• 한국안전학회지
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• 제17권4호
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• pp.146-152
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• 2002

The steel shows plastic deformation after the yield point exceeds. Because of overloads, the plastic deformation occurs at the interior support of a continuous bridge. The plastic deformation is concentrated at the interior support, and the permanence deformation at the interior support remains after loads pass. Because local yielding causes the positive moment at the interior support, it is called "auto moment". Auto moment redistributes the elastic moment. Because of redistribution, auto moment decreases the negative moment at the interior support of a continuous bridge. In this paper, the moment-rotation curve from Schalling is used. The Plastic rotation is computed by using Beam-line method, and auto moment is calculated based on the experiment curve. The design example is presented using limit state criterion.

• 대한의용생체공학회:의공학회지
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• 제38권2호
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• pp.57-61
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• 2017

The purpose of this study was to investigate the effect of direction (pitch and roll) on the perception of support surface rotation while standing. Thirty young healthy subjects participated in this study. Support surface was rotated at an unexpected instant in a very slow speed (0.2 deg/s). The direction of support surface rotation was randomly chosen among pitch (forward and backward) and roll (right and left) directions. The experiment was performed with eyes open and closed. Perception performance was evaluated by the perception threshold, defined as the rotation angle of the surface at the instant when a subject recognized that the support surface was moving. Results showed that the perception threshold was smaller for roll directions than pitch directions irrespective of vision and gender (p < 0.01). This indicates that the perception of support surface rotation is more sensitive in roll direction than in pitch direction. Among three sensory functions related to postural perception, the effect of vestibular and visual functions on the direction difference of the perception should be little because of the very slow surface rotation and independence on visual conditions. Therefore, the direction dependence of perception would have been affected mainly by the somatosensory function.

• 한국의료질향상학회지
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• 제23권2호
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• pp.11-20
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• 2017

Purpose: The purpose of this study was to determine the effects of rotation direction during curved walking on gait parameters in stroke patients. Methods: A group of thirty subjects with stroke (Berg Balance Scale score${\geq}41$ were fifteen, Berg Balance Scale score${\leq}40$ were fifteen) were enrolled in this study. Testing indications included two directions for rotation in each subject. These indications were for rotation toward the affected and unaffected side in stroke patients. The gait speed, affected side single support duration, affected side double support duration were recorded. The obtained data were analyzed by using paired t-test and Wilcoxon signed rank test in the group that are below and above 40 points of Berg Balance Scale score. Results: There was significant increase affected side single support duration was turned the affected side in stroke patients that presented a Berg Balance Scale score${\geq}41$ (p<.05). There were significant increase gait speed, affected side single support duration, and significant decrease affected side double support duration while subjects were turned the affected side in stroke patients that presented a Berg Balance Scale score${\leq}40$ (p<.05). Conclusion: This result may be effective to rotate in the paralyzed direction to improve the ability of the paralyzed lower limb to gain weight during gait training for stroke patients with a Berg Balance Scale score<40. Therefore, walking training program for hemiplegic patient needs to be suggested in the direction of turning for suitable balance ability.

• 동력기계공학회지
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• 제20권2호
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• pp.26-31
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• 2016

The studies on the efficient ventilator to reduce fire and save energy have been proceeded actively. The purpose of this paper is to design a ventilator used in residential wood stove. The ventilator consists of rotation and support part, and it is operated by natural wind without power. The shape of rotation part of the ventilator is like airfoil to reinforce pressure drop. We designed direction controller for the rotation part to track the direction of wind continuously. The rotation and support part have point-contact each other to minimize a friction. We verify the properties of the proposed ventilator though simulation and experiment. The results show the proposed ventilator can exhaust safely combustion gas of the stove more than other ventilator.

• Structural Engineering and Mechanics
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• 제87권1호
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• pp.19-28
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• 2023

This paper describes the experimental investigation of steel pallet rack beam-to-column connec-tions. Total behavior of moment-rotation (M-φ) curve and the effect of particular characteristics on the behavior of connection were studied and the associated load strain relationship and corre-sponding failure modes are presented. In this respect, an estimation of SPRBCCs moment and rotation are highly recommended in early stages of design and construction. In this study, a new approach based on Support Vector Machines (SVMs) coupled with discrete wavelet transform (DWT) is designed and adapted to estimate SPRBCCs moment and rotation according to four input parameters (column thickness, depth of connector and load, beam depth,). Results of SVM-WAVELET model was compared with genetic programming (GP) and artificial neural networks (ANNs) models. Following the results, SVM-WAVELET algorithm is helpful in order to enhance the accuracy compared to GP and ANN. It was conclusively observed that application of SVM-WAVELET is especially promising as an alternative approach to estimate the SPRBCCs moment and rotation.

