• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 추계학술대회 논문집
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• pp.229-230
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• 2006

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.73-74
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• 2007

• 동굴
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• 제10권
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• pp.27-50
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• 1999

• 한국건설관리학회논문집
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• 제9권2호
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• pp.190-198
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• 2008

최근 고층화, 대형화, 복잡화 된 건물의 신축이 증가하면서 장비의 사용이 증가하고 있다 특히 공동주택이나 주상복합빌딩의 신축에 따른 고소작업이 증가하면서 타워크레인의 장비가 증가하고 있는 실정이다. 이러한 장비사용의 증가로 장비의 선정, 운용과 더불어 장비의 안정성 확보는 공사프로젝트의 중요한 관리요소로 작용한다. 최근 공사 시 구조물의 높이가 증가함에 따라 크레인의 위치가 수직상승하는 상승식 타워크레인의 사용이 증가하고 있다. 이에 본 연구는 상승식 크레인의 안정성을 검토하는 모델을 제시하였다. 본 모델은 상승식 크레인의 주변 환경 및 조건에 적절한 선정 뿐 아니라 제시된 3가지 타입의 지지부재인 Collar의 설계 및 안정성 검토 및 고정부의 설계, 검토 또한 손쉽게 이루어 질 수 있도록 하였다. 이러한 모델을 통하여 장비의 적절한 선정 뿐 아니라 지지부재 및 고정부의 설계검토를 통한 안정성 확보를 통하여 공사프로젝트의 효율적 수행이 가능해 질 것으로 기대 된다.

• 비파괴검사학회지
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• 제34권1호
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• pp.60-67
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• 2014

본 연구에서는 사장교의 핵심부재인 케이블 점검을 위한 자동화 검사 시스템을 개발하였다. 강자성체로 이뤄진 연속체 구조물인 케이블의 내외부 검사에 적합한 비파괴검사법으로는 선행연구를 통해 검증된 누설자속탐상법이 적용되었고, 홀센서와 영구자석을 이용하여 다채널의 누설자속 측정용 자기센서헤드를 제작하였다. 또한 케이블 검사의 자동화로 접근성을 높이기 위해 사장교 케이블을 따라 이동할 수 있는 바퀴굴림 방식의 케이블 등반 로봇을 설계 및 제작하였고, 로봇을 다양한 디바이스에서 모니터링 및 제어하기 위한 컨트롤 프로그램을 제작하였다. WLAN 방식의 무선통신기술을 적용하여 원격으로 계측 데이터 전송 및 로봇제어를 가능하게 하였다. 최종적으로 본 연구를 통해 개발된 세부 기술들이 연동된 누설자속탐상법 기반 케이블 이동형 진단 시스템을 이용하여 실제 운용중인 서해대교의 케이블을 대상으로 현장 시험을 수행함으로써 본 시스템의 현장 적용성을 검증해보았다.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1523-1531
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• 2011

본 다축 차량은 험지와 야전에서 높은 이동성 때문에 비포장도로를 주행해야 하는 군용차량으로 사용된다. 특히 군용차량은 군 요구 사항에 의거 기본적으로 60% 경사로에서 안정적인 등판 성능을 지녀야 한다. 따라서 본 논문은 최적 타이어 힘 분배 방법을 통한 6WD/6WS차량의 등판능력 향상을 다루었다. 경사로 등판 시 사용할 최적 타이어 힘 분배 방법을 위하여 운전자로부터, 목표로 하는 종 방향 힘과 횡 방향 힘, 요 모멘트를 계산하였고, 마찰 원이론과 목적함수에 따른 최적화 된 토크가 각 륜에 분배되었다. 알고리즘 성능을 확인하기 위해서, 트럭심 소프트웨어를 이용하여 시뮬레이션 하였고, 비교를 위하여 2대의 차량을 제안하였다. 한 대의 차량은 최적타이어 힘 분배 방법이 적용되었고, 나머지 한 대는 궤도 차량과 같은 균등 힘 분배 방법이 적용되었다. 경사로에서 등판능력은 최적 타이어 힘 분배 방법에 의해서 향상 되어졌다.

