• 사물인터넷융복합논문지
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• 제9권6호
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• pp.51-56
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• 2023

손 제스처의 인식은 구어 사용이 어려운 사람들의 의사소통을 위한 중요한 기술이다. 제스처 인식에 널리 사용되는 근전도 신호는 사전 자세에 따라 동작이 달라지기 때문에 제스처 인식의 어려움이 있을 것으로 예상되지만, 이에 관한 연구는 찾기 어렵다. 본 연구에서는 사전 자세에 따른 제스처 인식 성능의 변화를 분석하였다. 이를 위해 총 20명의 피험자에게서 사전 자세를 가지는 동작에 대한 근전도 신호를 측정하고, 제스처 인식을 실험하였다. 그 결과, 학습 및 테스트 데이터 간 사전 상태가 단일한 경우에는 평균 89.6%의 정확도를, 상이한 경우에는 평균 52.65%의 정확도를 보였다. 반면, 사전 자세를 모두 고려한 경우에는 정확도가 다시 회복됨을 발견하였다. 이를 통해 본 연구에서는 근전도를 활용하는 손 제스처 인식시에 사전 자세가 다양하게 고려하여야 함을 실험적으로 확인하였다.

• The Journal of Korean Physical Therapy
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• 제26권3호
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• pp.140-146
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• 2014

Purpose: Differences in scapular kinematics and muscle activity appear in the forward head and rounded shoulder posture (FHRSP). Thus, the aim of this study was to investigate the following effects according to different postures on scapular kinematics and muscle activity around scapular region in individuals with and without FHRSP during overhead reaching task. Methods: Thirty pain-free subjects with/without FHRSP participated in this study. All subjects were positioned into three positions: habitual head posture (HHP), self-perceived ideal head posture (SIHP) and therapist-perceived neutral head posture (TNHP). Muscle activities of upper trapezius (UT), lower trapezius (LT) and serratus anterior (SA) were measured during overhead reaching task. Results: Muscle activity of trapezius muscle (UT and LT) during HHP was significantly higher than SIHP and TNHP in FHRSP group (p<0.05), but there was no difference between SIHP and TNHP. SA also significantly increased muscle activity in HHP more than SIHP and TNHP in FHRSP group (p<0.05), but there was no significant difference between SIHP and TNHP. In Non-FHRSP group, although there was a tendency of different muscle activities among three postures, it was not statistically significant. Conclusion: This result demonstrates that muscle activity associated with overhead reaching task is increased in HHP which affects the scapular kinematics and SIHP contributes changed scapular kinematics and proper recruitment of muscle activity in FHRSP similarly to TNHP.

• 대한산업공학회지
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• 제23권4호
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• pp.779-791
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• 1997

The purpose of this study is to measure a perceived joint discomfort in the seated and standing position, and to provide ranking systems of perceived joint discomfort. Nineteen mole subjects with no history of musculo-skeletal disorders participated in the experiment. Their physical characteristics were: age $-25.4{\pm}2.7$years, stature $-171.9{\pm}6.0cm$, and body weight $-67.1{\pm}7.0kg$. The results showed that the perceived joint discomforts were different depending upon the joints involved in motion and their movement directions (degree of freedom of motions), which implied that the human body motions and their degrees of freedom should be classified into several distinct classes that need to be assigned different weights of postural stress. Therefore, three ranking systems based on the perceived joint discomforts were suggested, which were classified by the degree of freedom of motions and joints, by only degree of freedom motions, and by joints involved in motion, respectively. In the seated position, the hip movement was the most stressful, the bock was the second, and the shoulder was the third. Likewise, in the standing postures, the hip was the most, the bock was the second, and the ankle was the third. It was expected that these joint motion ranking systems could be used by practitioners of health and safety to improve the comfort of working postures in industry.

• 한국지능시스템학회논문지
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• 제24권4호
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• pp.450-456
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• 2014

휴머노이드 로봇은 인간-로봇 상호작용에 가장 효과적인 로봇 플랫폼이지만 20개 이상의 관절로 구성되어 있을 만큼 복잡한 구조여서 전통적인 역기구학적 방법으로 안정되면서도 정교한 자세를 생성하기가 어렵다. 본 논문에서는 고속 연산최적화 기법인 Particle Swarm Optimization 기법을 사용해서 앞쪽 지면에 놓인 물체를 단측지지 상태로 상체를 굽혀서 왼팔이나 오른팔로 집는 고난도의 자세를 생성하고, 이를 상용 휴머노이드 로봇 플랫폼에 적용하여 검증함으로써 제안 된 방법의 적용 가능성을 확인한다.

• 대한산업공학회지
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• 제24권2호
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• pp.167-173
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• 1998

Many workers like welders work in squatting postures with the object on the ground during an entire work shift. It is suspected that such prolonged squatting without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is to examine the physical stress caused by the prolonged squatting and to recommend a safe work/rest schedule for a welding task with squatting posture based on the lab experiments. In this study, 8 healthy student subjects participated in the experiment. They maintained a squatting work posture for 16 minutes with 4 different stool height conditions: no stool; 10cm height; 15cm height; and 20cm height. Every 2 minutes, the discomfort was subjectively assessed with the magnitude estimation method for the whole body, lower back, upper leg and lower leg. Based on discomfort ratings, we found that a 10cm height stool relieved the workload most. Discomfort rating results also indicated that a 20cm height stool showed the highest workload, and the there were no difference in workload between a 15cm height stool and no stool. We recommend to use low height stools and to maintain such working postures no longer than 6 minutes for prolonged squatting tasks.

