• 제목/요약/키워드: Center of Force

검색결과 2,554건 처리시간 0.035초

PECVD법에 의한 TiN, TiCN 증착 시 gradient plasma power가 코팅층에 미치는 영향 (Effect of Gradient Plasma Power on TiN, TiCN Coating Deposited by PECVD Process)

  • 김동진;신창현;허정;남태운
    • 열처리공학회지
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    • 제17권4호
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    • pp.236-240
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    • 2004
  • Effect of plasma power on PECVD process were investigated in this study. TiN and TiCN films were deposited on nitrided STD11 steel with 600W, 1,200W and 1,600W plasma power. As the plasma power was increased, the preferred orientation was reinforced from (200) to (111) and the hardness of films was improved. The low plasma power was, however, effective for improving of adhesion force of films. Regarding above properties, TiN and TiCN films were deposited by gradient plasma power. It was possible to get high hardness as well as adhesion force through gradient plasma power.

머리-목 회전이 편부전마비 환자의 팔꿈치 신전근력에 미치는 영향 (Influence of Head-Neck Rotation on Static Elbow Extension Force in Patients with Hemiparesis)

  • 유욱재;이상은;이정원
    • 한국전문물리치료학회지
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    • 제4권1호
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    • pp.39-47
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    • 1997
  • The purpose of this investigation was to examine the influence of head and neck(HN) position in the transverse plane on the static production of elbow extension force in the involved(paretic) upper extremity of patients with hemiparesis. On this study, thirty patients who had experienced a cerebrovascular accident were matched with neurologically intact subjects. Force of static elbow extension was tested with a hand-held dynamometer, twice with the HN rotated toward the paretic side and twice with the HN rotated toward the non-paretic side. Elbow extension force differed significantly with the HN in the two position in patients with hemiparesis but not in normal persons(${\alpha}$=0.05). Results of this study support the conclusion that HN position in the transverse plane influences the production of static elbow extension force on the paretic side in patients with hemiparesis.

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Optimized Design of a Planar Haptic Device Using Passive Actuators

  • Kim, Tae-Woo;Cho, Chang-Hyun;Kim, Mun-Sang;Song, Jae-Bok
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1565-1570
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    • 2003
  • Passive Haptic Devices have more benefit than the active in Stability. But Apart from benefits, it shows poor performance in haptic display. The author proposed the passive FME(Force Manipulability Ellipsoid) which can graphically show force generating ability of a passive haptic device. In this paper, performance indexes for the force approximation and pseudo friction cone are obtained with the passive FME and an optimized planar device with the indexes is proposed. Based on the above theory, experiment is conducted.

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그립악력과 각운동학을 이용한 골프 퍼팅 분석 (A Study on Grip Force and Angular Kinematics during Golf Putting Stroke)

  • 최진승;김형식;임영태;이정한;탁계래
    • 한국운동역학회지
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    • 제17권3호
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    • pp.125-131
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    • 2007
  • The purpose of this study was to evaluate the difference in grip force and angular kinematic variables between elite (handicap${\leq}2$) and novice golfers. Three-dimensional motion analysis system with synchronized grip force measurement system was used. The participants consisted of two groups based on their playing ability: 10 elite golfers and 10 novice golfers. Each subject performed 5 putting strokes at the distance of 1, 3, and 5m with randomly selected order. During entire putting phase, elite group showed relatively constant grip force but novice group showed continuously increasing grip force pattern. There existed a clear difference in the trajectory of shoulder line between two groups. As for novice group the rotational center did not converge into one point, for elite group the rotational center converged into precise single point. And there was a clear difference pattern in anterior-posterior directional movement at shoulder between two groups. These difference might be helpful for improving consistent putting skills.

FINITE ELEMENT ANALYSIS OF A STEADY-STATE ROLLING TIRE TAKING THE EFFECT OF TREAD PATTERN INTO ACCOUNT

  • KIM K. W.
    • International Journal of Automotive Technology
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    • 제7권1호
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    • pp.101-107
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    • 2006
  • The force and moment simulation of a steady-state rolling tire taking the effect of tread pattern into account is described using a steady-state transport method with ABAQUS. Tread meshes can not fully consider a tread pattern because detailed tread meshes are not allowed in the steady-state transport method. Therefore, the tread elements are modeled to have orthotropic property instead of isotropic property. The force and moment simulation has been carried out for the cases of both isotropic and orthotropic properties of tread elements. Both cases of simulation results are then compared with the experimental results. It is verified that the orthotropic case is in a better agreement with the experimental result than the isotropic case. Angle effects of tread pattern have been studied by changing the orientation angle of orthotropic property of tread. It is shown that the groove angle in the tread shoulder region has a more effect on force and moment of a tire than that in the tread center region.

