• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.999-1002
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• 2003

In this study, embodied supervisory system that apply motion detection technique to small web camera and detects watch picture. Motion detection technique that use pixel value of car image that use in existing need memory to store background image. Also, there is sensitive shortcoming at increase of execution time by data process of pixel unit and noise. Suggested technique that compare extracting motion information by block unit to do to have complexion that solve this shortcoming and is strong at noise. Because motion information by block compares block characteristic value of image without need frame memory, store characteristic cost by block of image. Also, can get effect that reduce influence about noise and is less sensitive to flicker etc.. of camera more than motion detection that use pixel value in process that find characteristic value by block unit.

• Korean Journal of Heritage: History & Science
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• v.36
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• pp.335-346
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• 2003

With the development of media and computer, Motion Capture system, recently used in the entertainment and computer graphics, is emerging as a new recording method. Motion Capture is a system that records time-varying position of sensors which are attached to a objects and translates it to 3-D coordinate on computer. The motion of object displays the time-varying positions of each sensors that are graphed, or the line connected man-shaped model's movements on the computer monitor. And by adding computer graphic character to it, the various angled images, which are difficult to be perceived on the stage, can be easily recorded. Recently in Japan, Motion Capture system is being actively studied in order to use it in recording and preserving the intangible cultural assets of dance and art. Especially, Warabiza in Tazawako art village at Akita plays the leading role in this area through the project to symbolize and establish the archive of cultural dance, further, Ritsumeikan Univ. is develops the system for coupling the motion capture system to Labanotation. This article introduces the motion capture and it's related studies in Japan, which are being actively studied as a new recording method of intangible cultural assets.

• KSTLE International Journal
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• v.2 no.1
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• pp.55-58
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• 2001

The most widely-used orthopaedic grade polymer bearing liner material, ultrahigh molecular weight polyethylene (UHMWPE), for the total joint arthroplasty degrades after gamma-irradiation sterilization through the progressive oxidation in a shelf and in vivo. Oxidative degradation makes UHMWPE brittle and leads to decrease in mechanical properties. In this study the relationship between post-gamma-irradiation aging time and wear of UHMWPE was investigated. Six retrieved polyethylene hip liners implanted for 3-16 years and then stored in air for 1.5-6.5 years until tests were used. Two types of pin-on-disk wear testing were conducted by the uni-directional repeat pass rotating and by the linear reciprocating stainless steel disks against stationary polyethylene pins under 4Mpa at 1Hz with bovine serum lubrication in ambient environment. Wear of retrieved polyethylene hip liners does not have direct correlation with in vivo or total aging time. Linear reciprocal sliding motion generated more remarkable wear than uni-directional repeat pass sliding motion. It indicates that kinematic motion affects very crucially on the wear of aged UHMWPE having brittle white band region.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.365-368
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• 2001

This work describes a real-time method, based on motion energy detection, for detecting and tracking moving object in the consecutive image sequences. The motion of moving objects is detected by taking the difference of the two consecutive image frames. In addition an edge information of the current image is utilized in order to further increase the accuracy of detection. We can track the moving objects continuously by detecting the motion of objects from the sequence of image frames. A prototype system has been implemented using a TI TMS320C6201 EVM fixed-point DSP board, which can successfully track a moving human in real-time.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.550-555
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• 2000

Nonlinear oscillation of a microbubble under ultrasound was investigated theoretically. The bubble radius-time curves calculated by the Rayleigh-Plesset equation with a polytropic index and by the Keller-Miksis equation with the analytical solution for the Navier-Stokes equations of the gases were compared with the observed results by the light scattering method. This study has revealed that the bubble behavior such as the expansion ratio and the bouncing motion after the first collapse under ultrasound depends crucially on the retarded time of the bubble motion to the applied ultrasound.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.5
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• pp.428-434
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• 2014

