• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.453-463
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• 2014

Objective:The purpose of this study is to identify motion patterns for cellular phone and propose a method to identify motion patterns using a motion capture system. Background: In a smart device, the introduction of tangible interaction that can provide new experience to user plays an important role for improving user's emotional satisfaction. Firstly, user's motion patterns have to be identified to provide an interaction type using user's gesture or motion. Method: In this study, a method to identify motion patterns using a motion capture system and user's motion patterns for using cellular phone was studied. Twenty-two subjects participated in this study. User's motion patterns were identified through motion analysis. Results: Typical motion patterns for shaking, shaking left and right, shaking up and down, and turning for using cellular phone were identified. Velocity and acceleration for each typical motion pattern were identified, too. Conclusion: A motion capture system could be effectively used to identify user's motion patterns for using cellular phone. Application: Typical motion patterns can be used to develop a tangible user interface for handheld device such as smart phone and a method to identify motion patterns using motion analysis can be applied in motion patterns identification of smart device.

• IE interfaces
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• v.14 no.3
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• pp.302-309
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• 2001

Direction-of-motion stereotypes between ON/OFF controls were tested using a paper-and-pencil test and interview method. One hundred and forty eight subjects of both genders and from a wide range of ages were asked to indicate the control movement they would make to turn on the light. Stereotypes were obtained for nine types of ON/OFF controls in two different planes. The results show that stereotype for left-right power switches is right for on, and stereotype for up-down switches is up. And, a strong stereotype was found in the case of left-right switches than up-down switches. Some stereotypes are significantly different between genders and age groups. These findings identified in this study can be used to design the ON/OFF switches of the facilities and equipments.

• Physical Therapy Korea
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• v.15 no.2
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• pp.54-63
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• 2008

The purpose of this study was to examine the effect of the hip internal rotation on knee extensor and hip abductor electromyographic (EMG) activity during stair up and stair down mobility. Eighteen healthy subjects were recruited. All subjects performed stair up and down movements on a step of 30cm height while maintaining the hip in neutral (condition 1) and hip in internal rotation (condition 2). Surface EMG activity was recorded from five muscles (gluteus maximus, vastus lateralis (VL), vastus medialis oblique (VMO), posterior gluteus medius (Gmed), and tensor fascia latae (TFU)) and hip internal rotation angle was measured using a three dimensional motion analysis system The time period for stair up and down was normalized using the MatLab 6.5 program, and EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). The EMG activities according to the hip rotation (neutral or internal rotation) during the entire time period of stair up and down in each phase were compared using a paired t-test. During the entire period of stair up, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). During the entire period of stair down, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). However, the EMG activities of the other muscles were not significantly different between the conditions (p>.05). These results suggest that the stair up and down maintaining hip internal rotation was could be a contributing factor on patellar lateral tracking.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.20-23
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• 1996

The block matching algorithm for the motion estimation is relatively simple to implement, and thus widely applied in image sequence coding such as H.261, MPEG- I and MPEG-2. Most techniques of the block matching method use fixed-size blocks for the motion estimation. And their success relies on the assumption that the motion within each block is uniform. But if the block size is increased to reduce the number of motion vectors for high data compression, the estimated image brings about many errors. In this paper, the variable-sized blocks are used to solve this problem. And the top down method is used to select the block size.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.183-188
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• 2006

This research is to know differentiation of CP(center of pressure) pattern among four pitching sort(straight ball, raise ball, change up ball, drop ball). Subject are three national or junior athletes. We use the one camera, Novel Win pressure measurement system. Conclusions are as follows : 1. When we throw the straight ball, CP of left foot is effective to end movement at middle of foot in body balance on arm angular motion and enhanced speed. 2. When we throw the raise ball, to change CP from middle to post is more effective in order to raise the ball. 3.In drop ball pitching, in order to fall down the ball in front of hitter, CP of left foot move from post foot to interior part of forefoot 4. In change up ball pitching, if CP of left foot move into forefoot, it is a cause of high ball and hitter can recognize the change up ball because of late arm rotation motion.

