• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.2
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• pp.198-208
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• 1996

The plunge joints of C.V. Joint for vehicle tend to produce a cyclic axial disturbance at a frequency of three of six times shaft speed, in which this distrubance caused by internal frictional effect is related to joint angle, rotational speed, torque, and joint size. This principal axial thrust force might make vehicle shuddered when coinciding with vehicle frequency of tranverse direction, and be one of reasons to have driver feel uncomfortable, unesay, while driving vehicle. The paper makes analysis of axial thrust force & vehicle shudder through computer simulation, comparing the result with experimental data, and reviewing the effect by changing of variables such as dimensions and driving conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.74-79
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• 2008

The fracture strength of cross groove type constant velocity joint is largely determined by the fracture strength of the cage having window-like pockets for retaining the torque transmitting balls. A stress distribution acting on the cage is influenced by rigidities of the rim portion and of the column members, therefore requires a calculation such as FEA. To analyze fracture strength of cage, a 3-D elasto-plastic finite element analysis and a submodeling technique are used to achieve both computational efficiency and accuracy. The results are in reasonably good agreement with experiment.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.399-402
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• 2011

카메라를 이용하여 정지 영상을 획득할 때 발생할 수 있는 모션 블러 (motion blur) 현상을 보정하기 위해서는 정확한 블러파라미터 (블러의 방향, 블러의 크기)의 추정이 가장 중요하다. 본 논문에서는 블러된 영상의 로그 스펙트럼 (log spectrum)의 비등방성 (anisotropic)과 엔트로피 (Entropy) 특성에 기반한 블러 파라미터 추정 방법을 제안한다. 제안하는 기법은 1D 로그스펙트럼을 이용한 비등방성의 효과적인 분석과 블러 크기의 정확도를 증가시키기 위한 보상 과정을 포함한다. 실험 결과를 통해 제안하는 기법이 단일 영상에서의 등속 직선 운동의 모션 블러 현상을 더 효과적으로 보정하는 것을 보였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.211-214
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• 2000

An error analysis is very important for a precision machine tool to estimate its performance. This study proposes a new parallel device, a cubic parallel manipulator. Errors of the proposed cubic parallel manipulator include universal joint errors, errors occurring due to changes in the fore directions in the links, and actuation errors. An error analysis is performed for the manipulator platform moving at uniform velocity. The analysis shows how the position and orientation of the platform influences the directional link forces that change the errors in the manipulator. The analysis shows that the method can be used in predicting the accuracy of parallel devices.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.6
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• pp.371-378
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• 1986

In the reflection and transmission of a transverse magnetic wave(TM wave) from a dielectric plane osillating sinusoidally perpendicular to ist surface, one could assume that the boundary moves with a uniform nelocity equal to the instantaneous socillating velodity. According to the extended Lorentz transform, the reflected and the transmitted field are obatained as the function of the dielectric permittivity, the oscillating velocities, and the incident angles. The above results are analyzed graphically.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.4
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• pp.193-200
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• 1985

In the reflection and transmission of a plane wave(TE) from a dielectric plane surface oscillating sinusoidally perpendicular to its surface, one could assume that the boundary moves with a uniform velocity equal to the instantaneous oscillating velocity. The reflected and the transmitted fields are obtained as the function of the incident angles, the dielecri'c permittivity, and the oscillating velocities according to the extended Lorentz transform.

• Physical Therapy Korea
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• v.10 no.4
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• pp.61-68
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• 2003

본 연구의 목적은 운동강도(최대근수축의 10, 30, 50, 70%)에 따라 유발되는 국소적인 근피로가 슬관절의 위치감각 인지에 미치는 영향을 연구함으로써 근력강화의 운동치료적 효과와 운동학습과 관련된 효과를 동시에 만족시키는 최적의 운동강도를 제시하는 것이었다. 대상자는 건강한 성인여자 40명이었다. 청각을 통한 위치감각 정보를 제공하는 장치와 원판 각도계가 부착된 등속성 Cybex를 사용하였다. 근피로의 상태를 확인하기 위해서 근전도를 이용하여 주파수 스펙트럼 분석을 실시하였다. 청각되먹임이 주어진 각도와 대상자에 의해 재생되어진 각도의 오차값들과 근피로의 변화를 비교하기 위해 일요인 분산분석을 이용하였다. 오차값들의 평균은 50%의 군에서 가장 작았으며 근피로 또한 70%의 군에서만 크게 생성되었다. 따라서 최대 근 수축력의 50%가 운동치료 시 가장 효과적인 운동강도임을 알 수 있었다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.7
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• pp.877-884
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• 2001

A theoretical analysis is conducted on the Stokes flow in a narrow channel. A vertical fin is mounted on the bottom plate and the flow is induced by uniformly sliding top plate. The governing harmonic equation was solved in the transformed ζ-plane, which is obtained by applying conformal mappings to the physical plane. By using well-known transformation technique, closed-form expressions for velocity and skin frictional stress on the top and bottom plates were obtained.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.4
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• pp.8-13
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• 2010

The constant velocity internal grinding is a popular process for studying axle machine design and process in automobile industry. In this study, The program which gives the data of wheel size and truing diameter of ball groove is developed. As a result I obtained the data of grinding conditions makes good surface roughness get a grinding conditions. The grinding characteristics and conditions of constant velocity joint were investigated with respect to grinding feed, cutting depth, grinding time. At machine failure, the results were suddenly increased and the detailed surfaces were extremely obtained. Grinding condition was big more affected by grinding depth, grinding speed and grinding time.

• The Journal of Korean Physical Therapy
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• v.11 no.2
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• pp.103-109
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• 1999

The isokinetic exercise equipment generally allows a relatively safe application of maximal loading to a specific muscle group as well as an accurate and objective evaluation of muscle strength and endurance, it is more widely wing an the one of the important methods in rehabilitation and sports medicine. The aim of this paper was to compare the concept of the isometric and isotonic exercise and investigate the change of aerobic, anaerobic and fibers. In addition, the present study was designed to investigate the factors in measurement.