http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
벼수확 논에서 트랙터견인형 액비살포기의 소요견인력 측정에 관한 연구
오인환,김기덕,Oh, I.H.,Kim, K.D. 한국축산환경학회 2002 축산시설환경학회지 Vol.8 No.2
This study was conducted to improve utilization efficiency of slurry and choose a suitable type of tractor power which can be attached by manure spreader in the paddy field. In the paddy field, the pulling force for the spreader was measured by using a measurement system installed between tractors with and without the spreader. The soil moisture contents at the 0${\sim}$10cm and 10${\sim}$20cm depth of test soil(SiCL) were 28.45% d.b. and 23.47% d.b., respectively in average while Cone Index at l0cm and 15cm depth were 14.5kPa and 16.2kPa, respectively. It was impossible to measure the soil moisture contents and Cone Index below 20cm depth of the soil because the hardness of the soil increased greatly. Thereafter, hard pan of the sampled soil was found at 15${\sim}$20cm depth. While the required power only for the dragged tractor was found to be 3.44kW in the test field, the required pulling powers of tractor considering the pumping were 8.48${\sim}$12.48kW, 12.19${\sim}$16.19kW, 16.96${\sim}$20.96kW, respectively for 2 tons, 3 tons, and 4 tons of tank capacity. As the tank capacity increased, the sinkage of soil were also increased to 7cm, l0cm, and 12cm, respectively for the tractors with 2 tons, 3 tons and 4 tons of tank capacity. Considering about 60% of pulling efficiency of tractor, a tractor which had lower than 25.74kW of pulling power was suitable to pull the spreader and spread the slurry simultaneously for manure spreader with 2 tons of tank capacity. 29.42kW${\sim}$36.78kW of pulling power was found to be optimum for the tractor with 3 tons of tank capacity while over 40.45kW for 4 tons of tank capacity.
김기덕 ( K. D. Kim ),신범수 ( B. S. Shin ) 강원대학교 농업생명과학연구원(구 농업과학연구소) 2012 강원 농업생명환경연구 Vol.24 No.2
The purpose of this research was to construct the hardware to control tractors` steering autonomously using an electro hydraulic direction/flow control valve and steering angle sensors attached to king pins on both front wheels for the automatic driving as well as a DGPS for the navigation. A steering control algorithm is developed to drive the tractor straightforward from a position to the destination position for the parallel tracking farm-work operation. Contrary to previous steering control systems which use dead zones for starting point and finishing point, in this research, the dead zone for only finishing points was used in order to make it converged and proceed faster. The preliminary experimental results showed that P-control was sufficient as long as the control time of a loop maintained less than 50 ms. Since GPS provides data on every 200 ms, however, the same control of 50 ms interval was replicated 4 times, for a single period of position data acquisition. Through experiments conducted by changing the amount of steering angle at given ground speed, it was concluded that the desired RMS error should be less than 20 cm of GPS measurement error. The steering angle per control cycle should be within 2.65 ° when the ground speed of tractor is 0.836 m/s. If the tractor speed gets slow upto 0.491 m/s, the amount of steering angle should be less than 11.25 °.
선도적 R&D 기획을 위한 기술로드맵 및 미래 유망기술 탐색 동향
최윤호,김기덕,정형석,Y.H. Choi,K.D. Kim,H.S. Chung 한국전자통신연구원 2024 전자통신동향분석 Vol.39 No.2
As the scale of research and development (R&D) increases, countries and companies are consistently establishing R&D directions to meet strategic goals and market demands as well as roadmaps to increase efficiency through concentration and selection. However, establishing an effective roadmap and discovering promising technologies are challenging under the current numerous technological possibilities and uncertainties. The importance of discovering promising technologies to secure future technological competitiveness is recognized worldwide, and Europe, the United States, and Japan are establishing processes to identify promising future technologies and support related R&D. Methods for discovering promising future technologies can be classified into future social needs analysis, forecasting, surveys, use of expert opinions, and data analysis. We describe the types and limitations of technology roadmaps and investigate the status of domestic and foreign organizations using weak signal search through quantitative data analysis.