• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.319-320
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• 2007

신경망이나 퍼지 시스템을 사용한 이족 보행 궤적 생성에 대한 연구는 있으나 로봇의 중심점이 변경되는 상황에 대한 보행 궤적 생성은 부족한 실정이다. 본 논문에서는 이족 보행 로봇의 보행에 대해 정의하고, 이를 기반으로 물체 운반시의 유전자 알고리즘을 통한 보행 궤적 생성을 제안하였다. 유전자 알고리즘은 최적화 문제에 있어서 기존의 다른 알고리즘보다 전역적이고 강인한 최적화 방법을 제시하면서도 간단한 구조로서 동작하는 장점을 가지고 있다. 따라서 본 연구에서는 기존 연구를 통해 구해진 로봇의 보행궤적을 모태로 부분 사상 교배, 순서교배, 주기교배의 교배 연산자를 순차적으로 이용하여 물체 운반시의 보행 궤적을 구하고 이를 검증하였다.

• Journal of Intelligence and Information Systems
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• v.15 no.4
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• pp.53-64
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• 2009

This paper presents a performance evaluation of shape descriptors for gait analysis in case of silhouette sequence images. We used moment descriptors(MD), Fourier descriptors(FD) and Zernike descriptors(ZD) as a shape descriptor. To evaluate their performance, we firstly defined the performance index, that is, AI(asymmetry index) and PI(periodic index) based on the periodic property of the gait images. This is why they are represented by periodic parameters due to periodic gait images. This index means that how the shape is represented periodically. According to these indexes, we evaluated the data sets with periodic images, downloaded from internet. The results showed that Zernike descriptors had better performance of AI = 1.09 and PI = 2.21 than others. And in case of FD and ZD, it's efficient to implement the gait analysis with 5~10 parameters.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.235-242
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• 1985

The mechanics of the walking shrimps is useful to clarify the fishing mechanisms in relation to the fishing gears. The gaiting behaviour concerning step positions and step timings on the flat board and the nettings, 16, 23 and 37mm in mesh size were experimented in the aquarium using video camera from June to October, 1984. It was found that the irregular movements of walking legs in step positions and step patterns were appeared on the nettings more than the flat surface due to the absence of mechanical contact with the substrates. The mean stride length and coefficient of variation of the periods in the walking shrimps on the flat board were significantly different from those values on the nettings, However, the velocity, the period and the ratio of forestroke to backstroke were unsteadily changed with the carapace length, and showed little difference under the four conditions. The mean phase difference on the flat board was greater than those values on the nettings which were decreased, while standard deviation on the flat board was smaller than those values on the nettings which were increased with increasing in mesh size.

• Journal of the Korea Society of Computer and Information
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• v.19 no.8
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• pp.119-127
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• 2014

TIn this paper, Hemiplegic patients have gait characteristics different from normal persons. This paper presents a posture measuring and display system reflecting their characteristics. Patients wear 3 sensor modules on thigh, calf and foot. To enhance measuring precision of each sensor module, 3D accelerometer and 3D gyroscope are combined. Gait posture is displayed in 3D by modeling thigh, calf and foot as connected 3D objects based on data of the sensor modules. For convenience in inspecting unusual gait posture of hemiplegic patients, any view angle of the 3D display can be selected. In addition, the current gait phase of RLA(Rancho Los Amigos) gait cycle is determined and displayed in real-time by utilizing the posture information, The phase sequence and duration of each phase can be used in evaluating gait quality of patients.

