• 한국전문물리치료학회지
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• 제20권3호
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• pp.89-99
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• 2013

The purposes of this study were: 1) to show the item difficulty hierarchy of walking/moving construct of the International Classification of Functioning, Disability and Health-Activity Measure (ICF-AM), 2) to evaluate the item-level psychometrics for model fit, 3) to describe the relevant physical activity defined by level of activity intensity expressed as Metabolic Equivalent of Tasks (MET), and 4) to explore what extent the empirical activity hierarchy of the ICF-AM is linked to the conceptual model based on the level of energy expenditure described as MET. One hundred and eight participants with lower extremity impairments were examined for the present study. A newly created activity measure, the ICF-AM using an item response theory (IRT) model and computer adaptive testing (CAT) method, has a construct on walking/moving construct. Based on the ICF category of walking and moving, the instrument comprised items corresponding to: walking short distances, walking long distances, walking on different surfaces, walking around objects, climbing, and running. The item difficulty hierarchy was created using Winstep software for 20 items. The Rasch analyses (1-parameter IRT model) were performed on participants with lower extremity injuries who completed the paper and pencil version of walking/moving construct of the ICF-AM. The classification of physical activity can also be performed by the use of METs that is often preferred to determine the level of physical activity. The empirical item hierarchy of walking, climbing, running activities of the ICF-AM instrument was similar to the conceptual activity hierarchy based on the METs. The empirically derived item difficulty hierarchy of the ICF-AM may be useful in developing MET-based activity measure questionnaires. In addition to convenience of applying items to questionnaires, implications of the finding could lead to the use of CAT method without sacrificing the objectivity of physiologic measures.

• 융복합기술연구소 논문집
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• 제4권2호
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• pp.55-59
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• 2014

A cat is able to quickly recover balance from unstable posture. To observe the balance recovery procedure of the cat, an impulse is applied to the cat while walking on a narrow bridge. We find that it rotates its tail toward the falling direction. In our previous research, the balance recovery procedure is analyzed based on the law of the angular momentum conservation and then a key equation is derived to maintain the balance. However, it did not consider the gravity, so the performance is not good. In this paper, a new dynamic model is proposed using the Lagrangian mechanics. In the method, the gravity is included in the potential energy. Through the proposed dynamic model, controlling the balance of a walking robot is possible.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.446-446
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• 2000

This paper presents the design of a passive biped walking robot based on limit cycle analysis. By using numerical analysis and experiment, we identify better design criterion for biped walking robot. In designing robot parameters we apply global search method to find limit cycles for given robot parameters and ground angle. Internal parameter variation changes limit cycle behavior, total energy, strides, etc and the characteristics of walking is analyzed by simulation and experiments.

• 한국정밀공학회지
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• 제28권4호
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• pp.446-454
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• 2011

In terms of the anatomy and mechanics of the human foot, a flexible robot foot with toes and heel joints is designed for a bipedal walking robot. We suggest three design considerations in determining foot design parameters which are critical for walking stability. Those include the position of the frontal toe, the stiffness of toes and heels, and the position of the ankle joint. Compared with the conventional foot with flat sale, the proposed foot is advantageous for human-like walking due to the inherent structural flexibility and the reasonable parameter values. Simulation results are provided to determine the design parameters and also show that the proposed foot enables smaller energy consumption.

• 정보처리학회논문지D
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• 제18D권2호
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• pp.143-148
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• 2011

본 논문에서는 3축 가속도 센서를 소형 디바이스(활동량 측정기)로 구성하고 이를 사람의 신체에 착용하고 사람이 보행 시 발생하는 가속도 센서의 Raw 데이터 출력 값을 획득하여 실시간 활동량으로 변환하고 모니터링 할 수 있는 활동량 측정기와 알고리즘을 개발하였다. 피험자 59명을 대상으로 트레드밀(Treadmill)에서 호흡가스대사분석기(K4B2), Actical 그리고 본 연구에서 개발된 활동량 측정기를 착용 후 36분 동안 테스트 프로토콜에 따라 다양한 속력의 걸음(느리게 걷기, 걷기, 빠르게 걷기, 천천히 뛰기, 뛰기, 빠르게 뛰기)에 대해서 실험을 하였다. 가속도 센서의 출력 데이터와 피험자 정보를 이용하여 에너지소비량(Energy Expenditure :EE)을 추정하는 회귀식을 도출하였으며 이는 실험시 같이 착용한 Actical보다 제안하는 활동량 변환 알고리즘의 성능이 1.61% 향상 되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.991-992
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1413-1414
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• 2011

