• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.130-136
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• 2013

This paper presents the magnetic equivalent circuit analysis of a double-excited, two-degree-of-freedom (DOF) motor. The double-excited, 2-DOF motor is a laminated structure, making it easy to manufacture and giving it simple operating principles. We explain the structure of the 2-DOF motor and analyze the static characteristics using a magnetic equivalent circuit (MEC) to reduce analysis time. The feasibility of MEC analysis was confirmed by experimental results of the tilting, panning motion. We also confirmed the occurrence of holding torque in every motion.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1989.10a
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• pp.46-50
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• 1989

Methods for the estimation of the coefficient matrices in the equation of motion for a linear multi-degree-of-freedom structure arc studied. For this purpose, the equation of motion is transformed into an auto-regressive and moving average with auxiliary input (ARMAX) model. The ARMAX parameters are evaluated using several methods of parameter estimation; such as toe least squares, the instrumental variable, the maximum likelihood and the limited Information maximum likelihood methods. Then the parameters of the equation of motion are recovered therefrom. Numerical example is given for a 3-story building model subjected to an earthquake exitation.

• Korean Journal of Applied Biomechanics
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• v.15 no.2
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• pp.21-29
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• 2005

The Purpose of this study was to seek determinant factors through analysis of 65 snatch skill kinematic factors of Athletics participated in 2001 Asian weightlifting competetion. The conclusion were as follows ; 1. In order to enhance snatch skill, when barbell move on knee position, One should be flex knee joint to 105-110 degree, and In pull motion, One should be move powerful extension of knee and hip joint. 2. In last pull motion, One try to make more lock out motion than extra extention motion of hip joint 3. In order to enhance snatch skill, It is inportant that elevate barbell highly by last pull motion through powerful knee extention, poweful hip flextion and One should be make lock out motion fast in the same time. 4. In order to enhance snatch skill, anterior-posterior movement width of shoulder joint should be small. 5. In order to enhance snatch skill, Hip joint should be move vertically on start and lock out phase, but In pull phase, extension motion of hip joint shoulde be performed more largely and powerfully.

• Clinics in Shoulder and Elbow
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• v.8 no.1
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• pp.14-18
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• 2005

Purpose: Limitation of motion of the elbow joint due to stiffness affect on life quality of the patients. So contracture of the elbow should be treated as soon as possible. Among the many treatment modalities, we described the result of arthroscopic treatment. Materials and Methods: From Mar. 2000 to Mar. 2003, 40 patients, who received the arthroscopic treatment by author for contracted elbow, were the subjects. We estimated the range of motion (ROM) of elbow joint before and after surgery by goniometer. The clinical result was evaluated by Severance elbow scoring system. The final ROM was evaluated at the point of no further increasement of joint motion. Male ware 30 cases, female ware 7 cases, average 42.6 years old and mean follow up period were 31 months. During arthroscopic treatment we had done release of the joint capsule or resection, synovectomy, removal of loose bodies. We used traditional portals. Results: The avarage preoperative ROM of elbow joint was 72.5 degree(range, 5 - 132 degree) and the increasement of ROM was totally 49.3 degree in flexion 26.5 degree and extension 22.8 degree. There was no other complication. Conclusion: Arthroscopic treatment for contracted elbow permit early joint ROM and it decrease the secondary injury to the elbow joint. Also there are few complications. It is thought to be a good treatment modality in contracted elbow joint.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.3
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• pp.22-33
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• 1993

A theoretical analysis of predicting the detailed motion of a piston-crank mechanism within piston-guide clearance is presented, and the analysis is applied to the piston motion in a gasoline engine. A piston movement program is developed to calculate the piston attitude relative to the bore, the piston to bore impact velocity and kinetic energy loss and the net transverse force acting on the piston. This paper presents the formulation of a set of differential equations governing the transverse and rotational motion of a piston. These equations of motion were solved by well established Runge-Kutta method. As a result of this study, it is possible to predict the effects of piston geometry and piston pin offset on a piston motion and kinetic energy loss.

