• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.349-354
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• 2002

쌀 소비량은 생활 수준 향상과 외식 및 식품 산업의 발달로 감소하고, 고품질 쌀을 요구하는 성향이 높아지고 있다. 현재, 고품질 쌀을 생산할 수 있는 기술과 제반 요건은 구비되어 있으나, 수확 후 건조·저장 중에 쌀의 품질이 저하된다. 특히 건조 중 품질 저하는 고온건조에 의한 동할 발생 및 과건조가 주요 원인이다. 이를 해결하기 위해 원적외선 건조 시스템에 관한 연구가 진행 중이다. 본 연구에서는 방사율이 높고, 접착성 및 내열성 등이 강한 곡물 건조기용 방사체 코팅원료를 개발하고, 이 원료를 원적외선 방사체에 코팅한 후 방사체의 형태와 크기에 따라 표면 온도 분포 및 연료 소비량 등을 측정 분석하여 방사체의 특성과 적정 조건을 규명하고자 하였다. 연구 결과를 요약하면 다음과 같다. (1) 세라믹 코팅 원료의 배합비는 세라믹분말 40%와 결합재 60%가 접착력과 가열경화 후 표면이 양호한 것으로 나타났다. (2) 노즐의 유량 및 분무각에 따른 버너의 화염길이 및 폭은 노즐유량이 증가함에 따라 증가하는 경향을 나타내었다. (3) 방사체 위치별 표면온도편차는 방사체 길이가 1350mm인 것이 작은 것으로 나타났고, 열풍유동관 직경이 Rounding type의 경우 76.3mm, Right angle type의 경우 89.1mm일 때 표면 온도편차가 적었다. (4) 연료소비량은 열 풍유동관 직경이 클수록, 방사체 길이가 길수록 증가하는 경향을 나타내었고, Right angle type이 Rounding type에 비하여 연료소비량이 약간 높은 것으로 나타났다.

• Journal of Power System Engineering
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• v.15 no.5
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• pp.49-53
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• 2011

This study concerns about wireless power generation that uses the energy harvester with EAP actuator. The UWSN(Underwater Wireless Sensor Network) has been considered many times by many researches. Because the information of underwater is getting important to secure the resource or to predict the meteorological phenomena. But the sensor node in the UWSN is driven by the acoustic wave to communicate with other sensor node. And this acoustic wave usually spends a 100 times energy than the RF(Radio Frequency) wave due to transfermation medium(sea water). Therefore the power source of the sensor node is very important that is needed to improve in the UWSN. For this purpose, the energy harvester is made by the acrylic elastomer in this study. And the electrode is modified with an aluminum impurity to improve the efficiency of energy harvester. After that, the modified energy harvester is experimented to confirm the improvement of the energy efficiency.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.6
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• pp.623-628
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• 2010

This paper presents a wind-power-driven portable power source based on piezoelectric effect. Positive piezoelectric effect is one of efficient and widely used mechanisms for converting mechanical energy to electrical energy. However, for this mechanism, a periodic mechanical stress with a high frequency, as in the case of AC, has to be exerted; such stress cannot be exerted by the natural wind in the environment. The natural wind has a constant velocity with slow and irregular variations, as in the case of DC. In this paper, we propose a novel and simple mechanism to convert mechanical energy into electrical energy. The DC-like wind flow is passed through a propeller to convert it to an AC-like wind flow; the resultant AC-like periodic flow induces vibrations in a piezoelectric cantilever, thereby, generating electrical power. This system is expected to be one of practical solutions for wireless energy supply to ubiquitous sensor networks (USNs).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.331-336
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• 2012

This study was carried out to evaluate the wheat cultivation system to reduce costs and mechanize wheat production. A field study was conducted for 2 years (2009 to 2010) at the National institute of crop science, Iksan, Korea. We used working system I and working system II for the experiment. Working system I is used a multiple machine attached with a spreader tractor (seeding, fertilization, seed coverage, and weed control functionality) and working system II is used a multiple machine with a tractor which works for simultaneous job when seeding step (seeding, fertilization, and seed coverage). Sowing to harvesting operation time is 118 hours/ha for mechanize with conventional planting. Working system I is a multiple machine and a combine machine with a tractor, which worked 26 hours/ha lower than conventional planting. Working system II is 18 hours/ha lower than conventional planting. The reduced work efforts of working system I and II were 78% and 85% respectively. The growth and yield of wheat according to working system I and II is lower than conventional planting. Therefore, a multiple machine needs to study for appropriate seeding rate. Mechanization cost in consideration of the mechanical break-even point when the working system I is 3.7 ha and working system II is 4.2 ha. The farm income is enhanced by working system I (778,110 won/ha) and working system II (849,930 won/ha). The results showed that application of a multiple machine lowered costs of wheat production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.550-556
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• 1992

Performance of a rice breeding line, Milyang 95 was evaluated at four cultural methods, direct seeding on dry soil covered by making ridges (DS ridged), direct seeding on dry soil covered by rotortilling (DS rotary), direct seeding on flooded soil (FS), and machine transplanting (MT). Days from seeding to emergence in both DS ridged and DS rotary was 15 days. The number of seedlings at DS ridged and DS rotary was lower than that at FS. Heading was earliest at MT, latest at DS rotary and DS ridged, and that at FS was between them. Days from seeding to heading was 115 days at MT, 94-95 days at DS ridged and DS rotary, and 87 days at FS. Lodging index was similar among the cultural methods and lodging was not occurred in the field although fresh weight of tillers and breaking strength at MT were higher than those of direct seedings. Yield and most of yield components were similar among the cultural methods although the number of spikelets per panicle at MT was higher and 1,000 grain weight at FS was lower compared to other cultural methods. Grain appearance (rusty, chalky abortive rice), protein and amylose contents and alkali digestibility were observed.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.8 no.4
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• pp.21-27
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• 1987

