• Title/Summary/Keyword: Gait Transition

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The Improved Joint Bayesian Method for Person Re-identification Across Different Camera

  • Hou, Ligang;Guo, Yingqiang;Cao, Jiangtao
    • Journal of Information Processing Systems
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    • v.15 no.4
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    • pp.785-796
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    • 2019
  • Due to the view point, illumination, personal gait and other background situation, person re-identification across cameras has been a challenging task in video surveillance area. In order to address the problem, a novel method called Joint Bayesian across different cameras for person re-identification (JBR) is proposed. Motivated by the superior measurement ability of Joint Bayesian, a set of Joint Bayesian matrices is obtained by learning with different camera pairs. With the global Joint Bayesian matrix, the proposed method combines the characteristics of multi-camera shooting and person re-identification. Then this method can improve the calculation precision of the similarity between two individuals by learning the transition between two cameras. For investigating the proposed method, it is implemented on two compare large-scale re-ID datasets, the Market-1501 and DukeMTMC-reID. The RANK-1 accuracy significantly increases about 3% and 4%, and the maximum a posterior (MAP) improves about 1% and 4%, respectively.

Lower Extremity Biomechanics while Walking on a Triangle-Shaped Slope (삼각경사면 보행 시 하지 관절 생체역학적 분석)

  • Hong, Yoon No Gregory;Jeong, Jiyoung;Kim, Pankwon;Shin, Choongsoo S.
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.3
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    • pp.153-160
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    • 2017
  • Gait analysis has been conducted in various environments, but the biomechanics during the transition from uphill walking to downhill walking have not been reported. The purpose of this study is to investigate the knee and ankle joint kinematics and kinetics during walking on a triangle-shaped slope compared with those during level walking. Kinematic and kinetic data of eighteen participants were obtained using a force plate and motion capture system. The greater peak ankle dorsiflexion angle and moment and the peak knee extension moment were observed (p<0.05) during both uphill and downhill walking on the triangle-shaped slope. In summary, uphill walking on a triangle-shaped slope, which showed a peak knee flexion of more than $50^{\circ}$ with greater peak knee extension moment, could increase the risk of patellofemoral pain syndrome. Downhill walking on a triangle-shaped slope, which involved greater ankle dorsiflexion excursion and peak ankle dorsiflexion, could cause gastrocnemius muscle strain and Achilles tendon overuse injury.

Relationship between Walking Speed and Smoothness of Movement (보행속력과 동작의 부드러움과의 상관관계에 관한 연구)

  • Tack, Gye-Rae;Han, Young-Min;Choi, Jin-Sung;Yi, Jeong-Han;Lim, Young-Tae;Jun, Jae-Hoon;Park, Sang-Kyoon;Stephanyshin, Darren;Park, Seung-Ha
    • Korean Journal of Applied Biomechanics
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    • v.16 no.1
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    • pp.11-17
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    • 2006
  • The purpose of this study was to evaluate the smoothness of movement during various walking speeds. Based on the maximum smoothness theory (or the minimum jerk theory), we hypothesized that the walking speed at the maximum smoothness (or minimum normalized jerk) is the same as that at the minimum energy consumption. Eleven university students participated in treadmill walking experiment with 11 different walking speeds (1.11, 1.19, 1.25, 1.33, 1.56, 1.78, 1.9, 2, 211, 233, and 2.47m/sec). Normalized jerk at 15 markers and the center of mass was calculated. Results showed that there existed a quadratic relationship between the normalized jerk of the vertical direction at the center of mass and the walking speed As the walking speed increased, the normalized jerk of all directions at the heel decreased Our hypothesis that the previously published energetically optimal walking speed ($1.25\;{\sim}\;1.4m/s$) is the same as the minimum jerk speed (1.78m/s) did not agree with this result. The minimum normalized jerk at the center of mass occurred at the walking speed of 1.78m/s which was the preferred walking speed by subjects' questionaries. Further studies concerning the energetically optimal walking speed, preferred walking speed, and walk-run transition speed or run-walk transition speed are necessary based on actual energy consumption experiment and various multi-dimensional analysis.

