• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.100-100
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• 2003

다목적실용위성 1호의 자세제어는 추력기를 이용한 방법과 반작용 휠을 이용한 방법으로 나눌 수 있다. 추력기를 이용한 방법은 위성이 안전모드에 진입하거나 궤도조정시 이용되며, 정상 운영모드에서 촬영임무를 수행할 때는 반작용 휠을 이용하여 위성의 자세를 제어하고 있다. 자세제어는 제로 모멘텀 바이어스(Zero Momentum Bias)를 이용하여 3축 제어방식을 사용하고 있다. 지구센서(CES, Conical Earth Sensor)와 자이로(Gyro)를 통하여 얻은 자세정보를 이용하여 위성의 탑재컴퓨터에서 제어로직을 수행하면 MDE(Motor Drive Electronic)를 통해 모멘텀을 입력받아 반작용 휠의 회전속도를 변화 시켜 자세제어를 수행한다. 본 논문은 위성의 임무기간 동안 반작용 휠을 이용하여 자세제어를 수행한 결과를 바탕으로 위성의 제로 모멘텀 바이어스를 통한 자세제어계의 변화를 분석하여 향후 연장 임무기간 동안 발생할 수 있는 운영상의 문제점을 확인하고, 이에 대한 조치 방법과 자세제어계의 운영 방안을 제시하고 한다.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2096-2099
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• 2003

본 논문에서는 입력 영상의 컬러 정보를 이용함으로써 조명 변화나 얼굴의 자세 변화에 둔감하게 얼굴 정보를 고속 검출하는 알고리듬을 제안하였다 계산복잡도가 작으면서도, 조명의 변화에 민감하지 않은 특성을 가진 NCC (normalized color component) 좌표계에서 정의한 살색에 기반하여 얼굴 후보 영역을 검출하고, 검출된 얼굴 후보 영역 내에서의 눈의 검출에도 색상 분포 특성을 이용함으로써 얼굴의 숙임(nod), 돌림(shake), 기울임(tilt)등에 의한 자세 변화에 대해서도 둔감하게 두 눈의 위치를 고속으로 찾도록 하였다. 특히 집중자(concentrator)를 제안 적용하여 유동적인 눈썹의 영향을 줄이고 눈안의 중심 위치를 찾도록 가중치 눈지도(eye map)를 도입하였다. 제안된 알고리듬이 조명 변화나 얼굴의 다양한 자세 변화가 있는 영상에서 얼굴 후보 영역과 두 눈의 위치를 효과적으로 검출함을 실험을 통해 확인하였다.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.67-74
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• 2019

The purpose of this study was to determine whether changes of position might effect the convergence pulmonary function of the 20s men of mild intellectual disabilities with obesity. Ten subjects of mild intellectual disabilities with obesity(fat group) and ten contrary subjects without obesity(control group) were participated in the experiment. Subjects were assessed for their pulmonary function by using Fit mate according to the position changes(supine position, 45 lean sitting position, 90 sitting position). One-way repeated ANOVA analyzed each region data of pulmonary function of both the fat group and the control group according to their position changes. The result of the experiment showed that the 20s men of mild intellectual disabilities with obesity have lower pulmonary function than the contrary subjects in the each given posture. In comparison with three experimental positions, supine position was the lowest in the pulmonary function. This study showed the 20s men of mild intellectual disabilities with obesity have lower function of pulmonary volume than the control group, and thus, it suggests that the pulmonary functional data of 20s men of mild intellectual disabilities with obesity in this experiment can be used as a basic respiratory one for the various exercise programs in the area of the physical activities.

• Science of Emotion and Sensibility
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• v.5 no.4
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• pp.67-75
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• 2002

The purpose of this study is to assess the ability of balance control in virtual moving surround stimulation using head mount display (HMD) device and force platform in patients with brain injury. Fifteen patients with stroke (mean age 54.47 yrs) and fifteen healthy normal persons participated. COP parameters were obtained total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) during comfortable standing with opened or closed eyes, (2) during virtual moving surround stimulation delivered using HMD with four different moving pattern. Moving patterns consisted of close-far, superior-inferior lilting (pitch) , right-left tilting (roll) and horizontal rotation (yaw) movement. In all parameters, the test-retest reliability was high. Also, the construct validity of virtual moving surround stimulation was excellent (p＜0.05). A posturographic balance assessment system equiped with virtual moving surround stimulation using HMD is considered clinically useful in evaluation of balance control in patients with brain injury.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.169-175
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• 2019

