• Journal of Biosystems Engineering
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• 제43권4호
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• pp.331-341
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• 2018

Purpose: This study was conducted to develop a linear Proportional-Integral-Derivative (PID) control algorithm for the ascending and descending system of a rice transplanter and to analyze its response characteristics. Methods: A hydraulic model using a single-acting actuator, proportional valve and a PID control algorithm were developed for the ascending and descending system. The PID coefficients are tuned using the Ziegler-Nichols (Z-N) method and the characteristics of unit step response are analyzed to select the PID coefficients at various pump speeds. Results: Results showed that the performance of the PID controller was superior in any condition. It was found that the highest settling time and maximum overshoot were less than 0.210 s and 5%, respectively at all pump speed. It was determined that the steady state errors were 0% in all the cases. The lowest overshoot and settling time were calculated to be nearly 2.56% and 0.205 s, respectively at the pump rated speed (2650 rpm). Conclusions: The results indicated that the developed PID control algorithm would be feasible for the ascending and descending system of a rice transplanter. Finally, it would be helpful to plant the seedlings uniformly and improve the performance of the rice transplanter.

• 드라이브 ㆍ 컨트롤
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• 제21권2호
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• pp.30-35
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• 2024

Domestic rice is more expensive than imported products, so it is necessary to reduce production costs to secure competitiveness. Low-density planting developed in Japan is a cultivation technology that reduces labor and production costs without yield loss. The area of low-density cultivation is continuously increasing. However, research on how rice transplanters adapt to low-density planting has not been conducted. Therefore, this study was carried out to determine the optimal working conditions of a rice transplanter for low-density planting. Three types of rice transplanters were used and treated based on 3 conveying distance levels. The number of picked seedlings, pick missing rate, the number of planted seedlings, and the mis-planted rate were investigated to evaluate planting accuracy according to the transfer distance to the seedling tray. The results showed that the number of planted seedlings was 4.31~4.95 EA with an L1 seedling tray transfer distance (horizontal 9 mm, vertical 8 mm), but the mis-planted rate was higher than in other conditions. At L2 (horizontal 9 mm, vertical 10 mm) and L3 (horizontal 11 mm, vertical 8 mm) transfer distance conditions, the number of planted seedlings were 4.89-5.68 EA and 4.69-5.66 EA, respectively, with a low mis-planted rate of less than 3%. The results showed that if the transfer distance is adjusted properly, a rice transplanter can be used for low-density planting with high planting accuracy.

• Journal of Biosystems Engineering
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• 제31권3호
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• pp.194-202
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• 2006

Using a multi-variable linear regression technique and SUR(seemingly unrelated regression) model, the demand functions of tractor, combine and rice transplanter were estimated. The demand was regarded as an annual supply of each machine and modeled as a function of 11 independent variables which reflect the actual farmer's income, actual prices of farm machines, previous supply, previous stock, actual amount of available subsidy, actual amount of available loan, arable land, import of farm machines and rice price. The actual amount of available loan affects most significantly the demand functions. The actual farmer's income, actual farmer's asset, loan coverage, and rice price affect the demand positively while prices of farm machines and import negatively. The annual demands of tractor, combine and rice transplanter estimated using the demand functions were also presented over the next 4 years.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.446-459
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• 2000

This study was carried out in order to find out an effective machinery utilization strategy by conducting a survey on utilization and maintenance of agricultural machinery. The survey showed that the no. of utilization hours for power tiller in a year was 190.2hrs, 208.6hrs for tractor, 59.1hrs for rice transplanter, 74.0 hrs for combine, 44.6 cultivator and 254.4hrs for 4.4hrs for grain dryer. The period covered the time the machine was until it became unserviceable. The results are as follows: 10.0yrs for power tiller, 7.5yrs for tractor, 7.4yrs for rice transplanter and 5.4yrs for combine. This indicate that the actual period of use for power tiller and rice transplanter was longer than the expected period of duration years so there is a need for adjustment. The factors considered by the farmers for purchasing agricultural machine were: farm size(32%), machine operation (26.0%), performance(l4.0%) and post or after sales service(12.6%), according to the survey. It showed that repair cost rate in a year was classified into major agricultural machine; 4.8% for combine; 3.9% for tractor; 3.5% for rice transplanter; 2.0% for power tiller; 1.6% for grain dryer; and 1.2% for cultivator. The reasons for poor maintenance were insufficient after sales service(25%) and difficulty in buying parts(75%) because of the unavailability of parts in local shops(55%), imported models(30%) and outmoded model(15%).

• Journal of Biosystems Engineering
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• 제23권4호
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• pp.319-326
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• 1998

A herbicide applicator attached to a rice transplanter was developed to perform herbicide application and transplanting simultaneously. The prototype machine was composed of herbicide tank, discharge device, spinner, scattering plate and power drive. The application rate of the machine could be adjusted from 10 to 30 kg/㏊ and the application swath was 1.8m. According to the field test, application uniformity showed the range of 13.6~43.9％ in terms of CV(coefficient of variation) depending on the spinner speed, application height and shape of diffuser. The best uniformity could be achieved with the spinner speed of 30.8m/s and application height of 20cm. Field efficiency of the prototype was 4.7hr/㏊. Transplanting machine has field efficiency of 4.6hr/㏊ in Korea. By attaching the herbicide applicator, field efficiency became lowed only by 0.1hr/㏊, which was counted for filling time of herbicide. Simultaneous operation of transplanting and herbicide application had a of labor saying. The weed control efficacy was measured to be 96% in field when AC140 + Stomp and Londax + YRC was applied at the 65th day after transplanting. Nonanmae was treated by manual application to be compared to.

