Application of the Sawyer-Eliassen Equation to the Interpretation of the Synoptic-Scale Dynamics of a Heavy Rainfall Case over East Asia

Dong-Kyou Lee,Jong-Chul Ha,Joowan Kim 한국기상학회 2008 Asia-Pacific Journal of Atmospheric Sciences Vol.44 No.1

RF 통신을 이용한 DCS 터미널 원격 감시 미들웨어 구현

하종현(Ha Jong Hyun),최성규(Choi Seong Kyou),노주영(Rho Ju Yong),정헌만(Jung Heon Man),이세훈(Lee Se Hoon) 한국컴퓨터정보학회 2006 한국컴퓨터정보학회지 Vol.14 No.2

이 논문에서는 터미널 부분의 중요 신호를 유무선 방식을 통하여 통합적으로 감시, 관리하기 위한 DCS 터미널 원격 감사 미들웨어를 설계 및 구현하고 미들웨어의 성능 및 기능을 평가하기위해 터미널 부분의 릴레이들의 동작 상태 및 퓨즈의 이상 유무를 실시간으로 감시하기 위한 보드를 설계 제작한다. 제안된 DCS 터미널 원격 감시 미들웨어는 각 릴레이들의 동작 상태를 실시간으로 확인이 가능하며 에러 발생 시 에러 유형을 즉시 제공하며 또한 릴레이의 규격 및 사용기간을 고려하여 교체시기를 알려주어 릴레이의 고장을 사전에 예방함으로써 산업분야의 경제적인 효과가 기대된다. In this paper, we designed and implemented DCS terminal remote monitoring middleware for real-time auditor and management terminal status signal with relay and fuse status at power management room. The middleware consist of four component as event analyzer, event manager, service manager and user interface. We expected economic effects extend relay life-time that pre-detected errors and prevented relay fault.

Performance Evaluation of a Driving Power Transmission System for 50 kW Narrow Tractors

Hong, Soon-Jung,Ha, Jong-Kyou,Kim, Yong-Joo,Kabir, Md. Shaha Nur,Seo, Young Woo,Chung, Sun-Ok Korean Society for Agricultural Machinery 2018 바이오시스템공학 Vol.43 No.1

Purpose: The development of compact tractors that can be used in dry fields, greenhouses, and orchards for pest control, weeding, transportation, and harvesting is necessary. The development and performance evaluation of power transmission units are very important when it comes to tractor development. This study evaluates the performance of a driving power transmission unit of a 50 kW multi-purpose narrow tractor. Methods: The performance of the transmission and forward-reverse clutch, which are the main components of the driving power transmission unit of multi-purpose narrow tractors, was evaluated herein. The transmission performance was evaluated in terms of power transmission efficiency, noise, and axle load, while the forward-reverse clutch performance was evaluated in terms of durability. The transmission's power transmission efficiency accounts for the measurement of transmission losses, which occur in the transmission's gear, bearing, and oil seal. The motor's power was input in the transmission's input shaft. The rotational speed and torque were measured in the final output shaft. The noise was measured at each speed level after installing a microphone on the left, right, and upper sides. The axle load test was performed through a continuous equilibrium load test, in which a constant load was continuously applied. The forward-reverse clutch performance was calculated using the engine torque to axle torque ratio with the assembled engine and transmission. Results: The loss of power in the transmission efficiency test of the driving power unit was 6.0-9.7 kW based on all gear steps. This loss of horsepower was equal to 11-18% of the input power (52 kW). The transmission efficiency of the driving power unit was 81.5-89.0%. The noise of the driving power unit was 50-57 dB at 800 rpm, 70-77 dB at 1600 rpm, and 76-83 dB at 2400 rpm. The axle load test verified that the input torque and axle revolutions were constant. The results of the forward-reverse clutch performance test revealed that hydraulic pressure and torque changes were stably maintained when moving forward or backward, and its operation met the hydraulic design standards. Conclusions: When comprehensively examined, these research results were similar to the main driving power transmission systems from USA and Japan in terms of performance. Based on these results, tractor prototypes are expected to be created and supplied to farmhouses after going through sufficient in-situ adaptability tests.

Performance Evaluation of a Driving Power Transmission System for 50 kW Narrow Tractors

( Soon-jung Hong ),( Jong-kyou Ha ),( Yong-joo Kim ),( Shaha Nur Kabir ),( Young Woo Seo ),( Sun-ok Chung ) 한국농업기계학회 2018 바이오시스템공학 Vol.43 No.1

