• Journal of Biosystems Engineering
• /
• v.5 no.2
• /
• pp.58-66
• /
• 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
• /
• v.12 no.2
• /
• pp.1-15
• /
• 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
• /
• v.17 no.1
• /
• pp.27-36
• /
• 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
• /
• v.11 no.1
• /
• pp.1-7
• /
• 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.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.291-296
• /
• 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.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.4_2
• /
• pp.661-667
• /
• 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.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.11 no.2
• /
• pp.90-96
• /
• 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
• /
• v.7
• /
• pp.1-10
• /
• 1989

This experiment was conducted at the Kyungpook National University Agriculture college farm during 1988 to determine the effect of tiller no. Per hill on growth and competitive response of the rice plant. The results obtained were summarized as follows : As tiller no. Per hill, Rice yield increased and also yield component such as 1000-grain weight and ripening ratio were increased up to at 10 tiller no. Per hill but they decreased at 13 tiller no. Per hill in used four rice varieties. Culm length of four rice varieties was shortest at one tiller no. Per hill however as tiller no. Per hill increased culm length significantly decreased in all rice varieties. Flag leaf length was highest at one tiller no. Per hill in all varieties while flag leaf length decreased with increased tiller no. Per hill. Highest harvest index exhibited at 13 tiller no. Per hill in all varieties and also showed that Chil seongbyeo and Samgang byeo of Tongil variety were higher harvest index compared to Nagdongbyeo and Palgongbyeo of Japonica Variety. Tiller no. Per hill did not significantly affect the heading date except by delayed heading date on Chilseong and Samgangbyeo at one tiller no. Per hill. The correlation coefficients of competitive index and ripening ratio and harvest index were 0.60 and 0.77 respectively while panicle length was 0.43 and grain weight was 029.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.4 no.1
• /
• pp.13-17
• /
• 1983

This experiment was carried out in order to know the relationship between morphological characters and dry matter yield at vegetative growth stage in Meadow fescue grown under plant basis. 1. The dry weight of a plant (PW) indicated positive significant correlation with plant height (pH), leaf area (LA) and stem area (SA). It means that increase in dry of a plant was resulted from interactions among above morphological characters. 2. Stem area (SA) is an important morphological character for increasing the dry weight of a plant. 3. The varieties could be classified into 3 types based on plant type index (PTI, dry weight of a plant/ (no. of tiller)$^2$), it were M in tiller weight type, Leto, First and Trader in medium type and, Bundy and Tammisto in tiller number type, respectively. 4. The variety with tiller weight type had more havier tiller and larger stem thickness than those of variety with tiller number type. But, tiller number type showed higher plant height. 5. In order to obtain the highest yield in tiller weight type, there were necessary to increasing the number of tillers and higher plant height.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.3 no.1
• /
• pp.22-29
• /
• 2001

In Korean high yielding varieties developed by crosses between indica and japonica rice, the most limiting factor for yield may be attributed to the less number of the tillers in the unit area. The goals of this study is to find out the effect of the temperature factors as well as cultural practices on the development and increase of tillers of Dasanbyeo, the high yielding indica crossed japonica cultivar. The effect of temperature was examined under controlled phytotron condition with 6 levels of temperature, 15, 17, 19, 22, 24 and 26$^{\circ}C$, respectively, For the experiment, the leading japonica variety in Korea, Hwaseongbyeo, was used for the check cultivar for the comparison with Dasanbyeo. The high temperature also accelerated the initiation and termination of tiller development. The cultivar difference in the speed of tiller development was observed, for example, more rapid development of tiller in Dasanbyeo than in Hwaseongbyeo was observed at the high temperature range of 24-26$^{\circ}C$, while the vice versa phenomena was observed at lower temperature range of 17-22$^{\circ}C$. The first secondary tiller of Dasanbyeo was observed on the 16, 17, 23, 27 and 38 days after transplanting (DAT) at 26$^{\circ}C$, 24$^{\circ}C$, 22$^{\circ}C$, 19$^{\circ}C$, and 17$^{\circ}C$, respectively. Those of Hwaseongbyeo was 19-22, and 26 DAT at 19-26$^{\circ}C$ and 17$^{\circ}C$, respectively. The last effective tiller of Dasanbyeo was observed on 27-33 DAT for the primary tiller, 20-41 DAT for the secondary tiller. Those of Hwaseongbyeo were 23-40 DAT for primary tiller, and 24-40 DAT for the secondary tiller, and 24-40 DAT for the secondary tiller.