• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.1
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• pp.96-102
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• 2003

Video copy detection is a complementary approach to watermarking. As opposed to watermarking, which relies on inserting a distinct pattern into the video stream, video copy detection techniques match content-based signatures to detect copies of video. Existing typical content-based copy detection schemes have relied on image matching. This paper proposes two new sequence matching techniques for copy detection and compares the performance with color techniques that is the existing techniques. Motion, intensity and color-based signatures are compared in the context of copy detection. Comparison of experimental results are reported on detecting copies of movie clips.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.254-255
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• 2005

The effect of surrounding air velocity on the soot deposition process from a diffusion flame to a solid wall was investigated in a microgravity environment to attain in-situ observations of the process. An ethylene($C_2H_4$) diffusion flame was formed around a cylindrical rod burner in surrounding air velocity of $v_{air}$=2.5, 5, and 10 cm/s with oxygen concentration of 35 % and wall temperature of 300 K. Laser extinction was adopted to determine the soot volume fraction distribution between the flame and burner wall. The experimental results show that the soot particle distribution region moves closer to the surface of the wall with increasing surrounding air velocity. A numerical simulation was also performed to understand the motion of soot particles in the flame and the characteristics of the soot deposition to the wall. The results successfully predicted the differences in the motion of soot particles by different surrounding air velocity near the burner surface and are in good agreement with observed soot behavior in microgravity. A comparison of the calculations and experimental results led to the conclusion that a consideration of the thermophoretic effect is essential to understand the soot deposition on walls.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.210-215
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• 2000

A fundamental study on the under water harvest-type ice storage system and its temperature characteristics in ice storage system was performed experimentally. The experiments were conducted by changing the inlet refrigerant temperature of an evaporator to analyzing the thermal fluid motion inside the ice storage tank. From the experimental results, the cold storage characteristics were investigated by measuring the axial and radial temperature variations inside the ice storage tank with respect to the inlet and outlet refrigerant temperatures of an evaporator. In case of the under water harvest-type ice storage system, thermal fluid motion inside the ice storage tank was shown differently in comparison with that of other ice storage systems. During the cooling storage process, there was no supercooling phenomenon in the ice storage tank. These results show the characteristic of this system and the possibility of application to other fields.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.4
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• pp.392-397
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• 2014

Recently, there is an increase in the need for precision linear stages with vacuum compatibility in such areas as lithography equipment for wafer or mask manufacturing, mask mastering equipment for optical data storage and electron beam equipment. A simple design, high stiffness and low cost can be achieved by using ball bearings. However, a ball bearing have friction and wear problems just as in ambient air. In order to decrease the friction, a special finish, a diamond-like carbon (DLC) film coating, is applied to the surface of a guide rail by sputtering deposition. This paper presents the result of an experimental investigation on the control performance of a ball bearing-guided linear motion stage under two environmental conditions: in air and vacuum. A comparison between the results with and without the DLC coating was also considered in the experimental investigation.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.4
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• pp.330-337
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• 2015

When a tower crane is carried by a transporter in shipyard, the height and length of the tower crane should be adjusted to meet the safety guidelines. Since the guidelines came from the field experience, the safety limitation needs to be analyzed by a computer simulation. In this paper, modeling methods are addressed to implement the appropriate transportation simulation of a tower crane. For the relation between the tower crane and the transporter, normal contact force, friction force, and kinematic constraints are compared. Assignment of relevant linear acceleration and angular velocity is considered for the transporter to start or move on an inclined ground surface. By using the examined modeling methods, the dynamic motion of tower crane transportation is analyzed by a dynamic simulation program, and comparison between the simulation result and analytic solution is made to verify the feasibility of the modeling methods.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.1
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• pp.103-108
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• 2011

Purpose : The purposes of this study were to compare the muscle activity ratio of tibialis anterior (TA) / extensor digitorum longus (EDL) during the active ankle dorsiflexion in subjects with the normal toe (NT) and the hammer toe (HT). Methods : Nineteen subjects with the NT group and nineteen subjects with the HT group were recruited for this study. The muscle activities of TA and EDL were measured by using surface electromyography (EMG) and the angles of ankle dorsiflexion and eversion of the subtalar joint were measured by using 3-dementional motion analysis during the active ankle dorsiflexion in prone position. Results : The muscle activity ratio of TA / EDL was significantly lower in the HT group compared to the NT group (p<.05). The angle of ankle dorsiflexion was significantly lower in the HT group compared to the NT group (p<.05). Conclusions : These results suggest that muscle imbalance between TA and EDL muscle and decreased ankle dorsiflexion range of motion may contribute to hammer toe deformity. Further studies are needed to confirm that the correcting of this imbalance and the increasing ankle dorsiflexion could improve toe alignment in the subjects with HT.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.81-88
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• 2018

