• 제목/요약/키워드: traction coefficient

검색결과 55건 처리시간 0.023초

국어통증척도의 타당도 연구 (A Study for Testing Validity of Korean Pain Measurement Tool)

  • 김주희
    • 대한간호학회지
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    • 제16권1호
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    • pp.81-88
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    • 1986
  • The main purpose of this study was to clarify the validity with patient's general background of Korean Pain Measurement tool. The subjects of this study were 195 patient from the 8 Med-Surgical wards in H. University Hospital in Seoul. The study was conducted over a 40 day period from Oct. 5, 1985 to Nov. 15, 1985. All patients had pain. Korean Pain Measurement tool and simple discriptive pain scale as Graphic Rating Scale were used to measure the pain, The Pearson Correlation Coefficient test was exercised to measure the correlation between the two kinds of pain tools. To clarify the Sensitivity of Korean Pain tool was used frequency with patient's response. To compare the difference in Pain levels with patient's general background, ANOVA and t-test was employed. To compare the difference in pain levels existed due to pain area of the body used mean numbers. The outcome of the study was as follows : 1. A positive correlation did exist between two pain measurement tools. (r=.2028∼.7768, p <0.002) 2. The sensitive subclass in Korean Pain Measurement tools was 7 subclass. The 7 subclass are inflammatory repeated pain, simple stimulating, traction pressure, dull pain, cavity pain, digestion related pain, suffering. related pain. 3. The existence of levels of pain in accordance with patient's general background, the department of hospital, pain area of the body and school age was supported. Age, sex, religion, marrital status, economic status, acute or chronic status was not supported. 4. The existence of higher pain levels of the body area was anus, chest, and lower pain levels of the body area was eye, ear, nose and throat. Based on the above results, it was found that sensitive subclasses of the Korean Pain Measurement tool was 7 subclass among all of 20 subclass. Thus it can be concluded that Korean Pain Mea-surement tool when partialy used and supplemented, can be an effective tool of pain measurement for the patient in Korea.

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상승저항력을 고려한 로터리경운작업을 위한 승용트랙터의 설계 (Tractor Design for Rotary Tillage Considering Lift Resistance)

  • 사카이 준;윤여두;최중섭;정창주
    • Journal of Biosystems Engineering
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    • 제18권4호
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    • pp.344-350
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    • 1993
  • The purpose of this study is to develop design equations to calculate optimum specifications and dimensions such as weight, engine horsepower, etc. of the tractor necessary to perform stable rotary tillage. The main results of this study are as follows. 1. A wheel-lug ought to receive a special resistance in downward direction which resists the lug's upward motion on wet sticky soil surface. The authors introduce a new academic name of the "lift resistance(上昇抵抗力, 상승저항력)" for such a force which resists retraction of a wheel lug from the soil in the upward trochoidal motion. This force is composed of the frictional force acting on the trailing and the leading lug side, and the "perpendicular adhesion(鉛直付着力, 연직부착력)" acting on the lug face and the undertread face on adhesive soil. 2. The "lift resistance ratio(上昇抵抗力係數, 상승저항력계수)" and the "perpendicular adhesion ratio(鉛直付着力係數, 연직부착력계수)" were defined, which are something similar to the definition of the motion resistance ratio, the traction coefficient, etc. 3. The design equation of the optimum weight of a rotary tiller mounted on the tractor derived by calaulating the forces acting on the rotary blades. 4. The design equations to calculate optimum specifications and dimensions such as weight, engine horsepower, etc. of the tractor necessary to perform stable rotary tillage were derived. It becomes clear that the optimum weight of a rotary tiller and a tractor can be estimated in planning design by means of putting about 21 design factors of the target into the equation. These equations are useful for planning design to estimate the optimum dimensions and specifications of a rotary tiller as well as a tractor by the use of known and/or unknown design parameters.