• Journal of Digital Convergence
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• v.15 no.4
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• pp.529-536
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• 2017

The purpose of this study is to examine the immediate effects of spiral taping applied to an affected leg on gait ability in stroke patients. Forty two stroke patients were divided into a spiral taping group (n=21) and a quadriceps femoris group (n=21), and each taping method was applied. Spatiotemporal Gait Parameters (Cadence, speed, gait cycle duration, stance phase duration, double support duration) were measured using the 10-meter walk test, the dynamic gait index (DGI) and an accelerometer for both groups. Both groups showed a significant increase in a 10-minute walk, the DGI, cadence, speed before and after the intervention, whereas no significant difference was detected in stance phase duration, gait cycle duration and double support duration on the affected side in all groups. All groups revealed no significant difference in variation. It has been found that the two taping methods augment gait ability in patients with stroke. This study suggests that spiral taping can be an easily applicable method at home.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1241-1251
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• 2016

We consider a correlated discrete-time random walk in which the current jump size depends on the previous jump size and a noncorrelated discrete-time random walk where the jump size is determined independently. By using the strong law of large numbers of Markov chains we derive the formula for the asymptotic means of the random mixture and the periodic pattern of these two random walks and then we show that there exists Parrondo's paradox where each random walk has mean 0 but their random mixture and periodic pattern have negative or positive means. We describe the parameter sets at which Parrondo's paradox holds in each case.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.204-207
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• 2005

Until present, most studies about energy efficiency of quadruped walking robot are mathematical modelings, dynamic analysis or simulation consumption energy per period by basic efficiency evaluate in this paper, a quadruped walking robot Titan-VIII is used for walking experience. The total moving length is about 2[m]. The stride length is 0.1, 0.2, 0.3, walking period is changed by 1.0, 1.5, 2.0, 3.0[sec] per each stride length. So consumption energy of 12 cases are measured. The energy efficiency of quadruped walking robot was analyzed by data that is saved by an experiment.

• 전자공학회논문지 IE
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• v.43 no.4
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• pp.52-59
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• 2006

Walking robot is able to move in regular or irregular terrain. It can walk that change adaptive algorithms according to the terrain. Existing papers about adaptive gaits of blind robot are based on intelligent foothold selection. However, this paper proposes a algerian that is based on the variations of stroke and period to adapt the irregular terrain. If thus adaptive algorithms is used, robot can maintain periodic gait walking and constant speed using only force sensor even in the irregular terrain without external sophisticated sensor. In this paper Quadruped robot with 2 DOF in each leg, is walk experiment with the wave gait in regular and irregular terrain. So the adaptive algorithm is proved useful through walk experiment.

• Journal of Biomedical Engineering Research
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• v.24 no.4
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• pp.363-367
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• 2003

Contact area and pressure are important factors which directly influence a life of knee implants. Since implant's mechanical functions should be experimentally evaluated for clinical use, many studies using a knee simulator and a pressure sensor system have been conducted. However it has not been reported that the contact pressure's distribution of a knee implant motion was estimated in real-time during a gate cycle. Therefore. the objective of this study was to analyze the contact pressure distribution for the motion of a joint using the knee simulator and I-scan sensor system. For this purpose, we developed a force-controlled dynamic knee simulator to evaluate the mechanical performance of artificial knee joint. This simulator includes a function of a soft tissue and has a 4-degree-of-freedom to represent an axial compressive load and a flexion angle. As axial compressive force and a flexion angle of the femoral component can be controlled by PC program. The pressure is also measured from I-scan system and simulator to visualize the pressure distribution on the joint contact surfaces under loading condition during walking cycle. The compressive loading curve was the major cause for the contact pressure distribution and its center move in a cycle as to a flexion angie. In conclusion, this system can be used to evaluate to the geometric interaction of femoral and tibial design due to a measured mechanical function such as a contact pressure, contact area and a motion of a loading center.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.6
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• pp.88-95
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• 2020

In this paper, we propose a new arm swing walking pattern-based walking safety system for safe walking of elderly pedestrians. The proposed system is a walking safety system for elderly pedestrians using haptic-based devices such as smart bands and smart watches, and arm swing-based walking patterns to solve the problem that it is difficult to recognize the fall situation of pedestrians with the existing walking patterns of lower limb movements. Use. The arm swing-based walking pattern recognizes the number of steps and the fall situation of pedestrians through the swing of the arm using the acceleration sensor of the device, and creates a database of the location of the fall situation to warn elderly pedestrians when walking near the expected fall location. It delivers a message to provide pedestrian safety to the elderly. This system is expected to improve the safe walking rights and environment of the elderly.