• 한국운동역학회지
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• 제19권1호
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• pp.27-36
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• 2009

본 연구에서는 수직점프시 몸통운동의 제약이 수직점프의 수행에 미치는 영향을 알아보기 위해 10명의 성인 남성을 대상으로 몸통을 자유롭게 사용한 일반적인 형태와 몸통동작을 제한한 형태의 수직점프를 비교, 분석하였다. 분석 결과 몸통동작을 제한한 경우 비 제약점프에 비해 10% 정도의 수행 손실이 있었는데, 이는 이지 순간의 중심 높이보다는 이 지속도의 차이에 의해 발생하였다. 몸통의 운동은 엉덩관절의 모멘트 파워를 증가시켜 추진의 초기 시점부터 지면반력의 증가에 기여하였는데 이러한 요인이 수행력 증가의 주요한 요인으로 작용하였다. 반면 몸통운동이 제한된 점프에서는 엉덩관절에서의 역학적 출력의 감소를 보상하는 측면에서 무릎관절의 역할이 증가하였으나 충분치 못하였다. 또한 몸통동작의 제한으로 엉덩관절 무릎관절 발목관절의 순차적인 신전패턴과는 상이하게 추진시점 직후 엉덩관절과 무릎관절이 동시에 신전하는 형태의 점프가 이루어져 협응패턴의 변화가 나타났다. 결국 본 연구의 결과 몸통의 적절한 사용은 수직점프의 수행 향상에 효과적으로 기여하는 것으로 나타났다.

• Physical Therapy Rehabilitation Science
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• 제6권2호
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• pp.96-104
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• 2017

Objective: The purpose of this study was to investigate the effect of the hip joint strengthening exercises using proprioceptive neuromuscular facilitation (PNF) on the clinical symptoms and the treatment effects in balance, sit to stand, and gait abilities in patients with TBI. Design: A single case study. Methods: A 13-year-old adolescent with quadriplegia and hip joint control impairment participated in this four-week training intervention. The patient, diagnosed with TBI, wastreated with hip joint strengthening exercises using PNF. In the first week, we focused on strengthening the body, relaxing the hip flexors and activating the hip extensor muscles in order to solve the patient's physical function and body structure. From the 2nd and 4th week, we improved the motivation through the task-oriented method, and then weight-bearing training of the right lower extremity was proceeded by kicking a soccor ball with the left lower extremity. The exercises were performed for 4 weeks, 5 days a week, for 60 minutes with the exercise intensity gradually increased according to the subject's physical abilities. Results: As a result of the study, the patient demonstrated improvements in the physical examination, which were evaluated before and after intervention and included the manual muscle test, modified Ashworth scale, sensory assessment, coordination assessment, Berg balance scale, 5-time sit to stand test, and the 10 meters walk test. Conclusions: The results of this case suggest that a hip joint strengthening exercise program using PNF may improve hip control ability, balance, sit to stand and gait ability in a patient with TBI.

• 전기학회논문지
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• 제59권5호
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• pp.847-853
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• 2010

This paper describes switching surge analysis for reclosing decision in 345kV combined transmission line with XLPE power cable. Reclosing operation should be decided based on the detailed technical analysis in combined transmission line because this line includes power cable section which is week on insulation. Insulation of power cable can be breakdown at the week point in case of reclosing moment. Therefore the detailed analysis has to be carried out by considering several conditions such as length ratio of power cable section, arrestor, inserting resistance, charging rate, grounding resistance, etc.. On the other hand sheath voltage on IJ(Insulated Joint) is analyzed to check dangerous condition on cable cover. Analysis is performed by EMTP/ATP. Analysis results show that reclosing can be operated as the single line-to-ground fault occurs on overhead line in 345kV combined transmission line, if the inserting resistance is considered before the operation of main circuit breaker.

• 대한전자공학회논문지
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• 제27권10호
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• pp.44-52
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• 1990

공간상에 움직여야할 길이 주어진 두 대의 로보트의 속도계획 문제를 두 단계의 부문제로 나누어 각각의 독립적으로 다루는 방법을 도입하여 최소시간 속도계획 방법을 제안하였다. 제안된 방법은 i) 로보트가 각자의 길을 따라 이동한 거리를 두 축으로하는 코오디네이션 공간이라는 2차원 공간을 구축하고 이공간상에서 충돌을 피할 수 있도록 코오드네이션 곡선을 선정하고, ii)선정된 곡선을 따라 최소시간을 보장하는 속도계획을 하는 두 단계의 문제중 두 번째 단계의 문제에 대해 로보트의 동력학 및 각 관절의 최대 회전속도등을 고려하여 최적해를 구하는 방법을 제안하였다. 또한 신경 최적화 회로망의 이론을 응용하여 간단한 반복 계산 알고리듬으로 최적해를 구하였다. 제안된 방법은 두 대의 SCARA형 로보트의 경로계획의 예로 시뮬레이션하여 유용성을 보였다.