Precision Circular-path Walking of a Biped Robot with Consideration of Rotational Effects (회전효과를 고려한 이족 로봇의 정밀 원형 경로 보행)

  • Lim, Seungchul;Kwak, Byungmoon;Lim, Jooyoung;Son, Youngik
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.4
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    • pp.299-309
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    • 2014
  • When biped robots make turns, the ability to walk stably and precisely along any circular path is crucial. In this context, inverse kinematics solutions are found for accurate gait realization, and new zero moment point(ZMP) equations are derived with respect to the cyclindrical coordinate system to facilitate generation of stable walking patterns. Then, appropriate steady and transitional walking patterns are both proposed in form of time functons. Subsequently, walking patterns for a path but of different speeds are generated using the functions and associated formulas, and preliminarily checked for stability based on the ZMP equations. Upon comparison of those cases, one can see how and when robots may fall down during circular walking. Finally, those patterns are put to test on the sample robot by ADAMS(R) along with the inverse kinematics solutions and a new balance control scheme compensating for insufficient stability particulary during the initial transition period. Test results show that the robot can walk along the circular path as predicted at a resonably high speed despite the distributed mass and ground contact effects, validating effectiveness of the suggested approach.

The Effect of Watsu Therapy on Muscle Tone in Adult Hemiparesis Patient After Stroke (Watsu 치료가 뇌졸중 이후 성인 편부전마비환자의 근긴장도에 미치는 영향)

  • Chon, Seung-Chul
    • Journal of Korean Physical Therapy Science
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    • v.11 no.2
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    • pp.46-56
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    • 2004
  • The purpose of this study was to investigate the effect of watsu therapy on muscle tone in adult hemiparesis patient after stroke. The subject was a 66 year old patient with left hemiparesis whose self gait was independent with minimal assist. The subject was ambulatory with some degree of limitation and demonstrated a little tremor and asymmetry in the body. A multiple treatment design(A-B-C-B) for a single-subject research was used for this study. The watsu therapy consisted of basic moves, head cradle, underfar leg, near leg cradle in watsu I (transition flow), for 25 minutes, which lasted 12 sessions for a total 21 sessions. A baseline was conducted for a first time and a general ROM exercise was conducted after the first watsu therapy. Tone assessment scale was tested : 1. posturing at rest 2. response to passive movement 3. associated reaction Comparing to the baseline and general ROM exercise, The results showed that the watsu therapy had some positive effects on improvement of three tests and there was a more positive effects of both response to passive movement and associated reaction.

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Movements of the Center of Pressure During Stance Phase in Free Level Walking of Normal Adults (정상인의 지면수평자보행에 대한 입각기 압력중심의 이동)

  • 김영호;양길태;문무성;박시복
    • Journal of Biomedical Engineering Research
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    • v.20 no.5
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    • pp.587-592
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    • 1999
  • 압력측정시스템은 입각기동안 동적압력분포를 성공적으로 측정할 수 있으나 하중수용기-중간입각기, 말기입각기-전유각기의 전환기들에 대해서는 운동분석시스템을 사용하지않고는 정확한 정의가 불가능하다. 따라서 저자들은 수평자유보행 시 압력중심의 이동을 이해하기 위해서 정상적인 발을 가진 20-30대 성인남자 78명을 대상으로 동작분석과발바닥 압력측정을 동시에 수행하였다. 결과로 하중반응기-중간입각기 전환시기의 발바닥 압력중심점은 후족부와 중족부의 경계선에서 앞쪽으로 1.9$\pm$1.5frame(32$\pm$24msec)에 위치하였으며 말기입각기-전유각기 전환시기에는 중족골두 최대 압력점의 앞쪽으로 2.3$\pm$2.0 frame(38$\pm$33msec)에 위치하였다. 정상수평보행에 있어서 최초접지 순간 압력중심은 전방으로 빠르게 이동하다가 바로 급속히 감소하여 하중반응기-중간입각기의 전환시기에는 작은 속도로 이동하였다. 압력중심의 이동속도는 그 후 다시 서서히 증가하다가 전체 보행주기의 25% 전후에서 서서히 감소하여 비교적 일정하다가 말기입각기-전유각기의 전환시점에서 다시 급격한 증가를 보였다. 족부질환과 보행특성을 판단하는데 있어서 압력중심의 이동궤적은 매우 유용한 인자가 될 것으로 기대된다. 본 연구를 통해서 압력측정시스템만으로는 정의할 수 없었던 두 전환기인 하중반응기-중간입각기, 말기입각기-전유각기를 결정할 수있게 되었다.

