• 한국공간구조학회논문집
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• 제4권4호
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• pp.65-76
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• 2004

Walking loads are usually considered as nodal loads in the finite element vibration analysis of structures subjected to walking loads. Since most of the walking loads act on elements not nodes, the walking loads applied on the elements should be converted to the equivalent nodal walking loads. This paper begins with measuring walking loads by using a force plate equipped with load cells and investigates the characteristics of the walking loads with various walking rates. It is found that the walking loads are more affected by walking rates than other parameters such as pedestrian weight, type of footwear, surface condition of floor etc. The measured walking loads are used as input loads for a finite element model of walking induced vibration. Finally, this paper proposes the equivalent nodal walking loads that are converted from the walking loads acting on elements based on finite element shape functions. And the proposed equivalent walking loads are proved to be applicable for efficient analysis of floor vibration induced by walking loads.

• 한국시스템다이내믹스연구
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• 제13권2호
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• pp.25-45
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• 2012

The purpose of this study is to estimate the effects of healthy city policies on residents' walking. In order to estimate promotion of walking rates by healthy cities policies, it developed System dynamics(SD)-based model which showed causal relationships among urban design, public health policies, and walking levels. SD technique is useful for future forecast and policy impact assessment. The spatial units of the SD-based system for policy impact assessment included 66 cities, counties, and communities in Seoul Metropolitan Area. The system simulation was planned to be run for 21 years from 2009 to 2030. For this study, 3 alternatives were proposed with combinations of length of bike lanes, number of bus routes, crime rates, self-reported good health status rates, and obesity rates. As a result of simulations, residents' participation rates for walking were increased from 1.00% to 9.98%. This study contributes to better understanding the benefits of healthy cities that are associated with individual walking. It further provided useful insights into planners' role in promoting health. The paper concluded with a discussion on future research opportunities and implications for public policies in urban and transportation and public health.

• The Korean Journal of Physiology
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• 제4권1호
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• pp.1-11
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• 1970

Studies on the analysis of walking were performed on 33 male subjects. A prescription of physical exercise (walking at a speed of greater than 6 km/hr for more than one hour daily) for the promotion of individual health is presented on the basis of walking analysis. Presumptions were made that adequate physical exercise does promote health and is beneficial for the healthy life and increases the life span. These presumptions were derived from the numerous experimental literatures. The literatures support indirectly the presumptions. The following results were obtained and prescription of physical exercise is presented. 1. Oxygen uptake in a walking on a treadmill at a speed of 4 km/hr was only 3 times of the resting oxygen uptake. This kind of moderate exercise did not stimulate the cardiopulmonary system adequately. Heart rate at a 4 km/hr walking was 101 beats/min in boys of less than 20 years old and 83 beats/min in adults. Oxygen uptake at a 6 km/hr walking exceeded 4 times of the resting oxygen uptake. It was interpreted that walking at 6 km/hr stimulated the cardiopulmonary system for the promotion of health. Heart rate at this speed was greater than 110 beats/min in boys and greater than 100 beats/min in adults. 2. Heart rates in a walking of 10 km/hr were 172 beats/min in boys, and 143 beats/min in adults, respectively. Maximal heart rates were 185 beats/min in boys, 180 in office clerks, and 168 beats/min in construction site laboreres. 3. The correlation between heart rate and oxygen uptake was high, namely, r>0.95. Subsequently heart rate could be used as a measure of degree of intensity of physical exercise instead of the cumbersome oxygen uptake measurement. 4. The prescription of physical exercise for the promotion of health is: Daily walking for more than one hour at a speed of greater than 6 km/hr. Bodily functions in this daily walking are in boys (body weight, 50 kg): heart rates of 110 beats/min; breathing frequency, 28/min; oxygen uptake, greater than 4 times of the resting uptake; pulmonary ventilation, 351/min; stride, 124 strides/min; cumulative number of strides for one hour, 7,440 strides, and energy expenditure of more than 300 kcal. In adults (body weight, 60 kg) the bodily functions are: heart rates of 100 beats/min, breathing frequency, 28/min; oxygen uptake, greater than 4 times of the resting uptake; Pulmonary ventilation, 301/min; stride, 127 strides/min; cumulative number of strides for one hour, 7,670 strides, and energy expenditure of more than 300 kcal.

