• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.979-990
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• 2010

Although a centrifuge model test is performed with scaled models, it has a lot of advantages compared with usual scale model tests, for the reproduction of stress levels equal to a full scale test is possible. At the beginning of the Daewoo Institute of Construction Technology, a servo-motor-driven single axis actuator was introduced and has been in use with a geo-centrifuge. However, for variety of experiments and construction stage simulation, various apparatuses have been developed, such as a vacuum generator, a lateral actuator for tidal power simulation, a gravel hopper and a sand drainer for filled-up ground, and a water level controller. The apparatuses have been manufactured with enough strength and durability to be operated under specific g levels. This paper presents the properties of the apparatuses and the results of the tests performed with those.

• 한국기계가공학회지
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• 제17권3호
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• pp.22-27
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• 2018

One problem of the Discrete Element Method is the assumption of a spherical particle shape, which reduces the computing time but significantly limits the application of the DEM to analysis. This limitation can be overcome by a recently developed rigid-rod model. However, the rigid-rod model has an essential problem related with friction: it always contains friction error because of the bumpy surface. To overcome this issue, we suggest a superposed rigid-rod model in this paper. The superposed rigid-rod model is notably consistent with the theoretical value in terms of the velocity and angular velocity after the collision. The estimated error is negligible(less than 2%). Then, the developed model is applied to hopper discharging. The developed model shows no problem in the discharging flow from the hopper.

• Journal of Biosystems Engineering
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• 제33권4호
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• pp.230-238
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• 2008

Mechanization such as machine harvesting, precleaning, drying and cleaning for rapeseed harvested with high moisture content should be accomplished for biodiesel production. In addition, machine drying and cleaning is inevitable in the mechanization of work, just because rice should be transplanted right after harvesting rapeseed in Korea. Particularly, early harvested rapeseed with the combine have high moisture content and undesirable materials such as stalks and stones which make drying-process difficult and lower the efficiency of drying. Therefore, this study was conducted to develop precleaner and cleaner which could remove foreign substances from harvested rapeseeds. The precleaner consists of throw-in hopper, conveyor, feeding hopper, two precleaning sieves and discharging sections. Precleaning capacity was 1,505 kg/hr in shaking frequency of 370 cpm (cycles per minute) and tilt angles of between $5^{\circ}$ and $7^{\circ}$. The efficiency of precleaning was between 90.9% and 91.5%. The cleaner consists of feeding, shaking, blowing, cleaning and discharging sections. Cleaning performance was 435.4kg/hr in the number of rocking motions of 475 cpm and tilt angle of $10^{\circ}$. The ratios of cleaning, foreign substances and loss were 96.5%, 3.5% and 0.2%, respectively.

• 한국컴퓨터그래픽스학회논문지
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• 제4권2호
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• pp.1-13
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• 1998

캐릭터 애니메이션의 가장 중요한 목표는 효율적으로 캐릭터의 동작을 제어하는 것이다. 지금까지 인간 보행 애니메이션을 위한 많은 기법들이 제안되었고, 파라미터 보간이나 동작 데이터 매핑 을 사용하여 지친 걸음이나 활기찬 걸음과 같은 보행의 감정을 표현하는 기법도 제안되었다. 본 논문은 하나의 다리를 가진 평면 뜀뛰기 모델에 기반한 인간 주행 모델을 제시한다. 본 논문의 기법은 동작 최적화를 위해 유전자 프로그래밍을 사용하며 다양한 캐릭터 모델에 쉽게 적용될 수 있다. 본 논문은 에너지 최소화 기법을 확장하여 감정 표현을 위한 파라미터 설정에 따라 다양한 동작을 생성할 수 있도록 한다.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.81-84
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• 2013

일반적인 Bulk carrier는 Single deck, Double bottom, Hopper side tank, Top side tank와 함께 Single side skin 또는 Double side skin으로 구성되어 Single hull bulk carrier 또는 Double hull bulk carrier라 불린다. 본 논문의 연구선박인 Double hull bulk carrier는 CSR에서 규정짓고 있는 Double hull bulk carrier의 특징 중 Hopper side tank가 없기에 일반적인 Double hull bulk carrier와는 다른 구조를 가진다. 구조적 특징으로는 Inner bottom과 Inner hull 연결부위에 응력 집중 발생, Side shell의 Shear에 대해 구조적 안전성, Double hull에 대한 CSR for bulk carrier의 Rule적용 여부에 대한 판단 등이 있다. 따라서 본 연구에서는 Double hull bulk carrier의 구조적 특징과 구조해석을 통한 응력 집중 부위의 평가 및 Fatigue analysis을 통한 피로수명을 계산하여 이를 통해 구조의 안전성을 살펴보고자 한다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.438-445
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• 2000

