• Structural Engineering and Mechanics
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• 제64권2호
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• pp.225-232
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• 2017

Leaning-type arch bridge is a new spatial structural system composed of two vertical arches and two leaning arches. So far there has been no contrast analysis of leaning type arch bridge with different systems. This paper focus on a parametric study of leaning type arch bridge with different systems to find the influential rules on structural forces and stability and to provide some reference for practical designs. The parametric analysis is conducted with different rise-to-span ratios and bending rigidities of arch ribs by comparing internal forces. The internal forces decline obviously with the increase of the rise-to-span ratio. The bending moments at the centers of the main arches and the leaning arches are sensitive to the bending rigidities of arch ribs. Parametric studies are also carried out with different structural systems and leaning angles of the leaning arch by comparing the static stability. The lateral stiffness of leaning-type arch bridge is less than the in-plan stiffness. Compared with the leaning-type arch bridge without thrust, the leaning-type arch bridge with thrust has a lower stability safety coefficient. The stability safety coefficient rises gradually with the increase of inclining angle of the leaning arch. This study shows that the rise-to-span ratio, bending rigidities of arch ribs, structural system and leaning angles of the leaning arch are all critical design parameters. Therefore, these parameters in unreasonable range should be avoided.

• Architectural research
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• 제3권1호
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• pp.45-52
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• 2001

In this paper, a pressurized single vertical arch and a pressurized leaning arch composed of flexible fabric material are considered. These arches have also been considered as a possible support structure for the tent-like structures. Two different boundary conditions are considered in leaning arches with fixed bases and pinned bases. The behaviors of the leaning arches are investigated for two tilt angles as 15, 30. For each angle, two loading conditions are considered as uniformly distributed load and wind loads. The F.E.M. is used through the all analysis procedures. For the results, load-deflection relationships, buckling modes, differences between two boundary conditions and deformed configurations are discussed.

• 국제물리치료학회지
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• 제11권4호
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• pp.2229-2236
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• 2020

Background: Few comparative studies have been conducted on strengthening the anterior and posterior muscles of the trunk via lumbar stabilization exercises. Objectives: To compare the effects of forward leaning exercise and supine bridging exercise in stability exercise. Design: Randomized controlled clinical trial (single blind). Methods: Thirty subjects with spondylolisthesis were participated in this study. Fifteen subjects performed the bridging exercises and fifteen subjects performed the forward leaning exercises. Each exercise was held for ten seconds per repetition, and four repetitions were considered one sub-session. A total of four sub-sessions were performed in one full exercise session. The full exercise session required thirty minutes, including rest time. Trunk strength and range of motion and Oswestry disability index were measured. Results: Two weeks later, trunk flexion strength and trunk extension range of motion were significantly increased in the forward leaning exercise group than in the supine bridging group, trunk extension strength were significantly increased in the supine bridging exercise group than in the forward leaning group. After two weeks, the pain score was significantly lower in the forward leaning exercise group than in the supine bridging group. Conclusion: This study has shown that stabilization exercises are effective in increasing range of motion and strength in spondylolisthesis subjects. It was especially confirmed that the method of strengthening the anterior muscles of the trunk is more effective than the standard stabilization exercise method.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.413-414
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• 2008

Abstract should be in English. The leaning angle optimization of turbine blade using the genetic algorithm was conducted in this paper. The calculation CFD technique was based upon the Diagonalized Alternating Directional Implicit scheme(DADI) with algebraic turbulencemodeling. The leaning angle of VKI turbine blade was represented using B-spline curve. The control points are the design variable. Genetic algorithm was taken into account as an optimization tool. The objective was to minimize the total pressure loss. The optimized final geometry shows the better aerodynamic performance compared with the initial turbine blade.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.192-193
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• 2013

The purpose of this research is to comprehend experimentally the nature of human static load to wall for making use of the result as basic data to evaluate resisting force of lightweight wall. Human motions exerting static load are classified to 4 types, and two-hands pushing and shoulder pushing are defined as the instantaneously forcing motions with hands or shoulder put on the load plate, respectively. Back leaning and one-hand leaning are defined as motions of taking a rest in their respective comfortable posture. Measurement of static horizontal load caused by each motion showed that the highest load ratio depends on hardness of load plane and was 1.17~1.25 times of weight in two-hands pushing, 0.95~0.99 times in shoulder pushing, 0.16~0.18 times in back leaning, and 0.12~0.15 times in one-hand leaning.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.686-689
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• 2008

The leaning angle optimization of turbine blade using the genetic algorithm was conducted in this paper. The calculation CFD technique was based upon the Diagonalized Alternating Directional Implicit scheme(DADI) with algebraic turbulence modeling. The leaning angle of VKI turbine blade was represented using B-spline curve. The control points are the design variable. Genetic algorithm was taken into account as an optimization tool. The objective was to minimize the total pressure loss. The optimized final geometry shows the better aerodynamic performance compared with the initial turbine blade.

