standard+5-day" (medium quality, MQ), and "Standard+10-day" (high yield, HY) were chosen for the first cutting, and 30-day (HQ) and 35-day (HY) for the second cuttings. The third and fourth cuttings in 2016 were timed near final harvest date and in 2017 occurred at 35-day (MQ) and 40-day (HY). Variety by harvest schedule interaction was not significant, but the whole plot and sub-plot effects were significant. Hi-Gest 360 was consistently higher in nutritive value and with a similar yield as Gunner. Harvest schedules did not consistently differ in forage yield and nutritive values. HS-1 ("Standard" + 35-day + Medium Quality + High Yield) with shorter first two cutting intervals provided lower acid detergent fiber (ADF), neutral detergent fiber (NDF), higher relative feed value (RFV), and similar forage yield compared to other schedules. HS-1 had the highest economic incomes when considering RFV and yield among the six different harvest schedules.

• 한국식품과학회지
• /
• 제26권5호
• /
• pp.512-519
• /
• 1994

박하를 대상으로 재배조건 및 수확시기에 빠른 방향 성분의 함량변화를 조사한 결과 박하의 생육은 비닐보온시험구에서 초기에 왕성한 생육을 보였지만, 수확기가 가까와 짐에 따라 다른 시험구와 유사하게 성장하였으며, 강유량과 일조시간에 따라 줄기와 잎의 성장속도에서 매우 많은 차이를 보였다. 수확시기에 따른 조성분의 변화는 l-menthone의 l-menthol로의 환원과정이 일조시간의 차이에 따라 그 진행속도가 빨라졌으며, 수확말기에 가서는 특히 menthofuran의 함량이 급속히 증가하는 현상을 보였다. 따라서 전체적으로 정유 조성분의 비율이 가장 양호한 시험구는 7월 5일과 7월 7일 수확분으로서, 이 시기가 수확 적기임을 알 수 있었고 정유의 우율도 이 시기에 가장 높게 확인되었다.

• 한국조경학회지
• /
• 제32권2호
• /
• pp.120-129
• /
• 2004

This study was carried out to develop new varieties with early maturing and large fruit size in the Korean native dogwood (Cornus kousa) for woody landscape plants from native sites or cultivated area. The results are obtained as follows; We selected strains with early maturing and large fruit. size from the habitats from 2000 to 2003. ‘SKK 2-1’ had 4.0cm of fruit size while 2.0 cm of native variety. In addition, ‘SKK 2-2’, ‘SKK 2-3’, ‘SKK 2-4’, and ‘SKK 2-5’ with large fruit and early maturing were preliminary selected from the habitats. In the preliminary selections, ‘SKK 2-1’ was finally selected as new early maturing variety with large fruits in 2003. New early maturing variety with large fruit size, C. kousa var. ‘SKK 2-1’ was selected from 200 plants of 5-year-old seedlings in C. kousa in 5-12 Nung wean ri Goo sung myun Yong In, Kyung gi do, Korea in 2000. Their fruits were colorized in September 18, 20∼25 days earlier than October 7 of native varieties. Its fruit diameter is larger than 4cm. Its fruit weight was 5 times as heavy as native cultivars grown in Korea. This useful characters were still inherited after grafting. However, characteristics of growth, leaf, flower, and flowering period were not different from those of native varieties. Therefore, it was very promising landscape woody plant, having large fruits in early fall season. The rooting rate of Korean dogwood was high by the IBA treatment. The optimum date for softwood cutting was on June 25 ∼ July 25 when the rooting rate was more than 80%. In addition. Korean dogwood was easily propagated by grafting. Therefore, new early maturing variety with large fruits, C. kousa var. ‘SKK 2-1’ is easily propagated by softwood cutting or grafting and then is a promising cultivar as a woody landscape plant.

• 한국토양비료학회지
• /
• 제45권6호
• /
• pp.992-997
• /
• 2012

수수의 재생력과 양분 흡수력을 이용해 시설재배지에 집적된 토양양분의 효율적 이용방법 개발을 위한 기초자료를 얻고자 비닐하우스에 수수를 재배하여 주요 생육시기별로 예취한 후 재생경의 생육 및 양분흡수 특성을 구명한 결과는 다음과 같다. 예취 후 재생경의 출수 소요일수는 유숙기 예취시 35일로 가장 짧게 나타났으며, 가장 긴 소요일수를 보인 출수기도 44일로 관행재배시보다 짧은 소요일수를 나타냈다. 예취 후의 누적 초장에서는 유숙기에서 379.4 cm로 가장 길게 나타났고, 예취 시기가 늦을수록 작은 경향을 보였으며 가장 짧은 무예취구와는 약 2배의 차이를 보였다. 그러나 수수의 Biomass는 초장과 달리 출수기 예취구가 1.73 Mg $10a^{-1}$로 가장 많은 생산량을 나타냈으며 종실은 무예취구에서 가장 많은 수량을 나타냈다. 식물체 부위별 농도에서 T-N은 잎>이삭>줄기 순으로 나타났으며, 대체적으로 생육초기인 10엽기에서 각 부위별로 높은 양분함량을 보였으며 수확시기에서는 $K_2O$를 제외한 나머지 $P_2O_5$, CaO와 MgO가 줄기보다는 잎에서 높은 함량을 보였다. 지상부의 양분흡수량은 예취시기에 따라 출수기>무예취구>유수형성기${\geq}$유숙기>10엽기 순으로 나타났다. N의 흡수량은 출수기의 $P_2O_5$을 제외한 $K_2O$, CaO, MgO은 무예취구에서 가장 많은 흡수량을 보였으며 평균 흡수량보다 모두 높은 처리구는 출수기와 무예취구로 나타났다.

