• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.142-143
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• 2013

• 한국융합학회논문지
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• 제11권5호
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• pp.175-182
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• 2020

계단 보행 시 로봇의 최적 궤도 계산은 유전자 알고리즘과 계산 토크 컨트롤러를 사용하여 수행되었다. 첫째, 생식, 교배, 돌연변이로 이루어진 실시간 유전 알고리즘 (RCGA)을 사용하여 총 에너지 효율이 최소화되었다. 보폭의 시작과 끝, 그리고 조인트, 각도, 각속도 위치 어셈블리 관련 재현성 조건은 선형 제약이다. 다음은 고르지 못한 제약은 코너 스윙 다리와 계단의 외부와의 충돌을 막기 위한 조건, 운동 학적 특이성을 막기 위한 무릎 관절의 조건 및 진행 방향의 안전은 보장되지 않음 이란 조건을 따른다. 마지막으로, 각 관절의 각도 궤도는 염색체를 근사 계수를 가지는 4차 다항식에 의해 정의된다. 이것은 보통 도보를 의미한다. 이 연구에서는 최적의 궤도의 에너지 효율을 7개의 링크로 구성된 7자유도의 2족 로봇을 통한 컴퓨터 시뮬레이션을 통해 분석했다.

• 원예과학기술지
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• 제33권1호
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• pp.133-142
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• 2015

This study aimed to identify the exercise intensity associated with four common physical activities for adults (running, skipping rope, walking, and muscle strength exercises) and two horticultural activities (creating a vegetable bed and garden maintenance). For this experiment, 19 males (mean age: $25.8{\pm}2.3$ years) randomly participated in the activities at a glasshouse at Konkuk University. Each of the six activities lasted for 5 minutes; the subjects rested for 5 minutes during intervals between the activities. A portable metabolic analyzer was used to store the oxygen and energy consumption values obtained upon measurement of each activity. In addition, a wireless heart rate monitor was used to measure the subjects' heart rate. According to the results, the four types of physical activities and two horticultural activities carried out by the subjects are moderate- to high-intensity activities [i.e., $3.8{\pm}0.9$ to $9.9{\pm}2.1$ metabolic equivalents (METs)]. Running ($9.9{\pm}2.1$ METs) and skipping rope ($8.8{\pm}2.2$ METs) were categorized as high-intensity physical activities, whereas creating a vegetable bed ($5.0{\pm}1.2$ METs), walking ($4.9{\pm}0.8$ METs), muscle strength exercises ($4.5{\pm}1.3$ METs), and garden maintenance ($3.8{\pm}0.9$ METs) were classified as moderate-intensity physical activities. The exercise intensities of horticultural activities in this study were similar to those of walking and muscle strength exercises. Therefore, participating in these horticultural activities is expected to garner health benefits similar to those reaped from the physical activities described in the current study.

• 대한기계학회논문집A
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• 제24권1호
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• pp.118-123
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• 2000

Most quadruped walking robots under current research are individually controlling every joint ic make them step or walk according to an integrated strategy. Such methods are characterized by at least one pair of an actuator and a sensor installed per each 'oint so that the robots weigh execssively and move inefficiently in terms of energy expenditure. In addition, the task of controlling all the joints simultaneously is quite complex and prone to destabilize the robot motion. These respects keep the existing walking robots away from realistic applications such as transportation even if they have potentially, outstanding adaptability to swamps or uneven terrains as opposed to wheeled vehicles. So, this paper presents a new conceptual quadruped robot developed to walk and steer only with a minimal number of actuators owing to a closed-chain mechanism. To prove its actual performance including the adaptability to various types of terrains. experiments are done with the mammal-type prototype. And. it is also shown that the same concept can be easily extended to carry out different gait forms. for instance, that of spiders only with minor modifications.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2493-2503
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• 2018

Passive dynamic walking exhibits humanoid and energy efficient gaits. However, optimal design of passive walker at multi-variable level is not well studied yet. This paper presents a Chaotic Particle Swarm Optimization (CPSO) algorithm and applies it to the optimal design of flexible passive walker. Hip torsional stiffness and damping were incorporated into flexible biped walker, to imitate passive elastic mechanisms utilized in human locomotion. Hybrid dynamics were developed to model passive walking, and period-one gait was gained. The parameters global searching scopes were gained after investigating the influences of structural parameters on passive gait. CPSO were utilized to optimize the flexible passive walker. To improve the performance of PSO, multi-scroll Jerk chaotic system was used to generate pseudorandom sequences, and chaotic disturbance would be triggered if the swarm is trapped into local optimum. The effectiveness of CPSO is verified by comparisons with standard PSO and two typical chaotic PSO methods. Numerical simulations show that better fitness value of optimal design could be gained by CPSO presented. The proposed CPSO would be useful to design biped robot prototype.

