• Journal of Drive and Control
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• v.13 no.1
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• pp.70-71
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• 2016

• Proceedings of the Speleological Society Conference
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• 1995.09a
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• pp.65-66
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• 1995

1. 석회암의 성인 (1) 암석의 풍화로 암석 중의 탄산수소칼슘이 되어 녹아 나온다. (2) 탄산수소칼슘은 액체로만 존재하며 이는 물에 섞여 호수나 바다로 유입된다. (3) 탄산수소칼슘이 수온 변화로 이산화탄소를 잃어버리면 탄산칼슘(방해석이나 아라고나이트-석회암)의 결정으로 정출 퇴적되어 석회암층을 만든다. 수중 식물이 탄산수소칼슘을 흡수하여 석회질인 껍데기(조개류, 유공충 등), 뼈(산호 및 기타 동물)를 만든다.(중략)

• Proceedings of the Speleological Society Conference
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• 1997.10a
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• pp.85-86
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• 1997

1. 석회암의 성인 (1) 암석의 풍화로 암석 중의 탄산수소칼슘이 되어 녹아 나온다. (2) 탄산수소칼슘은 액체로만 존재하며 이는 물에 섞여 호수나 바다로 유입된다. (3). 탄산수소칼슘이 수온 변화로 이산화탄소를 잃어버리면 탄산칼슘(방해석이나 아라고나이트-석회암)의 결정으로 정출 퇴적되어 석회암층을 만든다. 수중 식물이 탄산수소칼슘을 흡수하여 석회질인 껍데기(조개류, 유공충 등), 뼈(산호 및 기타 동물)를 만든다.(중략)

• Journal of Drive and Control
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• v.8 no.1
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• pp.44-49
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• 2011

• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.121-125
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• 2004

Recently, High Tensile Steel is adapt to thin plate on the steel structure and marine structure is used widely, It is possible for buckling happens great. Specially, Initial deflection of ship structure happens in place absence necessarily by heat processing of welding or cutting etc. This Initial Deflection is exerted negative impact when thin plate absence complicated nonlinear behaviour accompanied secondary budding. As a result, must idealize initial deflection that occurrence is possible to endow stability and accuracy in the hull structure or marine structure and reflect in early structure design considering secondary buckling. Longi direction of compressive load interacts and analyzed finite element series analysis that apply various kinds initial deflection shape measured actually on occasion that is arranged simply supported condition in this research. Applied ANSYS (elasto-plasticity large deformation finite element method) to be mediocrity finite element program for analysis method and analysis control used in Newton-Raphson method & Arc-length method.

• Journal of Korean Society of Steel Construction
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• v.15 no.3
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• pp.271-279
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• 2003

Many researches have been conducted to describe the elastic and inelastic behavior of H-shaped beams with web openings, and were generally concentrated on the uniaxial loading conditions. With previous research results, the formulae for the design of beams with web openings, considering local buckling, have been proposed by Darwin. Although the formulae are so simple and useful to apply to real situations, it needs more research on cyclic loading conditions. In this experimental study, a total of seven H-shaped beams with circular web openings under cyclic loading conditions were investigated. The dimension criteria were based on the formulae proposed by Darwin. The suitability of the existing design formulae, the effects of plastic hinges on beams with web openings, and the local bucking around the web openings to the beam strength under cyclic loading were also investigated through by the observations of the behavior of these beams with various dimensional openings.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.3
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• pp.121-130
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• 2018

'Mats-kyeong-chae (Brassica lee ssp. namai cv. Tongssamchoo)', a new type of sweet Korean cabbage for fresh wrapping and soup cooking, was released by the Korea National College of Agriculture and Fisheries. The shelf-life and quality changes of this new cultivar was evaluated by packaging with PP (polypropylene) film bag and storing at three temperatures ($5^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$). As control, the cabbage was packaged in a corrugated paper box and stored at $25^{\circ}C$. At the storage temperature of $5^{\circ}C$, the degree of freshness, weight loss, hue angle and SPAD on cabbage packaged with PP film bag maintained its good quality and exhibited a longer period of marketable life compared to the samples stored in other treatments. Results showed that the use of PP film packaging and storing at $5^{\circ}C$ could be the optimum condition for commercial storage of 'Mats-kyeong-chae'. Further investigation on other quality parameters according to different packaging methods would be useful in maintaining the quality of 'Mats-kyeong-chae' at postharvest stages.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.113-113
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• 2022