• 대한의용생체공학회:의공학회지
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• 제28권1호
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• pp.1-7
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• 2007

To determine the effect of posture change on autonomic activity and to investigate valid parameters to reflex the autonomic activity from time-series pupil size data, a posture-related experiment was performed with 15 subjects, which involved measuring their electrocardiograms and pupil sizes. The experimental procedure consisted of three-sequence postures-supine, sitting and upright-for 5 minutes each, with rest sessions between postures. The subjects were notified of the entire experimental procedure. The parameters of the subjects' heart rate variability showed significant differences between the postures (heart rate: 63-70-80 beat, normalized low frequency power: 28-50-75, normalized high frequency power: 72-49-25 and ratio: 0.5-1.2-4.4 in supine-sitting-upright position respectively) as did the parameters of their mean pupil sizes (41300-53900-53700 pixels respectively) and the major frequencies (the third trend: 0.23-0.2-0.18 Hz respectively) of their pupil size variability according to changes in their autonomic activities induced by posture change. The experiment thus proved that posture change affects autonomic activity and that such activity can be estimated by the parameters of pupil size as similar as heart rate variability.

• 정보처리학회논문지B
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• 제18B권5호
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• pp.305-314
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• 2011

사람의 의도를 인지하기 위해 감정을 시각적으로 인식하는 연구는 전통적으로 감정을 드러내는 얼굴 표정을 인식하는 데 집중해 왔다. 최근에는 감정을 드러내는 신체 언어 즉 신체 행동과 자세를 통해 감정을 나타내는 방법에서 감정 인식의 새로운 가능성을 찾고 있다. 본 연구는 신경생리학의 시각계 처리 방법을 적용한 신경모델을 구축하여 행동에서 기본 감정 의도를 인식하는 방법을 제안한다. 이를 위해 시각 피질의 정보 처리 모델에 따라 생물학적 체계의 신경모델 검출기를 구축하여 신체 행동의 정적 자세에서 6가지 주요 기본 감정을 판별한다. 파라미터 변화에 강건한 제안 모델의 성능은 신체행동 자세 집합을 대상으로 사람 관측자와의 평가 결과를 비교 평가하여 가능성을 제시한다.

• 대한기계학회논문집A
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• 제39권6호
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• pp.603-610
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• 2015

본 논문에서는 기울기 센서와 고도계 센서로 구성된 다중모드 센서를 통하여 일정 공간내의 거주자의 자세 및 행동 패턴을 수집, 분석하여 거주자의 위치를 추론함으로써, 현재 거주자가 위치한 공간을 인지하는 시스템을 제안한다. 여기에서 제안된 센서 시스템의 하드웨어 구성과 소프트웨어 알고리즘에 대하여 설명하고, 다중모드 센서를 통하여 획득한 데이터로부터 거주자의 자세 및 행동을 분석한 후에 거주자가 존재하는 공간을 추론하는 프로세스에 대하여 설명한다. 마지막으로 거주자의 자세 및 행동 분석과 공간인지 기능을 검증하기 위하여 실제 환경 실험을 통하여 본 논문에서 제안한 시스템의 효용성과 타당성을 검토한다.

• 한국생활과학회지
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• 제18권2호
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• pp.451-463
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• 2009

Although they generally undergo less change in somatotype than other age groups, women in their early twenties have postural changes incurred with their inappropriate postures during the growth period. Since such somatotype changes reduce their satisfaction in the fitting of ready-made clothing, the study intends to examine the inadequate postures and life habits of women in their twenties and to analyze their self-recognition and actual conditions of the bad fit of ready-made clothes. A survey questionnaire was conducted on 225 customers and 29 sellers of ready-made clothes. According to the result, it was found that their inappropriate postures had made their back and shoulders undesirably bent and led to their low satisfaction in the fitting of ready-made clothes. Therefore, it is necessary to perform researches for developing renovated design in consideration of their somatotype changes.

• The Journal of Korean Physical Therapy
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• 제24권3호
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• pp.208-215
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• 2012

Purpose: We attempt to assess the differences in the degree of lumbar lordosis in patients with lower back pain caused by the herniation of the nucleus pulposus and in normal people (divided into male and female groups). Methods: This study was conducted with 14 patients (7 males, 7 females) diagnosed with, and being treated for, lumbar herniated nucleus pulposus and 14 normal people (7 males, 7 females). In order to examine the degree of lumbar lordosis in these subjects, hip flexor lengthening tests were conducted and the lumbar curves were measured in three postures (supine, sitting, and prone) and the results were compared. Results: The measured values of the curves for the standing and prone postures showed statistically significant differences between the normal group and the patient group, between the normal male group and the male patient group, and between the normal female group and the female patient group (p<0.05). Conclusion: The measurement method that uses flexible curve rulers in the standing or prone postures can be usefully utilized in assessing the lumbar lordosis of patients with lumbar herniation of the nucleus pulposus.