• Journal of the Ergonomics Society of Korea
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• v.34 no.5
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• pp.437-445
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• 2015

Objective: The aims of this study are to investigate the trends of intellectual property in order to identify the ergonomic approaches on musculoskeletal disorders, harmful factors of musculoskeletal disorders, and to find the potential applicability of motion capture technology. Background: Ergonomic posture assessment tools often showed interrater variance, though the usage is easy and practical in industrial fields. Moreover new technologies such as motion capture showed the potential applicability in posture assessment. So ergonomists and practitioners became interested in the intellectual properties on musculoskeletal disorder and motion capture technology. Method: Intellectual properties were collected with the combination of keywords such as ergonomic, musculoskeletal disorder, and motion capture using the KIPRIS (Korea Intellectual Property Rights Information Service). Collected intellectual properties were classified into ergonomic area and non-ergonomic area, except unexamined intellectual properties. This study investigated the trend of application of intellectual properties and the probability of using motion capture technology. Results: Few intellectual properties with ergonomic approach on musculoskeletal disorders were founded, despite many products for rehabilitation and sports. One hundred twenty five patents in 1105 patents on musculoskeletal disorders and 138 patents in 1908 patents on motion capture technology were classified into the patents that ergonomic approach can be applied. The patents related to ergonomics area are rapidly increasing after 2010, and there are good opportunities for ergonomists to apply the patents. Conclusion: This study found opportunities on novel methodology in detecting the harmful factors of musculoskeletal disorders, and that the motion capture technology is applicable in ergonomic posture assessment. Application: The results of this study can help ergonomists prepare the ergonomic patents, and can show the potential use of motion capture technology in detecting the harmful posture of musculoskeletal disorders.

• Earthquakes and Structures
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• v.2 no.2
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• pp.171-187
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• 2011

Rational scaling of design earthquake ground motions for tall buildings is essential for safer, risk-based design of tall buildings. This paper provides the structural designers with an insight for more rational scaling based on drift and input energy demands. Since a resonant sinusoidal motion can be an approximate critical excitation to elastic and inelastic structures under the constraint of acceleration or velocity power, a resonant sinusoidal motion with variable period and duration is used as an input wave of the near-field and far-field ground motions. This enables one to understand clearly the relation of the intensity normalization index of ground motion (maximum acceleration, maximum velocity, acceleration power, velocity power) with the response performance (peak interstory drift, total input energy). It is proved that, when the maximum ground velocity is adopted as the normalization index, the maximum interstory drift exhibits a stable property irrespective of the number of stories. It is further shown that, when the velocity power is adopted as the normalization index, the total input energy exhibits a stable property irrespective of the number of stories. It is finally concluded that the former property on peak drift can hold for the practical design response spectrum-compatible ground motions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8A
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• pp.669-678
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• 2012

In this paper, we propose an efficient fast integer-pel motion estimation for H.264/AVC using local statistics of local motion vectors. Using neighboring motion vectors, we define a new statistical property that is used to determine a mode of motion search range of current block. In addition, an adaptive motion search range compensated method that is based on cumulative statistics of previous coded blocks is addressed to solve the problem of the statistical motion search range decision method. Experimental results show that proposed algorithm has the capability to reduce the computational cost over the other methods.

• Earthquakes and Structures
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• v.17 no.4
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• pp.411-424
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• 2019

In this study, a numerical model of a shield tunnel with an assembled segmental lining was built. The seismic response of the segmental lining of the section of the shield tunnel in Line 1 of the Chengdu Metro is analyzed as it passes through the interface of sand-cobble and mudstone layers. To do so, the node-stress seismic-motion input method was used to input the seismic motion measured during the 2008 Wenchuan earthquake, and the joint openings and dislocations associated with the earthquake action were obtained. With reference to the Ethylene-Propylene-Diene Monomer (EPDM) sealing gaskets used in the shield tunnels in the Chengdu Metro, numerical simulation was applied to analyze the contact pressure along the seepage paths and the waterproof property under different joint openings and dislocations. A laboratory test on the elastic sealing gasket was also conducted to study its waterproof property. The test results accord well with the numerical results and the occurrence of water seepage in the section of the shield tunnel in Line 1 of the Chengdu Metro during the 2008 Wenchuan earthquake was verified. These research results demonstrate the deformation of segmental joint under earthquake, also demonstrate the relationship between segmental joint deformation and waterproof property.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.302-305
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• 1999

