• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.169-176
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• 2004

Offshore structure crossing navigation waterways must not only be designed to resist gravity, wind, and earthquake load, but also be capable of resisting ship and barge collision load. Current specifications for offshore structure design provide empirical relationships for computing impact loads generated during barge collision, however, these relationships are based on the limited experimental data. In this paper, the dynamic finite element analysis is used to computing force for vessel collision scenarios to offshore structures. Results obtained from the ANSYS/LS-DYNA are compared to AASHTO bridge design specifications.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.655-658
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• 2004

This study was performed to verify the possibility of the integrity estimation of the bridge substructure focusing on the dynamic property change of concrete pier with penetration depths using experimental modal analysis. As a result of the impact vibration test, it is found that scour reduces the stiffness of the foundation, and measurement the accelerance residue and natural frequency can be used for the estimation of the integrity index.

• Journal of the Korean Society of Safety
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• v.13 no.3
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• pp.126-134
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• 1998

In this paper, the field test by truck load and the structural analysis were performed on a prestressed concrete beam bridge to investigate the load carrying capacity of the prestressed concrete beam bridges. From the results of the field test and the structural analysis, CAF (composite action factor), TIF(transformed impact factor), and $P_n$(load carrying capacity) of the prestressed concrete beam bridges were studied, and the load carrying capacity assessment of the prestressed concrete beam bridges were carried out using these factors.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.139-140
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• 2016

본 논문은 위상천이 풀브리지 컨버터의 전압 제어기 설계에 있어 게인값의 선정에 따른 위상 이득, 게인 이득을 통해 안정도를 판별하고 게인값에 따른 시스템의 응답특성을 고려하여 최적값을 설계하는데 목표를 두고 있다. MATLAB의 Bode plot을 통해 안정도 및 응답특성을 확인하였고 PSIM 시뮬레이션을 통해 제어가 잘 되는지 확인하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.4
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• pp.95-101
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• 1985

In this study, impact fracture and Fatigue behaviors of SWS50 steel are investigated in terms of macroscopic view. Then the fundamental data needed to trace the relationship between macroscopic and microscopic views and the data for fracture control of steels manufactured in domestic are represented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.724-728
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• 1996

The instrumented Charpy impact test is generally used to evaluate the dynamic fracture toughness for varying engineering materials. However, the test is known to be difficult to evaluate the dynamic fracture toughness for very brittle materials because of the small crack initiation load. To evaluate the dynamic fracture toughness of verybrittle materials, it is necessary to develop a load sensitive instrumented tup. In this study, a polymer tup, which has small Young's modulus, is used for the instrumented Charpyimpact test and a proper testing method is developed. The results show that the developed method can measure rapidly changing loads from the moment of contact between the tup and the specimen to dynamic crack initation of the very brittle materials.

• Journal of Environmental Impact Assessment
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• v.20 no.5
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• pp.697-703
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• 2011

The purpose of this study aims to preserve biodiversity in increasingly fragmented green patches for spatial analysis of planting on the eco-corridors and to optimize the target species, the location, width, cross section of the eco-corridors. It was suggested that eco-corridors should have to planned at early stages of road planning so that the number and locations of eco-corridors in advance. Ecological corridor is the facility to connect two habitats fragmented by road, dam, housing and industrial area. And, everyone agree that ecological corridor is important useful structural component that help animal movement in fragmented landscapes. However, ecological corridors have many problems of the recorded the size of corridor, planting species to nearby exiting vegetation species and structure. The most important facts that there are no consideration for location of animal migration and behavior using eco-corridors. This study was carried out to spatial analysis of eco-corridors location, satellite data and GIS were used to analyze for searching optimum location of the eco-corridors.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.351-354
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• 2005

In this study ship collision risk analysis is performed to determine the design vessel for collision impact analysis of the maritime bridge. Method II which is a more complicated probability based analysis procedure is used to select the design vessel for collision impact. The AF allocation by weights seems to be more reasonable than the pylon concentration allocation method because this AF allocation takes the design parameter characteristics quantitatively into consideration although the pylon concentration allocation method brings more economical results when the overestimated design collision strength of piers compared to the strength of pylon is moderately modified.

• International Journal of Safety
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• v.9 no.2
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• pp.16-21
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• 2010

In this study, the variations of transformed impact factors and load carrying capacity of highway bridges measured from the state of expansion joint are evaluated. the field loading tests were performed on the highway bridge with damaged expansion joint to investigate the variation of the load carrying capacity. From the field loading tests in case that damaged expansion joint exist or do not exist, the static displacements and dynamic displacements were measured, and TIF were calculated, respectively. dynamic test is performed in order to estimate dynamic displacement and TIF according to the level of damage of expansion joint. From the results of TIF, the load carrying capacity of highway bridges with damaged expansion joint were estimated.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.209-218
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• 2012

In this study, suitable types and measures of Wildlife Crossing Structures (WCS) for mammals of Korea were analyzed to suggest basic information for design guidelines of WCS. In order to find the types and measures, we conducted field surveys on 79 WCS and literature reviews on 159 WCS. The results of our study were as follows; Small-medium sized carnivores usually use all measures of wildlife underpass, meanwhile large sized herbivores as water deer need lager measures than 0.7 Openness Index(OI). Furthermore, we found that wildlife overpasses were usually used at the measure of 6.8 m width by every mammal. Therefore, we concluded that the proper measures should be lager than 0.7 OI for underpass and 7 m width for overpass.