• 한국전문물리치료학회지
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• 제27권4호
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• pp.264-271
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• 2020

Background: Because a forward-leaning posture can cause increased back muscle activity and pain. Therefore, an innovative method to reduce back muscle activity and pain is required. Objects: This study aimed to investigate the effects of a head support on muscle activity and pain in a forward-leaning posture. Methods: A total of 14 male and 16 female students (average age, 21.65 ± 2.37 years; height, 166.15 ± 7.90 cm; and weight, 60.65 ± 9.00 kg) were recruited for the experiment. Two of them were excluded due to musculoskeletal disorders. The muscle activity and pain in the forward-leaning posture were assessed while participants washed dishes for 7 minutes with and without a head support. The condition of using a head support was randomly performed with a 5-minutes break. To confirm a lumbar flexion angle of 30° during the experiment, myoVIDEO was used, and surface electromyography was used to measure muscle activity. Pain was assessed using a 10-point visual analog scale (VAS). The Wilcoxon signed-rank test was used to analyze the data, with p < 0.05 indicating statistical significance. Results: The cervical, thoracic, and lumbar erector spinae muscle activities significantly decreased with the use of the head support, but there was no significant change in the gluteus maximus. There was a significant decrease in the VAS score for the lumbar erector spinae (p < 0.05), but there was no significant change in the VAS score for the cervical region. Conclusion: The use of a head support in a forward-leaning posture reduced cervical, thoracic, and lumbar erector muscle activity and pain. Therefore, it could be recommended during working in a forward-leaning posture, such as during dishwashing, cooking, and working as a factory employee.

• 한국지구과학회지
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• 제25권8호
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• pp.739-747
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• 2004

본 연구에서는 유의미 학습을 촉진시키고 학습자들이 나름대로 개념을 형성하는 과정을 확인할 수 있는 방법인 개념도를 이용하여 중학생들의 ‘해수‘ 개념 형성에 미치는 영향에 대해 알아보았다. 이를 위하여 부산광역시의 중학교 1학년 4개 학급 128명을 대상으로 개념도를 활용한 수업 전-후에서 과학 학업 성취도와 자기 주도적 학습특성 및 개념도에 대한 인식을 조사해 본 결과는 다음과 같다. 첫째, 과학 학업 성취도에 미치는 효과는 유의수준 .05에서 유의미한 차이가 있는 것으로 나타났다. 둘째, 개념도를 활용한 수업은 전통적 수업 집단에 비해 학습자의 자기 주도적 학습특성을 향상시키는데 효과적인 것으로 나타났다. 셋째, 개념도를 활용한 수업이 개념 형성에 궁극적인 반응을 하는 것으로 나타났다.

• 한국지구과학회지
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• 제25권8호
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• pp.731-738
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• 2004

본 연구는 중 ${\cdot}$고등학교 과학 교사를 대상으로 탐구 학습에 관한 인식을 조사하고 교사 수준의 탐구 학습 실태를 조사하기 위한 것이다. 탐구 학습 인식에 관한 설문지를 개발하여 서울교육과학연구원의 실험 연수에 참여한 서울지역 중 ${\cdot}$ 고등학교 과학 교사를 대상으로 조사한 결과에 의하면, 교사들은 과학 교육의 중요한 목표가 과학에 대한 흥미를 높이는 것이라고 생각하고 있으며, 실생활과 관련된 소재를 수업에 활용하는 것으로 조사되었다. 대부분의 교사가 탐구 학습을 학습자 중심의 열린 탐구 학습에 대한 인식하고 있었고, 대학 입시 제도, 탐구수업 보조 자료의 부족, 학생들의 의지 부족, 교사들의 탐구 학습에 대한 인식의 부족 등이 탐구 학습의 실현을 저해하는 요인으로 조사되었다.

• 대한인간공학회지
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• 제28권2호
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• pp.35-55
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• 2009

The purpose of this study was to analyze the somatotypes of women in the early 20's, which were likely to deform due to bad posture in growth period. Accordingly, bodies of women aged 20 to 24, whose growth stopped, were measured directly and indirectly, and factors related to body shapes were extracted, body shapes were categorized based on the data, and the characteristics of each body shape were analyzed. As a result, 10 factors related to body shapes were extracted in the factor analysis, and body shapes were categorized into 6 types. Type 1 was the volume of body that was big and the longest; and the general frame was large. The straight body shape with small back protrusion; the shoulder is relatively thick and the width of the shoulder was normal. Type 2 was the volume of body that was the biggest and the upper body was the longest; the general frame was of average height. The forward body shape with the back flat; the shoulder was very thick, wide, and serious leaning forward. Type 3 was a body that was thin and the shortest. The sway-back body shape with big curvature at the back; the shoulder was thin, narrow, and straight. Type 4 was a body that was short stature, and the general frame was of average build. The forward body shape with the most serious back protrusion; the shoulder was normally thick, narrow, and straight. Type 5 was a group with small body, and the lower body and general frame are long. The sway-back body shape with protrusion at the upper shoulder and the sides leaning backward; the shoulder was thin, wide, and leaning forward. Type 6 was a thin and short body; and the general frame was small. The lean-back body shape with the smallest back protrusion and leaning backward; the shoulder was thin, narrow, and leaning backward. Characteristics of the classified body shapes can be used in producing ready-made clothes, and it is hoped that there will be follow-up studies on clothing pattern design and production based on this result.