• 한국정밀공학회지
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• 제30권1호
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• pp.32-38
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• 2013

Small mobile robots which use round wheels are suitable for driving on a flat surface, but it cannot climb the obstacle whose height is greater than the radius of wheels. As an alternative, legged-wheels have been proposed by many researchers due to its better climbing performance. However, driving and climbing performances have a trade-off relationship so that their driving performance should be sacrificed. In this study, in order to achieve both driving and climbing performances, a new transformable wheel was developed. The developed transformable wheel can have a round shape on a flat surface and change its shape into legged-wheel when it makes a contact with an obstacle. For design of the transformable wheel, the performance of legged-wheel was analyzed with respect to the number and curvature of the leg, and then the new transformable wheel was designed based on the analysis. Contrary to the existing transformable wheels that contain additional actuators for the transformation, the developed transformable wheel can be unfolded without any additional actuator. In this study, in order to validate the transformable wheel, a simple robot platform was fabricated. Consequently, it climbed the obstacle whose height is 2.6 times greater than the wheel radius.

• 보존과학회지
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• 제37권4호
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• pp.322-339
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• 2021

This paper focuses on the dating and provenance of two paintings, Climbing the hill and View from St. John's Fort by the prominent Singaporean artist Liu Kang (1911-2004). Climbing the hill, from the National Gallery Singapore collection, was believed to have been created in 1937, based on the date painted by the artist. However, a non-invasive examination unveiled evidence of an underlying paint scheme and a mysterious date, 1948 or 1949. These findings prompted a comprehensive technical study of the artwork in conjunction with comparative analyses of View from St. John's Fort (1948), from the Liu family collection. The latter artwork is considered to be depicting the same subject matter. The investigation was carried out with UVF, NIR, IRFC, XRR, digital microscopy, PLM and SEM-EDS to elucidate the materials and technique of both artworks and find characteristic patterns that could indicate a relationship between both paintings and assist in correctly dating Climbing the hill. The technical analyses were supplemented with the historical information derived from the Liu family archives. The results showed that Climbing the hill was created in 1948 or 1949 on top of an earlier composition painted in Shanghai between 1933 and 1937. As for the companion View from St. John's Fort from 1948, the artist reused an earlier painting created in France in 1931. The analytical methods suggested that Liu Kang used almost identical pigment mixtures for creating new artworks. However, their painting technique demonstrates some differences. Overall, this study contributes to the understanding of Liu Kang's painting materials and his working practice.

• 대한건축학회논문집:구조계
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• 제35권7호
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• pp.171-178
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• 2019

Auto Climbing Formwork System (ACS) for construction of high-rise building is a construction method for automatically lifting the formwork system supported by the anchor on the pre-constructed concrete wall. It has excellent construction speed and quality, but it has the possibility of structural failure depending on the quality of concrete and also has low economical efficiency due to the use of foreign technology. In order to overcome these problems, this study conducted an optimum design for the development of a new concept of Corner Supported Auto Climbing System (CS-ACS) in conjunction with the development of corner steel-reinforced concrete core wall system. For the design the formwork system, the basic module and structural member compositions were planned, and the structural analysis program was used to analyze the optimum member's cross section and spacing. As a result, the horizontal displacement and the stress of the horizontal members were influenced by the spacing more than the cross-section of the member. On the other hand, vertical members did not affect the displacement and stress of the formwork system. The form tie was very effective in controlling the displacement when adjusting the spacing of the horizontal members, but when the spacing of the form tie is more than 1,500mm, it is analyzed that form tie is yielding in basic module. When the span of the formwork system is more than 30m, it is analyzed that the basic module needs to be changed because of the increase of overall displacement.

• Physical Therapy Rehabilitation Science
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• 제10권1호
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• pp.32-39
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• 2021

Objective: The weakness of muscle strength due to stroke affects the posture control and gait in the patients with stroke. Stroke This study examined the effects of the stair climbing training with functional electrical stimulation on muscle strength, dynamic balance, and gait in individuals with chronic stroke. Design: Randomized controlled trial. Methods: Total forty-eight patients were randomly assigned to the 3 groups. Participants randomly divided to stair climbing training with functional electrical stimulation group (SCT+FES group, n=16), stair climbing training group (SCT group, n=16) and control group (n=16). Subjects in the SCT+FES group and SCT group performed stair walking training with and without functional electrical stimulation for 30 minutes, 3 sessions per week for 4 weeks and all subjects received conventional physical therapy for 30 minutes with 5 sessions per week for 4 weeks. Outcome measurements were assessed using the sit-to stand Test for strength, timed up and go test and modified-timed up and go test for dynamic balance, and 10m walk test and GaitRite system for gait. Results: In the SCT+FES group, subjects have been shown the significant increase in lower extremity strength (p<0.05), significantly improve in dynamic balance (p<0.05), and significantly improve in their temporal gait parameter (p<0.05). The SCT+FES group was significantly better than other groups in all parameters (p<0.05). Conclusions: This result suggested that the SCT+FES may be effective strategy to improve muscle strength, dynamic balance, and gait for individuals with chronic stroke.