Purpose: The development of compact tractors that can be used in dry fields, greenhouses, and orchards for pest control, weeding, transportation, and harvesting is necessary. The development and performance evaluation of power transmission units are very important when it comes to tractor development. This study evaluates the performance of a driving power transmission unit of a 50 kW multi-purpose narrow tractor. Methods: The performance of the transmission and forward-reverse clutch, which are the main components of the driving power transmission unit of multi-purpose narrow tractors, was evaluated herein. The transmission performance was evaluated in terms of power transmission efficiency, noise, and axle load, while the forward-reverse clutch performance was evaluated in terms of durability. The transmission’s power transmission efficiency accounts for the measurement of transmission losses, which occur in the transmission’s gear, bearing, and oil seal. The motor’s power was input in the transmission’s input shaft. The rotational speed and torque were measured in the final output shaft. The noise was measured at each speed level after installing a microphone on the left, right, and upper sides. The axle load test was performed through a continuous equilibrium load test, in which a constant load was continuously applied. The forward-reverse clutch performance was calculated using the engine torque to axle torque ratio with the assembled engine and transmission. Results: The loss of power in the transmission efficiency test of the driving power unit was 6.0-9.7 kW based on all gear steps. This loss of horsepower was equal to 11-18% of the input power (52 kW). The transmission efficiency of the driving power unit was 81.5-89.0%. The noise of the driving power unit was 50-57 dB at 800 rpm, 70-77 dB at 1600 rpm, and 76-83 dB at 2400 rpm. The axle load test verified that the input torque and axle revolutions were constant. The results of the forward-reverse clutch performance test revealed that hydraulic pressure and torque changes were stably maintained when moving forward or backward, and its operation met the hydraulic design standards. Conclusions: When comprehensively examined, these research results were similar to the main driving power transmission systems from USA and Japan in terms of performance. Based on these results, tractor prototypes are expected to be created and supplied to farmhouses after going through sufficient in-situ adaptability tests.

A Comparative Study of Experimental Rat Models of Renal Calcium Oxalate Stone Formation

Oh, Seung Young,Kwon, Jong Kyou,Lee, Seo Yeon,Ha, Moon Soo,Kwon, Yong Wook,Moon, Young Tae Mary Ann Liebert 2011 Journal of endourology Vol.25 No.6

임신 중 체중증가 양상과 연관된 요인에 관한 연구

유영욱 ( Yung Wook Yoo ),하정이 ( Jeong Yi Ha ),강창성 ( Chang Seong Kang ),박성철 ( Sung Chul Park ),박종규 ( Jong Kyou Park ) 대한산부인과학회 2010 Obstetrics & Gynecology Science Vol.53 No.1

목적: 산모의 특성과 임신결과 자료를 이용하여 임신 중 체중증가 양상을 조사한다. 연구 방법: 2002년 1월부터 2009년 8월까지 비합병 단태임산부 1,825명의 임신 중 체중 자료를 이용하여 각 삼분기별로 임신 중 체중증가율을 구하고, 산모의 특성과 임신결과에 따른 임신 중 체중증가 양상과 이들 상호간의 연관성을 분석하였다. 결과: 각 삼분기별 평균 체중증가율 (kg/week)은 제1 삼분기가 가장 낮았으며 (0.06±0.30), 제2 삼분기가 최고였으며 (0.52±0.23), 제3 삼분기에서 다소 감소되는 양상을 보였으며 (0.47±0.23), 중회귀분석에 사용된 일곱 변수 중에서 신생아 성별을 제외한 모든 변수 (출산력, 나이, 키, 신체질량지수, 임신중독증, 임신성 당뇨)가 적어도 한 개 이상의 삼분기에서 임신 중 체중증가와 유의한 연관성이 있었다. 임신 중 체중증가의 중요한 예측인자로는 제1 삼분기에는 신체질량지수, 산모의 키, 나이, 제2 삼분기에는 신체질량지수, 출산력, 키, 제3 삼분기에는 키, 나이, 출산력 순이었다. 결론: 임신 중 체중증가 양상은 산모의 신체적 특성과 임신 결과와 연관이 있었으며, 임신 중 체중증가에 영향을 끼치는 중요한 예측인자는 각 삼분기 별로 서로 달랐다. Objective: To examine the pattern of gestational weight gain using maternal characteristics and pregnancy outcomes. Methods: We used maternal weight data from 1,825 women who had noncomplicated pregnancy between Jan. 2002 and Aug. 2009. The rate of maternal weight gain in each trimester, the associations between gestational weight gain per trimester and maternal characteristics and pregnancy outcomes, and the relationship between maternal characteristics and trimester weight gain were analyzed. Results: The average rate of weight gain (kg/week) was lowest during the first trimester (0.06±0.30), peaked during the second trimester (0.52±0.23), and slowed slightly in the third trimester (0.47±0.23). With the exception of infant sex, all six maternal characteristics and pregnancy outcomes included in the multivariate analyses (parity, maternal age, height, BMI, preeclampsia, gestational DM) were associated significantly with maternal weight gain in at least one trimester. The important maternal predictors of weight gain per trimester were prepregnancy BMI, height and age in the first trimester; prepregnacy BMI, parity and height in the second; and height, age and parity in the third. Conclusion: The pattern of gestational weight gain is associated with a number of maternal characteristics and pregnancy outcomes, and these relationships vary according to which trimester is being examined.

