• Journal of Biosystems Engineering
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• 제5권2호
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• pp.58-66
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• 1980

A survey was conducted to investigate the power tiller accidents. Eight provinces were covered for this study, and 278 power tiller owners were selected randomly by computer random generator. The results are summarized as follows : A. Frequency of accident. (1) Each power tiller had an accident 0.98 times a year and once every 361 hours of use. Higher frequency of accident was found during the miscellaneous operations including the preparation for farming operation, and there was one accident for every 92 hours of use. (2) The power tiller, which are more than six years old, met an accident 1.19 times a year , or one every 311 hours of use. This value was the highest one compared with any other group. (3) Kerosene engine power tillers met an accident 0.97 times a year, or one every 389 hours of use. It was one tie a year, or once every 329 hours of use for diesel engine power tillers. (4) Among diesel-engine power tillers, 10 horse-power group showed a higher frequency tillers. B. Cause of accident (1) The accidents of power tiller were mainly of sefety , which occurred due to the lack of attention during the operation and 47.4% of the total accidents. The next was of accidental, which represented 26.3% of the total accidents. (2) High percentage of safety accidents occurred during the preparation for farming operation including adjustment. Most of the accidental accidents occurred during the transportation. (3) Lower frequency of accident was found in the power tiller group which were operated by the 21-40 years old operator in comparison with that of the power tiller which was operated by other age group. Power tillers which were operated by high school graduates experienced less accidents compared to other education levels. C. Damage by accident (1) Eighty seven pescents of the total accidents caused damage to the power tiller operator , and 13 % of the total accidents caused property damage only. (2) With regard to the damage to the power tiller operator, 73.8% of the total accidents caused light injury but 26.3% caused heavy injury. (3) Accidents which occurred during machine preparation , and farming operations caused minor injury to the operator, but the accidents during transportation caused heavy injury which cost more than 15 days for recovery. (4) Among the 39 accidents , which caused property damage 18 accidents were from the transportation . Among the total property damage accidents 53.8% were light one which cost only less than 1,000 won. (5) The property damage from each accident cost 1,017 won, on the average, with regard to the kinds of operation, the highest property damage occurred during transportation work, with the value of 2, 965won.

• Journal of Biosystems Engineering
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• 제12권2호
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• pp.1-15
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• 1987

A mathematical model is developed and computer programmed for simulation of power tiller motion. The model consists of a main body and two driving wheels resulting in an 8 degrees of freedom system. Drawbar loading is also included by coupling the model with a sub-model representing the implement to be used. The computer program SIMPTL can predict motion characteristics and static stability of power tiller under a given set of ground and operation conditions.

• Journal of Biosystems Engineering
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• 제17권1호
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• pp.27-36
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• 1992

Computer simulation was carried out to predict the motion and overturns of power tiller-trailer system this system when traveing over an obstacle on inclined planes. To estimate the effects of design factors (mass center of main body and wheel base), ground factors (ground inclination and height of obstacle), and operation factors (traveling velocity) on the sideways overturn, the motion of power tiller-trailer system was simulated as the factors were varied with five different levels.

• Journal of Biosystems Engineering
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• 제11권1호
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• pp.1-7
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• 1986

An 8-degree of freedom mathematical model for the motion of power tiller was developed. The model was designed to predict the motion characteristics under the given field and operating conditions. The simulation model devleoped in this study can be used to characterize the behavior of power tiller and to find ways for potential improvement of power tiller design from the viewpoint of stability increment.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.291-296
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• 1993

Taking a bledes axle of rotary tiller as a example, this paper discusses influences of four loading essential factors, which are strengthened amplitude, cycle times, loading sequence and loading frequency. in fatigue life. Determination principles of above four factors and monitoring methods of fatigue damage by local strain are dealt with. The actual field testing check of farm machinery is rapidly simulated by laboratory program fatigue test can shorten the period of development and improvement of a product. In the time of in-door simulation test, damage monitoring and four loading essential factors, which are strengthened amplitude , cycle times, loading sequence and loading frequency, have to be dealt with . If these problems are solved successfully, it is possible to accelerated test speed, reduce costs and manhours, and raise accuracy of test result. However strengthening method, loading pattern and influence of loading frequency on test result have not so far been discu sed systematically, damage monitoring is even more a difficult problem. Authors have studied above problems with the object of blades axle of rotary tiller.

• 한국산업융합학회 논문집
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• 제23권4_2호
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• pp.661-667
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• 2020

The optimal shape modeling of core parts through 3D modeling and structural analysis for the development of small and medium-sized ships. The goal is to improve the efficient structure of the hydraulic system for controlling the rudder among the core steering parts in small and medium-sized ships. Through 3D modeling and structural analysis, a new concept of tiller parts and a double-acting hydraulic cylinder control system were proposed and operational structural stability was evaluated. Structural analysis of the three different tiller designs that can be replaceable onto existing fishing vessels was conducted to derive the final shapes. The emphasis was placed on evaluating the structural stability of the key drive components, the tiller, pin, and cylinder rodin the maximum torque condition of the hydraulic cylinder.