도라지(Platycodon grandiflorum)는 초롱꽃과 도라지속에 속하는 여러해살이풀로 7~8월에 보라색이나 흰색의 꽃을 피우고, 뿌리는 다육질로 원주형 또는 분지형이다. 잎은 거의 엽병이 없는 대생이며, 종자는 난형으로 3개의 모서리가 있다. 항염증 성분인 플라티코딘이 들어있어 편도염을 비롯한 후두염, 폐렴 등에 효과가 있어 우리나라 약용작물 재배면적의 상위를 차지하고 있는 주요 작물이다. 최근, 백수오, 감초 등 심근성 약용작물은 뿌리의 수확 비용 절감을 위해 용기재배가 도입되고 있다. 본 연구는 도라지 용기재배에 적합한 용기의 규격과 고온 경감을 위한 용기 재료 선발을 위해 수행하였다. 도라지 용기재배에 적합한 용기의 규격 선발은 기본 용기로 플라스틱 플륨관을 사용하였고, 높이는 40cm로 고정하여 직경을 10, 20, 30cm로 처리하였다. 2019년 4월 하순에 도라지 종자를 파종하여 용기 규격별로 각각 1주(10cm), 4주(20cm), 8주(30cm)를 남겨 두고 솎음 다음, 2020년 10월 하순에 수확하였다. 도라지의 생육 및 수량성을 조사한 결과, 용기의 직경이 증가함에 따라 근장, 근경, 근중 등 지하부 생육이 우수한 경향이었다. 또한, 10a당 수량은 노지재배 749kg에 비해 직경 10cm 778kg, 20cm 849kg, 30cm 1,156kg로 직경 30cm가 가장 우수하였다. 직경이 증가할수록 수량성이 증가하였으나 직경 30cm 이상의 용기는 수확 시 노동력이 증가하고, 배양토 비용이 증가하여 사용하지 않았다. 고온 경감을 위한 용기 재료 선발은 흰색과 검정색 플라스틱 플륨관을 높이 40cm × 직경 30cm 규격으로 절단하여 2020년 4월에 도라지 종자를 파종하였고, 2021년 10월 하순에 수확하였다. 이 중 검정색 용기는 무처리(대조), 유공, 반유공, 흰색부직포, 반사필름 처리를 하였다. 도라지의 수량성을 조사한 결과, 검정색 용기 중 유공처리가 무처리 대비 수량이 21%(1,080 → 1,304kg/10a) 증가하였다. 위의 결과로 도라지는 직경 30cm의 검정색 유공 용기가 용기재배에 적합한 것으로 판단되었다.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.3
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• pp.8-13
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• 2006

It is very important for the manufacturers to predict the life of hydraulic system components according to the results of life tests. Since it takes too much time to test the hydraulic system components until failure, the no-failure test method is applied for the life test of them. If the shape parameter of Weibull distribution, the number of samples, the confidence level, and the assurance life are given, the no-failure test times of hydraulic system components can be calculated by given equation. Here, the procedures to obtain the no-failure test times of the hydraulic system components such as hydraulic motors and pumps, hydraulic cylinders, hydraulic valves, hydraulic accumulators, hydraulic hoses, and hydraulic filters are described briefly.

• Transactions of The Korea Fluid Power Systems Society
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• v.2 no.4
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• pp.7-13
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• 2005

This paper presents modeling and ostimator/controller design for the hydraulic system in Vehicle Stability Control(VSC) system. A nonlinear mathematical model of the VSC hydraulic system is proposed and its accuracy is experimentally verified. A brake pressure estimator is then designed based on the derived mathematical model of VSC hydraulic system. And a disturbance observer, which compensates the estimation error between the brake pressure and the computed brake pressure is also designed to enhance the accuracy of the estimator. The proposed controller has the form of a feedback controller and determines explicitly the on/off ratio of valves' driving PWM signals by means of making use of the simplified mathematical model in the VSC hydraulic system. The performance of the designed controller whose feedback signal is generated by the brake pressure estimator is validated through experimental results.