• 제목/요약/키워드: Farm-scale

검색결과 421건 처리시간 0.024초

Refined numerical simulation in wind resource assessment

  • Cheng, Xue-Ling;Li, Jun;Hu, Fei;Xu, Jingjing;Zhu, Rong
    • Wind and Structures
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    • 제20권1호
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    • pp.59-74
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    • 2015
  • A coupled model system for Wind Resource Assessment (WRA) was studied. Using a mesoscale meteorological model, the Weather Research and Forecasting (WRF) model, global-scale data were downscaled to the inner nested grid scale (typically a few kilometers), and then through the coupling Computational Fluid Dynamics (CFD) mode, FLUENT. High-resolution results (50 m in the horizontal direction; 10 m in the vertical direction below 150 m) of the wind speed distribution data and ultimately refined wind farm information, were obtained. The refined WRF/FLUENT system was then applied to assess the wind resource over complex terrain in the northern Poyang Lake region. The results showed that the approach is viable for the assessment of wind energy.

소규모영농에 적합한 가축분뇨액비살비살포기 개발 (Development of Animal Liquid Manure Field Spreader Suited to Small Scale Crop Production Farms)

  • 최광재;오권영;유병기;이성현
    • 한국축산시설환경학회지
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    • 제12권3호
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    • pp.151-160
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    • 2006
  • For even distribution of liquid manure in the field, a boom nozzle type spreader was designed and studied to determined its suitability for small scale crop production farms. Boom nozzle type spreader was compared in the impact triple nozzle and impact single nozzle type spreader. Spreading uniformity of the boom nozzle type liquid manure spreader showed 5.2% (C.V.) and impact single nozzle type spreader showed 6.9% (C.V.). The spreading uniformity of the impact triple nozzle type spreader was quite uneven, therefore, the spreader could be modified as twin nozzle for spreading in orchard farm. The wheel axle height adjustable type liquid manure spreader has higher the stability and it considered much useful on the hilly agricultural land.

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축산시설에서 발생되는 악취의 축종별 특성에 대한 설문조사 (An Investigation on the Odor Characteristics of Livestock Facilities)

  • 장영기;송기봉;김호정;유용희
    • 환경영향평가
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    • 제13권1호
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    • pp.33-40
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    • 2004
  • At Recent the number of livestock is rapidly increased and the scale of farm has changed to large operations in Korea. So the odors from livestock feeding operations have increased and become major environmental problem. The odor emission are dependent on the types of manure management system and the meteorological factors. This report presents the results of a questionnaire on the odor characteristics from livestock facilities for the beef, dairy, swine and poultry. It is founded that the impact by odors from the facilities for swine and poultry is higher than cow and dairy, and the odor intensity at morning is higher than other times.

지속가능한 농업 인식도 및 수용의향 분석 (An Analysis of the Factors Affecting Farmers' Recognition and Acceptance on Sustainable Agriculture)

  • 김창길;정학균;문동현;한재환
    • 한국유기농업학회지
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    • 제23권2호
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    • pp.247-265
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    • 2015
  • This study analyzes the factors affecting farmers' recognition and acceptance of sustainable agriculture. To accomplish the objectives of the study a farm survey was conducted using target respondents which were made of the local correspondents and reporters of Korea Rural Economic Institute. The Heckman's model was employed for an empirical analysis on determining the extent of farmers' acceptance of sustainable agriculture. The analysis results show that the more farmers think it is important for Korea to adopt sustainable farming practices, the more they adopt sustainable agriculture. It is also shown that the high incomes farmers earn, the more interest they have in the environment and thus the more likely they are to adopt sustainable agriculture. Based upon the empirical results it is suggested that an adoption of economic incentive instruments, education of sustainable agriculture, research and development of sustainable agriculture technology, and an establishment of sustainable agriculture infrastructure to expand the scale of sustainable agriculture.

근년의 한국 양계 전개 양상 (Recent Developments of Poultry Industry in Korea)

  • 김선중
    • 한국가금학회지
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    • 제26권2호
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    • pp.73-79
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    • 1999
  • The poultry industry in Korean has expanded considerably during the last 15 years. While the number of chicken farms of commercial scale has decreased steadily during the period average farm size increased rapidly. Though the gross national product per capita increased 4.5 folds during ten years period, consumption of chicken meat, like other meats, recorded only 2 folds increase during the period. When domestic market for chicken meat had been open for two years on the basis of minimum market access quotas, importation remained at levels below the quota during the first one and half years. Nevertheless, during the last six months and thereafter, chicken meat importation recorded a steep increase, threatening the domestic industry. Poor productivities of the commercial chicken farms might be the main cause for the inferior competitiveness. For the sustainability of the industry some suggestions were made.