• Structural Engineering and Mechanics
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• 제54권5호
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• pp.937-953
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• 2015

This paper investigates the load model for single footfall trace of human walking. A large amount of single person walking load tests were conducted using the three-dimensional gait analysis system. Based on the experimental data, Fourier series functions were adopted to model single footfall trace in three directions, i.e. along walking direction, direction perpendicular to the walking path and vertical direction. Function parameters such as trace duration time, number of Fourier series orders, dynamic load factors (DLFs) and phase angles were determined from the experimental records. Stochastic models were then suggested by treating walking rates, duration time and DLFs as independent random variables, whose probability density functions were obtained from experimental data. Simulation procedures using the stochastic models are presented with examples. The simulated single footfall traces are similar to the experimental records.

• 생명과학회지
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• 제13권1호
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• pp.21-28
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• 2003

본 연구의 목적은 10명의 비만여성을 체지방율에 의해 두 그룹(A:30~35%, B:35~40%)으로 분류하여 여러 동일한 속도(5.5, 6.0, 6.5, 7.0km.$hr^{-1}$)에서 걷기와 달리기 시 에너지 소비율과 심박수, 호흡교환율, 근동원량 등을 비교하는 것이었다. 본 실험결과 트레드밀 속도증가에 따른 산소 소비량은 두 그룹모두 걷기시 비선형적으로 증가하는 경향을 나타내었으나, 달리기 시에는 선형적 증가를 나타내어 두 그룹 모두에서 속도 6.5~7km/hr내에서 걷기의 에너지 소비율이 달리기시보다 높아지는 시점을 나타내었다. 두 그룹간 비교에서 유의한 차이는 나타나지 않았으나 A그룹 보다 B그룹이 다소 낮은 속도에서 걷기의 에너지효율성이 달리기시보다 떨어지는 경향을 보였다. 심박 수의 측정결과에서는 체 지방 율이 높은 그룹이 낮은 그룹보다 높은 심박 수 반응을 보여 체 지방 율이 높을수록 운동스트레스가 커지는 결과를 보였다. 호흡교환율 또한 체 지방 율이 낮은 그룹 보다 높은 그룹에서 운동시 탄수화물의 에너지참여비율이 높게 나타나 대사적 스트레스가 높은 것으로 나타났다. 이상의 결과로써 비만여성에서 걷기와 달리기 시 체 지방 율이 높을수록 대사적 스트레스를 증가시킬 수 있는 것으로 나타났고 에너지 소비 율도 영향을 받음으로써 걷기시 에너지 효율성에 비만인간 차이가 발생될 수 있지만, 이러한 차이는 크지 않은 것으로 생각된다.

• 한국환경생태학회지
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• 제9권1호
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• pp.49-55
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• 1995

본 연구는 계룡산 국립공원과 오대산 국립공원의 9개 등산로를 대상으로 등산로의 물리적 조건이 심장박동수에 미치는 영향을 밝히기 위하여 수행되었다. 산오르기 등산은 피검자가 에르고메타를 이용하여 측정한 최대심박수의 84~96%에 해당하는 고된 신체운동이며, 동일한 코스를 내려올 때의 최대심박수는 올라갈 때의 최대심박수에 약 78~93%에 해당하는 값을 나타내었다. 등산로의 경사도는 심박수에 영향을 미치는 것으로 나타났으나, 노폭은 심박수와 무관한 것으로 판단된다. 비시설 등산로에 비하여 나무 또는 돌계단식과 같은 등산로 노면재료가 심박수의 증가에 영향을 크게 미치는 것으로 나타났다.

• 한국전산구조공학회논문집
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• 제15권1호
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• pp.173-188
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• 2002

보행하중을 받는 바닥판 구조물의 진동해석을 위해서 일반적으로 계측한 보행하중을 적용하거나 Bachmann의 보행하중식을 사용하게 된다. 다양한 매개변수의 영향을 받는 보행하중은 계측이 쉽지 않으며 Bachmann 보행하중식은 보행진동수가 2.OHz와 2.4Hz로 제한적이기 때문에 다양한 보행진동수에 따른 보행하중을 적용하기가 곤란하다. 따라서 보행하중을 받는 구조물의 진동해석을 위해서 보행하중의 매개변수 분석과 다양한 보행진동수에 적용이 가능한 보행하중의 모형화가 필요하다. 본 논문에서는 로드셀이 장착된 계측 플레이트를 이용하여 바닥판에 가해지는 보행하중을 직접 계측하고 매개변수를 분석하였다. 그리고 퓨리에 변환을 이용하여 계측한 보행하중을 다양한 진동수를 가지는 조화하중으로 분해하였다. 분해과정을 거쳐 얻은 조화하중의 계수들을 보행진동수에 대한 일정한 함수관계로 유도하여 보행하중을 모형화하였다. 본 논문에서 제안한 보행하중식을 이용하면 다양한 보행진동수에 따라 다르게 나타나는 보행하중을 구조물의 진동해석에 용이하게 적용할 수 있다.

