• 한국산림과학회지
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• 제63권1호
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• pp.9-11
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• 1984

우리나라 중부(中部) 산간지방(山間地方) 고산지대(高山地帶)에 분포(分布)하고 있는 들메나무 천연림(天然林)에서 종자(種子)를 채취(採取)하여 3가지 방법(方法)으로 발아촉진(發芽促進) 처리(處理)를 하여 묘상(苗床)에 파종(播種), 발아율(發芽率)을 비교(比較)하고, 생육밀도(生育密度)를 다르게 조절(調節)하여 육묘후(育苗後) 묘목(苗木)의 생장(生長)을 비교(比較)하였다. 그 결과(結果)를 요약(要約)하면 다음과 같다. 1) 들메나무의 1-0 묘(苗)의 경우(境遇) 양묘시업(養苗施業) 기준(基準) 본수(本數)는 $1m^2$당(當) 80본(本)을 생립(生立)시켜 육묘(育苗)하는 것이 적정(適正)할 것으로 생각되었다. 2) 들메나무 종자(種子)의 발아촉진(發芽促進) 처리(處理)에 따른 3 방법중(方法中) 당년(當年)의 발아율(發芽率)은 항온습윤저장(恒温濕潤貯藏) 19.9%, 변온급여저장(變温給與貯藏) 2.3%, 노천매장(露天埋藏) 0.4 %로 나타났다. 3) 들메나무의 전(全) 시험(試驗) 묘목중(苗木中) 8.1%에 해당(該當)하는 묘목(苗木)은 2차(次) 상장생장(上長生長)을 하였다.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.119-128
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• 2004

With the growing traffic density and increasing comfort requirements, the automation of the drive train will gain importance in vehicles. The automatic clutch actuation relieves the drivers especially in urban driving and stop-and-go traffic conditions. This paper describes the dynamic modeling of a clutch actuator and clutch spring. The dynamic model of the clutch system is developed using MATLAB/Simulink, and evaluated by experimental data using a test rig. This performance simulator is useful to develop the clutch-by-wire (CBW) system for an automated manual transmission (AMT). The electro-mechanical type CBW system is also implemented as an automatic clutch for AMT. The prototype of CBW system is designed and implemented systematically, which is composed of an electric motor, worm gear and slider-crank mechanism. The test rig is developed to perform the basic function test of the automatic clutch, and the developed prototype is validated by the experimental data on the test rig.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.35-40
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• 2004

Rotavirus virus-like particle (VLP) composed of VP2, VP6, and VP7 was expressed in the Baculovirus Expression Vector System (BEVS). Sf9 cell, a host of the baculovirus, was cultured from a 0.5-1 spinner flask to the 50-1 bioreactor system. Sf9 cell was maintained at cell density between 3.0E＋05 and 3.0E＋06 cells/ml and grew up to 1.12E＋07 cells/ml in the bioreactor. Growth kinetics was compared under different culture systems and showed similar growth kinetics with 20.1-25.2 h of doubling time. Early exponentially growing cell culture was infected with three recombinant baculoviruses expressing VP2, VP6, and VP7 protein at 1.0, 2.0, and 0.2 moi, respectively. The expression of rotavirus proteins was confirmed by Western blot analysis and its three-layered virus-like structure was observed under an electron microscope. Rotavirus VLP was semipurified and immunized in ICR mice intramuscularly. Rotavirus-specific serum antibody was detected from 2 weeks after the immunization and lasted at least 21 weeks of the post-immunization, indicating its possible use as a vaccine candidate.

• 한국임상수의학회지
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• 제26권5호
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• pp.467-471
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• 2009

