• Journal of KIISE:Software and Applications
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• v.33 no.5
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• pp.499-507
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• 2006

Recently human gait has been considered as a useful biometric supporting high performance human identification systems. This paper proposes a view-based pedestrian identification method using the dynamic silhouettes of a human body modeled with the Hidden Markov Model(HMM). Two types of gait models have been developed both with an endless cycle architecture: one is a discrete HMM method using a self-organizing map-based VQ codebook and the other is a continuous HMM method using feature vectors transformed into a PCA space. Experimental results showed a consistent performance trend over a range of model parameters and the recognition rate up to 88.1%. Compared with other methods, the proposed models and techniques are believed to have a sufficient potential for a successful application to gait recognition.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.1
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• pp.100-108
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• 2008

This paper proposes a method of adaptively generating a gait pattern of biped robot. The gait synthesis is based on human's gait pattern analysis. The proposed method can easily be applied to generate the natural and stable gait pattern of any biped robot. To analyze the human's gait pattern, sequential images of the human's gait on the sagittal plane are acquired from which the gait control values are extracted. The gait pattern of biped robot on the sagittal plane is adaptively generated by a genetic algorithm using the human's gait control values. However, galt trajectories of the biped robot on the sagittal Plane are not enough to construct the complete gait pattern because the bided robot moves on 3-dimension space. Therefore, the gait pattern on the frontal plane, generated from Zero Moment Point (ZMP), is added to the gait one acquired on the sagittal plane. Consequently, the natural and stable walking pattern for the biped robot is obtained.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1292-1294
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• 2015

4족 보행 로봇이 환경에 동적으로 적응하여 자신에게 최적의 운동을 만들어 내는 연구는 중요하다. 우리는 유전알고리즘을 이용하여 전진 걸음새 동적 학습 시스템을 제안하였다. 이 시스템의 핵심은 로봇의 운동과 이 운동의 결과를 피드백해주는 센서들이다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.294-300
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• 2013

The purpose of this study was to analyse the effects of yoga exercise on balance ability and gait velocity in stroke patients. Subjects were categorized in to a control group and yoga program group with 9 for each group. Yoga program was conducted for 60minute for 8weeks, three times a week. For the purposes, the study measured Stability Index(SI, postural sway) and Weight Distribution Index(WDI) using Tetrax, Functional Reach Test(FRT), Dynamic Gait index(DGI) and 10 meter walking test. At pre- and post-exercise after appling the yoga exercise, the data was analyzed. Yoga exercise group's SI and WDI were decreased, FRT and DGI were increased in comparison with control group. But 10 meter walking test was no significance. It suggests that the yoga exercise could promote recovery from balance disorder after stroke.

• Smart Media Journal
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• v.1 no.2
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• pp.12-22
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• 2012

Today we are witnessing an increasingly widespread use of cameras in our lives for video surveillance, robot vision, and mobile phones. This has led to a renewed interest in computer vision in general and an on-going boom in human activity recognition in particular. Although not particularly fancy per se, human gait is inarguably the most common and frequent action. Early on this decade there has been a passing interest in human gait recognition, but it soon declined before we came up with a systematic analysis and understanding of walking motion. This paper presents a set of DBN-based models for the analysis of human gait in sequence of increasing complexity and modeling power. The discussion centers around HMM-based statistical methods capable of modeling the variability and incompleteness of input video signals. Finally a novel idea of extending the discrete state Markov chain with a continuous density function is proposed in order to better characterize the gait direction. The proposed modeling framework allows us to recognize pedestrian up to 91.67% and to elegantly decode out two independent gait components of direction and posture through a sequence of experiments.