• 한국초지조사료학회지
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• 제11권2호
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• pp.90-96
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• 1991

This experiment was carried out in order to estimate the recovery days of root and stubble to the days after cutting, and contribution of specific stubble weight on the regrowth was examined using the relationships between the dry weight of shoot and yield components, and regrowth parameters by the days after cutting. The varieties examined were Maprima, Manhattan, Tove, Peramo, Caliente, Tempo and P-2 grown under individual plant basis. The results are may be summarized as follows: 1. Dry weight of root and stubble were recovered up to 13.5 and 11 days after cutting, respectively. 2. Dry weight of shoot(regrowth parts+stubble) was affected significantly by the varieties, stages of regrowth and variety x stage of regrowth. 3. The variety with tiller weight type showed higher average productivity of shoot than those of the variety with tiller number type. 4. Absolute growth rate(AGR) of shoot was correlated significantly with regrowth parts, stubble, root and weight of a tiller at the early stage of regrowth(up to 12 days after cutting), and correlated with regrowth parts, stubble, weight of tiller and stubble area at the late stage of regrowth(up to 20 days after cutting). 5. Contribution of specific stubble weight to absolute growth rate of shoot was different between the stages of regrowth. Thus, regrowth parts per specific stubble weight(RP1SSbW) and weight of tiller per specific stubble weight(WT1SSbW) contributed to absolute growth rate of shoot at the early stage of regrowth, and efficiency of specific stubble weight(ESSbW), regrowth parts per specific stubble weight (RPISSbW) and weight of a tiller per specific stubble weight(WT1SSbW) contributed to absolute growth rate of shoot at the late stage of regrowth. 6. Regrowth utilization rate(RUR) was one of the useful regrowth parameter to indicate the regrowth potential of grasses.

• Current Research on Agriculture and Life Sciences
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• 제7권
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• pp.1-10
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• 1989

수도(水稻) 주요(主要) 품종(品種)들의 분설상태(分薛狀態)에 따른 수도(水稻)의 생육변이(生育變異)와 수량구성요소(收量構成要素)의 변이양상(變異樣相)을 검토(檢討)하고 품종간(品種稈)의 반응(反應)을 비교(比較)하기 위해서 통일형(統一型) 품종(品種)인 삼강(三剛)벼와 칠성(七星)벼와 일본형(日本型) 품종(品種)인 낙동(洛東)벼와 팔공(八公)벼를 공시(供試)하여 pot당(當) 분설경수(分薛莖數)를 분설(分薛)되는 순서(順序)에 따라 1, 4, 7, 10 그리고 13개(個)씩 확보(確保)한 후(后) 출수후(出穗后) 20일(日)까지 과다분설경(過多分薛莖)을 인위적(人爲的)으로 제거(除去)하여 재배(裁培)한 후(后) 수량(收量) 및 수량구성요소(收量構成要素)를 조사(調査)하였던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 분설경수(分薛莖數)가 증가(增加)함에 따라 주당수량(株當收量)은 감소(減少)되었으나 총수량(總收量)은 증가(增加)되었고 수량구성요소(收量構成要素)인 등숙율(登熟率), 천립중(千粒重)은 수수(穗數)가 10개(個)일때 가장 높게 나타났으며 13개(個)일때는 품종(品種)에 상관(相關)없이 감소(減少)하는 경향(傾向)이었으며 분설경수(分薛莖數)가 증가(增加)함에 따라 간장(稈長)은 낙동(洛東)벼, 칠성(七星)벼, 삼강(三剛)벼는 증가(增加)하였으나 팔공(八公)벼는 간장(稈長)의 변이(變異)에는 차이(差異)를 나타내지 않았다. 그러나 분설경수(分薛莖數)에 따른 지엽(止葉)의 길이는 분설경수(分薛莖數)가 1개(個)일때 지엽(止葉)의 길이가 짧아졌다. 분설경수(分薛莖數)가 l개(個)일때에는 여러개(個)에 비(比)해 출수기(出數期)가 지연(遲延)되는 현상(現像)을 나타내었지만 분설경수(分薛莖數)가 4개이상(個以上)일때는 출수기(出穗期)의 차이(差異)를 뚜렷하게 볼 수가 없었다. 한편 출수소요기간(出穗所要期間)은 품종간(品種間)의 차이(差異)는 뚜렷하였지만 분설경수(分薛莖數)에 의(依)한 변이(變異)를 나타내지 않았다. 수확지수(收穫指數)는 품종간(品種間)에 통일형(統一型) 품종(品種)인 칠성(七星)벼와 삼강(三剛)벼가 일본형(日本型) 품종(品種)인 팔공(八公)벼와 낙동(洛東)벼 보다 높았고, 분설경수(分薛莖數)가 증가(增加)함에 따라 수확지수(收穫指數)도 증가(增加)하는 경향(傾向)이었다. 경쟁반응지수(競爭反應指數)와 등숙율(登熟率)과 수확지수간(收穫指數間)에는 높은 상관(相關)을 나타내었으며 경쟁지수(競爭指數)와 수장(穗長)과 수량간(收量間)에는 부(負)의 상관(相關)을 나타내었다.

