• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.148-150
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• 2001

본 논문은 복합제품의 진화환경에서 버전과 콘피규레이션 관리기법을 사용하여 제품의 진화를 관리하면서 복합제품의 구조정보뿐만 아니라 진화하는 버전과 콘피규레이션에서 다양하게 생성된 개별제품에 대한 접근을 지원하는 복합제품추적시스뎀을 설계하고 구현하였다.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.04a
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• pp.172-179
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• 2001

비감쇠 혹은 비비례감쇠 시스템의 고유치를 구하기 위한 대부분의 방법들은 저차의 몇 개의 모드만을 사용하여 동적응답을 구하는 경우 누락된 고유치의 존재여부를 검사하기 위해 잘 알려진 Sturm 수열 성질(Sturm sequence property)을 이용한다. 반면 감쇠시스템 즉, 지반-구조물의 진동제어 시스템, 복합재료 구조물과 같은 경우에는 저차 몇 개의 모드만을 사용할 경우 누락 고유치를 검사할 수 있는 효율적인 기법이 아직 확립되지 않은 상태이다. 본 논문에서는 Gleyse의 정리를 이용하여 감쇠스템의 누락된 고유치를 검사하는 기법을 제안하고 이 방법의 효용성을 수치예제를 통하여 검증하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.3
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• pp.63-76
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• 2004

This paper presents LRB-based hybrid base isolation systems employing additional active/semiactive control devices for mitigating earthquake-induced vibration of a cable-stayed 29 bridge. Hybrid base isolation systems could improve the control performance compared with the passive type-base isolation system such as LRB-installed bridge system due to multiple control devices are operating. In this paper, the additional response reduction by the two typical additional control devices, such as active type hydraulic actuators controlled by LQG algorithm and semiactive-type magnetorheological dampers controlled by clipped-optimal algorithm, have been evaluated bypreliminarily investigating the slightly modified version of the ASCE phase I benchmark cable-stayed bridge problem (i.e., the installation of LRBs to the nominal cable-stayed bridge model of the problem). It shows from the numerical simulation results that all the LRB based hybrid seismic isolation systems considered are quite effective to mitigate the structural responses. In addition, the numerical results demonstrate that the LRB based hybrid seismic isolation systems employing MR dampers have the robustness to some degree of the stiffness uncertainty of in the structure, whereas the hybrid system employing hydraulic actuators does not. Therefore, the feasibility of the hybrid base isolation systems employing semiactive additional control devices could be more appropriate in realfor full-scale civil infrastructure applications is clearly verified due to their efficacy and robustness.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.191-192
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• 2009

Multi-purpose spatial structure is easy to modify the inner part of the building that is required vertical and horizontal enlargement and service change. Thus, the results indicate the effective lateral resistance system of multi-purpose spatial structure using mega elements.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.340-340
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• 2020

본 연구는 산지-도심-해안으로 연결된 해안도시의 지역적인 특성으로 인해 해일과 같은 조위 상승 원인이 침수 및 홍수 위험을 증가시키는 복합재난에 대응하기 위하여 실시간 침수 위험정보 확인 및 대응, 대시민 상황전파 등이 가능하도록 IoT 융합 침수 대응시스템을 개발하는 것이다. 또한, 침수 및 홍수방어벽 등의 구조적대책을 검토하여 실시간 IoT 융합 침수 대응시스템과 연계운영함으로써 해안도시의 시설 및 재산을 보호하고 시민의 안전을 확보하는데 기여할 수 있는 실증연구를 수행하는 것을 목표로 한다. 침수 대응을 위한 구조적 대책은 양산형 IoT 침수 및 하천수위 감지 장비, 센서 연동 침수 및 홍수방어벽, 복합재난알림 디스플레이 등의 개발이며, 비구조적 대책은 강우-하천수위-조위 실측자료기반의 머신러닝 침수위험 분석 모듈 개발, 수치모의에 의한 예상 침수심 및 침수위험지도 작성, 재난상황 전파 알림서비스 등이 있으며 개발된 시제품과 기술을 테스트베드에 적용하고 부산광역시에서 운영하는 재난상황관리시스템인 스마트빅보드(SBB, Smart Big Board)에 연계 및 탑재함으로써 향상된 침수대응 및 대시민 서비스가 가능한 시스템을 구축 및 실증하고자 한다. 센서, 통신, 자료연계 및 분석에 대한 IoT 융합 기술을 침수 대응 기술개발에 적극 활용하여 실측자료와 수치모의 분석 결과가 연계된 침수위험정보를 생산하고 실시간 대응이 가능한 효율적이고 실질적으로 피해를 저감 할 수 있는 기술을 개발하고 적용성을 입증한다면 국내외 해안도시에 확대 보급이 가능해져 침수 피해로부터 효과적으로 국민의 재산과 생명 보호할 수 있다. 또한, IoT 기술을 연계한 재난 모니터링 시스템의 확산으로 복합재난 대응 연구에 기여할 수 있고 상대적으로 실측자료 수집, 연구에 소외되어 온 소하천 등에도 적용이 가능하여 재난으로 인한 사회적 비용을 경감시킬 수 있을 것으로 기대된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.3
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• pp.123-131
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• 2007