Measurement of the absolute displacement of the moving machinery components in three-dimensions (3D) is of critical functional importance. This paper describes the system that measures motion associated with six degrees-of-freedom in 3D. Wire-sensors are used to estimate the positions of an object in a 3D Cartesian coordinate system, based on the values of their initial position and the measured values. For inducing the transfer function, which represents the motion of an object, the number of the minimum measurement points is determined. Also, the experimental measuring device is configured to visualize the behavior of a rectangular object in real-time. The software for measuring the six types of motions is directly programmed using a commercial software.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.105-108
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• 2003

The local motion at the top of an A-frame fixed on a research vessel for deep sea ROV floating in irregular waves is studied in the time-domain. The motion is analyzed in the time-domain using the convolution integral of the radiation forces. The memory effect functions and infinite frequency added masses are obtained from the solution of the three dimensional improved Green integral equation in the frequency domain by making use of the Fourier transformation.

• Korean Journal of Applied Biomechanics
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• v.27 no.1
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• pp.53-58
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• 2017

Objective: The purpose of this study was to compare the accuracy of stride time and stride length provided by a commercial APDM inertial sensor system (APDM) with the results of three dimensional motion capture system (3D motion) during treadmill walking. Method: Five healthy men participated in this experiment. All subjects walked on the treadmill for 3 minutes at their preferred walking speed. The 3D motion and the APDM were simultaneously used for extracting gait variables such as stride time and stride length. Mean difference and root mean squared (RMS) difference were used to compare the measured gait variables from the two measurement devices. The regression equation derived from the range of motion of the lower limb was also applied to correct the error of stride length. Results: The stride time extracted from the APDM was almost the same as that from the 3D motion (the mean difference and RMS difference were less than 0.0001 sec and 0.0085 sec, respectively). For stride length, mean difference and RMS difference were less than 0.1141 m and 0.1254 m, respectively. However, after correction of the stride length error using the derived regression equation, the mean difference and the RMS difference decreased to 0.0134 m and 0.0556 m or less, respectively. Conclusion: In this study, we confirmed the possibility of using the temporal variables provided from the APDM during treadmill walking. By applying the regression equation derived only from the range of motion provided by the APDM, the error of the spatial variable could be reduced. Although further studies are needed with additional subjects and various walking speeds, these results may provide the basic data necessary for using APDM in treadmill walking.

• Journal of the Korea Society of Computer and Information
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• v.27 no.8
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• pp.85-90
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• 2022

In this study, to reduce the time and cost disadvantages of the traditional motion graphic production method in order to realize the movement of a virtual camera identical to that of the real camera, motion graphics virtualization using AR Core-based mobile device real-time tracking data A method for creating a camera is proposed. The proposed method is a method that simplifies the tracking operation in the video file stored after shooting, and simultaneously proceeds with shooting on an AR Core-based mobile device to determine whether or not tracking is successful in the shooting stage. As a result of the experiment, there was no difference in the motion graphic result image compared to the conventional method, but the time of 6 minutes and 10 seconds was consumed based on the 300frame image, whereas the proposed method has very high time efficiency because this step can be omitted. At a time when interest in image production using virtual augmented reality and various studies are underway, this study will be utilized in virtual camera creation and match moving.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.441-449
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• 2007

In video coding, motion estimation is a process to estimate the pixel of the current frame from the reference frame, which affects directly the predictive quality and the encoding time. This paper is related to AHHS(Adaptive Hierarchical Hexagon Search) using spatio-temporal motion activity for fast motion estimation. The proposed method defines the spatio-temporal motion activity of the current macroblock using the motion vectors of its spatio-temporally adjacent macroblocks, and then conventional AHS(Adaptive Hexagon Search) is performed if the spatio-temporal motion activity is lower, otherwise, hierarchical hexagon search is performed on a multi-layered hierarchical space constructed by multiple sub-images with low frequency in wavelet transform. In the paper, based on computer simulation results for multiple video sequences with different motion characteristics, the performance of the proposed method was analysed and assessed in terms of the predictive quality and the computational time. Experimental results indicate that the proposed method is both suitable for (quasi-) stationary and large motion searches. The proposed method could keep the merit of the adaptive hexagon search capable of fast estimating motion vectors and also adaptively reduce the local minima occurred in the video sequences with higher spatio-temporal motion activity.