• 한국통신학회논문지
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• 제36권4A호
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• pp.318-324
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• 2011

본 논문에서는 두 셀 대칭적 간섭 채널 환경에서 세 가지 방식의 협력적 불규칙 빔형성 방법을 분석한다. 먼저, 기지국 선택을 통한 간단한 형태의 부분 협력 빔형성 방법은 연계적 인코딩을 적용한 불규칙 빔형성 방법과 동일한 평균 합 전송률을 갖는다는 것을 증명한다. 또한, 전송 모드 선택 방법을 적용하는 경우에 시스템의 사용자가 많을 때에 부가적인 합 전송율의 이득이 발생하는 것을 증명하였다. 모의 실험 결과를 통해서 성능에 대한 분석이 유효함과 정확성을 확인하였다.

• 한국운동역학회지
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• 제31권2호
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• pp.126-132
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• 2021

Objective: The purpose of this study was to investigate how three gaze directions (bottom, normal, up) affects the coordination and stability of the lower limb during drop landing. Method: 20 female adults (age: 21.1±1.1 yrs, height: 165.7±6.2 cm, weight: 59.4±5.9 kg) participated in this study. Participants performed single-leg drop landing task on a 30 cm height and 20 cm horizontal distance away from the force plate. Kinetic and kinematic data were obtained using 8 motion capture cameras and 1 force plates and leg stiffness, loading rate, DPSI were calculated. All statistical analyses were computed by using SPSS 25.0 program. One-way repeated ANOVA was used to compared the differences between the variables in the direction of gaze. To locate the differences, Bonferroni post hoc was applied if significance was observed. Results: The hip flexion angle and ankle plantar flexion angle were significantly smaller when the gaze direction was up. In the kinetic variables, when the gaze direction was up, the loading rate and DPSI were significantly higher than those of other gaze directions. Conclusion: Our results indicated that decreased hip and ankle flexion angles, increased loading rate and DPSI when the gaze direction was up. This suggests that the difference in visual information can increase the risk of injury to the lower limb during landing.

• 재활복지공학회논문지
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• 제10권3호
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• pp.207-214
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• 2016

본 연구의 목적은 무릎 신전 제한형 보조기 착용 후 보행시 하지 내 협응에 미치는 영향을 평가하는 하는 것이다. 본 연구에는 7명의 건강한 성인 남성($32.3{\pm}2.7$ 세, $175.2{\pm}3.8cm$, $76.2{\pm}8.7kg$)이 참여하였다. 이들은 무릎보조기를 착용하거나 착용하지 않고 10m의 평지를 보행하였다. 이때 시공간적 파라미터, 하지의 각도, 하지 내 연속상대 위상(CRP)를 측정 및 계산하였다. 그 결과 시공간적 요인은 차이가 없었다 (all p > 0.05). 무릎보조기 착용 시 엉덩관절의 가동범위 및 각도 변화는 없었으나, 무릎관절의 가동범위는 감소하였으며 ($65.5{\pm}3.75^{\circ}$ vs. $60.5{\pm}3.5^{\circ}$, p < 0.05), 최대 굴곡 역시 감소하였다 (입각기: $31.9{\pm}4.6$ vs. $25.6{\pm}5.5$, 유각기: $76.7{\pm}3.1$ vs. $68.9{\pm}3.4$, all p < 0.05). 발목관절의 가동범위는 변화가 없었으나, 최대 배측굴곡 ($22.4{\pm}2.6$ vs. $19.2{\pm}2.1$, p< 0.05)은 감소하였으며, 최대 족저굴곡이 증가하였다 ($9.5{\pm}3.0$ vs. $15.7{\pm}2.2$, p<0.05). 대부분의 CRP는 차이가 없었으며, 유각기 엉덩관절과 무릎관절 사이의 CRP만 감소하였다 ($93.0{\pm}7.8$ vs, $84.7{\pm}4.9$, p < 0.05). CRP의 표준편차는 대부분 증가하였다 (유각기 엉덩관절과 무릎관절사이: $25.1{\pm}6.7$ vs. $32.4{\pm}1.9$, 입각기 무릎관절과 발목관절사이: $46.0{\pm}12.9$ vs. $80.1{\pm}31.1$, 유각기 무릎관절과 발목관절 사이: $34.5{\pm}4.1$ vs. $37.6{\pm}3.1$, all p < 0.05). 이와 같은 결과로부터 무릎 신전 제한형 보조기 착용은 관절의 각도, 하지 내 협응에는 영향을 미치지만, 보행특성에는 큰 영향을 미치는 않는다는 것을 확인하였다.