• 한국전문물리치료학회지
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• 제26권1호
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• pp.67-74
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• 2019

Background: Uncontrolled lumbopelvic movement leads to asymmetric symptoms and causes pain in the lumbar and pelvic regions. So many patients have uncontrolled lumbopelvic movement. Passive support devices are used for unstable lumbopelvic patient. So, we need to understand that influence of passive support on lumbopelvic stability. It is important to examine that using the pelvic belt on abdominal muscle activity, pelvic rotation and pelvic tilt. Objects: This study observed abdominal muscle activity, pelvic rotation and tilt angles were compared during active straight leg raise (ASLR) with and without pelvic compression belt. Methods: Sixteen healthy women were participated in this study. ASRL with and without pelvic compression belt was performed for 5 sec, until their leg touched the target bar that was set 20 cm above the base. Surface electromyography was recorded from rectus abdominis (RA), internal oblique abdominis (IO), and external oblique abdominis (EO) bilaterally. And pelvic rotation and tilt angles were measured by motion capture system. Results: There were significantly less activities of left EO (p=.042), right EO (p=.031), left IO (p=.039), right IO (p=.019), left RA (p=.044), and right RA (p=.042) and a greater right pelvic rotation angle (p=.008) and anterior pelvic tilt angle (p<.001) during ASLR with pelvic compression belt. Conclusion: These results showed that abdominal activity was reduced while the right pelvic rotation angle and anterior pelvic tilt angle were increased during ASLR with a pelvic compression belt. In other words, although pelvic compression belt could support abdominal muscle activity, it would be difficult to control pelvic movement. So pelvic belt would not be useful for controlled ASLR.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.556-561
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• 2005

The steel shows plastic deformation after the yield point exceeds. The plastic deformation due to overloads occurs at the interior support of a continuous bridge. The plastic deformation is concentrated at the interior support and the permanence deformation at the interior support remains after loads apply. Because local yielding causes the positive moment at the interior support, it is called 'auto-moment'. Auto-moment redistributes the elastic moment. Because of redistribution, auto-moment decreases the negative moment at the interior support of a continuous bridge. In this paper, the plastic rotation is evaluated using the moment-rotation curve proposed by Schalling and Beam-line method. Moreover, auto-moment is derived from the experiment curve.

• 대한물리의학회지
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• 제12권1호
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• pp.43-49
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• 2017

PURPOSE: This study investigated the relationship among hip adduction angle, tibial rotation, and ITB length during an Ober test to determine the most appropriate position for performing the test. METHODS: The study included thirty-nine asymptomatic participants (23 males, 16 females). Their hip adduction angles were measured using the Ober test during three tibial rotation conditions (internal tibial rotation, external rotation, and neutral position). ITB length was calculated by measuring the position of the patella to lateral femoral condyle using ultrasonography (patella-condyle distance; PCD). RESULTS: The relationship among hip adduction angle, tibial rotation, and ITB length was analyzed under the three conditions using the Pearson correlation. The hip adduction angle of the internal tibial rotation, the external rotation, and the neutral position were significantly related to ITB length. Moreover, the hip adduction angle measured during the internal tibial rotation had the highest correlation with ITB length among the three conditions (r=.58, p<.001). CONCLUSION: Internal tibial rotation caused by the Ober test led to increased iliotibial band (ITB) tension and a decreased adduction angle. These findings support that tibial rotation influences the flexibility of ITB. Therefore, therapists should consider the position of the internal tibial rotation when taking measurements using an Ober test.

• 한국철도학회논문집
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• 제16권3호
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• pp.217-225
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• 2013

본 연구에서는 교량 단부의 레일지지점 간격, 교량과 교대사이 거리(유간) 및 교량 단부 회전각을 고려하여 콘크리트 궤도가 부설된 교량 단부 궤도의 거동을 분석하였다. 궤도구조가 고려된 교량 및 교대 시험체를 이용한 실내시험 결과, 동일한 유간(레일지지점 간격)에서 교량 단부 회전각이 증가함에 따라 레일의 변위가 선형적으로 비례하는 것으로 나타났다. 또한 이러한 레일의 변위는 레일 및 체결구의 발생응력에 직접적인 영향을 미치는 것으로 분석되었다. 실험결과를 바탕으로 다중 회귀분석을 수행하여 레일지지점 간격 및 교량의 단부 회전각을 매개변수로 하는 철도교량 단부 궤도의 궤도-교량 상호작용력 예측식을 도출하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.460-469
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• 2006

It is widely known that the temperature variation introduces the axial force along a CWR(Continuous Welded Rail) in the railway bridges. Additional axial forces are generated due to many other reasons. These includes the interaction between the bridge girder and the CWR; acceleration or deceleration of the vehicles; support rotation (or deflection) of the girder. Among aforementioned reasons, this study investigates the influence of the support rotation on additional axial forces throughout the numerical study and the field test. Several strains gauges are installed along the CWR and the strains are measured under passing trains. It is expected that the elaborated estimation of the axial force on CWR will be beneficial for future railway maintenance.