• 한국멀티미디어학회논문지
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• 제11권6호
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• pp.787-795
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• 2008

Human recognition on camera is an interesting topic in computer vision. While fingerprint and face recognition have been become common, gait is considered as a new biometric feature for distance recognition. In this paper, we propose a gait recognition algorithm based on the knee angle, 2 feet distance, walking velocity and head direction of a person who appear in camera view on one gait cycle. The background subtraction method firstly use for binary moving object extraction and then base on it we continue detect the leg region, head region and get gait features (leg angle, leg swing amplitude). Another feature, walking speed, also can be detected after a gait cycle finished. And then, we compute the errors between calculated features and stored features for recognition. This method gives good results when we performed testing using indoor and outdoor landscape in both lateral, oblique view.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2887-2890
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• 2003

This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh, knee, and foot, and two potential electrodes are applied to the lateral, medial, and posterior position of lower leg. The correlation coefficients of the joint angle and the impedance change from human leg movement was obtained using electrogoniometer and 4ch impedance measurement system developed in this study. We found the optimal electrode position for ankle, knee and hipjoint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. The correlation coefficients of the ankle, knee, and the hip movements -0.87, 0.957 and 0.80. respectively. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level. This system showed possibility that lower leg movement could be easily measured by impedance measurement system with a few skin-electrodes.

• 한국운동역학회지
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• 제16권2호
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• pp.145-151
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• 2006

A large interindividual variability and some abnormally kinematic patterns at the lower extremity were the main features of the gait in children with Down syndrome. The purposes of this study were to investigate the gait asymmetry and biomechanical difference between dominant leg and non dominant leg in children with Down syndrome. Seven boys with Down Syndrome(age: $120{\pm}0.9yrs$, weight $34.4{\pm}8.4kg$, leg length: $68.7{\pm}5.0cm$) participated in this study. A 10.0 m ${\times}$ 1.3 m walkway with a firm dark surface was built and used for data collection. Three-dimensional motion analyses were performed to obtain the joint angles and range of motions. The vertical ground reaction forces(%BW) and impulses($%BW{\cdot}s$) were measured by two force plates embedded in the walkway. Asymmetry indices between the legs were computed for all variables. After decision the dominant leg and the non dominant leg with max hip abduction angle, paired samples t-test was employed for selected kinematic and ground reaction force variables to analyze the differences between the dominant leg and the non dominant leg. The max hip abduction angle during the swing phase showed most asymmetry, while the knee flexion angle at initial contact showed most symmetry in walking and running. The dominant leg showed more excessive abduction of hip in the swing phase and more flat-footed contact than the non dominant leg. Vertical peak force in running showed more larger than those of in walking, however, vertical impulse showed more small than walking due to decrease of support time. In conclusion, the foot of dominant leg contact more carefully than those of non dominant leg. And also, there are no significant difference between the dominant leg and the non dominant leg in kinematic variables and ground reaction force due to large interindividual variability.

• 한국철도학회논문집
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• 제20권1호
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• pp.43-54
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• 2017

본 논문에서는 철도차량 추진시스템을 위한 3-레그 인버터와 5-레그 인버터의 성능을 비교/분석하고 철도차량에 5-레그 인버터를 적용함에 있어 최적의 동작 조건을 제시한다. 5-레그 인버터는 두 대의 3-레그 인버터에 비해 2개의 스위치가 감소되며, 하나의 제어보드로 두 대의 3상 전동기를 독립적으로 제어할 수 있다. 이로 인해 두 대의 3-레그 인버터를 이용할 경우보다 시스템의 비용 감소와 소형화가 가능하다. 본 논문에서는 먼저 도시철도 차량에서 사용중인 유도전동기 제어 기법과 PWM 방법을 분석한다. 다음으로 5-레그 인버터의 기본 동작과 특징을 분석한다. 이러한 분석을 바탕으로 동일한 유도전동기 제어 기법과 PWM 방법을 3-레그 인버터와 5-레그 인버터에 적용했을 때 유도전동기의 속도와 토크 특성을 비교하고 분석한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2891-2894
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• 2003

This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh and foot., and two potential electrodes are applied to the lateral aspect. medial aspect, and posterior position of lower leg. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least Interference, and maximum magnitude of impedance change. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.414-417
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• 2002

This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh and foot., and two potential electrodes are applied to the lateral aspect, medial aspect, and posterior position of lower leg. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.940-942
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• 2003

This paper describes the possibility of analyzing gait pattern from the variation of the lower leg electrical impedance. This impedance is measured by the four-electrode method. Two current electrodes are applied to the thigh and foot, and two potential electrodes are applied to the lateral aspect, medial aspect, and posterior position of lower leg. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. From such features of the lower leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권8호
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• pp.506-509
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• 2003

This paper describes the possibility of analyzing gait pattern from the changes of the lower leg electrical impedance. This impedance was measured by the four-electrode method. Two current electrodes were applied to the thigh, knee, and foot., and two potential electrodes were applied to the lateral, medial, and posterior position of human leg. The correlation coefficients of the joint angle and the impedance change from human leg movement was obtained using a electrogoniometer and 4ch impedance measurement system developed in this study. We found the optimal electrode position for knee and ankle joint movements based on high correlation coefficient, least interference, and maximum magnitude of impedance change. The correlation coefficients of the ankle, knee, and the hip movements were -0.913, 0.984 and 0.823, respectively. From such features of the human leg impedance, it has been made clear that different movement patterns exhibit different impedance patterns and impedance level. This system showed feasibility that lower leg movement could be easily measured by impedance measurement system with a few skin-electrodes.

• 대한간호학회지
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• 제42권3호
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• pp.396-404
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• 2012

Purpose: The purpose of this study was to identify the features, risk scores and risk factors for deep vein thrombosis in critically ill patients who developed deep vein thrombosis in their lower extremities. Methods: The participants in this prospective descriptive study were 175 adult patients who did not receive any prophylactic medication or mechanical therapy during their admission in the intensive care unit. Results: The mean age was 62.24 (${\pm}17.28$) years. Men made up 54.9% of the participating patients. There were significant differences in age, body mass index, and leg swelling between patients who developed deep vein thrombosis and those who did not have deep vein thrombosis. The mean risk score was 6.71(${\pm}2.94$) and they had on average 4.01(${\pm}1.35$) risk factors. In the multiple logistic regression, body mass index (odds ratio=1.14) and leg swelling (odds ratio=6.05) were significant predictors of deep vein thrombosis. Conclusion: Most critically ill patients are in the potentially high risk group for deep vein thrombosis. However, patients who are elderly, obese or have leg edema should be closely assessed and more than one type of active prophylactic intervention should be provided.

• Structural Engineering and Mechanics
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• 제76권3호
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• pp.367-378
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• 2020

This paper presents a new design concept for ocean nuclear power plants (ONPPs) using a tension leg platform (TLP). The system-integrated modular advanced reactor, which is one of the successful small modular reactors, is mounted for demonstration. The authors define the design requirements and parameters, modularize and rearrange the nuclear and other facilities, and propose a new total general arrangement. The most fundamental level of design results for the platform and tendon system are provided, and the construction procedure and safety features are discussed. The integrated passive safety system developed for the gravity based structure-type ONPP is also available in the TLP-type ONPP with minor modifications. The safety system fully utilizes the benefits of the ocean environment, and enhances the safety features of the proposed concept. For the verification of the design concept, hydrodynamic analyses are performed using the commercial software ANSYS AQWA with the Pierson-Moskowitz and JONSWAP wave spectra that represent various ocean environments and the results are discussed.