• Journal of computational fluids engineering
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• v.20 no.2
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• pp.103-108
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• 2015

Fluid-body interaction analysis of floating body with six degree-of-freedom motion is presented. In this study, three-dimensional incompressible Navier-Stokes equations are employed as a governing equation. The numerical method is based on a finite-volume approach on a cartesian grid together with a fractional-step method. To represent the body motion, the immersed boundary method for direct forcing is employed. In order to simulate the coupled six degree-of-freedom motion, Euler's equations based on rigid body dynamics are utilized. To represent the complex body shape, level-set based algorithm is utilized. In order to describe the free surface motion, the volume of fluid method utilizing the tangent of hyperbola for interface capturing scheme is employed. This study showed three different continuums(air, water and body) are simultaneously simulated by newly developed code. To demonstrate the applicability of the current approach, two different problems(dam-breaking with stationary obstacle and water entry) are simulated and all results are validated.

• Journal of the Korean Society of Physical Medicine
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• v.1 no.1
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• pp.109-116
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• 2006

Purpose : To identify the effects of flexion-extension of stretching on the functional improvement of patients with neck myofascial pain syndrome. Methods : the present research investigated 30 patients with neck myofascial syndrome, dividing them into a group doing flexion-extension of stretching. This study examined degree of recovery from neck pain by comparing their neck myofascial pain syndrome before and after the treatment, and compared to find difference in the degree of recovery from myofascial pain syndrome. Results : The results are as follows. For the flexion of stretching, 1. For the visual analogue scale (VAS) decreased significantly for six weeks treatment, 2. For the flexion decreased significantly for six weeks treatment. and the range of motion of cervical vertebrae increased significantly(p>.05). 3. For Stretching, range of motion left rotation indicated significant difference after pre test and after two week but no significant difference after six week. 4. For the left rotation decreased significantly for six weeks treatment. and the range of motion of cervical vertebrae increased significantly(p>.05). 5. For the right rotation decreased significantly for six weeks treatment. and the range of motion of cervical vertebrae increased significantly(p>.05). Conclusion : This study suggest that flexion-extension of stretching have an effect on the functional improvement of patients with neck myofascial pain syndrome.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.3 s.96
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• pp.259-265
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• 2005

A two-degree-of-freedom out-of-plane model with contact stiffness is presented to describe dynamical interaction between the pad and disc of a disc brake system. It is assumed that the out-of-plane motion of the system depends on the friction force acting along the in-plane direction. Dynamic friction coefficient is modelled as a function of both in-plane relative velocity and out-of-plane normal force. When the friction coefficient depends only on the relative velocity, the contact stiffness has the role of negative stiffness. The results of stability analysis show that the stiffness of both pad and disc is equally important. Complex eigen value analysis is conducted for the case that the friction coefficient is also dependent on the normal force. The results further verify the importance of the stiffness. It has also been found that increasing the gradient of friction coefficient with respect to the normal force makes the system more unstable.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.3
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• pp.109-116
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• 2003

In this paper. we Propose an UXGA class LCD controller for controlling the LCD panel. The proposed controller supports the full screen display using GCD between input and output resolutions. The proposed LCD controller includes the motion detector based on median filter which can detect the motion of input image for the enhancement of a image quality. Also, it divides the motion into 3 stages such as still, semi-moving and moving, and uses the different interpolation algorithms according to the degree of motion. In order to evaluate the performance of the proposed interpolation algorithm, we use PSNR method and compare the conventional algorithm by using computer simulation. For the proposed motion detection algorithm, we use a visual verification and the estimation of pixel changes. The proposed LCD controller has been designed and verified by VHDL. It has been synthesized using Xilinx VirtexE FPGA.

• The Journal of Korea Robotics Society
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• v.3 no.3
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• pp.203-211
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• 2008

This work proposes structure of spring backbone micro endoscope. For effective surgery in narrow and limited space, many manipulators are developing that different to existed structure. This device can move like elephant nose or snake unlike the existing robots. For this motion, a mechanism that uses spring backbone and wires has been developed. The new type endoscope that has Z axis motion for spring structure, therefore it has 3 degree of freedom, two rotations and one linear motion. And new kinematics for backbone structure is proposed using simple geographic analysis. The Jacobian and stiffness modeling are also derived. Exact actuator sizing is determined using stiffness model. Finally, the proposed kinematics are verified by simulation and experiments.