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Development and verification of an underground crop harvester simulation model for potato harvesting

  • Md. Abu Ayub Siddique;Hyeon-Ho Jeon;Seok-Pyo Moon;Sang-Hee Lee;Jang-Young Choi;Yong-Joo Kim
    • 드라이브 ㆍ 컨트롤
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    • 제21권1호
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    • pp.38-45
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    • 2024
  • The power delivery is crucial to designing agricultural machinery. Therefore, the tractor-mounted potato harvester was used in this study to conduct the field experiment and analyze the power delivery for each step. This study was focused on an analysis of power delivery from the engine to the hydraulic components for the tractor-mounted harvester during potato harvesting. Finally, the simulation model of a self-propelled potato harvester was developed and validated using the experimental dataset of the tractor-mounted potato harvester. The power delivery analysis showed that approximately 90.22% of the engine power was used as traction power to drive the tractor-mounted harvester, and only 5.10% of the engine power was used for the entire hydraulic system of the tractor and operated the harvester. The statistical analysis of the simulation and experimental results showed that the coefficient of determinations (R2) ranged from 0.80 to 0.96, which indicates that the simulation model was performed with an accuracy of over 80%. The regression models were correlated linearly with the simulation and experimental results. Therefore, we believe that this study could contribute to the design methodology and performance test procedure of agricultural machinery. This basic study would be helpful in the design of a self-propelled potato harvester.

선상 가열을 위한 가스 토치와 강판 사이의 열유동 해석 (Analysis of the thermal fluid flow between the gas torch and the steel plate for the application of the line heating)

  • 우종훈;신종계
    • 대한조선학회논문집
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    • 제39권2호
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    • pp.52-60
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    • 2002
  • 선상가열은 고온의 열원을 강판에 가하여 잔류변형을 얻음으로써 곡면을 성형하는 과정이다. 잔류 변형 제어를 위해서 열원과 강판 사이의 열전달 현상 및 강판의 온도 분포에 대한 이해가 필요하다. 본 연구는 가스 토오치로부터 분출된 연소 불꽃에 의한 가스가 강판을 가열하는 선상 가열 과정을 고온, 고속의 충돌 분출류와 그에 의한 열 대류 전달 현상으로 간략화 하여 강판의 온도 분포에 대한 해석을 시도하였다. 해석을 위하여 토오치에서의 연소 현상을 고온, 고속의 충돌 분출 현상으로 간략화 시키고 난류열 유동 해석을 수행하였다. 난류 열 유동 해석을 통하여 토오치와 강판 사이의 온도장 분포를 계산하였고 충돌 분출류에 관한 근사 누설트 실험식을 이용하여 분출류와 강판 사이의 열 대류 계수를 계산하였다. 온도 분포와 열 대류 계수를 통해서 강판에 유입되는 열 유속을 계산할 수 있었고 열 유속을 표면력으로 하는 열 전도 전달 해석을 통해 강판 내의 온도장 분포를 구할 수 있었다. 난류 열 유동 해석 및 전도 열 전달 해석을 위하여 유한 요소법을 이용하였으며, 유한 요소 해석결과를 실험 결과와 비교함으로써 본 연구에서 수행한 해석 과정의 타당성에 대한 검증을 수행하였다.

ISO 9613-2를 이용한 철도 환경소음 예측 모델 개선에 관한 연구 (Study on the improvement of prediction model for the railway environmental noise using ISO 9613-2)

  • 장승호;고효인;홍지영
    • 환경영향평가
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    • 제26권1호
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    • pp.11-26
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    • 2017
  • 철도 소음의 환경영향평가 업무에 있어서 소음도에 대한 정확한 예측이 중요하지만, 국내에서는 overall 소음도의 거리별 측정을 통한 경험식이 근사적으로 이용되고 있다. 본 논문에서는 소음원과 소음전파의 주파수 특성을 고려하여 철도 소음의 예측 정확도를 향상할 수 있는 예측 모델을 제안하였다. 먼저 철도 소음원을 궤도(레일 및 침목), 차륜, 동력, 공력 성분으로 구분하여 각각의 옥타브 밴드 주파수별 음향파워와 속도계수를 정의하고 음향 조도와 궤도/교량 특성을 반영할 수 있는 보정항을 도입하였다. 소음원에서 수음점까지의 전파 특성은 ISO 9613-2를 적용하여 기하학적 확산, 대기 흡음, 지면 효과, 장애물의 회절에 따른 감쇠 및 지향특성을 반영하여 계산하였다. 소음원 음향파워와 지향인자를 추정하기 위하여 전동 소음원 해석 모델 및 수치해석 결과와 통과 소음도 측정값을 이용하였다. 본 철도 소음 예측 모델을 이용하여 여러 철도 차량과 궤도 유형에 따라서 예측한 소음도를 측정값과 비교하여 정확도를 검증하였으며 기존 예측 모델보다 비교적 정확한 예측이 가능하였다. 따라서 본 결과는 철도 환경 소음의 정확한 영향 예측과 효율적인 소음 저감 대책 수립에 활용될 수 있을 것이다.