• Journal of the Korean housing association
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• v.20 no.3
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• pp.19-26
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• 2009

The purpose of this study is to classify roof styles about high-rise apartment complexes in these days. Specially, it is focused on those in Daegu city. It has analyzed for 75 apartment complexes in Daegu city. Those complexes are all over 300 houses each and were built from 2004 to 2007. Generally, roof styles about high-rise apartment complexes are classed as a flat roof style and a slope-sided roof style. Types of the flat roof style were divided a flat roof style and a eyebrows roof style. And, types of the slope-sided roof style were divided a single slope-sided roof style, a gable roof style, and a hipped roof style. The curved roof style didn't show up at these cases. According to this study, the slope-sided roof style including the gable roof style was revealed the most common roof style about high-rise apartment complexes in Daegu city from 2004 to 2007. Among 76 cases of roof styles, the number of the gable roof style is 52, and the number of flat roof style is 18. Each roof style was changed for more decorative shape. Specially, in case of the flat roof style, 17 cases for 18 cases are built as a decorative flat roof style. and, 15 for 52 gable roof style cases are built as a decorative style, too. According this case study, we are able to know that the sort of roof style was advanced variously and decoratively, and the shape of roof style was combined more than 2 decorative factors. The roof style of high-rise apartment complex in future will be more various and decorative than this time and will be develop compositively.

• KIEAE Journal
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• v.12 no.3
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• pp.83-88
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• 2012

This study analyzed the measured value came out by the field test to verify the surface temperature reduction of the flat roof due to green roof, and confirmed the influence of the green roof based on it, and assessed the possibility of saving structures' energy and reducing $CO_2$ emission of structures. For the actual measurement, the differences of the average atmospheric temperature of the green roof and non-green roof flat roof were $8.67^{\circ}C$ and $0.787^{\circ}C$, and the average floor temperature gaps were $11^{\circ}C$ and $2.008^{\circ}C$ in October and November respectively. It was expected that if it's measured on around summer solstice that the temperature gets higher, the deviation of the surface temperature should be bigger, and it was confirmed that the green roof eventually raises insulating effect of structures and will influence on cooling and heating effects such as energy saving and insulating.

• Journal of the Korean association of regional geographers
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• v.22 no.2
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• pp.369-382
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• 2016

The studies on the rural housing have focused on folk housing, but this study focuses on the contemporary rural housing with special reference to the roof types/materials and the outer wall materials. The research area of this study is the fourteen rural settlements in Jeju Island. The hip roof type, the hip/flat roof type, the simple-flat roof type, the gable roof type, and the eyebrow-and-flat roof type are the most frequent roof types. Among the roof materials, the precoated steel plate, the artificial slate, the cement, the cement/roof tile, and the cement/artificial slate are the most frequent materials. The cement holds more than a half of the outer wall materials, and the cement/basalt rock, the tile/cement, the tile, and the diverse siding are the next frequent outer wall materials. The comparison of the rural housing reveals that there are some clear differences between Jeju Island and Gyeongnam Province in terms of the roof types and the outer wall materials.

• Wind and Structures
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• v.19 no.2
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• pp.113-144
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• 2014

Separation bubble and conical vortices on a large-span flat roof were observed in this study through the use of flow visualization. The results indicated that separation bubble occurred when the flow was normal to the leading edge of the flat roof. Conical vortices that occur under the cornering flow were observed near the leading edge, and their appearance was influenced by the wind angle. When the wind changed from along the diagonal to deviating from the diagonal of the roof, the conical vortex close to the approaching flow changed from circular to be more oblong shaped. Based on the measured velocities in the conical vortices by flow visualization, a proposed two-dimensional vortex model was improved and validated by simplifying the velocity profile between the vortex and the potential flow region. Through measured velocities and parameters of vortices, the intensities of conical vortices and separation bubble on a large-span flat roof under different wind directions were provided. The quasi-steady theory was corrected by including the effect of vortices. With this improved two-dimensional vortex model and the corrected quasi-steady theory, the mean and peak suction beneath the cores of the conical vortices and separation bubble can be predicted, and these were verified by measured pressures on a larger-scale model of the flat roof.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.10
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• pp.922-929
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• 2005

