• Journal of the Korean Society of Safety
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• v.27 no.5
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• pp.111-116
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• 2012

This study analyzed the accidents and researched on risk of the actual condition in roof works. This study revealed that 68% of accidents in roof works occurred on small sized construction sites. And 79% of accidents are caused by fall. It is simply because most laborers do not wear the safety harness and the mounted equipment is not properly installed. According to our research, we realize that most of roof works have some risk of the fall accidents. Most of roof working sites have the danger of falling at ladder and temporary walkway. In oder to prevent accidents in roof works, the basic rule such as wearing the safety harness must be followed.

• Wind and Structures
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• v.17 no.2
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• pp.185-202
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• 2013

The goal of this study was to investigate the vulnerability of roof tile systems and metal shutters to roof tile debris. Three phases addressed the performance of tile roof systems and metal shutters impacted by roof tile debris. The first phase experimentally evaluated the tile fragment size and quantity generated by a tile striking a tile roof system. The second phase experimentally quantified the puncture vulnerability of common metal panel shutter systems as a function of tile fragment impact speed. The third phase provided context for interpretation of the experimental results through the use of a tile trajectory model. The results provide supporting evidence that while metal panel window shutters provide significant protection against a prevalent form of windborne debris, these systems are vulnerable to tile fragment puncture in design level tropical cyclones. These findings correlate with field observations made after Hurricane Charley (2004).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.10
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• pp.109-115
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• 2011

Apartments covered with a metal roof made from galvalume steel are prevailing due to their economic and technical advantages. The metal roof, however, has disadvantages in terms of the installation of air-termination system on it because of the slip thickness of the metal roof. In this paper, the impacts of the lightning current to a metal roof were verified experimentally with a short lightning impulse current (10/350[${\mu}s$]). Also, we developed various supporters of air-termination conductor for the metal roof and verified their excellent workability and economical strength through field application test.

• Geomechanics and Engineering
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• v.16 no.2
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• pp.151-157
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• 2018

The constrained conditions of roof and floor for the coal pillar affect the strength of coal pillar very seriously. To analyze the influence of rock mass for the roof and floor on the stability of coal pillar comprehensively, one method based on the mechanical method for the composite rock mass was proposed. In this method, the three rock layers of roof, floor and coal pillar are taken as the bedded composite rock mass. And the influence of rock mass for the roof and floor on the elastic core of coal pillar has been analyzed. This method can obtain not only the derived stress by the cohesive constraining forces for the coal pillar, but also the derived stress for the rock mass of the roof and floor. Moreover, the effect of different mechanical parameters for the roof and floor on the stability of coal pillar have been analyzed systematically. This method can not only analyze the stability of strip coal pillar, but also analyze the stability of other mining pillars whose stress distribution is similar with that of the strip coal pillar.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.338-343
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• 2005

We have evaluated the structural integrity of a sandwich composite train roof which can find a lightweight, cost saving solution to large structural components for rail vehicles in design stages. The sandwich composite train roof was 11.45 meter long and 1.76 meter wide. The reinforced frame was inserted in sandwich panels to improve the structural performance of train roof structure and had the shape of hollow rectangular box. The finite-element analysis was used to calculate the stresses, deflections and natural frequencies of the sandwich composite train roof against the weight of air-condition system. The 3D sandwich FE model was introduced to simulate the hollow aluminum frames which jointed to both sides of the sandwich train roof. The results shown that the structural performance of a sandwich composite train roof under load conditions specified was proven and the use of aluminum reinforced frame was beneficial with regard to weight savings in comparison to steel reinforced frame.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.5 s.118
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• pp.32-38
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• 2006

Roof greening in a city can contributes to not only providing network opportunities for dispersed greenspace patches but also bringing more greenspaces into a city. In addition, it can help to flooding and microclimate control in the city. Recently, a number of roof greening projects have been introduced, mainly to public buildings and schools. Roof peening need to offers both ecological functions and convenience and satisfaction for urban residents. This study aims to provide directions for improving ecological benefits and visual preference of roof greening. Twelve scene slides were adopted to measure people's visual preference. The survey results show that landscape images can be categorized into naturalness, visual diversity, uniqueness, and spatial flexibility. Physical scenes can be classified into type I mostly greened by plants, type II mixed between convenience facilities and plants, and type III constructed with pond. People show high preferences to type I and type II when visual diversity is high. The results of this study suggest to enhance the visual preference by considering visual diversity when applying the ecological design methods to improve naturalness for roof greening.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.689-693
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• 2008

Ancient Chinese in the roof of the building referred to as "the big roof". This paper make a research on style of roof,to find out the identify contemporary social construction of a representative, the distinctive features of varying roof styles with examples. Using pictures and text, contrast to the situation, to explain why the roof of the ancient form of modern architecture can be widely used. Ultimately concluded that the ancient traditional roof styles in contemporary architecture in the use of a wide range is traditional culture and promoting the inheritance.

• Geomechanics and Engineering
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• v.11 no.6
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• pp.867-877
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• 2016

Collapse shape of tunnel roof in layered Hoek-Brown rock media is investigated within the framework of upper bound theorem. The traditional collapse mechanism for homogeneous stratum is no longer suitable for the present analysis of roof stability, and it would be necessary to propose a curve failure mode to describe the velocity discontinuity surface in layered media. What is discussed in the paper is that the failure mechanism of tunnel roofs, consisting of two different functions, is proposed for layered rock media. Then it is employed to investigate the impending roof failure. Based on the nonlinear Hoek-Brown failure criterion, the collapse volume of roof blocks are derived with the upper bound theorem and variational principle. Numerical calculations and parametric analysis are carried out to illustrate the effects of different parameters on the shape of failure mechanism, which is of overriding significance to the stability analysis of tunnel roof in layered rock media.

• Journal of architectural history
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• v.28 no.4
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• pp.7-16
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• 2019

In this study, I would like to inquire about the composition of oegi(外機) on the hip and gable roof. Oegi purlin compose the basic member of framework of a hip and gable roof in both sides roof, supporting the inside end of the side rafter. However, the oegi purlin is not simply used to form hip and gable roof. The effects of using oegi purlin have the advantages of spatial. The spatial advantages are the width of the toekan(退間) increases as the oegi purlin escapes from column row and to increase the ceiling height by becoming a point of staying the ceiling. That reflect the desire to expand indoor space due to changes in worship behavior. Oegi purlin was used not only for structural needs, but also for altering in indoor space due to the changing times.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.4
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• pp.32-38
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• 1998

In order to investigate the relationship between the stiffness and structure of the automotive roof panels, two kinds of glass fiber reinforced plastic(GFRP) roof panels without and with insert material were fabricated by resin transfer molding(RTM) method. The stiffness test was performed at the same condition as it of actual driving. The structural design and material selection for improving the recyclability of GFRP roof panels were also covered.