• Journal of Biosystems Engineering
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• 제29권3호
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• pp.207-216
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• 2004

This study was intended to investigate the characteristics of ride vibrations transmitted to tractor operator during rotary tillage and plowing operations. Seat accelerations of a 41 ps diesel tractor in rotary tillage and plowing were measured and evaluated as specified in the ISO 2631-1. Effects of working speed and tilling depth on ride vibration were investigated. The level of ride vibration was also evaluated in terms of health guidance caution zones. Some of the results of the study are as follows: 1. The level of ride vibration in plowing was about 4.3 times greater than in rotary tillage. 2. The effect of working speed in rotary tillage differs depending upon the tillage depth. The level of ride vibration was increased with the speed, but it decreased over a certain tillage depth. Fore and aft vibration was 2.2-2.7 times severer than horizontal and vertical vibrations. Dominant frequency band was 1-3.15 ㎐ in fore and aft, 1-3.15㎐ and 16-25㎐ in horizontal, and 16-25㎐ in vertical directions. 3. Plowing reduced the ride vibration by 42.8-50.2%. But its positive effect decreased as the plowing speed increased. In plowing operation, ride vibration was similar degrees in fore and aft, horizontal and vertical directions. The dominant frequency band in plowing operation was 1-2.5㎐ in fore and aft, 1-2.5㎐ in horizontal, and 1-8㎐ in vertical directions. 4. On a basis of daily work hours of 4, total level of ride vibrations in plowing operation is likely to be harmful to operator's health.

• Tribology and Lubricants
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• 제15권1호
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• pp.83-89
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• 1999

The fretting wear behaviour of Zircaloy-4 tube used as the fuel rod cladding in PWR nuclear power plants has been investigated at the different test environment, in light water and in air as a function of slip amplitude, normal load, test duration and frequency. Zircaloy-4 tubes were used for both of oscillating and stationary specimens. A fretting wear tester was designed to be suitable for this fretting test. The wear volume and specific wear rate of Zircaloy-4 tube in water was greater than those in air under various slip amplitude. Delaminates and surface cracks were observed at low slip amplitude and high load of fretting test in water, but the traces of adhesion and plowing were observed at and above 200 Um. The water accelerates the wear of Zircaloy-4 tube at lower slip amplitude in fretting.

• 한국초지조사료학회지
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• 제27권3호
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• pp.209-218
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• 2007

본 실험은 파종시기 및 경운횟수가 옥수수의 생육특성, 건물수량, 영양수량 및 사일리지 기호성에 미치는 영향을 구명하기 위하여 파종시기 및 경운횟수를 통한 5처리(C : 파종 5월 5일, 경운회수 1회, 인력제초 1회, T1 ; 파종 5월 12일, 경운회수 2회, T2 : 파종 5월 19일, 경운회수 3회, T3 : 파종 5월 21일, 경운회수 4회, T4 : 파종 6월 2일 경운회수 5회) 3반복으로 2006년 5월부터 2006년 10월까지 상주대학교 부속 실습농장내 사료포장에서 실시하였으며, 그 결과를 하면 다음과 같다. 초장과 착수고는 C > T1 > T2 > T3 > T4구순으로 높게 나타났지만 초장에서는 유의적인 차이가 없었으며 착수고에서는 처리구간 유의적인 차이를 보였다(p<0.05). 엽장은 T2가 96.0cm로 가장 길게 나타났지만 처리구간 유의적인 차이는 나타나지 않았다. 엽폭은 C와 T3구가 (11.2cm), 고사엽은 C 및 T1구가 각각 4.6엽으로 가장 높게 나타났다. 경의 굵기에 있어서는 T3구가 31mm로 가장 높았던 반면 T2구가 25mm로 가장 가늘게 나타났다(p<0.05). 암이삭 둘레는 C(17.1 cm) > T1(15.6 cm) > T4(15.4 cm) > T3(15.3 cm) > T2(15.2cm) 순으로 높게 나타났으며(p<0.05), 암이삭 충실도는 C구가 8.8로서 가장 높았던 반면 T4구가 6.0으로서 가장 낮게 나타났다 (P<0.05). 경의 경도와 알곡 경도는 파종시기가 빠른 순 인 C > T1 > T2 > T3 > T4순으로 나타났다(p<0.05). 그리고 경의 당도는 T1구가 6.1%로 가장 높고, T2구가 3.0%로 가장 낮게 나타났다(p< 0.05). 잡초 발생량은 C구가 500 kg/ha으로 가장 적게 T1구가 44,100 kg/ha로서 가장 높게 나타났으며 (P<0.05), 잡초의 피복도는 T1 > T2 > T3 > T4 > C구순으로 높게 나타났다(p<0.05). 생초수량은 C구가 73,550 kg/ha로서 가장 높았던 반면 T4구가 65,500 kg/ha로서 가장 낮은 수확량을 보였다(p<0.05). 건물수량에 있어서는 C(26,978 kg/ha) > T1(26,130 kg/ha) > T2(20,255 kg/ha) > T3(20,255 kg/ha) > T4(17,508 kg/ha)구 순으로 높게 나타났다(P<0.05). 조단백질 함량은 T1 > T4 > T2 > T3 > C구순으로 높았으며(p<0.05), 조지방은 C > T1 > T2 > T3 > T4구순으로 높았다. 상대기호성은 Holstein, 염소 및 꽃사슴에서는 C구가 가장 높은 기호성을 보였으나 한우에서는 T1구가 가장 높게 나타났다.