• 한국멀티미디어학회논문지
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• 제21권8호
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• pp.982-990
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• 2018

In recent years, many wearable devices and mobile apps related to life care have been developed, and a service for measuring the movement during walking and showing the amount of exercise has been provided. However, they do not measure walking in detail, so there may be errors in the total calorie consumption. If the user's behavior is measured by a multi-axis sensor and learned by a machine learning algorithm to recognize the kind of behavior, the detailed operation of walking can be autonomously distinguished and the total calorie consumption can be calculated more than the conventional method. In order to verify this, we measured activities and created a model using a machine learning algorithm. As a result of the comparison experiment, it was confirmed that the average accuracy was 12.5% or more higher than that of the conventional method. Also, in the measurement of the momentum, the calorie consumption accuracy is more than 49.53% than that of the conventional method. If the activity recognition is performed using the wearable device and the machine learning algorithm, the accuracy can be improved and the energy consumption calculation accuracy can be improved.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2012년도 전기공동학술대회 논문집
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• pp.206-207
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• 2012

여객선에서 불특정 일반 승선자의 피난성능 향상과 인명피해의 최소화를 위해 선박 내에서 피난자를 안전한 곳으로 유도하는 지능형 스마트카드 개발에 앞서 승선자의 피난특성을 연구해야 한다. 이에 비숙련 일반인을 대상으로 피난특성의 기본이 되는 보행속도 측정 데이터를 실측하였다.

• 대한물리치료과학회지
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• 제13권3호
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• pp.65-75
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• 2006

This study was to find out whether MBT shoes were more effective than general sporting shoes on the kinematic physiology. We comparatively analyzed energy consumption, heart rates, rating of perceived exertion, lactic acid density in blood and muscle activity with EMG. The subjects were 10 regular students of K Univ.(5 male and 5 female). They wore the general sporting shoes for stage 1(group 1), the MBT walking shoes for stage 2(group2) under the same conditions. There was one week interval between stages. 1. There was no significant difference in the energy consumption and the heart rates between two groups. Group 1 showed a higher energy consumption and heart rates than Group 2 under the speed of 4.0 mph. On the other hand, Group 2 showed higher ones over the speed of 4.0 mph. 2. There was no significant difference in the rating of perceived exertion and lactic acid density in blood between two groups. But Group 2 showed a lower fatigue strength than Group 1. 3. Group 2 showed a higher muscle activity with EMG than group 1, especially at the speed of 2.0, 2.5, 3.0, 3.5 mph in quadratus lumborum muscle and at 4.0mph in tibialis anterior muscle. In conclusion, we are less tired in MBT shoes than in general sporting shoes. Also, we can dorsiflex better in the ankle joint, straighten the lumbar region well and walk erect in MBT shoes. Specially, when it walks slowly, it is favorable in an erection walk and when it walks quickly, we have advantage of obesity management.

• 한국학교보건학회지
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• 제29권3호
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• pp.218-225
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• 2016

Purpose: The purpose of this study was to investigate the factors affecting energy drinks consumption among adolescents in South Korea. Methods: The study is a secondary analysis. Using statistics from the 11th (2015) Korea Youth Risk Behavior Web-based Survey, any variations among the subjects were presented as percentages and analyzed by $x^2$ test and logistic regression analysis. The study sample comprised 68,043 middle and high school students in South Korea. Results: In Model 1 including general characteristics, the significant factors of energy drinks consumption were gender, weekly allowance, cohabitation with family. and economic status. In the final model where health-related characteristics were added, the significant factors were gender, school type, weekly allowance, cohabitation with family, stress level, sadness, drinking, smoking and walking days. Conclusion: The result suggests that intensified education on energy drinks consumption is needed not only at schools, but in the whole community. Also, adolescents' awareness of potential health effects of energy drinks, in particular when mixed in alcoholic beverages, should be increased through health education.

• 대한의용생체공학회:의공학회지
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• 제27권6호
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• pp.301-309
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• 2006

The main purpose of this study is to derive a regression equation that predicts the individual differences in activity energy expenditure (AEE) using accelerometer during different types of activity. Two subject groups were recruited separately in time: One is a homogeneous group of 94 healthy young adults with age ranged from $20\sim35$ yrs. The other subject group has a broad spectrum of physical characteristics in terms of age and fat ratio. 226 adolescents and adults of age ranged from $12\sim57$ yrs and fat ratio from $4.1\sim39.7%$ were in the second group. The wireless 3-axis accelerometers were developed and carefully fixed at the waist belt level. Simultaneously the total calorie expenditure was measured by gas analyzer. Each subject performed walking and running at speeds of 1.5, 3.0, 4.5, 6.0, 6.5, 7.5, and 8.5 km/hr. A generalized sensor-independent regression equation for AEE was derived. The regression equation was developed fur walking and running. The regression coefficients were predicted as functions of physical factors-age, gender, height, and weight with multivariable regression analysis. The generalized calorie estimation equation predicts AEE with correlation coefficient of 0.96 and the average accuracy of the accumulated calorie was $89.6{\pm}7.9%$.