농업용 저수지 실태파악 및 저수지 개발방향 분류에 관한 연구

최원 ( Choi Won ),김한중 ( Kim Han Jung ),윤성수 ( Yoon Seong Su ),이정재 ( Lee Jeong Jae ) 한국농공학회 2006 한국농공학회 학술대회초록집 Vol.2006 No.-

There are many facilities(46.7%), which are about half of all facilities, that have been over 30 years in the Republic of Korea. At last, particularly abnormal weather for summer season has ruined a lot of rural communities too. So, in ability of agricultural facility, flood control have been more important than irrigation. The number of all agricultural reservoir is 18,000(among these reservoir, 3,000 are managed by Korea Rural Community & Agriculture Corporation and the others are managed by local governments) but the ratio of reservoir is 53% before 1945, 35% from 1946 to 1971. Therefore, it may have been required that new management systems and maintenance techniques are introduced. So, This study may suggest that reservoir(that takes charge of the greatest deal of weight in all agricultural facilities) must be considered as new concept through the change of usage and the unification. On the other hand, reservoir works must be developed as amenity resources, other circumstances and district values.

농업용 파이프 하우스의 2차원 및 3차원 구조해석 비교분석

최원 ( Choi Won ),윤성수 ( Yoon Seong Soo ),이정재 ( Lee Jeong Jae ) 한국농공학회 2001 한국농공학회 학술대회초록집 Vol.2001 No.-

The scope has been small and the specification has been not suggested yet when the pipe house was planed by farmer in Korea. The construction has been made by the suitable agreement of builder and farmer. Also, life cycle time of the pipe house material under serviceability load is not suggested yet. This study is to consider problems of past 2-dimension modeling, to introduce new 3-dimension modeling about pipe house analysis and to know that how the structure under various loads conditions behaves. Therefore, the object is to discuss the current design and to suggest new analysis modeling of the pipe house.

시ㆍ군 관리 저수지 실태 조사 및 정비방안에 관한 연구

최원 ( Choi Won ),김한중 ( Kim Han-jung ),윤성수 ( Yoon Seong-su ),김종옥 ( Kim Jong-ok ),정남수 ( Jung Nam-su ),이형진 ( Lee Hyung-jin ),한이철 ( Han Yi-cheol ),이정재 ( Lee Jeong-jae ) 한국농공학회 2008 한국농공학회논문집 Vol.50 No.3

There are many agricultural facilities (46.7%) that have been over 30 years in the Republic of Korea (the ratio of reservoirs built before 1945 is 53%, from 1946 to 1971 is 35%). In the case of reservoirs which do most important functions among these facilities, only 3,000 reservoirs are managed by Korea Rural Community & Agriculture Corporation (KRC) and the other 15,000 reservoirs are managed by local authorities (City and Gun). But, 15,000 reservoirs included in City. Gun have been built in more wide area than KRC and the reservoir management system has not been operated well because of shortage of budget and manpower of the local authorities. Particularly, the abnormal weather happened during every summer season recently has ruined a lot of rural community facilities. So flood control function have been more important than irrigation function in agricultural reservoir system and it may be required to introduce new safe, management and maintenance techniques in City Gun reservoirs. So we investigated landscapes and deteriorations of agricultural reservoirs managed by local small governments for revealing not only present usage but also future value. Survey shows that there are no structural managements except typical hydrological reportings and the deterioration of small darn is very serious. There are needs for more systematic management system and equipment methods. Therefore, this study may suggest that reservoir (that takes charge of the greatest deal of weight in all agricultural facilities) must be considered as new concept of the usage and the unification. On the other hand, reservoir must be also developed as amenity resources, natural circumstances and district values.

