• Advances in aircraft and spacecraft science
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• v.2 no.4
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• pp.391-401
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• 2015

Crashworthiness design and certification have been and will continue to be the main concern in aviation safety. The effects of roll angles on fuselage section crashworthiness for typical civil transport category aircrafts were investigated. A fuselage section with waved-plates under cargo floor is suggested, and the finite element model of fuselage section is developed to simulate drop test subjected to 7 m/s impact velocity under conditions of 0-deg, 5-deg, 10-deg and 15-deg roll angles, respectively. A comparative analysis of failure modes, acceleration responses, and energy absorption of fuselage section under various conditions are given. The results show that the change of roll angles will significantly affect fuselage deformation, seat peak overloads, and energy absorption. The crashworthiness capability of aircraft can be effectively improved by choosing appropriate landing way.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2008.05a
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• pp.258-263
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• 2008

This study aims to investigate the changing roles of Local Government and the ways to improve the space plan, especially focusing on the Local Government civil service space of Seoul City. Recently, many Local Government have endeavored to get rid of the authoritative images and change themselves to a space featuring cultural functions and efficient performance. Local Government buildings in Seoul City are trying to decorate the inner and outer images through new construction or extension of buildings so as to become more friendly to residents. Such efforts are visualized especially in civil service space. Civil service space represents the whole image and role of the Local Government. In addition, civil service space and resting space, which are frequently used, are correlated and more and more accessible to each other as administrative and civil services are increasing. By integrating and developing such features, civil service space of Local Government that meets the requirements of the new era will be presented.

• Proceedings of the Korea Water Resources Association Conference
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• 1994.02a
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• pp.107-112
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• 1994

• Structural Engineering and Mechanics
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• v.30 no.1
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• pp.131-133
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• 2008

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.259-263
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• 2006

Civil appeals under constructions cause a lot of difficulties of doing construction because of compensations, interruption of works, administrative punishments, etc. So this research focused on the characteristics of civil complaints against constructions by analyzing the causes of civil appeals and treatment conditions classified by year, geography, and breaking time. This research indicates three points. (l) As the level of civil life and consciousness is increased, the number of civil appeals against constructions are tending upwards in view of the results so far achieved by year. (2) Analysis about civil appeals classified by geography shows that the rate of civil affairs in Gang-nam District are higher than that of others.(3) 96% of the civil appeals by breaking time are occurred under the constructions. By predicting and treating of what type of civil appeals are occurred, this research can be used as data which make damage minimized.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.3
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• pp.319-327
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• 2016

Korea faces a wide range of problems in areas such as safety, environment, and traffic due to the rapid economic development and urbanization process. Despite the local governments’ efforts to deal with electronic civil complaints and solve urban problems, civil complaints have been on the increase year by year. In this study, we collected civil complaint data over the last six years from a small and medium-sized city, Jinju-si. In order to conduct a spatial distribution pattern analysis, we indicated the location data on the area through Geocoding after classifying the reasons for civil complaints and then extracted the location data of the civil complaint occurrence spots in order to analyze the correlation between electronic civil complaints and land use. Results demonstrated that electronic civil complaints in Jinju-si were clustered in residential, central commercial, and residential-industrial mixed-use areas—areas where land development had been completed within the city center. After analyzing the civil complaints according to the land use, results revealed that complaints about illegal parking were the highest. Regarding the analysis results of facility distribution within a 50m radius from the civil complaint areas, civil complaints occurred a lot in detached housing areas located within the commercial and residential-industrial mixed-use areas. In the case of residential areas(old downtown), civil complaints were condensed in the areas with many ordinary restaurants. This research explored civil complaints in terms of the urban space and can be expected to be effectively utilized in finding solutions to the civil complaints

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.1
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• pp.32-42
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• 2009

Required system and technology for the civil helicopter and the military helicopter are almost similar. A lot of mount helicopters are converted from military to civil, or converted oppositely, or new developed considering civil-military dual use in order to reduce development cost and period. In the case of converting the military to the civil, the military helicopters are developed based on sufficient requiring amount following conversion to the civil helicopters with minor modification. This paper presents the investigation and the analysis for the case and the approach of dual use helicopter development from military helicopters to civil helicopters.

• Structural Engineering and Mechanics
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• v.17 no.3_4
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• pp.493-526
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• 2004

Semiactive control systems have received considerable attention for protecting structures against natural hazards such as strong earthquakes and high winds, because they not only offer the reliability of passive control systems but also maintain the versatility and adaptability of fully active control systems. Among the many semiactive control devices, magnetorheological (MR) fluid dampers comprise one particularly promising class. In the field of civil engineering, much research and development on MR fluid damper-based control systems has been conducted since this unique semiactive device was first introduced to civil engineering applications in mid 1990s. In 2001, MR fluid dampers were applied to the full-scale in-service civil engineering structures for the first time. This state-of-the-art paper includes a detailed literature review of dynamic models of MR fluid dampers for describing their complex dynamic behavior and control algorithms considering the characteristics of MR fluid dampers. This extensive review provides references to semiactive control systems using MR fluid dampers. The MR fluid damper-based semiactive control systems are shown to have the potential for mitigating the responses of full-scale civil engineering structures under natural hazards.

• Smart Structures and Systems
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• v.22 no.4
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• pp.425-432
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• 2018

Predicting the compressive strength of concrete has been considered as the initial phase across the cement production processing. The current study has focused on the integration of the concrete compressive strength in 28 days with the mix of the major oxides and fine aggregates as an experimental formula through the use of two types of Portland cement resulting the compressive strength of the concrete highly dependent on time.

• Structural Engineering and Mechanics
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• v.84 no.2
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• pp.285-293
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• 2022

Lumped damage mechanics (LDM) is a recent nonlinear theory with several applications to civil engineering structures, such as reinforced concrete and steel buildings. LDM apply key concepts of classic fracture and damage mechanics on plastic hinges. Therefore, the lumped damage models are quite successful in reproduce actual structural behaviour using concepts well-known by engineers in practice, such as ultimate moment and first cracking moment of reinforced concrete elements. So far, lumped damage models are based in the strain energy equivalence hypothesis, which is one of the fictitious states where the intact material behaviour depends on a damage variable. However, there are other possibilities, such as the energy equivalence hypothesis. Such possibilities should be explored, in order to pursue unique advantages as well as extend the LDM framework. Therewith, a lumped damage model based on the energy equivalence hypothesis is proposed in this paper. The proposed model was idealised for reinforced concrete structures, where a damage variable accounts for concrete cracking and the plastic rotation represents reinforcement yielding. The obtained results show that the proposed model is quite accurate compared to experimental responses.