• Journal of Biosystems Engineering
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• 제38권1호
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• pp.9-17
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• 2013

Purpose: The goal of this study was to develop a methodology for the demand forecast of tractor, riding type rice transplanter and combine harvester using an ARIMA (autoregressive integrated moving average) model, one of time series analysis methods, and to forecast their demands from 2012 to 2021 in South Korea. Methods: To forecast the demands of three kinds of machines, ARIMA models were constructed by following three stages; identification, estimation and diagnose. Time series used were supply and stock of each machine and the analysis tool was SAS 9.2 for Windows XP. Results: Six final models, supply based ones and stock based ones for each machine, were constructed from 32 tentative models identified by examining the ACF (autocorrelation function) plots and the PACF (partial autocorrelation function) plots. All demand series forecasted by the final models showed increasing trends and fluctuations with two-year period. Conclusions: Some forecast results of this study are not applicable immediately due to periodic fluctuation and large variation. However, it can be advanced by incorporating treatment of outliers or combining with another forecast methods.

• 농업과학연구
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• 제8권2호
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• pp.203-211
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• 1981

수도작(水稻作) 기계화일관작업체계(機械化一貫作業體系)를 통(通)하여 이앙시기(移秧時期)의 노동(勞動)Peak를 해소(解消)하고 또한 소요노동력(所要勞動力) 절감(節減)으로 수도생도비(水稻生度費)의 절감(節減)을 위한 이앙작업(移秧作業)의 기계화(機械化)는 우리나라 현여건하(現與件下)에서 매우 시급(時急)한 과제(課題)이다. 본(本)연구(硏究)는 수도이앙작업(水稻移秧作業) 기계화(機械化)의 보다 적극적(積極的)인 추진(推進)을 위한 기초자료(基礎資料)를 얻기 위해 충청남도(忠淸南道) 일반농가(一般農家) 381호(戶)를 대상(對象)으로 이앙기(移秧機) 이용실태(利用實態) 및 소유성향(所有性向)에 대(對)하여 설문조사 및 청취조사를 실시(實施)하였다. 이 조사자료는 충남대학교(忠南大學校) 전자계산소(電子計算所)의 Computer로 통계(統計) Package인 STATS에 의(依)해 분석(分析)되었다. 이 연구(硏究)에서 밝혀진 중요(重要)한 결과(結果)는 다음과 같다. 1. 이앙기(移秧機) 소유(所有) 형태(形態)는 76.09%가 개인소유(個人所有)이나 앞으로 2~3년이내(年以內)에 구입희망농가(購入希望農家)는 52.27%가 공동소유(共同所有) 공동이용(共同利用) 희망(希望)하므로 공동(共同) 이용체제(利用體制)에 대(對)한 연구(硏究)가 보다 강화(强化)되어야 할 것이다. 2. 이앙기(移秧機)로 이앙(移秧)한 수도(水稻)의 수량(收量)은 응답자(應答者)의 91.33%가 증수(增收)되거나 별차(別差)가 없는 것으로 나타나 앞으로 수도이앙기(水稻移秧機)의 농촌보급(農村普及)이 증가(增加)될 것으로 전망(展望)된다. 3. 이앙기소유농가(移秧機所有農家)의 73.26% 산파묘(散播苗) 4조용(條用)을 보유(保有)하고 있으나 2~3년내(年內)에 구입(購入) 희망(希望)하는 농가(農家)의 25.0%가 띠묘(苗) 4조용(條用)을 희망(希望)하므로 띠묘(苗) 4조용(條用)에 대한 농촌보급문제(農村普及問題)도 그 기계(機械)의 특성(特性)으로 보아 재고(再考)되어야 할 것이다. 4. 이앙기소유농가(移秧機所有農家) 및 구입희망농가(購入希望農家)의 부락공동육묘(部落共同育苗)에 대(對)한 희망도(希望度)가 49.71~57.83%로 높으므로 공동육묘(共同育苗)에 대(對)한 기술지원(技術支援) 체제(體制)가 보다 강화(强化)되어야 할 것이다.

• 한국농공학회지
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• 제14권4호
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• pp.2777-2792
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• 1972

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2001년도 동계 학술대회 논문집
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• pp.426-431
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• 2001

• Journal of Biosystems Engineering
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• 제30권2호
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• pp.81-88
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• 2005

Manual transplanting Chinese cabbage needs 184 hours per ha in Korea. Mechanization of Chinese cabbage transplanting operation has been highly required because it needs highly intensive labor during peak season. This study was conducted to developed walking-type Chinese cabbage transplanter. In order to find out design factor of the transplanter, a kinematic analysis software, RecurDyn, was used. The prototype was tested in the circular soil bin and its operating motion was captured and analyzed using high speed camera system. Prototype was one row type which utilized original parts of engine, transmission and etc. from walking-type rice transplanter in order to save the manufacturing cost. Success ratio of pick-up device of hole-pin type and latch type were $96.0\%$ and $99.2\%$, respectively. which was highly affected by feeding accuracy of feeding device of seedling. Transplanting device of the prototype produced a elliptic loci which were coincident with those produced by the computer simulation. Prototype proved good performance in transplanting with mulching and without mulching operation, either. Working performance of prototype was 22 hours per ha and operation cost of the prototype was 961,757 won per ha. So, it would reduce $88\%$ of the labor and $29\%$ of operation cost.