• Title/Summary/Keyword: 경작력

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A Study on the Mechanical States of Machined Surface by Considering Cutting Edge (절삭날을 고려한 절삭가공면의 기계적 성질에 관한 연구)

  • Kim, Joo-Hyun;Woo, Hee-Sun;Chang, Yoon-Sang
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.7
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    • pp.188-195
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    • 1999
  • Cutting edge plays an important role in generating machined surface. In order to consider the geometric effects of the cutting edge on mechanical states, the concept of ploughing force and stagnation point was introduced which explains the generating mechanism of machined surface during cutting. The effects of edge radius and nose radius of cutting tool on the distribution of residual stresses of the machined surface having several hardness were studied. Good machined surface having high compressive residual surface stresses can be achieved if cutting tools having large edge radius and small nose radius are used for cutting work materials having high hardness with high depth of cut. The magnitude of edge radius and the hardness of work material also affected the shape of the chip in orthogonal cutting.

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A Study on the Fallow of Depopulation Area in Rural Korea - The Case Study of Deoggali, Sangju Gun - (과소농촌지역(過疎農村地域)의 휴경요인(休耕要因)과 유형(類型) - 경북 상주시 사벌면 덕기리의 사례연구 -)

  • Lee, Han-Bang
    • Journal of the Korean association of regional geographers
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    • v.7 no.3
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    • pp.74-90
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    • 2001
  • Serious depopulation has occurred since the rapid economic growth after $1965{\sim}1995$. As a result, nowadays most of mountain villages face difficulty in maintaining and managing their settlement, because of the elderly population and the extremely small size of the settlement. Population change is understood as the origin of depopulation problems and the criterion for the depopulation. This study aims to identify the problems of over-depopulation in rural Korea and to classify the patterns and process of follow and to provide policy alternatives. It consists with the three parts : identifying the problems of over- depopulation, classifying the socio-economic factors of fallow land, analyzing a detailed case study of follow land in over-depopulation rural area-Sangju Gun and to provide policy alternatives. The results are summarizes as follows: 1) In the study area, the amount of fallow and abandoned cultivated land has increased since 1975. With the increased urbanization, the cause of the increase in fallow and abandoned cultivated-land is the labor shortage of quantity and quality. The underlying reasons for the abandonment of farmland are poor field conditions and the lack of rented farmland. 2) The secondary cause is a relative labor shortage through specialization into intensive horticulture. In the study area, specialization into pear requires intensive labor input. It has caused a relative labor shortage. 3) The third causes are landowner and the lack of rented farmland due to labor shortage. The declining of agriculture and forestry have caused out-migration and increased non-residents' landowner. 4) The fallow patterns are devided into two types the less favored farmland fallow type, non-residents' landowner(out-migrator) fallow type. The significant causes of the increase in fallow and abandoned cultivated land are the labor shortage, intensive farming, less favored farmland conditions, non-residents' landowner. The factors which caused the follow processes in Korea are socio-economic factors (labor shortage, intensive farming, less favored farmland conditions) and cultural factor(non-residents' landowner, psychological ties between rural areas and urban areas).

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Trend and direction for plant factory system (식물공장 시스템의 동향과 발전방향)

  • Kim, Jae-Whune
    • Journal of Plant Biotechnology
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    • v.37 no.4
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    • pp.442-455
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    • 2010
  • Plant factory is the fruit of the most advanced modern agricultural technology. This is a crop-producing technology that controls systematically sowing, cultivating, and harvesting crops within an indoor factory. Growing crops in a factory has advantages over traditional farming because it produces safer crops all year around due to clean environment and it is easier to hire workers at the factory. Developed countries has invested actively in this field for several decades because its economical and industrial impact are predicted to be enormous. Recently, Korea also begins to investigate this field actively to develop a system that may be competitive at global market, using technologies and human resources that Korea already has. The plant factory technology is currently less competitive than traditional farming because it requires a large initial investment and management cost and lacks cultivation technologies for various crops. However, I believe in solving these problems if plant biotechnologists participate in developing the plant factory system. If this technology is developed well in Korea, then it will play a great role in solving food and environmental issues.