This report describes Neural Tube Defects (NTDs) with Abdominal Wall Defects (AWDs) on the sibling of Yorkshire terriers. The NTDs and AWDs are rare serious congenital defects. The NTDs are neurulation abnormality that results from to failed transformation of the neurual tube by the incomplete closure of the embryonic neural plate. These dysraphic states range form mild to severe according to developmental malformation that include fusion defects of skull (crania bifida; CB) and fusion defects of vertebrae (spina bifida; SB). The AWDs are genetic defects that results from to failed formation of abdominal wall and cavity. These dysraphic states are omphalocele and gastroschisis. The 12-month dam was delivered by caesarian section and 4 littermate had obvious malformations. One male dead stillbirth fetus (L1) was revealed the extruded abdominal viscera, omphalocele. One female fetus (L2) was died within 1 hour after birth with defects of abdominal muscle upper umbilicus, gastroschisis. 3rd fetus (L3) was died within 36 hours after parturition and revealed a copious dermal and vertebral defects on the midline thorax, upper SB asperta. 4th fetus (L4) is still growing well now at 6 months but at the 2 week age, appears hairy nevus on the frontal cranium and dorsal thoracic portion. The radiograph of L1 and L2 are shown decrease bony density of calvarium and L3 was shown defect of spinose processes of the T9-T13. On our knowledge, this is first report of the SB and CB in Yorkshire terrier. And also sibling of NTDs with AWDs that has not previously been reported in the dog.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.184-184
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• 2011

Using first-principles density-functional calculations, we investigate the chain reaction mechanism of allyl alcohol (ALA) molecules on the H-terminated Si(001)-2${\times}$1 surface. Recently, it was reported [1] that allyl mercaptan (ALM) molecules show a self-directed line growth across the dimer rows through a chain reaction involving several reaction processes: (i) The created radical at the C atom is transferred to the S atom, (ii) the resulting S-centered radical easily abstracts an H atom from the neighboring dimer row, and (iii) the generated S-H group further reacts with the neighboring dimer row to produce the Si-S bond on the neighboring dimer row, accompanying the associative desorption of H2. This H2-desorption process creates a new DB on the neighboring dimer row, setting off the chain reaction across the dimer rows. In the present study, we find that although the structure of ALA with -OH functional is analogous to that of ALM with -SH functional, ALA and ALM lines show a difference in their growth direction. We predict that ALA undergoes the chain reaction to show a line growth along the dimer row, contrasting with the ALM line growth across the Si dimer rows. Our analysis shows that the different growth direction of ALA is due to the strong instability of oxygen radical intermediate, which prevents from growing across the dimer rows. Thus, we demonstrate that the stability of the radical intermediate plays a crucial role in determining the direction of molecular line growth.

• Journal of Biosystems Engineering
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• 제4권1호
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• pp.48-57
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• 1979

In order to obtain a standard reference for designing an adequate power rice transplanter, the cutting forces depending upon variety of seedling, sowing density, seedling age and soil moisture content of mat-type seedling were measured by the rice transplanter installed with force measuring device of dynamic strain gage system in the laboratory. The result of this study are summarized as follows : 1. Cutting velocity and acceleration transplanting hoe obtained from jinematic analysis of planting mechanism was 1.32m/sec and 81.5m/$sec^2$ when planting crank-shaft rpm was 160. 2. Little difference between cutting forces on 30-days old seelings of japonica and Indica type was observed, as the cutting forces determined were 2.0kg per hill for Japonica type and 2.1kg per hill for Indica type. 3. Cutting forces determined on 40-days old seedlings were 2.5kg, 2.3kg, 3.1kg and 2.9kg per hill for Milyang No.15, Tongil, Akibare and Milyang No.23 compared to the other varieties. 4. The cutting force was not greatly affected by the sowing densities , only five percent of differences were observed epending upon the sowing densities. 5. Cutting forces were 2.7kg and 2.0kg per hill on 40-days old seedlings and 30-days old seedlings respectively. About 38 percent of more forces was required in cutting 40-days old seedling than in cutting 30-days old seedlings. 6. More cutting forces were required as soil moisture content of mat-type seedling was decreased. 7. Root length after cutting by the planting hoe and their relationships with soil moisture content on 30-days old seedlings, are as follows ; $y=4.147-11.384x+ 28.854x^2$ where , $y$=root length after cutting. (cm) , $x$=soil ture content of mat type seedlings.(%, d.b.) 8. Cutting forces were varied with the width of cuttings ; those on 40-days old mat type seedlings were 2.7kg and 2.2kg per hill when cutting with 14 mm and 10mm of width respectively, about 32 percent of more forces was required when cuting with 14mm of width compared to 10mm of width.