• 한국운동역학회지
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• 제22권3호
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• pp.325-332
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• 2012

This study aimed to analyze the effects of external load between male and female on angular velocity, moment, and absorbed energy of the lower-extremity joints during drop landing. The study subjects were 9 male($mass=70.82{\pm}4.64kg$, $height=1.71{\pm}0.04m$, $age=24.5{\pm}1.84years$), 9 female($mass=50.14{\pm}4.09kg$, $height=1.61{\pm}0.03m$, $age=23.6{\pm}2.62years$), without any serious musculoskeletal, coordination, balance, or joint/ligament problems for 1 year before the study. The angular velocity, flexion/extension and abduction/adduction moments, and absorbed energy of the lower-extremity joints were compared between the men and women during drop landing under 4 different conditions of external load(0%, 8%, 16%, and 24%) by using two-way repeated ANOVA(p < .05). The women landed with a greater peak angular velocity of the ankle joint, greater peak inversion moment, and lower peak hip-extension moment than the men did, under all 4 conditions. Additionally, the landing characteristics of the women were distinct from those of the men; the women showed a greater peak knee-adduction moment and greater absorbed energy of the knee joint. These differences indicate that anterior cruciate ligament(ACL) strain was greater in the women than in the men and therefore, women may be at a higher potential risk for noncontact injuries of the ACL with an increase in external load.

• The Journal of Korean Physical Therapy
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• 제26권3호
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• pp.163-168
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• 2014

Purpose: The purpose of this study was to investigate whether ipsilateral shoulder pain affects the sensorimotor function of the same side shoulder in patients with stroke. Methods: Thirty stroke patients, who were divided into the ipsilateral shoulder pain group (n=15) and the ipsilateral shoulder non-pain group (n=15). Subjects were evaluated on performance of a tracking task, joint reposition test and 9-Hole pegboard test for sensorimotor functions, and Fugl-Meyer test and Motricity Index for functional ability of the contralateral side. Results: In comparison of the two groups, significant differences in performance on functional ability, including the Fugl-Meyer test(both upper and lower limb) and Motricity Index(only lower limb) were observed (p<0.05). With regard to sensorimotor functions, the ipsilateral shoulder pain group were observed significantly poor scores on the Accuracy Index, joint reposition score and 9-Hole pegboard test, when compared with the ipsilateral shoulder non-pain group (p<0.05). Conclusion: We found that ipsilateral shoulder pain could impede accurate performance of a movement and result in deteriorated proprioception of the ipsilateral shoulder. Therefore, careful evaluation and appropriate therapeutic intervention are essential for stroke patients who suffer from ipsilateral shoulder pain.

• Nuclear Engineering and Technology
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• 제31권3호
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• pp.267-275
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• 1999

This paper deals with the industrial problem of thermal striping damage on the French prototype fast breeder reactor, Phenix and it was studied in coordination with the research program of IAEA. The thermomechanical and fracture mechanics evaluation procedure of thermal striping damage on the tee-junction of the secondary piping using Green's function method and standard FEM is presented. The thermohydraulic(T/H) loading condition used in the present analysis is the random type thermal loads computed by T/H analysis on the turbulent mixing of the two flows with different temperatures. The thermomechanical fatigue damage was evaluated according to ASME code section 111 subsection NH. The results of the fatigue analysis showed that fatigue failure would occur at the welded joint within 90,000 hours of operation. The assessment for the fracture behavior of the welded joint showed that the crack would be initiated at an early stage in the operation. It took 42,698.9 hours for the crack to propagate up to 5 mm along the thickness direction. After then, however, the instability analysis, using tearing modulus, showed that the crack would be arrested, which was in agreement with the actual observation of the crack. An efficient analysis procedure using Green's function approach for the crack propagation problem under random type load was proposed in this study. The analysis results showed good agreement with those of the practical observations.