This paper compared ventilation performance between the sound roof tunnel with flat roof and the sound roof tunnel with gable roof. The ventilation rate of the sound roof tunnel is calculated by natural ventilation rate plus ventilation by vehicle. The roof type is divided by the shape of the roof and the ventilator location on the roof. The results between calculation and CFD on the ventilation rate are almost alike. The ventilation rate on the flat roof is $558.4\;m^3/s$ with mid-ventilator and $496.8\;m^3/s$ with left-right ventilator. The ventilation rate on the gable roof is $653.2\;m^3/s$ with mid-ventilator and $611.6\;m^3/s$ with left-right ventilator. The ventilation rate of soundproof with gable roof is higher than that with flat roof. The ventilation rate and with mid-ventilator is higher than that with left-right ventilator the soundproof roof. Therefore, the ventilation performance of soundproof roof depends on the roof shape and ventilator location on the roof.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.83-86
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• 2005

This paper presents a method for point-based 3D building reconstruction using LiDAR data and digital map. The proposed method consists of three processes: extraction of building roof points, identification of roof types, and 3D building reconstruction. After extracting points inside the polygon of building, the ground surface, wall and tree points among the extracted points are removed through the filtering process. The filtered points are then fitted into the flat plane using ODR(Orthogonal Distance Regression). If the fitting error is within the predefined threshold, the surface is classified as a flat roof. Otherwise, the surface is fitted and classified into a gable or arch roof through RMSE analysis. Based on the roof types identified in automated fashion, the 3D building reconstruction is performed. Experimental results showed that the proposed method classified successfully three different types of roof and that the fusion of LiDAR data and digital map could be a feasible method of modelling 3D building reconstruction.

• Wind and Structures
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• v.24 no.1
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• pp.25-41
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• 2017

The effects of finite cylinder free end shape on the mean and fluctuating wind pressures were investigated experimentally and numerically by using three different roof shapes: flat, conical and hemispherical. The pressure distributions on the roofs and the side walls of the finite cylinders partially immersed in a simulated atmospheric boundary layer have been obtained for three different roof shapes. Realizable $k-{\varepsilon}$ turbulence model was used for numerical simulations. Change in roof shapes has caused significant differences on the pressure distributions. When compared the pressure distributions on the different roofs, it is seen from the results that hemispherical roof has the most critical pressure field among the others. It is found a good agreement between numerical and experimental results.

• Wind and Structures
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• v.8 no.5
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• pp.357-372
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• 2005

Mean and extreme pressure distributions on a large cantilevered flat roof model are measured in a boundary layer wind tunnel. The largest peak suction values are observed from pressure taps beneath conical "delta-wing type" corner vortices that occur for oblique winds, then the characteristics and causes of the local peak suctions are discussed in detail. Power spectra of fluctuating wind pressures measured from some typical taps located at the roof edges under different wind directions are presented, and coherence functions of fluctuating pressures are also obtained. Based on these results, it is verified that the peak suctions are highly correlated with the conical vortices. Furthermore, according to the characteristics of wind loads on the roof, an aerodynamic solution to minimize the peak suctions by venting the leading edges and the corners of the roof is recommended. The experimental results show that the suggested strategy can effectively control the generation of the conical vortices and make a reduction of 50% in mean pressures and 25% in extreme local pressures at wind sensitive locations on the roof.

• Journal of the Korean Solar Energy Society
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• v.25 no.2
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• pp.35-43
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• 2005

This study aims to evaluate the natural lighting performance in the sound barrier tunnel. Therefore, to evaluate the daylighting performance, the combinations of 3 tunnel roof types which are flat-roof-type(type A), slope-roof-type(type B), arch-roof-type(type C) and 3 window types which are side-window-type(type 1), one-window-roof type(type 2), two-window-roof type(type 3) are evaluated by experimenting small scaled models. In this 9 cases of experiment, illuminance levels of each case are analyzed and evaluated. The conclusion of this study is that slope-roof-type(B) and arch-roof-type(C) is preferable to flat-roof-type(A) and one-window-roof-type(B) and two-window-roof-type(C) is preferable to side-window-type(A) for daylighting in the sound barrier tunnel.

• Wind and Structures
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• v.32 no.1
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• pp.1-9
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• 2021

Vortex generators are commonly used in mechanical engineering and the aerospace industry to suppress flow separation owing to their advantages of simple structure, economic viability, and high level of efficiency. Owing to the flow separation of the incoming wind on the leading edge, a suction area is formed on the roof surface, which results in a lifting effect on the roof. In this research, vortex generators were installed on the windward surface of a flat roof and used to disturb to roof flow field and reduced suction based on flow control theory. Computational fluid dynamics (CFD) simulations were performed in this study to investigate the effects of vortex generators on reduce suction. It was determined that when the vortex generator was installed on the top of the roof on the windward surface, it had a significant control effect on reduce suction on the roof leading edge. In addition, the influence of parameters such as size, placement interval, and placement position of the vortex generator on the control effect of the roof's suction is also discussed.