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대규모 풍력 발전단지 계통 연계 시 영향 평가 절차 연구 (Study on impact assessment procedures for Large Scale Wind Farm)

  • 전영수;최영도;전동훈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 제40회 하계학술대회
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    • pp.268_269
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    • 2009
  • 세계 각국의 풍력 발전기의 계통연계 운영 경험에 비해 아직까지 우리나라의 풍력 발전 단지에 대한 운영 경험은 매우 제한적이며, 연계 기준 수립에 대한 기초가 부족한 실정이다. 따라서 국내 계통의 특성을 고려한 연계 기준 및 최적 운영 방안의 수립을 위해서는 다양한 국가에서 적용하고 있는 풍력 발전 단지에 대한 연계 및 운영 기준에 대한 검토 및 계통 영향 평가에 대한 절차가 필요한 실정이다. 이에 본 논문은 계통운영자가 풍력발전기를 계통 연계하기 전 그 영향을 충분히 평가하여 허가 여부를 결정하거나 필요한 제어 요건을 갖출 수 있도록 풍력 발전기의 계통 연계 시 그 영향을 평가하는 절차에 대해 제안을 하였으며, 이 과정을 제주 계통 풍력발전 연계 모의 적용하였다.

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위성 관측 자료를 이용한 서해 해상 풍력자원 평가 (The Estimaion of Wind Energy Resources through out the QuikSCAT Data)

  • 장재경;유병민;유기완;이준신
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.486-490
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    • 2009
  • In order to investigate the offshore wind resources, the "QuikSCAT Level 3" data by the QuikSCAT satellite was analyzed from Jan 2000 to Dec 2008. QuikSCAT satellite is a specialized device for a microwave scatterometer that measures near-surface wind speed and direction under all weather and cloud conditions. Wind speed measured at 10 m above from the sea surface as extrapolated to the hub height by using the power law model. It has been found that the high wind energy prevailing in the south sea and the east sea of the Korean peninsula. From the limitation of seawater depth for piling the tower and archipelagic environment around the south sea, the west and the south-west sea are favorable to construct the large scale wind farm. Wind map and monthly variation of wind speed are investigate at the positions.

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$\cdot$재생에너지 원별 경제성 분석 - 태양광, 풍력, 소수력 발전을 중심으로 - (Analysis of Economic Feasibility of New & Renewable Energies)

  • 김진오;김정완;부경진
    • 신재생에너지
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    • 제1권1호
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    • pp.79-86
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    • 2005
  • This study conducted an analysis of economic feasibility with unit generating costs calculated based on scenarios of capacity factors, discount rates, government supporting rates, installation costs. However, It Is clear that few new and renewable energies can meet the tariffs [government purchasing prices] set by the government in light of the current market reality. Without the government support, solar PV is not economically feasible at the tariff of \716.40/kWh. in the case of wind Power, the current tariff of \107.66/kWh is not enough to make it competitive except for a mid- and large-scale wind farm The analysis showed that even small hydro is not economically acceptable at the current tariff of \73.69/kWh.

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유전자 알고리즘을 이용한 경지 구획 결정 지원 시스템 개발에 관한 연구 (A Study of Development of land use design system using GA for Agricultural area)

  • 정연철;윤성수;이정재
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2001년도 학술발표회 발표논문집
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    • pp.228-235
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    • 2001
  • For standard size of farmland in Korea is small, we have to consume huge labor for cultivation and efficiency of machine is low. We practice the project, which make size of farmland enlarge. For many factors have to consider in design process in case of large-scale farmland, there are difficulties for comparing alternatives if we design it manually. So we need to techniques for establishing various alternatives and choosing the optimum design by the computer. In this study, fixing the boundary of project using the RGIS (Rural Geographical Information System) which standard electronic map in Korea. In the boundary, we analysis the many characteristics of farm land, optimize the adjustment process of field unit of farmland. In this process, we develop automatic farmland division techniques. The results of adapting the developed system show the usefulness to enlarge the size of farmland about 200%.

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대단위 풍력발전단지에 의한 제주도의 과도안정도 특성에 관한 연구 (Effect of a large-scale wind farm on power system transient stability in Jeju-do)

  • 윤동희;김철우;장길수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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    • pp.332-334
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    • 2006
  • 전세계적으로 풍력발전은 많은 분산전원 가운데 가장 각광을 받고 있는 발전방식이다. 이미 많은 나라에서 풍력발전단지의 건설이 이루어졌으며 우리나라의 경우 제주 행원, 경북 영덕에 풍력발전단지가 건설되어있다. 제주도의 경우 관광특구라는 특수성에 기인하여 친환경적인 풍력발전단지의 건설이 앞으로 계속 이어질 전망이다. 이러한 풍력발전단지는 기존의 발전원과 달리 간헐적인 출력특성을 가지고 있으며, 이러한 출력특성은 계통에 영향을 미치게 된다. 본 논문은 제주도 계통에서 대규모의 풍력발전단지가 주는 영향을 파악하고 풍력발전단지의 적정 용량 및 위치를 계통의 안정도 측면에서 고려해본다.

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