Survey on Pest Management Practice and Scheme of Increasing Income in Sweet Persimmon Farms in Korea (단감원의 병해충 관리 실태와 소득 증대 방안에 대한 농가 의식조사)

  • Lee, Dong-Woon;Lee, Seong-Wook;Park, Chung-Gyoo;Choo, Ho-Yul;Shin, Chang-Hoon;Lee, Gyoo-Chul
    • The Korean Journal of Pesticide Science
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    • v.5 no.4
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    • pp.45-49
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    • 2001
  • As a series of studies to develop pest management system for sweet persimmon production matched with the quarantine criterion of sweet persimmon-imported county, a survey was conducted by questionnaire on pest management practice and scheme of increasing income in sweet persimmon farms in Korea. Above 80% of sweet persimmon farmers was over fifties in age. The greatest limiting factor for sweet persimmon production was thought to be disease by the farmers. Percentage of farmers who answered that the most important pest is anthracnose cause by Gloeosporium kaki, and stink bugs was 64.6% and 73.5%, respectively. In particular, the farmers did not consider Dichocrocis punctiferalis, a main targer insect for quarantine in USA, as serious problem. Obtaining information on pest management practice or decision-making on both selection of pesticide and time of pesticide application depended highly on their own experience with the highest proportion. Eight to nine times of pesticide applications a year was highest among farms with 56.6%. More than 80% of farmers recorded the diary of pesticide application. farmers considered increasing cost for pest management as the greatest problem with 35.4% in proportion, and 34.5% of farmers pointed out that increase in export is essential for increasing farm income with highest proportion.

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The Detection and a Quantitative Evaluation of Entomopathogenic Nematodes in Cultivated Rhizosphere Soil (경작지 근권 토양내 곤충병원성 선충의 검출 및 정량적 평가)

  • 황경숙;한상미;김윤지;남필원;한송이
    • Korean Journal of Environmental Biology
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    • v.21 no.3
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    • pp.271-275
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    • 2003
  • The direct count and MPN (Most Probable Number) methods were used to measure the number of nematodes in soils collected from cultivated and non-cultivated fields. As a result, the number of nematodes from cultivated soils was higher than the non-cultivated soils (NC -1, NC -2). On the other hand, upon measuring the value from the organo farming cultivated soils (OC, OR) and conventional cultivated soils (CC, CR), the former showed 16 times higher than the latter. These results indicate that nematode population which can multiply in the organic compounds abundantly exist in the organo farming cultivated soil. Isolated entomopathogenie nematodes are composed of two orders, which were Rhabditida and Diplogasterida. To determine the pathogene-city of them using the 5th larvae and pupae silkworm, and the following mean $LD_{90}$ values were found: 24 to 30 hours in Rhabditida and 36 to 48 hours in Diplogasterida nematode, respectively. This study indicates that nematodes are sensitive to this kind of environmental disturbance. Isolated entomopathogenic nematodes were suggested that aye quite within the realms of possibility for biological control agents.

A Study on the Development of Jeonbuk-Ginseng (전북인삼 명품화 방안 연구 - 진안인삼산업 중심으로 -)