The buckling behavior of a fiber reinforced plastic pipe was researched. When a cylindrical structure is made of isotropic material, it shows two dimensional buckled shape which has same deformed section along the longitudinal direction. But an anisotropic cylindrical structure shows three dimensional buckled shape which has different deformed section along the longitudinal direction. Because the modulus of elasticity is varied in a certain direction when ply angles are changed, the strength of a pipe are changed as ply angles are changed. In this study, the limitation of two dimensional and three dimensional buckling mode was investigated and the buckling strength of a laminated composite pipe was evaluated.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.4
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• pp.149-160
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• 2008

In this study, the research was carried out on how to identify the modal parameter by acquiring the output response of the structure only through the smart sensor system. The objective of this research is to verify the performance and the on-site adaptability of the smart sensor system that have been actively researched as the advanced measuring system so far. Smart Sensor System was developed so that the real-time dynamic measurement can be performed by means of MEMS-type accelerated sensor, 8 bit CPU, wireless MODEM. In the modal parameter identification test, random excitation was added to the cantilever beam, and then the response of the structure was obtained using the smart sensor system and the wire measurement system respectively. In analyzing the data, modal parameter was identified using NExT & ERA algorithm. Furthermore, the optimal measurement location was selected through EOT algorithm in order to obtain the qualified output response. Result of the test, it was possible to verify the on-site applicability of the smart sensor.

• Journal of Aerospace System Engineering
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• v.13 no.6
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• pp.52-59
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• 2019

The rotor blade is a key component that generates the lift, thrust, and control forces required for helicopter flight by the torque transmitted through the hub and the blade pitch angle control, and should be designed to factor vibration characteristics so that there is no risk of resonance with structural safety. In this study, the structural design of the main rotor blade for MPUH(Multi-Purpose Unmanned Helicopter) was conducted and the sectional stiffness measurement of the fabricated blade was performed. The evaluation of the vibration characteristics of the main rotor system was then conducted factoring the measured stiffness distribution. The interior of the rotor blade comprised of the skin, spar, and torsion box, and carbon and glass fiber composites were applied. The Ksec2D program was applied to predict the stiffness of blade, and the results were compared to the measured data. CAMRADII, a comprehensive rotorcraft analysis program, was applied to investigate the natural frequency trends and resonance risks due to the rotor rotation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.293-295
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• 2004

In this research, we suggest the effective technique that the thickness of slab isn't increased, and considering proper shock absorbing material and supporting point, we make the floating floor which has multi-supporting system floating floor. As the result, it is effective in reduction of heavy weight system as well as one of light weight

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.928-931
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• 2003

In this research, we suggest the effective technique that the thickness of slab isn't increased, and considering proper shock absorbing material and supporting point, we make the floating floor which has multi-supporting system floating nut. As the result, it is effective in reduction of heavy weight system as well as one of light weight