The purpose of this study was to determine whether changes of multiple lying position might effect the convergence pulmonary function of the 20s men of mild intellectual disabilities. Twenty subjects of mild intellectual disabilities were participated in the experiment. Subjects were assessed for vital capacity by using Fit mate according to the multiple lying position changes(supine position, right sidelying position, left sidelying position, prone position). One-way repeated ANOVA analyzed each region data of vital capacity of subjects according to their multiple lying position. The result of the experiment showed that the 20s men of mild intellectual disabilities have more higher vital capacity to right sidelying position than another lying position. This study suggests that the pulmonary functional data of 20s men of mild intellectual disabilities in this experiment can be used as a basic respiratory one for the bed exercise programs in the area of the physical activities.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.233-234
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• 2014

하지전신계측검사(low extremity teleography)에서 자세 변화에 따른 중요장기의 방사선량을 측정하고 영상을 비교 분석하여 검사방법에 따른 유용성을 알아보고자 하였다. 대상은 하지전신계측검사를 시행한 성인남자 10명을 대상하였고 촬영조건은 관전압 73 kVp, 관전류량 32 mAs, SID 180 cm로 설정하였다. 방사선량 측정은 란도 팬텀을 이용하여 수정체, 갑상선, 생식선 부위에 유리선량계(ion chamber)를 부착한 후 전후방향자세와 후전방향자세를 각각 5번씩 시행하여 부위별로 방사선량을 측정한 후 Paired T-test로 비교 분석 하였다. 영상평가는 전후방향자세와 후전방향자세를 시행한 영상을 blind test를 실시하여 5점 척도로 평가하였다. 결과적으로 전후방향자세검사에 비해 후전방향자세검사가 수정체 약 6%, 갑상선 약 6%, 생식선에 미치는 방사선량을 약 27% 감소시킬 수 있으며 영상평가에서도 두 그룹 간에 큰 차이가 없어, 하지전신계측검사에서 전후방향자세검사보다 후전방향자세검사가 유용할 것으로 사료된다.

• Journal of Oral Medicine and Pain
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• v.31 no.2
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• pp.147-154
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• 2006

This paper studies natural head position and orofacial pain. For this study. 27 persons with dental service were selected, we examine head & neck pain, factor affecting pain severity, stress, stressful facial symptom with questionarre and interview. We have photograph for natural head position in front of 5cm posture scale pate. Data obtained were statistically processed by the SPSS Windows program and the results of this study were as follows: 1. There were significant difference from plum line to acromion line, from plum line to tragus line, eye- tragus angle, SCM angle. 2. Between group with head and neck pain and group without head and neck pain, the study shows no significant difference on average NHP measurement and NHP amount. 3. Between group with head and neck pain and group without head and neck pain, the study shows no significant difference on SRRS. 4. In this paper we indicate more stressful symptom in group with head and neck pain than group without head and neck pain. 5. There have no difference in head and neck pain level according to hobby.

• Journal of IKEEE
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• v.14 no.4
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• pp.291-296
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• 2010

This paper handles, pitching and rolling posture change detection using the visual image changes due to the road slope conditions. When the moving vehicle is slanted to a direction, the objects in the visual images of the vehicle are moving to up or down and right or left. This is similar to the human's balancing behavior depending on the visual image change detection as well as the vestibular organs and semicircular canal in the ear. The proposes method shows the visual image through the camera can be used for the image information itself and for the posture change detection through the experiments.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.2
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• pp.43-49
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• 2010

Autonomic nervous system (ANS) acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The activity of the ANS has been assessed by means of the heart rate variability (HRV). It has been reported that HRV is dependent on sex, age, body mass index, and smoking, etc. However, the effects of posture and sleep deprivation on HRV have rarely been reported. Objective of our work was to find out which posture is appropriate for stable HRV. We measured the number of sleep deprivation and HRV using power spectrum in six stages for 30 minutes. Increased low frequency (LF) power and high frequency (HF) power indicate enhanced sympathetic and parasympathetic activity, respectively. We determined the LF/HF ratio to minimize individual difference. It was found that sleep deprivation by awakening up subjects was affected by posture, which resulted in changes of LF/HF. Although LF/HF varied with time, it was more stable in sitting than in supine. In conclusion, we recommend sitting posture when measuring HRV because of less sleep deprivation resulting in less variation in LF/HF.

• Life and Agrochemicals
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• s.251
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• pp.30-31
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• 2009

오랫동안 잘못된 자세로 척추에 부담을 주게 되면, 척추 관절염과 같은 퇴행성 변화를 촉진시켜, 결국 척추관협착증과 같은 노인성 질환을 불러오므로 평소에 의식적으로라도 바른 자세를 취하려는 노력이 필요하다.