• 한국운동역학회지
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• 제18권4호
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• pp.109-114
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• 2008

본 연구의 목적은 신체활동 시에 간단하고 실용적인 방법으로 에너지 소비를 예측하는데 있다. 신체활동은 허리에 부착된 3축 가속도계 센서를 사용하여 가속도의 함으로써 정량화하였다. 에너지 소비량과 가속도계 데이터의 관계를 찾기 위하여 11명(남성 6명, 여성 5명)의 피험자를 상대로 1.5, 3.0, 4.5, 6.0, 6.5, 7.0, 8.5km/hr의 속도로 트레드밀에서 걷거나 달리는 동작을 시행하였다. 각 피험자는 트레드밀 속도가 6.0km/hr 일 경우에는 걷는 동작을 6.5km/hr 이상일 경우께는 달리는 동작을 수행하였다. 실제 에너지 소비량은 가스분석기를 통하여 측정되었다. 예측 식은 피험자의 성, BMI(Body Mass Index), 가속도 데이터로 이루어졌으며 걷기, 달리기로 총 2개의 다중회귀식으로 구현되었다. 실제 측정된 에너지 소비량과 예측된 에너지 소비량 간의 상관계수와 결정계수는 걷기와 달리기에서 각각 R=0.956, R2=0.876와 R=0.881, R2=0.776를 나타내었다. 추후의 연구에서는 보다 많은 피험자의 데이터를 이용하여 보다 신뢰성 있는 에너지 소비량 예측의 회귀식을 구현하고자 한다.

• 한국초지조사료학회지
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• 제38권4호
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• pp.343-348
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• 2018

In this study, the effect of daily short-distance walking exercise on milk production and metabolic status of the lactating dairy cows was investigated. The experiment was conducted with 10 lactating dairy cows comprising 2 groups (5 dairy cows/group), which were walking activity and non-walking activity. The walking activity (WA) group lactating dairy cows walked outdoors for 1 km/d, and the non-walking activity (non-WA) lactating dairy cows were maintained within a cowshed from $18^{th}$ April to $30^{th}$ May. The activity volume of the neck was not significantly different between the groups, but the activity volume of the leg was higher in WA group compared with non-WA (p<0.05). The rectal temperature was higher in the WA group ($38.6^{\circ}C$) compared with non-WA ($38.2^{\circ}C$) (p<0.05). No significant differences in dietary NE intake, milk production and milk composition were found between the groups. The plasma cortisol concentration was higher in WA group ($2.14{\mu}g/dl$) compared to non-WA ($0.95{\mu}g/dl$) (p<0.05). However, plasma cortisol level of WA dairy cows was significantly decreased as compared with non-WA cows. On the contrary, the level of plasma melatonin was increased in WA cows than that of non-WA dairy cows. It may be interpreted as a change in physical fitness. From this study, we suggest that walking activity can be improved energy balance. Further investigation is needed to determine whether different combinations of distance, rate or doing in morning or afternoon will stimulate energy balance.

• 기본간호학회지
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• 제15권1호
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• pp.53-59
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• 2008

Purpose: The purpose of this study was to examine the effects of treadmill walking exercise on the BMD (Bone Mineral Density) and BMI (Body Mass Index) of middle-aged women in their forties. Method: A nonequivalent control group pretest-posttest design was used for this study. The experiment was conducted for 10 weeks from May 17 to July 25, 2004 with 29 middle-aged women in their forties, who were assigned to a walking exercise group (16) or a control group (13). The experimental group had not exercised regularly before participating in this program. The control group received no exercise treatment during the research period. The BMD and BMI were measured with peripheral dual energy x-ray absorptiometry and bioelectrical impidence analysis, respectively. $X^2-test$ and Mann-Whitney U test with the SPSS version 11.0 program were used to analyze the data. Result: Treadmill walking exercise was effective for middle-aged women in increasing BMD and decreasing BMI. Conclusion: The findings of this study indicate a need to develop walking exercise protocols for middle-aged women to help them achieve a healthy life.