• 한국노년학
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• v.29 no.4
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• pp.1261-1275
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• 2009

Age related decrease of muscle strength, balance, and gait abilities bring about physical inactivity in the elderly. Virtual reality (VR) training has been used successfully to rehabilitate functional balance and mobility in elderly subjects. This study was aimed at determining the effect of VR-based exercise programs by using a video game on the muscle strength, balance, and gait abilities in the elderly. 48 old people were randomly divided into two groups; VR-group (men: 11, women: 14, age: 68.42yrs) and control group (men: 10, women: 13, age: 67.58yrs). VR-group performed an exercise program twice a week for 8 weeks and control group had no intervention. The VR-based exercise program was composed of warm up(10 mins), VR-program(40 mins), and cool down(10mins). It was performed by playstation eyetoy play that provided visual and auditory feedback as well as movements of the upper and lower extremities. Muscle strengths of the knee and ankle were measured using manual muscle tester. Static balance was estimated using computerized posturography. Dynamic balance was measured by Timed up and go test (TUG), Functional reach test (FRT). 10m walk test and 6-min walk test were used to assess gait abilities. After the completion of the VR-exercise program, muscle strength, balance, and gait abilities were improved significantly (p<0.05). In conclusion, the VR-based exercise program showed improvement on the muscle strength, balance, and gait ability in the elderly. This exercise program is both effective and interesting for this age group.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.566-569
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• 2000

This hybrid position/force control for the dynamic walking of the biped robot is performed in this paper. After the biped robot was modeled with 14 degrees of freedom of the multibody dynamics, the equations of motion are constructed using velocity transformation technique. Then the inverse dynamic analysis is performed for determining the driving torques and the ground reaction forces. From this analysis, obtains the maximum ground contact force at the moment of contacting which act on the rear of the sole of swing leg and the distribution curve of the ground reaction. Because these maximum force and distribution type acts an important role to the stability of the whole dynamic walking, they are reduced and distributed smoothly by means of the trajectory of the modified ground reaction force. This new trajectory is used to the reference input for more stable dynamic walking of the whole walking region.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.9
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• pp.133-144
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• 2000

The dynamic walking planning and the inverse dynamics of the biped robot is investigated in this paper. The biped robot is modeled with 14 degrees of freedom rigid bodies considering the walking pattern and kinematic construction of humanoid. The method of the computer aided multibody dynamics is applied to the dynamic analysis. The equations of motion of biped are initially represented as terms of the Cartesian corrdinates then they are converted to the minimum number of equations of motion in terms of the joint coordinates using the velocity transformation matrix. For the consideration of the relationships between the ground and foot the holonomic constraints are added or deleted on the equations of motion. the number of these constraints can be changed by types of walking patterns with three modes. In order for the dynamic walking to be stabilizable optimized trunk positions are iteratively determined by satisfying the system ZMP(Zero Moment Point) and ground conditions.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.548-555
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• 2000

The dynamic walking and the inverse dynamics of the biped walking robot is investigated in this paper. The biped robot is modeled with 14 degrees of freedom rigid bodies considering the walking pattern and kinematic construction of humanoid. The method of the computer aided multibody dynamics is applied to the dynamic analysis. The equations of motion of biped are initially represented as terms of the Cartesian coordinates, then they are converted to the minimum number of equations of motion in terms of the joint coordinates using the velocity transformation matrix. For the consideration of the relationships between the ground and foot, the holonomic constraints are added or deleted on the equations of motion. The number of these constraints can be changed by types of walking pattern with three modes. In order for the dynamic walking to be stabilizable, optimized trunk positions are iteratively determined by satisfying the system ZMP(Zero Moment Point) and ground conditions.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.5
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• pp.35-45
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• 2001

Recently, the floor systems those require large open space may have low inherent damping due to the decline of the use of curtain walls. Furthermore, the use of the high strength materials has resulted in more flexible and longer spanning in floor systems. The long span structures such as shopping malls, offices and large assembly rooms may lead to significant dynamic response due to human activities. Excessive vibrations make the occupants uncomfortable and deteriorate the serviceability of buildings. It is now proved that footfall loading is the major source of floor vibrations. The common method of application of walking loads for the vibration analysis of structures subjected to walking loads is to inflict measured walking loads and periodic function at a node. But this method could not account for the moving effect of walking. In this study, natural frequency and damping ratio of example structure are evaluated by heel drop tests. And the application of equivalent walking loads is used for on efficient vibration analysis of the plate structures subjected to walking loads.