파이프하우스 구조해석 방법에 대한 연구

최원 ( Choi Won ),김한중 ( Kim Han Jung ),윤성수 ( Yoon Seong Su ),이형진 ( Lee Hyung Jin ),이정재 ( Lee Jeong Jae ) 한국농공학회 2008 한국농공학회 학술대회초록집 Vol.2008 No.-

There are many pipe houses in South Korea because the construction cost of pipe house is very low than other facilities and pipe house is adapted to small agriculture scope of South Korea. But recently, it is important to know that snow load is increased than the past by abnormal climate and many pipe houses are collapsed by that load. Therefore, South Korea government has paid many cost for reconstruction of pipe houses. The construction has been made by the suitable agreement of builder and farmer not to consider standard design format and the life cycle time of the pipe house material under serviceability load is not suggested yet. But current structure analysis method for pipe house is limited to 2-D structure analysis. In fact, the largest deflection of the pipe house is occurred in middle zone of longitude direction not to be considered in 2-D structure analysis method. The deformation of pipe house is also more larger than other structures. But the other engineers do not consider non-linear analysis methods. Therefore, I suggest that 3-D non-linear structure analysis method is adapted to pipe house structure analysis and the software of pipe house is developed being based on internet circumstances to help efficient standard drawing and to make clear construction economy. The object of this study is to consider problems of past 2-D modeling and to suggest new analysis modeling (non-linear 3-D structure analysis) of the pipe house. If the compensation cost of government is decreased by new concept analysis method, the agricultural works will have more competitive power.

격자망과 수정된 진화론적 구조 최적화 기법을 이용한 3차원 구조물의 구조해석

이형진 ( Lee Hyung-jin ),최원 ( Choi Won ),이정재 ( Lee Jeong-jae ) 한국농공학회 2007 한국농공학회 학술대회초록집 Vol.2007 No.-

In designing for the structure the stress path is of utility of the basic data of the design like its shape and assigned load. but total automation of the design system has not been achieved because there is no rule about setting up reinforcing steel quantity and arrangement location. There is many researches for solving this problem, but they are instinctive and empirical method for initial geometrical formation. So we made the frame element unidimensional structure with the triangle irregular network to pass the limit and then analysis structure with FEA. And the refined evolutionary structural optimization(ESO) used in structural topology optimization is applied to this study. For this process we expect to show the direction of the stress and reduce the burden of the calculation.

FE-BEM을 결합한 벽체의 해석모델 개발

정남수,최원,이호재,김한중,이정재,김종옥,Jung , Nam-Su,Choi, Won,Lee, Ho-Jae,Kim , Han-Joong,Lee , Jeong-Jae,Kim, Jong-Ok 한국농공학회 2004 한국농공학회논문집 Vol.46 No.5

Methodologies of the finite element and boundary element are combined to achieve an efficient and accurate analysis model of frame structure containing shear wall. This model analyzes the frame by employing the finite element method and the shear wall by boundary element method. This study is applicable to a specific situation, where the boundary element is surrounded by finite elements. By employing FE dominant method in which boundary stiffness matrix is transformed into finite element stiffness matrix, boundary element and finite element method are combined to analyze frame structure with walls.

불규칙 삼각망과 수정된 진화론적 구조 최적화 기법을 이용한 평면구조의 응력 경로 탐색 모델의 개발

이형진 ( Lee Hyung Jin ),최원 ( Choi Won ),이정재 ( Lee Jeong Jae ) 한국농공학회 2007 한국농공학회논문집 Vol.49 No.6

In designing the structure, the stress path is the basic data. But the stress path is not standardized to analysis the structure. So the one-dimensional frame element structure model with the triangle irregular network is used to solve the problem. And the refined evolutionary structural optimization(RESO) used in structural topology optimization is applied to this study. Through this process, the search method of the stress path is advanced and the burden of the calculation. is reduced.

농가 고령화를 고려한 지역별 벼농사의 지속가능성 평가

이지민 ( Jimin Lee ),최원,이정재 ( Jeong-jae Lee ) 한국농공학회 2019 한국농공학회 학술대회초록집 Vol.2019 No.-

우리나라 경지면적은 지속적으로 감소하고 있으며, 통계청 발표에 의하면 1975년 대비 약 30%의 경지가 줄어들었다. 이러한 경지 감소는 도시화, 농가인구 감소 등 다양한 원인이 있으며, 그 중 하나로 고령화로 인한 농업 포기 농가의 증가를 들 수 있다. 본 연구에서는 벼경작 경영주의 연령자료를 통하여 지역별 벼농사의 지속가능성을 평가하고자 하였다. 2015년과 2010년 벼 경작기를 비교한 결과 98,341ha가 감소한 것으로 나타났으며 경상북도 지역이 가장 크게 감소하였다. 65세이상 경영자 대비 75세이상 경영자 비율을 통해 지역별 벼농사 지속가능성을 평가한 결과 2015년 기준 충청 북도가 가장 취약한 것으로 나타났으며, 2010년과 비교한 경우 강원도가 경영자 취약성비가 가장 많이 증가한 것으로 나타났다. 또한 공간분석을 통해 읍면동지역(2010년 3,197, 2015년 3,244개)중 고령화 집중지역의 분포를 살펴보았다. 이러한 연구 결과는 고령화에 의한 벼농사 포기 위험이 높은 지역을 찾아내고 차별화된 정책 적용에 활용될 수 있을 것이다.