Control of the Lateral Displacement Restoring Force of IRWs for Sharp Curved Driving

  • Ahn, Hanwoong;Lee, Hyungwoo;Go, Sungchul;Cho, Yonho;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • 제11권4호
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    • pp.1042-1048
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    • 2016
  • This paper presents a lateral displacement restoring force control for the independently rotating wheelsets (IRWs) of shallow-depth subway systems. In the case of the near surface transit, which has recently been introduced, sharp curved driving performance is required for the city center service. It is possible to decrease the curve radius and to improve the performance of the straight running with the individual torque control. Therefore, the individual torque control performance of the motor is the most important point of the near surface transit. This paper deals with a lateral displacement restoring force control for sharp curved driving. The validity and usefulness of the proposed control algorithm is verified by experimental results using a small-scale bogie system.

YBCO 초전도 벌크 합성 (Fabrication of YBCO Superconducting Bulk Magnets)

  • 이상헌
    • 한국전기전자재료학회논문지
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    • 제37권4호
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    • pp.407-411
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    • 2024
  • In this study, we fabricated single grain YBCO bulk superconductors with control of the distance between the seed and the upper surface of the YBCO compacts. The magnetic levitation force of the YBa2Cu3O7 superconducting bulk, which corresponds to the energy amount of the superconducting bulk, was measured to be 32.634 N at the center of the bulk where the seed was placed. Under field cooling conditions, a capture magnetic force of 2.17 kG was observed at the center of the bulk. The trapped magnetic force curve corresponding to the stability of the superconducting bulk means that the superconducting specimens were well grown in the form of single grains.

A Study on the Closed Linear Movement of the Center of Mass in the Rotatory Movement of a Rigid Body

  • Chung, Byung-Tae
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -2
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    • pp.1216-1219
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    • 2002
  • It is understood so far that the center of mass does not make any linear movement from the rotatory movement of a rigid body in the closed system. However, it has been found that the center of mass of the system could make a closed linear movement due to production of an instantaneous center of mass by the Coriolis force in the rotatory movement of a rigid body in the closed system. The nature of the closed linear movement in the non-inertial system and that of the open movement in the inertial system are different from each other. That is, the closed movement is described like the time integration of frictional forces, which is different from the open movement usually considered and described like the time integration of external forces. It is shown in this paper that the Coriolis forces, called a fictitious force in the classical mechanics, is similar to the frictional force so that it causes to move the center of mass of a closed system. In this paper, following an explanation of the closed linear movement of a non-inertial system and the open movement of an inertial system, the source of the closed linear movement phenomenon of a rotatory rigid body is presented.

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정적 보행모델에 기반을 둔 4족 보행로봇의 온라인 틸팅 제어알고리즘

  • 이순걸;조창현;홍예선
    • 한국정밀공학회지
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    • 제17권3호
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    • pp.83-91
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    • 2000
  • During static walking of a quadruped walking robot, stability of the robot depends on whether the projection of the mass center is located within the supporting area that is varying with leg motion and formed by standing legs. In this paper, force margin instead of the mass center was used to determine stability and body-tilting method was used to enhance it. On-line control of body tilting was realized with simple reaction feedback based on force margin of the static walking model of the robot instead of complicated calculation. Model reference on-line control where the model searches stable pose for predefined force margin also gave good walking performance.

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Trail Rolling Method for Control of Buckling Distortion in AA5083 GMA Butt Weldment

  • LEE, DONG-JU;SHIN, SANG-BEOM
    • Journal of Welding and Joining
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    • 제34권6호
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    • pp.20-27
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    • 2016
  • This study deals with the proper conditions of the trail rolling method (TRM) for the prevention of the buckling welding distortion at the AA5083 GMA butt weldment. For it, the effect of the working conditions of TRM including the rolling depth and the rolling distance between the welding torch and the roller on the longitudinal welding shrinkage force of the weldment was evaluated by using 3 dimensional thermo-mechanical FE analyses. The longitudinal welding shrinkage force inducing the buckling welding distortion at the GMA butt weldment was mitigated with an increase in the rolling depth and the rolling distance between the welding torch and the roller. Based on the results, the proper conditions of trail rolling method were established to reduce the longitudinal welding shrinkage force of the GMA butt weldment to below the critical value corresponding to the bucking distortion.