• Tribology and Lubricants
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• v.40 no.2
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• pp.67-70
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• 2024

Chemical mechanical planarization (CMP) is an essential process for ensuring high integration when manufacturing semiconductor devices. CMP mainly requires the use of polyurethane-based polishing pads as an ultraprecise process to achieve mechanical material removal and the required chemical reactions. A diamond disk performs pad conditioning to remove processing residues on the pad surface and maintain sufficient surface roughness during CMP. However, the diamond grits attached to the disk cause uneven wear of the pad, leading to the poor uniformity of material removal during CMP. This study investigates the pad wear rate profile according to the swing motion of the conditioner during swing-arm-type CMP conditioning using deep learning. During conditioning, the motion of the swing arm is independently controlled in eight zones of the same pad radius. The experiment includes six swingmotion conditions to obtain actual data on the pad wear rate profile, and deep learning learns the pad wear rate profile obtained in the experiment. The absolute average error rate between the experimental values and learning results is 0.01%. This finding confirms that the experimental results can be well represented by learning. Pad wear rate profile prediction using the learning results reveals good agreement between the predicted and experimental values.

• Korean Journal of Applied Biomechanics
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• v.16 no.4
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• pp.105-113
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• 2006

The purpose of this study was to analyze the joint torque of triple segmental system in golf driver swing. For this purpose, joint torque were calculated. In order to determine the load on the lumbar region, a triple segmental system was set for wrist, left shoulder and lumbar, torque working on the lumbar region were estimated. For this study, a total of 7 professional golfers were sampled, and then, their driver swings were recorded with two high-speed digital video cameras (180 frames/sec.) to be synthesized into 3-dimensional images and coordinated. Then, Eular's equation was used to produce some kinematic data, which were used to calculate joint torque with Newton's function. All data were calculated using LabVIEW 6.1 graphic program. The results of this study can be summarized as follows; It was found that the joint torque was generated in the direction opposite the target on wrist and shoulder during down swing, while in the direction towards the target on the lumbar region. During impact and release, the torque on the wrist joint was converted from the direction opposite the target to the direction towards the target, while the torque on the lumbar region was generated vice versa. The joints on the club-arm-shoulder were generated in the opposite direction at the beginning of down swing when the torque on the thorax-pelvis began to be generated, and then, the torque on the thorax-pelvis began to lower, while that on the club-arm-shoulder began to increase. Thus, a rapid decrease of the torque on the lumbar region linked to the low trunk acted to increase moment and joint torque on the arm-club region.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.267-276
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• 2010

The purpose of this study was to investigate the variations in gait parameters according to arm slings used in healthy adults. Twenty healthy adults (9 males, 11 females) participated in this study and walked at self-selected speeds on a GAITRite-instrumented carpet. They were randomly assigned conditions: without an arm sling, a care sling, a Harris hemi arm sling, a CVA sling, and a Rolyan humeral cuff sling. The following gait parameters were analyzed: the temporo-spatial parameters of gait velocity, swing phase, single support, cadence. In the comparison of parameters in each trial, step length was statistically significantly changed(p=.002). The right step length was significantly decreased in the Harris hemi arm sling and increased in the Rolyan humeral cuff sling when compared with no sling. This study found that several different types arm slings varied gait pattern in healthy adults.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.6 s.99
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• pp.660-666
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• 2005

Recently, the need for subminiature storage systems has increased with the diversification of portable devices. An actuator for small optical disk drives has to satisfy performance requirements such as higher access speed, lower power consumption, and smaller size. In this paper, we proposed the miniaturized rotary type VCM actuator that had an effective focusing mechanism and secured sufficient bandwidth for small form factor (SFF) optical disk drive (ODD). Initial model was designed by electromagnetic (EM) and structural analyses. Such a model was improved using design of experiments (DOE) procedure based on a Blu-ray disk (BD) 1x specifications.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.2 s.245
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• pp.128-134
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• 2006

