• Title/Summary/Keyword: Coefficient of Traction

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

  • 김주희
    • Journal of Korean Academy of Nursing
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    • v.16 no.1
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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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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
    • Journal of Drive and Control
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    • v.21 no.1
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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.

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

  • Sakai, J.;Yoon, Y.D.;Choe, J.S.;Chung, C.J.
    • Journal of Biosystems Engineering
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    • v.18 no.4
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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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Analysis of the thermal fluid flow between the gas torch and the steel plate for the application of the line heating (선상 가열을 위한 가스 토치와 강판 사이의 열유동 해석)

  • Jong-Hun Woo;Jong-Gye Shin
    • Journal of the Society of Naval Architects of Korea
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    • v.39 no.2
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    • pp.52-60
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    • 2002
  • Line heating is a forming process which makes the curved surface with the residual strain created by applying heat source of high temperature to steel plate. in order to control the residual strain, it is necessary to understand not only conductive heat transfer between heat source and steel plate, but also temperature distribution of steel plate. In this paper we attempted to analyze is temperature distribution of steel plate by simplifying a line heating process to collision-effusive flux of high temperature and high velocity, and conductive heat transfer phenomenon. To analyze this, combustion in the torch is simplified to collision effusive phenomenon before analyzing turbulent heat flux. The distribution of temperature field between the torch and steel plate is computed through turbulent heat flux analysis, and the convective heat transfer coefficient between effusive flux and steel plate is calculated using approximate empirical Nusselt formula. The velocity of heat flux into steel plate is computed using the temperature distribution and convective heat transfer coefficient, and temperature field in the steel plate is obtained through conductive heat transfer analysis in which the traction is induced by velocity of heat flux. In this study, Finite Element Method is used to accomplish turbulent heat flux analysis and conductive heat transfer analysis. FEA results are compared with empirical data to verify results.

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

  • Jang, Seungho;Koh, Hyo-In;Hong, Jiyoung
    • Journal of Environmental Impact Assessment
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    • v.26 no.1
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    • pp.11-26
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    • 2017
  • Approximate empirical equations obtained by measuring overall noise levels at different distances have been used to evaluate environmental influence of the railway noise though the accurate prediction of noise levels is important. In this paper, a noise prediction model considering the frequency characteristics of noise sources and propagation was suggested to improve the accuracy of noise prediction. The railway noise source was assorted into track, wheel, traction and aerodynamic components and they were characterized with the source strength and speed coefficient at each octave-band frequency. Correction terms for the acoustic roughness and the track/bridge condition were introduced. The sound attenuation from a source to a receiver was calculated taking account of the geometrical divergence, atmospheric absorption, ground effect, diffraction at obstacles and directivity of source by applying ISO 9613-2. For obtaining the source strength and speed coefficients, the results of rolling noise model, numerical analysis and measurements of pass-by noise were analyzed. We compared the predicted and measured noise levels in various vehicles and tracks, and verified the accuracy of the present model. It is found that the present model gives less error than the conventional one, so that it can be applied to make the accurate prediction of railway noise effect and establish its countermeasures efficiently.