PURPOSE: The present study aims to determine the effect of lower extremity muscle strength exercise at the non-paralyzed side of patients of stroke using a mirror on gait and balance. METHODS: Subjects were assigned randomly to a group of lower extremity exercise without using a mirror (n=10), a group of lower extremity motion exercise using a mirror (n=10), and a group of lower extremity muscle strength exercise using a mirror (n=10). The exercise is added to a physiotherapy program conducted at the hospital and subjects conducted their designed lower extremity exercises 30 times a day (5 sets), five days per week for four weeks. RESULTS: The study result showed that BBS(Berg balance scale)(p<.05) and TUG(timed up and go test)(p<.05) had a significant difference. In the comparison on gait ability, stride length, step length, step width and single support was a significant difference within two groups using a mirror before and after the intervention(p<.05). CONCLUSION: Conclusively, low extremity motion exercise using a mirror and low extremity muscle strength exercise using a mirror conducted along with general physiotherapy exercises had a positive effect on functions of lower extremity in patients with stroke and the recovery of paralyzed side thereby incurring a significant difference in balance and gait abilities.

• Wind and Structures
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• v.29 no.6
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• pp.441-455
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• 2019

In this study, vortex induced vibrations of a cylinder mounted on a flexible rod are analyzed. This simple configuration represents the key element of new conception bladeless wind turbine (Whitlock 2015). In this study the structure oscillations equation coupled to the wake oscillation equation for this configuration are solved using analytical perturbation method, for the first time. An analytical expression that predicts the lock-in phenomena range of wind speed is derived. The discretized equations of motion are also solved using RKF45 numerical method. The equations of motion are discretized by Galerkin method. Free vibration mode shape of the structure taking into account the discontinuity of the cross section are used as comparison function. Numerical results are compared to the analytical results, and they show a satisfying agreement. The effect of system parameters on the oscillations of structure and wake as well as on the lock-in domain are presented. Moreover, it is shown that the values of wind speed triggering the start and the stop of the lock-in phenomenon, for increasing wind speed are different from those values obtained during the reverse process, i.e., when the wind speed decreases.

• Korean Journal of Human Ecology
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• v.18 no.3
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• pp.729-740
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• 2009

This study is to research on the rate of expansion or contraction according to movement of the lower body of the man their twenties using Rapid Form software. And aim of this study is to get information of ease allowance in developing slacks pattern using 3D body surface scan data through comparison with existing slacks patterns. Considering on the contraction and expansion according to movement, it need to set the more ease allowance in hip circumference than waist circumference, and the more ease allowance in back hip width than front hip width in slacks. In crotch length, the length of front crotch is revealed contraction but the length of back crotch is revealed expansion. It is desirable lowering front waist line and raising back waist line to possess ease allowance in back crotch area. The length of side seam is revealed a little expansion but the length of inseam is showed a great expansion. To develop slacks pattern of scientific approach using 3D body surface scan data, it need to analysis the rate of expansion and contraction of the lower body based on the movement, shear deformation, slip in fabrics and skin, or in fabrics and fabrics, and slip down from waist line.

• Journal of the Institute of Convergence Signal Processing
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• v.6 no.3
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• pp.120-126
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• 2005

This paper presents the 3D wavelet based video compression system using quad-tree algorithm. The 3D wavelet based video compression system removes the temporal correlation of the input sequences using the motion compensation filter and decomposes the spatio-temporal subband using the spatial wavelet transform. The proposed system allocates the higher bit rate to the low frequency image of the 3D wavelet sequences and improves the 0.64dB PSNR performance of the reconstructed image in comparison with that of H.263. In addition to the limitation on the propagation of the motion compensation error by the 3D wavelet transform, the proposed system progressively transmits the input sequence according to the resolution and rate scalability.