• 한국추진공학회지
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• 제20권6호
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• pp.76-82
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• 2016

최근 기존 화약과 추진제의 환경 지속성은 에너지 물질 분야에서 중요한 이슈로 부각되고 있다. 예를 들어 고체추진제의 산화제인 ammonium perchlorate(AP)는 염산과 같은 독성 가스와 대기 오염을 발생시켜 환경적 문제를 야기한다. 산화제 중 hydrazinium nitroformate(HNF)는 높은 밀도와 압력 지수를 가지고 있으며, 추력 제어 시스템에서 연소하는 동안 소규모의 연기를 배출하는 성질을 가지고 있기 때문에 환경 친화적으로 효과적인 후보 물질이다. 본 발표에서는 다양한 조건을 통하여 결정의 입도 및 형상을 제어하였다. 결정의 형상은 장단축비가(L/D) 1:3 이하이며, 입도는 두 가지 종류로 대략 $200{\mu}m$와 $50{\mu}m$로 얻을 수 있었다.

• 식물분류학회지
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• 제41권2호
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• pp.130-137
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• 2011

제주도 한라산에 자라는 한라송이풀은 고유종 Pedicularis hallaisanensis Hurusawa로 인식되고 있다. 한편 이 식물은 근연종인 P. amoena, 구름송이풀 또는 이삭송이풀과 형태적으로 유사하여 분류학적 처리가 혼동되어왔다. 본 연구는 이 식물의 분류학적 위치를 파악하기 위하여 한라송이풀과 근연종을 대상으로 외부형태 및 핵 리보소옴 DNA 염기서열을 조사하였다. 한라산의 이 식물은 꽃받침 열편, 화판 상순과 하순의 길이 비, 식물체의 선모 밀도, 개화기 근생엽의 유무 및 염기서열 자료에서 P. amoena 및 구름송이풀과는 뚜렷한 차이를 보였다. 하지만 한라송이풀은 외부형태 및 ITS 염기서열에서 동북아에 분포하는 이삭송이풀과 뚜렷이 구별되지 않았다. 본 연구의 형태 및 분자생물학적 자료는 한라송이풀이 이삭송이풀로 통합되는 것을 지지하였다.

• 디지털콘텐츠학회 논문지
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• 제11권1호
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• pp.91-97
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• 2010

비휘발성, 저전력 소모, 안정성 등의 장점을 가진 NAND 플래시 메모리는 고집적화, 대용량화, 저가격화를 통하여 다양한 디지털시스템의 데이터 저장장치로 사용되고 있다. 플래시 메모리의 다양한 분야에서의 응용 확대와 동시에 플래시 메모리의 대용량화는 플래시 메모리의 주소 변환 테이블의 전체 크기를 증가시켜 SRAM에 저장하기에 용량이 부족한 문제점을 발생시킨다. 본 논문에서는 하이브리드 변환 기법 기반의 플래시 메모리 파일 시스템에서 페이지 주소 캐시를 이용한 효율적인 주소 테이블 관리 정책을 제안한다. 제안하는 기법은 다양한 메타 데이터 기반의 전체 테이블의 정보를 맵블록을 이용하여 효율적으로 통합 관리함으로써 높은 성능을 유지할 수 있다. PC 환경에서의 다양한 응용프로그램을 실험한 결과 제안하는 페이지 주소 캐시는 2.5% 이하의 낮은 미스율로 높은 효율성을 유지하며 전체 쓰기 연산 요청에서 평균 33%의 실제 쓰기 연산의 실행으로 전체 쓰기 연산에서 발생하는 오버헤드를 줄여 주었다.

• 한국방재학회 논문집
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• 제9권3호
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• pp.81-87
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• 2009

본 연구에서는 산림 내 가연물의 산불위험성을 판단하기 위하여 영동지역에서 자생하는 관목류(생강나무, 조록싸리나무, 초피나무, 산초나무, 개암나무)의 생엽을 대상으로 발화점시험기, 콘칼로리미터, 연기밀도시험기를 이용하여 연소특성을 고찰하였다. 조록싸리나무는 발화온도가 가장 낮고 착화시간이 가장 빨랐으며, CO와 $CO_2$의 평균방출농도가 가장 높은 것으로 나타났다. 초피나무는 가장 많은 열량을 방출하였으며, 산초나무는 가장 많은 연기를 발생한 것으로 나타났다. 따라서 산불발생 시 조록싸리나무는 다른 수종에 비하여 착화가 가장 용이하고 초피나무는 확산 및 화재강도가 가장 클 것으로 판단되며, 산초나무와 조록싸리나무는 다량의 연기발생에 따라 피난이 어려울 것으로 사료된다.