• 농업과학연구
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• 제40권1호
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• pp.53-59
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• 2013

Analysis of load data during field operations is highly important for optimum design of power drive lines for agricultural tractor. Objective of the paper was to analyze field load data using FFT to determine frequency and the energy levels of meaningful cyclic patterns. Rotary tillage, plowing, baling, and wrapping operations were selected as major field operations of agricultural tractor. An agricultural tractor with power measurement system was used. The tractor was equipped with strain-gauge sensors to measure torque of four driving axles and a PTO axle, speed sensors to measure rotational speed of the driving axles and an engine shaft, pressure sensors to measure pressure of hydraulic pumps, an I/O interface to acquire the sensor signals, and an embedded system to calculate power requirement. In rotary tillage, calculated frequency was decreased as travel speed increased. In baler operation, calculated frequency was increased as PTO speed was increased. The calculated peak frequency levels and expected levels were similar. Results of the study would provide information on power utilization patterns and on better design of power drive lines.

• 한국기후변화학회지
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• 제9권4호
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• pp.377-384
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• 2018

The chamber method is widely used for measuring methane emission from paddy rice fields. The closed static chamber has advantages of easy installation and removal in the field and low manufacturing cost. However, the manual chamber method requires a lot of labor and has a limited sampling time and frequency. To overcome the disadvantages of the manual chamber, the auto-chamber system is used for measuring methane emission. We compared the differences in methane flux between the auto-chamber and manual chamber. To investigate methane emissions by the two methods, a chamber was installed for each of the following treatments : control without rice straw (NA), spring plowing after autumn rice straw application (SPRA) and autumn plowing after autumn rice straw application (APRA). The total methane emission was lowest in the control and highest in APRA with both methods. There was no significant difference in total methane emission between the methods, but dynamic fluctuation in methane with temperature change was accurately measured in the auto-chamber. Measuring methane emission with an auto-chamber system is expected to reduce uncertainty and increase accuracy, accompanied by labor reduction.

• Journal of Ginseng Research
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• 제4권1호
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• pp.104-120
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• 1980

The effects of temperature on transpiration, chlorophyll content, frequency and aperture of stomata, and leaf temperature of Panax ginseng were reviewed. Temperature changes of soil and air under spade roof were also reviewed. Growth responses of responses of ginseng plant at various temperature were assessed in relation to suseptibillity of ginseng plants. Reasonable management of ginseng fields was suggested based on the response of ginseng to various temperatures. Stomata frequency may be increased under high temperature during leaf$.$growing stage. Stomata aperture increased by high temperature but the increase of both frequency and aperture appears not enough for transpiration to overcome high temperature encountered during summer in most fields. Serial high temperature disorder, i.e high leaf temperature, chlorophyll loss, inhibition of photosynthesis, increased respiration and wilting might be alleviated by high humidity and abundant water supply to leaf. High air temperature which limits light transmission rate inside the shade roof, induces high soil temperature(optimum soil temperature 16∼18$^{\circ}C$) and both(especially the latter) are the principal factors to increase alternaria blight, anthracnose, early leaf fall, root rot and high missing rate of plant resulting in poor yield. High temperature disorder was lessen by abundant soil water(optimum 17∼21%) and could be decreased by lowering the content of availability of phosphorus and nitrogen in soil consequently resulting in less activity of microorganisms. Repeated plowing of fields during preparation seems to be effective for sterilization of pathogenic microoganisms by high soil temperature only on surface of soils. Low temperature damage appeared at thowing of soils and emergence stage of ginseng but reports were limited. Most limiting factor of yield appeared as physiological disorder and high pathogen activity due to high temperature during summer(about three months).

• 여성건강간호학회지
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• 제7권4호
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• pp.631-641
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• 2001

This study is to investigate women have pre menstruation discomfort, The period of this research was almost one month (from 25, August 2001 to 25, October 2001). The PAF (Premenstrual assessment form), which was made by Park, Myonng-Wha, used for this study. The confidence rate is Crombach's $\alpha$= .9773. Correcting research papers are analyzed by SPSS 7.5 program and normal feature of the subject is divided by frequency, percentage, mean, standard deviation, t-test and ANOVA. The results of this study are as follows; 1. The average age of the subjects is 26.47 age. 220 subjects(44.6%) have gastroenteric trouble like, enteritis, stomachache, laxity. 278 subjects usually have caffeine drink in routine life. 123 subjects(24.9%) have controlled their diet. The average age of the first plowing is 13.55 ages and distribution is between 10 years and 20 years. The average of the uncomfortable point is 2.84. The way to reduce the uncomfortable feeling on the menstruation is taking relax time. 2. All subjects have experienced pre menstruation discomfort, even the degree uncomfortable feeling is different. Through eighteenth categories on the research papers, average point 2.21 were calculated and many subjects have fatigue ($2.89{\pm}1.0614$) and normal physical uncomfortable ($2.84{\pm}1.0633$) and undercurrent water symptom and unsuitability ($2.45{\pm}0.9857$). 3. According to the result of this study, that shows statistical difference; age (F=2.56. p=.037). marriage (t=2.60, p=.009) the number of children(t=2.83, p=.005), stress level(F=13.03, p=.000) job(F=3.91, p=.020). monthly income(t=2.14. p=.032) uncomfortable degree on the menstruation (F=19.121, p=.000), use of contraceptive appliance or pill(t=-2.20, p=.043), schooling (F=3.30, p=.038). Further research is need to understand pie menstruation discomforts, the variables associated with them. And nursing intervention has to considered in program to reduces of pre-menstruation discomforts.