• Journal of Korea Game Society
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• v.10 no.5
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• pp.65-73
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• 2010

In this paper, we developed the device for an interactive game interface using bio signals which were able to recognize user's motion intention using EMG signals and it was applied to the games which need the information of the muscle motion directions. The module for acquiring EMG signals consists of 4-Ch, wrist-motions were defined as up, right, down and left state. The user's intent was recognized through thresholding and comparing signals of each channel. The classification result of the motion directions could control the arrow keys on the keyboard of PC and it was applied on the various games. This proposed game device can be expected to induce an effective exercise with an interesting and enjoyment, and it can use both self-developed or commercial games.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.411-412
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• 2002

Piston-cylinder system are widely used in power engineering applications. In reciprocating refrigeration compressors, where extremely low friction losses are required, ringless pistons are being used to diminish the friction between piston rings and cylinder wall. Since the ringless piston has the freedom of lateral motion there is a potential danger that it will occasionally hit the cylinder wall while moving up and down along it's axis. A good design must therefore provide a smooth and stable reciprocating motion of the piston and ensure that the fluid film separating the piston from the cylinder wall is maintained all times. And the compromise between refrigerant gas leakage through the piston-cylinder clearance and the friction losses is required utilizing a dynamic analysis of the secondary motion for the high efficiency compressor. To this end, the computer program is developed for calculating the entire piston trajectory and the lubrication characteristics as functions of crank angle under compressor running conditions. The results explored the effects of some design parameters and operating conditions on the stability of the piston, the oil leakage, and friction losses.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.3151-3168
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• 2015

Automatic detection of estrus in cows is important in cattle management. This paper proposes a method of estrus detection by automatically checking cattle mounting. We use a side-view video camera and apply computer vision techniques to detect mounting behavior. In particular, we extract motion information to select a potential mount-up and mount-down motion and then verify the true mounting behavior by considering the direction, magnitude, and history of the mount motion. From experimental results using video data obtained from a Korean native cattle farm, we believe that the proposed method based on the abrupt change of a mounting cow's height and motion history information can be utilized for detecting mounting behavior automatically, even in the case of fence occlusion.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.39-47
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• 2011

The motion of a conductive spherical particle under uniform electric field is investigated in order to find a suitable method for removing the conducting solid impurities contained in liquid plastic. When the positive dc voltage applied to the upper electrode, the vertical up-and-down motion of a charged particle by electrostatic force is observed by a charge-coupled device (CCD) camera or a high-speed video camera. The experimental data of the static threshold voltage by which the particle starts to move toward the counter electrode in air or silicone oil are in good agreement with theoretical value. When the applied voltage is larger than the static threshold voltage, the particle motion pattern in silicone oil consists of four stages: upward motion, stopping at the upper electrode, downward motion and stopping at the lower electrode. The stopping motion on the electrode is thought to be caused by the liquid flow accompanied by the particle motion. The particle charge calculated by integrating the pulse current, which is generated by the charge exchange between the electrode and the particle, is approximately 0.1~0.25 times of the theoretical value. This study is expected to help understand the electric properties of microparticles in oil circuit breaker (OCB) and oil transformer and improve their performance and longevity.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.594-596
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• 2006

In this thesis, we propose a algorithm that is able to detect a user's motion. A minute noise of accelerometer arises cumulative error in case of converting velocity and distance, which makes it difficult to detect movement of sensor. We use a lowpass filter, ALS algorithm, and motion detection block to minimize such cumulative error. we experiment using a motion-detective module which is composed of accelerometer, micro-controller, and serial interface. Our scheme is capable of detecting such as up, down, left, right, forward, and backward movement of the module. It is expected that our scheme is applied to a game controller or user interface of a next generation PC.