솔라쉐어링 구조물 하부 일사량 시뮬레이션

이상익 ( Sang Ik Lee ),최진용 ( Jin-yong Choi ),이정재 ( Jeong Jae Lee ),최원 ( Won Choi ) 한국농공학회 2016 한국농공학회 학술대회초록집 Vol.2016 No.-

솔라쉐어링이란 농작물재배와 태양광발전을 포함하는 광범위한 에너지자립형 시설로, 식물재배에 필요한 빛은 유지하면서 초과되는 빛은 태양광발전의 에너지원으로 사용하는 상호 공조 시스템을 의미한다. 광포화점을 초과하는 태양에너지는 식물의 수분을 증발시켜 생장을 억제하는데, 솔라쉐어링이 설치된다면 태양광의 직접적은 노출을 제어할 수 있기 때문에 식물의 성장에 도움을 줄 수 있다. 또한 솔라쉐어링 시설은 비가람 시설로도 활용될 수 있는 장점을 가지고 있기 때문에 적절한 재식 간격을 유지한다면 여러모로 작물재배에 유리할 것으로 보인다. 따라서 한국형 솔라쉐어링 구조물 설치 후 솔라쉐어링을 운영하는 형태나 방식에 따른 구조물 하부 일사량을 파악하고, 그 지역에 맞는 적합 작물을 선정하는데 본 연구의 목적이 있다. 솔라쉐어링 시범단지는 충청북도 오창군 논 재배 지역에 17.5m×20.0m로, 가로 및 세로가 2.99m×0.35m인 태양열패널이 설치높이 3.0m, 설치간격 2.0m로 총 50개 소요되었으며, 실험 작물로는 벼를 선택하여 올해 재배하기 시작하였다. 시뮬레이션을 위한 기초자료로는 계절이나 시간 또는 운량에 따른 태양광 에너지를 측정하였고, 이러한 데이터를 분석하여 비선형 상관관계를 도출하였다. 특히, 태양에 너지는 조도계를 이용하여 측정하였으며, 설치 장소는 태양빛이 직접 들어오는 구역, 태양열패널에 의해 그림자가 지는 구역, 태양열패널의 그림자와 그림자 사이 태양광이 들어오는 중간 구역으로 구분하여 진행하였다. 시뮬레이션에서 고려된 인자는 테스트필드의 위치 및 형태, 시간별 태양의 방위각과 고도, 구름의 운량이 고려되었으며, C 언어를 이용한 직접 코딩을 통해 시뮬레이션을 진행하였다. 시뮬레이션에서 도출된 데이터는 향후 테스트필드에서 적합한 작물 선택을 위한 자료로 활용되기 때문에, 다양한 환경조건을 시뮬레이션을 통해 구현해보고, 최종적으로 그 지역에 맞는 적합 작물들을 선정할 예정이다.

기능특성을 고려한 생애주기 비용함수

이준구,김한중,윤성수,최원,이형진,김종옥,정남수,이정재,Lee, Joon-Gu,Kim, Han-Jung,Yoon, Seong-Su,Choi, Won,Lee, Hyung-Jin,Kim, Jong-Ok,Jung, Nam-Su,Lee, Jeong-Jae 한국농공학회 2008 한국농공학회논문집 Vol.50 No.6

An advanced model for assessing life cycle cost of the facility containing several subdivisions has been proposed with systems engineering approach. This model evaluates the maintenance cost in the sphere of the safety as well as in that of its functionality. The proposed approach has been shown to be more reasonable and practical than existing models. The serviceability and reasonability have been proved through evaluating life cycle cost of the reservoir which is a representative agricultural facility. In addition, the proposed method is helpful to make a maintenance strategy using the survival probability in the point of safety and functionality.