우리나라에서 지금까지 벼에 발생하는 바이러스병으로 알려져 있는 것은 줄무늬잎마름병(縞葉枯病), 오갈병(萎縮病), 검은줄무늬오갈병(黑條萎縮病)의 3종류가 있다. 그 중 가장 근년에 알려진 검은줄무늬오갈병은 1973년 경북 선산지방에서 처음으로 발견되어 1975년 검은줄무늬오갈병으로 확인된 이후 남부지방은 물론 중부지방까지 확산 피해를 주고 있다. 더욱 기계이앙기 보급으로 조식면적이 늘어남에 따라 이모작 지대(二毛作地帶) 일부에서는 피해가 심한 실정이다. 전남 보성군 조성지역은 전남지역에서 대표적인 남부 미맥(米麥) 이모작지대로 알려져 있는데 1984년에는 벼 검은줄무늬오갈병이 지금까지 보기드물 정도로 극심하게 발생되어 일부 포장에서는 벼 수확에 개무(皆無) 상태를 보인 바 있어 이와같은 피해를 다소나마 줄여 보고자 그동안 조사된 시험성적을 중심으로 피해상황과 방제법을 간단히 소개하고자 한다.

• Journal of Sericultural and Entomological Science
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• v.34 no.2
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• pp.71-74
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• 1992

우리나라 양잠의 안정적 성장 발전을 위해서는 생산기반의 재정비 및 호당 양잠 규모의 확대가 필요하다고 하는 것은 누구나 다 아는 사실이다. 따라서 이를 위한 생산체계의 획기적인 탈바꿈의 하나로 애누에 공동육을 함으로써 농가에서 누에의 사육기간을 단축하는 것이 시급히 요청된다고 림은 "잠사업이 국제 경쟁력 제고를 위한 기술적 대응방안"에서 주장한 바가 있었다. 1. 전제조건 1) 애누에 공동육이 꼭 이루어져야 한다. 2) 뽕밭 생산성이 저해 받아서는 안 된다. 3) 성력 기계기구 개발 및 지원이 이루어져야 한다. 4) 가장 중요한 것은 잠작안정이다. 5) 각 잠기별 표준관리된 잠종이 공급되어야 한다. 6) 각 수견 시기에 맞추어 고치공판이 이루어져야한다. 2. 누에 사육시간 선정 1) 뽕나무 생리를 감안한 가지뽕 수확법에 따른 누에 사육기간은 춘잠기는 5월 하순부터 6월 중순까지이고 추잠기는 9월 초순부터 하순까지이다. 2) 병충해 방제관리상으로는 하잠 및 초추잠만이 문제점이 있다. 3) 잠작에 따른 사육기간은 춘잠기는 5월 하순부터 6월 중순까지이며 추잠기는 9월 초순부터 중순까지잠작이 양호하다.(중략)

• Journal of Biosystems Engineering
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• v.35 no.3
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• pp.206-213
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• 2010

The purpose of this study is to analyze musculoskeletal injuries in combine harvesting operation using a digital human model. In order to analyze problems in combine harvesting operation, the operations were broken into 5 work processes and then we preformed ergonomic and biomechanical analyses such as RULA test, Comfort Assessment and joint kinetic analysis for the each process. As a result, there was a clear need to change the combine operating environment, as the RULA score ranged from 4 to 7. In addition, we could find two major musculoskeletal injury factors which are the standing posture with upperbody forward tilting and inappropriate location of operating levers.

• Journal of Biosystems Engineering
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• v.14 no.2
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• pp.104-114
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• 1989

The most important subject in developing agricultural robots for fruit harvesting is to detect accurately the location of a fruit about the given coordinate system. This study was carried out to develop an image processing algorithm which enables finding out the three dimensional locations of a fruit. The digital image processing device consisted of an optosensor (Closed-circuit TV camera), image processing interface board (Digitizer) and microcomputer (IBM PC/AT). A stereo-image processing method using the two cameras attached to the manipulator was evaluated through experiment with apples. The accuracy and quickness of detecting the location of apples by this method was not satisfactory. The maximum errors of the detected locations by the stereo-image processing method in x-, Y-, and z- directions were 3, 4 and 4 cm, respectively. The maximum time required to get the rectangular coordinate data of a fruit was about 2 minutes.

• Journal of Biosystems Engineering
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• v.18 no.2
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• pp.110-121
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• 1993

Pepper has been the second important income source of Korean farmer. Provided the agricultural market in Korea is opened, pepper of which price is more than three times of the world market price can not survive with current cultivation practice. Pepper harvesters have been developed in some countries but, they are not feasible in Korea due to difference of varieties, cultivation practice and climate between Korea and other countries. This is a fundamental study to develop a pepper harvester suitable to the current situation in Korea. Physical properties of a pepper plant and its fruit were investigated. Also, a pair of open helices was selected as a pepper removing mechanism and tested to determine the best operating conditions. This study revealed that a pepper harvester with more than 90% of pepper recovery is attainable. Best rotating speed of open helices with 30cm diameter and conveying velocity of pepper main stem were determined to be 180 rpm and 0.1 m/s respectively.