Twin-servo mechanism is used to increase the payload capacity and speed of high precision motion control system. In this paper, we propose a robust synchronizing motion control algorithm to cancel out the skew motion of twin-servo system caused by different dynamic characteristics of two driving systems and the vibration generated by high accelerating and decelerating motions. This proposed control algorithm consists of separate feedback motion control algorithm of each driving system and skew motion compensation algorithm between two systems. Robust model reference tracking controller is proposed as a separate motion controller and its disturbance attenuation property is shown. For the synchronizing motion, skew motion compensation algorithm is designed, and the stability of whole Closed loop system is proved based on passivity theory.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.3
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• pp.149-157
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• 2001

In the video retrieval system, visual clues of still images and motion information of video are employed as feature vectors. We generate the temporal textures to express the motion information whose properties are simple expression, easy to compute. We make those temporal textures of wavelet coefficients to express motion information, M components. Then, temporal texture feature vectors are extracted using spatial texture feature vectors, i.e. spatial gray-level dependence. Also, motion amount and motion centroid are computed from temporal textures. Motion trajectories provide the most important information for expressing the motion property. In our modeling system, we can extract the main motion trajectory from the temporal textures.

• Journal of applied mathematics & informatics
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• v.12 no.1_2
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• pp.385-393
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• 2003

Let Y(t) be a stochastic integral process represented by Brownian motion. We show that YHt (t) is continuous in t with probability one for Molder function Ht of exponent ${\beta}$ and finally we derive asymptotic self-similar process YM (t) which converges to Yw (t).

• Journal of the Korea Society of Computer and Information
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• v.24 no.4
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• pp.45-50
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• 2019

Recently, character motion have been used extensively in the entertainment business, and researchers have investigated algorithms of reproducing, editing, and simulating mimic human movements. Also, many recent researches have suggested how a character interacts with its surrounding environment in terms of motion. Specially, spatial relationships of the environment have been introduced for adapting and preserving character motion. In this paper, we propose a motion adaptation technique preserving a spatial property between a virtual character and the configuration of its surrounding space. Additionally, we report on experimental results of smoothly adapted motions in various environmental structures with original motions such as walk, jump, and tumbling.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10C
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• pp.948-955
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• 2006

In this paper, we propose motion estimation and compensation using Low-Band-Shift(LBS) with Integer Lifting Shift property. To overcome shift-variant property on wavelet coefficients, the LBS was previously proposed. This method which is applied to reference frame in video coding technique has superior performance in terms of rate-distortion characteristic. However, this method needs more memory and computational complexity. For the enhancement of those disadvantages, we propose motion estimation using Low-Band-Shift with Integer Lifting. The Integer Lifting implementation gives us good efficiency of calculation and storage.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.1144-1149
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• 2001

In this paper, a sliding mode controller of a fluid engine mount using MR (Magneto-Rheological) fluid was discussed When the MR fluid is applied to a fluid mount, resistance of MR fluid can be controlled by electro-magnetic valve installed in the inertia track. Since the rheological property of the MR fluid shows a function of shear rate, the damping characteristics of the mount will be change according to the frequency. Changing an applied magnetic field to the valve changes the property of the mount, such as the resistance of the MR fluid, the notch and the resonant frequencies due to the fluid passing, quantity of the fluid passing, the effective piston area of the volumetric damping and stiffness. Therefore, the fluid mount using MR fluid can be regarded as a variable structure system The sliding mode control known well as a particular type of variable structure control was introduced in this study. The sliding mode control, which has inherent robustness, is also expected to improve the control performance in the engine mount The sliding mode controller for the mount formatted by taking into account the response property with a time constant to MR fluid and the variable mount property. The motion equations of the fluid mount are derived from Newton's law of motion and used in numerical simulation. Numerical simulations illustrate the effectiveness of the sliding mode controller.