Topology optimization is an effective scheme to obtain the initial design concept: however, it is hard to apply in case of non-linear or multi-objective problems. In this study, a modified topology optimization method is proposed to generate a structure of a swing arm type actuator satisfying maximum compliance as well. as maximum stiffness using the multi-objective optimization. approach. The multi-objective function is defined to maximize the compliance in the direction of focusing of the actuator and the second eigen-frequency of the structure. The design of experiments are performed and the response surface functions are formulated to construct the multi-objective function. The weighting factors between conflicting functions are determined by the back-error propagation neural network and the solution of multi-objective function is acquired using the genetic algorithm.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.481-486
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• 2002

Automation of Field Robot has many advantages for efficiency and convenience. In this paper, mathematical equation of field robot is established and automation system is constructed. Hydraulic and Dynamic equation of field robot are constructed in this paper. Inputs of system are angle data from each link (boom, arm, bucket, swing) and pressure data from in, out port of each cylinder. Outputs of system are voltage into electo-proportional valve.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.6
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• pp.548-553
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• 2008

In this paper, we propose a new swing-up control strategy for rotary inverted pendulums with restricted rotation range. The control law is derived from a Lyapunov function. The Lyapunov function is defined as the square of the sum of the absolute value of the total mechanical energy and weighted squares of the arm's angular displacement and velocity. By adjusting the weighting parameters in the Lyapunov function, we can affect the swing-up strategy such that the restriction on rotation range can be satisfied. Finally, we verify the performance of the proposed control law through simulation and experiments.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.33-41
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• 2006

This study was to analysis three dimension angle of the upper extremity segment and trunk to putting the protector in women bowlers. For this study, the subjects selected 4 players of national and university team. All subjects putted in the same wrist support to satisfy the experiment conditions. To get three dimensions position coordination of swing motion used for 6 ProReflex MCU 240 camera produced by Qualisys. After position coordination calculation, Three dimension angle of the trunk and the upper extremity segment calculated for Matlab 6.5. the result is following; In the trunk motion, there were little differences among the subjects in a flexion and extension change. There were a lot of differences in motion change of the abduction-adduction and internal-external rotation, but the motion types translated to the adduction-abduction-adduction and from the internal rotation toward the external rotation. In the upper arm segment the Flexion and extension showed a consistent motion in the down swing and up swing phase. And the motion change of abduction-adduction and pronation-supination showed a abduction-adduction-abduction and pronation-supination change during swing phase. In the forearm segment changes, it showed a lot of differences among the subjects and a similar change with the upper arm segment. Especially, the hand segment showed a supination motion from the backswing apex to release phase, but for increasing a rotation velocity of ball, the hand segment translated toward pronation in follow throw phase.

• Journal of Biomedical Engineering Research
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• v.41 no.6
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• pp.264-271
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• 2020

The purpose of this study was to investigate the effects of active vibration exercise of upper limb on physical capacity index (endurance, grip strength, balance, and flexibility) and vasomotor index (capillary length and body surface temperature) in middle aged women. 20 participants randomly divided into two groups: vibro-swing exercise (VSE) and non vibro-swing exercise (NVSE). Subjects in each group measured the 30 second arm curl test, hand dynamometer, one leg standing test, back scratch test, nail fold capillary microscope (NFM), and digital infrared thermal imaging (DITI) before and after exercise. The results showed that active vibration exercise of upper limb with vibro-swing equipment increased the endurance, balance ability, and the capillary length. In addition, changes in body temperature immediately after exercise were predicted to affect vasomotor. Active vibration exercise of upper limb has the advantage of being able to exercise anywhere regardless of the location by inducing different frequency changes in movement of various ranges and velocity. For this reason, the combination of vibration and active movement can be expected the physiological effects when producing exercise programs for middle aged women.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.10-14
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• 2004

There is a large number of old athletes participating golf, and the shoulder, especially the nondominant or lead arm, appears to be at greatest risk for golf-related injury during extremes of motion. To reduce and prevent the risk of injury and improve the performance of golf, golfer should understand the biomechanics of the golf swing, increase flexibility, and perform stretching and strengthening exercises regularly .