• 한국초지조사료학회지
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• 제4권1호
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• pp.13-17
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• 1983

영양생장기(營養生長期)의 형태적(形態的)과 건물수량(乾物收量)과의 관계(關係)를 조사(調査)하여 수량(收量)에 관여(關與)되는 형태적(形態的) 형질(形質)과 품종(品種)의 특성(特性)을 비교(比較), 검토(檢討)하였다. 1. 개체중(건물중(乾物重))은 초장(草長), 엽면적(葉面積) 및 경면적(莖面積)과 유의(有意)한 정상관(正相關)을 나타내어, 개체중의 증가(增加)는 초장(草長), 엽면적(葉面積), 경면적(莖面積)의 상호작용(相互作用)이라고 할 수 있다. 2. 경면적(莖面積)은 건물중(乾物重)을 증가(增加)시키는 중요(重要)한 형태적(形態的) 형질(形質)의 하나라고 생각되었다. 3. 초형지수(草型指數)에 의하여 품종(品種)을 분류(分類)한 결과(結果), 경중형(莖重型)에는 M이 중간형(中間型)에는 Leto, First, Trader, 경수형(莖數型)에는 Bundy, Tammisto가 속(屬)하였다. 4. 경중형(莖重型) 품종(品種)은 초장(草長)이 낮고, 경수(莖數)가 적으나 경건(莖巾)이 두껍고 1 경중(莖重)이 무거웠으며, 경수형(莖數型) 품종(品種)은 초장(草長)이 크고 경수(莖數)는 많으나 1 경중(莖重)이 가벼운 특징(特徵)을 나타 내었다. 5. 경중형(莖重型) 품종(品種)(M)이 다수(多收)를 얻기 위해서는 경수(莖數)를 증가(增加)시키고 초장(草長)을 높게 하는 조건(條件)이 필요(必要)하다고 생각되었다.

• 한국농림기상학회지
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• 제3권1호
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• pp.22-29
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• 2001

벼 다수성 품종인 다산벼는 포장조건에서 단위면적 당 수수가 자포니카 품종보다 적어서 수량에 제한요인이 되고 있어 다수성 벼의 분얼특명을 구명 하고자 1999년 작물시험장 인공기상연구동에서 indica$\times$japonica 교잡종인 다산벼와 자포니카 품종인 화성벼를 공시하여 다수성 벼의 수량 향상을 위한 품종 육성 및 재배 기술의 기초 자료를 제공 하고자 시험한 결과는 다음과 같다. 1. 분얼과 출엽 관계는 다산벼가 y=0.8638x＋3.4901 ($R^2$=0.9529$^{**}$ ), 화성벼는 y=0.8844x＋3.2832($R^2$=0.9084$^{**}$ )으로 비슷하여, 분얼경 1개가 발생 할 때 엽 발생은 다산벼가 0.86엽, 화성벼가 0.88엽이 발생하여 뚜렷한 차이를 나타내지 않았다. 2. 온도별 분얼발생 및 종료시기는 두 품종 모두 26$^{\circ}C$까지 온도가 높을수록 일렀고, 분얼경 증가 속도는 26, 24$^{\circ}C$에서는 다산벼가 빠르고 22$^{\circ}C$~17$^{\circ}C$에서는 화성벼가 빨랐다. 3. 온도에 따른 1차 분얼경 최초 발생 시기는 다산벼는 7~9일, 화성벼는 8~10일이었으며, 2차 분얼경은 다산벼가 26$^{\circ}C$, 24$^{\circ}C$에서는 이앙 후 16, 17일, 22$^{\circ}C$에서 23일, 19$^{\circ}C$에서 27일, 17$^{\circ}C$에서 38일이었으며, 화성벼는 26~19$^{\circ}C$ 처리에서 이앙 후 19~22일, 17$^{\circ}C$에서는 26일이었다. 4. 유교분얼경 최종 출현일은 다산벼가 17~26$^{\circ}C$에서 1차 분얼경은 이앙 후 27~33일, 2차 분얼경은 20~41일이었으며, 화성벼는 1차 분얼경은 23~40일, 2차 분얼경은 24~40일이었다.