Positioning garlic cloves in upright standing in garlic field has been regarded as a very important job because it affects clove rooting, growing and, eventually, quality and yield in garlic production, Because of the geometrical uniqueness and irregularity of garlic cloves in shape, the planting operation has been conducted by manual work that needs a tremendous human labors and increases garlic production cost. The overall objective of this research was to develop garlic planting machine through investigating physical properties of garlic and designing clove upright positioning device after figuring out the factors affecting metering device and upright clove positioning mechanism. With the outcomes of the metering and posture positioning experiment, a garlic clove planter having twelve planting rows was developed for 37kW type tractor and feasibility test was carried out in the field. And, According to the performance test and cost analysis, the planter could accomplish planting operation of one hectare plot in 6.3 hours giving 48 times better efficiency, 6.3hrs/ha, and 74.2% of production cost reduction effect, 1,092,546won/ha, than the manual works of 299hrs/ha and 282,258won/ha. And, break-even point ofthe planter was calculated as of 2.71 hectares.

• Journal of Biosystems Engineering
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• 제34권4호
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• pp.211-219
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• 2009

In the process of oyster mushroom production, loading work of culture medium needs the most intensive labor power and cost. Therefore, the development of culture medium loading machine causes to reduce the manpower and cost. The main objectives of this study are identify cultivating environment, physical properties of culture medium and to make an element design of culture medium loading machine. The results are summarized as follows: 1. The moisture content and density of popularly used culture medium were 70%(w.b), $26\;kg/m^3$, respectively. 2. Pressure of the blower increased as the impeller speed increased, and the opening ratio of pressure controller decreased. 3. Recommendable c1earance(${\delta}$) between an impeller plate and a blower case was 25 mm at an impeller speed of 3183 rpm 4. Discharge device of type B with a hopper and suit was better than type A with a hopper.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.584-586
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• 2017

본 논문에서는 인터넷 장치의 보안을 위해 경량 대칭 암호화와 경량 인증을 통합 한 하드웨어 아키텍처를 제안한다. 암호화 핵심은 PRESENT 알고리즘과 제안된 새로운 경량 암호화 알고리즘으로 구성된다. 또한 HB 및 HB +, HB-MP, HB-MP + 인증 알고리즘들을 포함한다. 통합 보안 시스템은 Verilog HDL을 사용하여 설계되었으며 Modelsim SE 및 Xilinx Design Suite 14.3 프로그램을 사용하여 검증 및 합성되었다. 제안하는 암호화 코어 하드웨어 구조는 Spartan6 FPGA 장치에서 합성한 결과 189Mhz 주파수와 1130개 슬라이스를 가진다.

• 한국응용곤충학회지
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• 제15권1호
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• pp.39-46
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• 1976

As the technology of rice production in Korea has rapidly developed and progressed over the last few years, many problems in rice production have been solved. But with the introduction of new genetic material, the increased use of pesticides, higher fertilizer rates and closer plantings, new problems are beginning to emerge. The brown plant hopper outbreak in 1975 resulted to a great extent from some of the changes in management practices. Some rice diseases and nutritional problems that have existed in Korea but have not been considered of serious consequence, are now becoming increasingly severe and possibly as limiting as the hopper outbreak in 1975. Other diseases and nutritional problems are completely new and their cause and significance have not yet been adequately defined. In this discussion there is no Intention to state, nor is there evidence to support a statement, that any of these problems are going to be limiting factors in the future production of rice on the Korean peninsula. Rather this is an attempt to bring together some of the current field problems in Korean rice so that they can be discussed and where necessary receive suitable consideration for research and control.

• 식물병연구
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• 제15권2호
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• pp.57-62
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• 2009

우리나라 벼에 발생하는 주요 바이러스 중 애멸구에 의하여 전염하는 벼줄무의잎마름병(RSV)과 벼검은줄오갈병(RBSDV)에 대한 간편한 유전자 진단법인 VCHT-PCR 방법을 개발하였다. 벼 잎의 경우 즙액 추출 완충액은 0.5% sodium sulfite를 첨가한 0.01 M 인산완충액(pH 7.0)을 기본 완충액으로 이용하고 애멸구를 진단할 경우에는 기본 완충액에 2% PVP을 첨가하였을 때 VC/RT-PCR 진단이 잘 되었다. VC/RT-PCR을 이용한 진단에 적합한 RSV와 RBSDV 프라이머를 선발하였고 이것을 이용하여 동시진단으로 경기도 김포, 평택, 시흥지역에서 채집한 애멸구의 RSV와 RBSDV의 보독충을 쉽고 경제적으로 진단 할 수 있었다. ELISA에 의한 진단결과와 비교할 때 세 지역을 합하여 RSV에 대한 평균 보독충률은 9.2%로 동일하였으나 보독충 중 일부가 ELISA와 VC/RT-PCR 두 방법에 의한 진단결과가 다르게 나온 것은 RSV의 혈청학적, 유전적 계통 존재 가능성을 제시하고 있다. 포장에서 채집한 애멸구의 VC/RT-PCR 진단효율은 RSV와 RBSDV를 동시에 진단하므로 써 RSV만 진단이 가능한 ELISA 결과 보다 3.2% 높았다.