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Aneurysmal Bone Cyst in a Pomeranian (포메라이언견에서 발생한 동맥류성 골낭종 1례)

  • Shin, Beom-Jun;Lee, Jae-Yeon;Kim, Soo-Hyun;Park, Ji-Young;Lee, Young-Won;Cho, Sung-Whan;Kim, Myung-Cheol;Jeong, Seong-Mok
    • Journal of Veterinary Clinics
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    • v.27 no.1
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    • pp.117-120
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    • 2010
  • A 5-years-old 3.7 kg intact female Pomeranian dog was presented with the history of swelling and pain in the distal part of the right forelimb. The swollen lesion was firm as bony material on palpation. On radiographic examination, there was a well-marginated, radiolucent, and expansile bone lesion in the distal metaphysis of the right ulna. Because of very narrow zone of transition, well-defined margins and absence of any periosteal reactivity, benign bone cyst was strongly suspected. The lesion was removed by en bloc resection and packed the space with $Gelfoam^{(R)}$ and aneurysmal bone cyst was finally diagnosed according to histopathological examination. Normal gait was showed on postoperative day 9 and there have been no pain and complication for 1 year since then.

Intelligent Control of a Virtual Walking Machine for Virtual Reality Interface (가상현실 대화용 가상걸음 장치의 지능제어)

  • Yoon, Jung-Won;Park, Jang-Woo;Ryu, Je-Ha
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.9
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    • pp.926-934
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    • 2006
  • This paper proposes intelligent control of a virtual walking machine that can generate infinite floor for various surfaces and can provide proprioceptive feedback of walking to a user. This machine allows users to participate in a life-like walking experience in virtual environments with various terrains. The controller of the machine is implemented hierarchically, at low-level for robust actuator control, at mid-level fur platform control to compensate the external forces by foot contact, and at high-level control for generating walking trajectory. The high level controller is suggested to generate continuous walking on an infinite floor for various terrains. For the high level control, each independent platform follows a man foot during the swing phase, while the other platform moves back during single stance phase. During double limb support, two platforms manipulate neutral positions to compensate the offset errors generated by velocity changes. This control can, therefore, satisfy natural walking conditions in any direction. Transition phase between the swing and the stance phases is detected by using simple switch sensor system, while human foot motions are sensed by careful calibration with a magnetic motion tracker attached to the shoe. Experimental results of walking simulations at level ground, slope, and stairs, show that with the proposed machine, a general person can walk naturally on various terrains with safety and without any considerable disturbances. This interface can be applied to various areas such as VR navigations, rehabilitation, and gait analysis.

Experimental Research for Traction force Sensor Development on Drawing Exercise Medical Instrument (재활 및 교정을 위한 견인운동치료기의 견인측정센서 개발에 관한 실험적 연구)

  • Lee, Sang-sik;Park, Won-yeop;Lee, Choong-ho
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.2
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    • pp.3-8
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    • 2009
  • The traction system has been mainly used for rehabilitation and correction of patients with spine or gait diseases in orthopedics or at home. Some problems could occur in human body when patients forced their training using the traction system. So it needs to measure a traction force and control the training time. However, most of products on market have no sensor measuring traction force. Thus we designed and made a sensor detecting traction force using strain gauge, amplifier for transition to output signal and experiment devices for performance test. We carried out experiment of a sensor detecting a traction force and measured electric responses of it with respect to traction loads. Maximum error was within about 1% for experiments in static condition and the average error was about 0.7% for experiments in dynamic condition. We concluded that it is possible to use the developed sensor for measurement of traction force since the maximum output variation of a sensor detecting a traction force was about 0.3% in $0^{\circ}C-60^{\circ}C$ temperature condition.

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