  • Yoo, Byoung-Wan;Lm, Byung-Ok
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2011.10a
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    • pp.3-3
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    • 2011
  • 국내 주요 인삼재배 산지 기반을 가진 전북 진안지역의 인삼 홍삼산업은, 재배농가 895호, 재배면적 402ha, 생산량 1,628톤, 홍삼가공업체 80개소, 판매업소 50개소로 지역경제의 25% 이상을 차지한다. 그러나 재배농가의 계열화 미흡(22%), 산지수집상(포전매매)에 의한 인근 유사 도매시장으로 재배물량과 부가가치 유출(78%), 가공시설의 노후화, 가공업체의 영세성(매출규모 연평균 2억11백만원)과 함께 중국, 캐나다, 미국 등의 국제 가격경쟁과 국내의 대기업 및 인삼산업 주요지역과의 경쟁이라는 상황에 직면하고 있다. 이러한 상황을 극복하고 지역특화명품산업으로 발전할 수 있는 방안으로, 인삼재배산지로서 원료공급지를 기반으로 하는 재배, 유통, 가공, 품질관리, 시설분야에 이르는 발전방안을 연구하였다. 산업원료 확보를 위해서는 인삼계열화 확대를 통해 원물 확보력을 강화하여야 한다. 재배분야의 경우에는 친환경재배 확대와 GAP 확대를 통해 원물의 품질경쟁력 뿐만 아니라 시장수요에 따른 브랜드마케팅 요인으로 특성화해야 한다. 유통분야는 계열화 확대를 통한 원물확보라는 산업경쟁력을 바탕으로 원료중심의 수취, 매취, 보관, 가공, 대형거래, 도소매 등 유통활성화와 유통규격포장 및 선별등급표준화를 통한 유통표준화를 추진하여야 한다. 가공의 경우, 원료홍삼 공급기능을 중심으로 가공산업을 선택 육성해야한다. 품질관리는 원물중심관리(성분, 잔류농약, 식품위생), 유통중심관리(연근, 등급), 경작중심관리(재배지, 재배자, 경작), 프로세스중심관리(재배 유통 가공 판매정보)로 구체화해야한다. 시설분야는 유통시설(대규모 집하시설, 보관시설 등 종합유통처리시설)과 가공시설(가공설비현대화, 가공공장 공인규격화;ISO, GMP, HACCP)의 지속적인 시설개선과 현대화를 추진하여야 한다.

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The Effects of Tire Inflation Pressure on Soil Compaction and Tractive Performance of Tractor (타이어공기압에 따른 트랙터의 견인성능과 토양다짐)

  • 박원엽;이규승;오만수
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2002.02a
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    • pp.15-22
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    • 2002
  • 본 연구에서는 타이어의 공기압이 농용트랙터의 견인성능과 토양다짐에 미치는 효과를 실험적으로 조사하였으며, 다음과 같은 결과를 얻었다. 1) 타이어공기압에 따른 트랙터의 견인성능 실험 결과, 공기압의 감소는 트랙터의 운동저항은 감소시키고, 견인력과 견인효율은 증대시키는 것으로 나타났다. 따라서 연약지에서 운용되는 트랙터는 공기압의 조절을 통해(최소 허용 공기압까지 타이어공기압의 감소를 통해) 견인성능과 작업성능을 향상시킬 수 있을 것으로 판단된다. 2) 트랙터의 타이어공기압과 통과횟수의 증가는 모두 토양다짐을 증가시키는 것으로 나타났다. 따라서 토양다짐을 줄이기 위해서는 트랙터가 통과한 궤적상을 연속해서 통과할 수 있도록 작업 계획을 세우면 전체 경작 면적에 대한 토양 다짐을 줄일 수 있을 것으로 판단된다. 또한 타이어의 공기압을 최소 허용 공기압 수준까지 감소시킬 경우 토양다짐을 최소화할 수 있을 것으로 판단된다. 3) 위의 결과로부터 트랙터의 작업성능의 향상과 토양다짐의 최소화는 타이어공기압의 조절을 통해 어느 정도 이를 수 있는 것으로 판단된다. 따라서 이러한 목적을 달성하기 위해서는 운전석에 설치된 제어판을 통해 지면의 상태에 따라 타이어의 공기압을 운전자가 쉽게 조절할 수 있는 최첨단 기술인 CTI시스템을 농용트랙터에 적용하는 연구가 필요한 것으로 판단된다.