• Journal of Biosystems Engineering
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• 제33권5호
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• pp.326-332
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• 2008

A respiration measurement system for vital signs was developed. Respiration signals were measured, processed, and analyzed. Four electrodes, attached on the surface of the skin, were used to monitor respiration signals by impedance pneumography. The measured signals were amplified, detrended, filtered, and transferred toan embedded module. The Kalman filter was used to remove motion artifact from the respiration signals. Experiments were conducted at stable condition and walking condition to evaluate the performance of the system. Respiration rates of five males and five females were measured and analyzed at each condition. The referenced respiration signal was determined by temperature of nose surroundings. The results showed that the respiration rates at the walking condition had more motion artifacts than the stable condition. The accuracies of the respiration measurement system with Kalman filter were found as 96% at the stable condition and 95% at the walking condition. The results showed that the Kalman filter was an effective tool to remove the motion artifact from the respiration signal.

• 전기학회논문지
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• 제65권9호
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• pp.1551-1556
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• 2016

A combined CPG (Central Pattern Generator) based foot trajectory and GP (Genetic Programming) based joint compensation method is presented for the adaptive humanoid walking. The CPG based foot trajectory methods have been successfully applied to basic slops and variable slops with slow rates, but have a limitation for the steep slop terrains. In order to increase an adaptability of humanoid walking for the rough terrains, a GP based joint compensation method is proposed and combined to the CPG (Central Pattern Generator) based foot trajectory method. The experiments using humanoid robot Nao are conducted in an ODE based Webots simulation environmemt to verify a stability of walking for the various aslope terrains. The proposed method is compared to the previous CPG foot trajectory technique and shows better performances especially for the steep varied slopes.

• 대한지역사회영양학회지
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• 제21권6호
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• pp.520-532
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• 2016

Objectives: The objective of this study was to assess energy expenditure and metabolic cost (METs) of walking activities of college students and to compare treadmill based walking with self-selected hallway walking. Methods: Thirty subjects (mean age $23.4{\pm}1.6years$) completed eight walking activities. Five treadmill walking activities (TW2.4, TW3.2, TW4.0, TW4.8, TW5.6) were followed by three self-selected hallway walking activities, namely, walk as if you were walking and talking with a friend: HWL (leisurely), walk as if you were hurrying across the street at a cross-walk: HWB (brisk) and walk as fast as you can but do not run: HWF (fast) were performed by each subject. Energy expenditure was measured using a portable metabolic system and accelerometers. Results: Except for HWF (fast) activity, energy expenditures of all other walking activities measured were higher in male than in female subjects. The lowest energy expenditure and METs were observed in TW2.4 ($3.65{\pm}0.84kcal/min$ and $2.88{\pm}0.26METs$ in male), HWL (leisurely) ($2.85{\pm}0.70kcal/min$ and $3.20{\pm}0.57METs$ in female), and the highest rates were observed in HWF (fast) ($7.72{\pm}2.81kcal/min$, $5.84{\pm}1.84METs$ in male, $6.65{\pm}1.57kcal/min$, $7.13{\pm}0.68METs$ in female). Regarding the comparison of treadmill-based walking activities and self-selected walking, the energy expenditure of HWL (leisurely) was not significantly different from that of TW2.4. In case of male, no significant difference was observed between energy costs of HWB (brisk), HWF (fast) and TW5.6 activities, whereas in female, energy expenditures during HWB (brisk) and HWF (fast) were significantly different from that of TW5.6. Conclusions: In this study, we observed that energy expenditure from self-selected walking activities of college students was comparable with treadmill-based activities at specific speeds. Our results suggested that a practicing leisurely or brisk walking for a minimum of 150 minutes per week by both male and female college students enable them to meet recommendations from the Physical activity guide for Koreans.