자율주행 자동차용 전동회전시트 상부회전판의 핫스탬핑 성형에 관한 연구

육형섭(Hyung-sub Yook),편종권(Jong-Kweon Pyun),서창희(Chang-Hee Suh),오상균(Sang-Gyun Oh),권태하(Tae-Ha Kwon),김병기(Byung-Ki Kim),박동규(Dong-Kyou Park) 한국기계가공학회 2021 한국기계가공학회지 Vol.20 No.10

Seats in autonomous vehicles must be able to rotate to fully utilize the interior space. Generally, ultra-high strength steel is used for the rotation module because it should have high strength and high rigidity. In addition, the rotating parts are difficult to form because they have complex shapes. In this study, the upper plate of the rotating module, whose complex shape makes it difficult to form, was formed by applying the hot stamping method. The drawing method and the form-drawing method, which are generally used to form components of complex shapes, were compared. We showed that the form-drawing method increased the degree of freedom of the material flow to improve the formability, thus enabling the forming of the plate. In addition, the die and blank shapes were found to be important factors in determining the success of the hot stamping. The validity of the analysis results was confirmed through forming analysis and experiments.

Path planning for autonomous lawn mower tractor

Mingzhang Song,Md. Shaha Nur Kabir,Sun-Ok Chung,Yong-Joo Kim,Jong-Kyou Ha,Kyeong-Hwan Lee 충남대학교 농업과학연구소 2015 농업과학연구 Vol.42 No.1

Path planning is an essential part for traveling and mowing of autonomous lawn mower tractors. Objectives of the paper were to analyze operation patterns by a skilled farmer, to extract and optimize waypoints, and to demonstrate generation of formatted planned path for autonomous lawn mower tractors. A 27-HP mower tractor was operated by a skilled farmer on grass fields. To measure tractor travel and operation characteristics, an RTK-GPS antenna with a 6-cm RMS error, an inertia motion sensing unit, a gyro compass, a wheel angle sensor, and a mower on/off sensor were mounted on the mower tractor, and all the data were collected at a 10-Hz rate. All the sensor data were transferred through a software program to show the status immediately on the notebook. Planned path was generated using the program parameter settings, mileage and time calculations, and the travel path was plotted using developed software. Based on the human operation patterns, path planning algorithm was suggested for autonomous mower tractor Finally path generation was demonstrated in a formatted file and graphic display. After optimizing the path planning, a decrease in distance about 13% and saving of the working time about 30% was achieved. Field test data showed some overlap, especially in the turning areas. Results of the study would be useful to implement an autonomous mower tractor, but further research needs to improve the performance.

Path planning for autonomous lawn mower tractor

Song, Mingzhang,Kabir, Md. Shaha Nur,Chung, Sun-Ok,Kim, Yong-Joo,Ha, Jong-Kyou,Lee, Kyeong-Hwan Institute of Agricultural Science 2015 Korean Journal of Agricultural Science Vol.42 No.1

Path planning is an essential part for traveling and mowing of autonomous lawn mower tractors. Objectives of the paper were to analyze operation patterns by a skilled farmer, to extract and optimize waypoints, and to demonstrate generation of formatted planned path for autonomous lawn mower tractors. A 27-HP mower tractor was operated by a skilled farmer on grass fields. To measure tractor travel and operation characteristics, an RTK-GPS antenna with a 6-cm RMS error, an inertia motion sensing unit, a gyro compass, a wheel angle sensor, and a mower on/off sensor were mounted on the mower tractor, and all the data were collected at a 10-Hz rate. All the sensor data were transferred through a software program to show the status immediately on the notebook. Planned path was generated using the program parameter settings, mileage and time calculations, and the travel path was plotted using developed software. Based on the human operation patterns, path planning algorithm was suggested for autonomous mower tractor. Finally path generation was demonstrated in a formatted file and graphic display. After optimizing the path planning, a decrease in distance about 13% and saving of the working time about 30% was achieved. Field test data showed some overlap, especially in the turning areas. Results of the study would be useful to implement an autonomous mower tractor, but further research needs to improve the performance.

Study on performance test of orchard tractor power transmission systems

Nam-Seok Sung,Dong-Il Chang,Yun-Kun Huh,Sun-Ok Chung,Jong-Seung Cho,Jong-Kyou Ha 충남대학교 농업과학연구소 2013 농업과학연구 Vol.40 No.3

This study started to export an orchard tractor to Europe under the situations that R&D activities for orchard tractor were marginal and even it was not produced. The R&D for orchard tractor has been progressed and the most of it is accomplishing the goal. In this study, the durability of clutch friction part was tested for F/R clutch and moment of inertia of PTO clutch, and it was compared with the design criteria of transmission of tractor. According to the results of inertia test of F/R clutch, hydraulic pressures of clutch satisfied 1,961.33 ± 196.13 ㎪ of design criteria, and the variations of torque for forward and reverse operation were relatively constant. Therefore, it was found that the durability of clutch friction part was stable and reliable. Test results showed that the main hydraulic pressures were maintained 1,961.33 ± 196.13 ㎪ during the tests of moment of inertia of PTO clutch, and when it was operated, the hydraulic pressures were reached 1,961.33±196.13 ㎪. Therefore, it was found that the hydraulic pressures of PTO satisfied the design criteria. By the results that the time of the hydraulic pressures of PTO reaching main hydraulic pressure, and that of torque values restoring to the original was same as the time of the first gear of PTO reaching the maximum rotational speed, it was found that PTO could transfer power to attachments as it was designed.