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Ecological Characteristics of Vascular Plants by Habitat Types of Dry Field in Jeolla-do, Korea (전라도 밭경작지의 서식처 유형별 식물상 특성)

  • Cho, Kwang-Jin;Kim, Myung-Hyun;Kim, Min-Kyeong;Na, Young-Eun;Oh, Young-Ju;Choe, Lak-Jung
    • Korean Journal of Environmental Agriculture
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    • v.33 no.2
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    • pp.86-102
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    • 2014
  • BACKGROUND: According to the types of human interference, there are various plants that have strong vitality and ability to breed in the dry field. Recently, climate change alters the geographical distribution and phenology of the plant species. So, we need to understand present occurrence pattern and ecological characteristics of these plants. METHODS AND RESULTS: The plant species data were obtained from 8 regions in Jeolla-do. Flora investigation was done from May 2013 to September 2013. Habitat type of dry field in Jeolla-do was classified into 3 types (inside of dry field: IDF, embankment around the end of a dry field: EDF, levee slope of dry field: LS). The vascular plants of study area were listed 296 taxa which contain 68 families, 203 genera, 244 species, 43 varieties and 9 forms. The vascular plants of three different habitat types were IDF 174 taxa, EDF 249 taxa and LS 136 taxa. The occurrence rate of Therophyte was arranged by the order of IDF(67.6%), EDF(51.9%), LS(54.3%). Naturalized rate was analysed as IDF 27.9%, EDF 21.0%, LS 18.6%. Urbanization index was analysed as IDF 11.8%, EDF 13.7%, LS 10.0%. CONCLUSION: With these results, we found that three habitat types were ecological difference affected by the human impacts. Also, we found environmental indicators through the ecological characteristics of flora for the type of habitat of dry field. These indicators will help assess the agriculture environmental variability and the floral change according to the climate change in dry field.

The Effect of Working Angle of Non-power Disc Harrow on Traction (무동력 디스크 해로우의 작업각도가 견인력에 미치는 영향)

  • Jung, Ho Jun;Kim, Seong Sik;Jo, Jae Min;Kang, Dae Sik;Kim, Hyeon Tae
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2017.04a
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    • pp.72-72
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    • 2017
  • 국내 농업에서 토양의 반전, 쇄토, 배토, 가능한 복합작업기인 무동력 디스크해로우 방식의 경운과 배토 고효율 복합작업기의 수요가 증가 하고 있다. 경운작업에서 일련의 과정은 작물의 생육과 관리차원에서 큰 의미를 지니며 작물재배의 첫 단계로 중요시 다루어져야할 과정이다. 이러한 작업기의 성능 시험에서 포장시험을 통해 복합기의 신뢰도와 실제 필드에서 발생하는 문제들을 포괄적으로 해결 할 수 있는 방안이 필요하다. 토양 경작을 위한 농업기기의 작업 저항은 식물 생산에서 유용성을 평가하는 가장 중요한 지표중 하나이다. 작업 저항(수평, 수직 방향의 힘)은 트랙터의 힘에 의해 생성된 동작을 방해하므로 토양 경운 시 에너지 소비를 결정하고 설계 매개 변수 측면에서 최적의 작업 조건을 결정하는 데 중요한 영향을 미친다. 따라서 본 연구에서는 경상대학교 내 위치한 실험동에서 Soil-bin에 이송장치를 설치한 후, 이송장치에 디스크 해로우 (Multidisc Vario, Tulip Agri., Netherlands)를 부착하여 실험을 진행하였다. 디스크 해로우의 원주 평면과 수직 평면 사이의 각 a(토양 표면에 수직)와 디스크의 해로우의 원주 평면과 작업 방향 사이의 각 b의 값을 독립 변수로 두고 a, b를 변화 시키면서 발생하는 이송장치의 견인력을 측정하여 농가 및 효율적인 경운작업 시 기초자료로 활용하고자 한다.

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