• 한국산림과학회지
• /
• 제85권2호
• /
• pp.300-308
• /
• 1996

낙엽송(Larix leptolepis Gordon)의 삽목발근에 관련된 제(諸) 요인(要因)을 구명하기 위하여 녹지삽목 시기인 7월 10일을 전후해서 6월 24일부터 7월 25일까지 일주일 간격으로 5주간 삽수를 채취하여 삽수내 수분함량, 탄수화물함량, 무기물함량을 조사하고, IAA 함량은 2주일 간격으로 3회 조사하였으며, 십목 후 매주 삽수를 굴취하여 뿌리 발달과정을 조사하였다. 클론 별 IAA 함량에서는 발근이 잘되는 클론이 발근 어려운 클론의 삽수 생중량 g당 평균 $1.26{\mu}g$에 비하여 $1.31{\mu}g$으로 다소 많은 경향을 나타내었다. 녹지삽목의 적절한 시기로 판단되는 7월 8일에서 15일 사이 삽수의 수분 함량은 발근 잘되는 클론이나 그렇지 안은 클론 각각의 수분함량은 76%, 75%로 조사되었다. 갱생기(更生枝)(hedged branch) 삽수(揷穗)의 탄수화물, 인산, 질소 함량은 각각 19.8%, 0.61%, 1.87%로 처리하지 않은 비교목(比較木) 삽수(揷穗)의 13.8%, 0.41%, 1.42%에 비하여 함량이 많았다. 탄수화물의 함량과 C/N율도 갱생지의 삽수가 비교목의 삽수보다 높았다. 클론간 탄수화물의 함량은 삽목 시기인 7월 8일 과 15일에 발근이 우수한 클론은 16.2%와 12.6%인데 비하여 발근 불량한 클론은 10.2%와 7.8%로 우수클론이 비교적 많은 경향을 보였다. C/N율도 삽목 시기부터 발근이 우수한 클론에서 높은 값을 보였다. 무기성분의 경우 $Mg^{{+}{+}}$, $K^+$, $Ca^{{+}{+}}$은 발근 불량클론이 많았으나 인산은 발근 우수클론이 많았다. 낙엽송 삽목(揷木) 발근(發根)에 관여(關與)하는 물질(物質)은 특정한 한가지 물질에 의하여 좌우하는 것이 아니라 탄수화물, 질소, C/N율, K/C율, 인산 등의 여러 가지 물질이 복합적으로 관여하는 것으로 판단된다. 원근기(原根基)가 나타나는 시기는 삽목 1주일 후부터이며 그 위치는 대부분의 사부조직 이지만 극히 일부는 캘러스 조직에서도 관찰되었다. 근기(根基)는 대개 2주 후부터 관찰되었고 새로운 뿌리로의 발달은 빠르면 3주 후에 삽수의 표피 외부로 나타나고 대개 삽목 5주 후부터 뿌리로 발달되었다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집C
• /
• pp.88-93
• /
• 2001

As the development of High Speed Machining, It is applied in many fields of manufacturing. Among them is to manufacture die and mold. But it still remains as a hard-to-work to apply it in machining pre-hardened materials such as hardened QRO90. It also difficult to machine new materials because there is no machining date of them. Therefore, in this study, we are trying to improve the machinability of new material, QRO90 by applying various cutting conditions, and selecting the best condition which not only reduce the machining time but improve the quality of die and mold made of QRO90 material.

• 아시안잔디학회지
• /
• 제9권2호
• /
• pp.137-157
• /
• 1995

Some indices of species of the Arundinella hirta communities in Cheolwon area were studied and the following results were obtained. The vegetational date was analyzed from six grass stands selected with the distance away from the DMZ in Cheolwon area. Species diversity was higher in the stand away from the DMZ than in that neat to it. All six stands are not considered to be free of disturbance. Species composition of the stands might be related to the degree of disturbance. It can be said that the destruction of the vegetation by periodical fire or cutting simplifies the species composition. In the rear district the human inter ference is supposed to be more frequent. But it is supposed to be slight in near the DMZ and that the degree of disturbance is not so destructive. This could be the explanation of high diversity in these stands.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
• /
• pp.191-194
• /
• 2010

Construction companies are now trying a variety of cost-cutting strategies in the midst of recent slump of construction market. Notably, contract workers and local hires are accounting for increasing portion of management manpower as a part of their cost-reduction drive. However, construction site manpower researches to date have focused primarily on productivity analysis of site laborers, with little attention to the productivity of site management resources. This study aims to analyze the staffing status of office building construction site management manpower in reference to project size. Conclusions herein will provide basic inputs for subsequent attempts to build a model to enable efficient staffing of construction site management manpower.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.552-559
• /
• 2009

Most damage identification methods for structural health monitoring developed to date utilize modal domain responses which require postprocessing and inevitably contain errors in transforming the domain of responses. In this paper, the feasibility of a damage identification method based on dynamics responses from moving loads is experimentally verified. The experiment is performed via applying periodic and non-periodic moving loads to a steel beam and acceleration and displacement responses of the beam is measured. The moving loads is applied using steel balls and the damage of a structure is simulated by saw-cutting the beam. The damage identification results using the measured responses show that the moving load response based damage identification method successfully identify all damages in the beam.