• Title/Summary/Keyword: symmetric distance function

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Video Signature using Spatio-Temporal Information for Video Copy Detection (동영상 복사본 검출을 위한 시공간 정보를 이용한 동영상 서명 - 동심원 구획 기반 서술자를 이용한 동영상 복사본 검출 기술)

  • Cho, Ik-Hwan;Oh, Weon-Geun;Jeong, Dong-Seok
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.607-611
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    • 2008
  • This paper proposes new video signature using spatio-temporal information for copy detection. The proposed video copy detection method is based on concentric circle partitioning method for each key frame. Firstly, key frames are extracted from whole video using temporal bilinear interpolation periodically and each frame is partitioned as a shape of concentric circle. For the partitioned sub-regions, 4 feature distributions of average intensity, its difference, symmetric difference and circular difference distributions are obtained by using the relation between the sub-regions. Finally these feature distributions are converted into binary signature by using simple hash function and merged together. For the proposed video signature, the similarity distance is calculated by simple Hamming distance so that its matching speed is very fast. From experiment results, the proposed method shows high detection success ratio of average 97.4% for various modifications. Therefore it is expected that the proposed method can be utilized for video copy detection widely.

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The improvement of gait asymmetry ratio for hemiplegic patients by forceful respiratory exercise (노력성 호흡운동에 의한 편마비환자의 보행 비대칭율 개선)

  • Kim Byung-Jo;Lee Hyun-Ok;Ahn So-Youn
    • The Journal of Korean Physical Therapy
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    • v.16 no.4
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    • pp.38-58
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    • 2004
  • The regain of independent ambulatory ability is a important goal in the rehabilitation program of hemiplegic patient. Not only the function of lower extremity muscles, but also trunk muscles which stabilize extremities and pelvis, are important factors in normal gait. Therefor, it is necessary to develop an effective program which can improve muscle strength and symmetric activity of trunk muscles. The purpose of this study was to evaluate the influence of trunk muscle strengthening by forceful respiratory exercise on the gait asymmetry ratio in hemiplegic patient. 45 Hemiplegic patients due to stroke was randomized in 3 groups, forceful expiratory training(FET), forceful inspiratory training(FIT) and control group. In the experimental groups, ordinary physical therapy with forceful expiratory training and forceful inspiratory training for 20 minutes duration 3 times per week for 6 weeks were respectively performed. In the control group, only ordinary physical therapy was done. Before and after experiments, temporal-spatial gait parameters was measured in all patients. The data of 28 patients who carried out the whole experimental course were statistically analysed. The results of these experiment are as follows : 1. In comparison of difference of single support time asymmetry ratio among 3 groups, the FET group was significantly decreased than the control group (p<.05). 2. In comparison of difference of step length asymmetry ratio among 3 groups, the FIT group was significantly decreased than the control group (p<.05). Based on these results, it is concluded that the forced respiratory exercise program for 6 weeks can be improve the gait asymmetry ratio in hemiplegic patients. Therefore, the forced respiratory exercise is useful to improve the walking ability in hemiplegic patients. Since this study dealt only with the patients who could walk more than 3 meters in distance on floor independently, the further study for evaluating the influence of the forceful respiratory exercise on patients with acute stage stroke and also the development in various methods of use are expected.

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Numerical Simulation of Cone Penetration Tests in Sand Ground Using Critical State Mohr Coulomb Plasticity Model (한계상태 Mohr Coulomb 소성 모델을 활용한 콘관입시험의 수치적 모사)

  • Woo, Sang Inn;Chung, Choong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.35 no.2
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    • pp.37-51
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    • 2019
  • This study focuses on the numerical simulations of the cone penetration tests in a sand ground. The mechanical responses of sand were described using the modified Mohr Coulomb plasticity model based on the critical state soil mechanics. In the plasticity model, the dilatancy angle was not a constant, but a function of the distance to the critical state line from the current state of void ratio and mean effective stress. To simulate cone penetration tests numerically, this study relied on Lagrangian finite element method under the axisymmetric condition. To enable penetration of the cone penetrometer without tearing elements along the symmetric axis, the penetration guide concept was adopted in this study. The results of numerical simulations on the calibration chamber cone penetration tests had good agreement with the experimental results.