• Journal of ILASS-Korea
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• v.19 no.3
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• pp.136-141
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• 2014

This study reports numerically the characteristics of dust scattering around the coal storage pile yards, substantially affected by the windbreak wall height. The dust scattering is closely associated with the frictional effect of wind flows as well as the pressure variation that consequently affect the dust particle behavior. In the present study, with the use of the commercial code of FLUENT, the distribution of wind velocity and pressure are predicted around coal storage pile yard for four different heights of the wind break wall. From the results, it was found that for the case 1 with the outer windbreak wall height of 3 m and inner windbreak wall height of 6 m, the amount of scattering dust for a year was estimated to be 1451 kg, whereas for the case 4 where a height of outer windbreak wall is 10 m and a height of inner windbreak wall is 16 m, the amount of scattering dust for a year was 358 kg. It shows that the dust scattering can be reduced by 75%, indicating important role of windbreak wall height on particle scattering. The numerical results would be useful in decision of the appropriate height of windbreak wall for decreasing the amount of scattering dust under various environmental conditions.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.223-233
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• 1999

The wind-flow characteristics over a two-dimensional triangular prism with a porous windbreak are numerically investigated. The geometry is a simplified model of large outdoor stack with a frontal wall-type windbreak which is used to prevent particle dispersion by reducing wind speed over stak surface. In the present numerical model, the RNG k-$\varepsilon$ model, the orthogonal grid system and the QUICK scheme are employed for the successful simulation of separated flow. The predicted results are compared and validated with the associated wind-tunnel experiments. In addition, the trajectories of dispersed particles and their sedimentation characteristics are quantitatively investingated using a Lagrangian turbulent-dispersion model.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.145-154
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• 2013

Recently, damage occurrence by wind erosion has been increasing in society. In times past, such problems only took place in desert area ; however, in recent years, the wind erosion problem is spreading out to agricultural land. Wind erosion in agricultural land can cause loss of loam soils, the disturbance of the photosynthesis of the crop fields and serious economic losses. To overcome the mentioned problems, installation of windbreak fence can be recommended which function as disturbing strong wind and wind erosion. However, there is still no proper guideline to install the windbreak fence and the installation used to rely on the intuition of the workers due to the lack of related studies. Therefore, this study measured the aerodynamic resistance of screens of the windbreak fence using the apparatus for testing screens. The apparatus for testing screens was designed to measure pressure loss around the screen. Measured pressure loss by wall friction compensated for pressure loss to calculate the aerodynamic resistance of screens. The result of pressure loss by regression analysis derived the aerodynamic coefficient of Darcy-Forchheimer equation and power law equation. The aerodynamic resistance was constant regardless of the overlapped shape when the screen was overlapped into several layers. Increasing the number of layers of the screen, internal resistance increased significantly more, and pressure loss caused by the screen also increased linearly when the wind speed was certain conditions, but permeability had no tendency. In the future, the results of this study will be applied to the computational fluid dynamics simulation. The simulation models will be also validated in advance by wind tunnel experiments. It will provide standard of a design for constructing windbreak fence.

• Fire Science and Engineering
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• v.23 no.3
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• pp.1-10
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• 2009

This paper presents a study on the evacuation analysis in underground arcade. In this study, the effect of the exit with a windbreak door has been investigated by using evacuation simulation program (building EXODUS). Also, the simulation has included the impact of smoke, heat and toxic gases by fire simulation program (CFAST). The results were obtained for the conditions of without and with door of the two exit with 1,088 evacuation population. As a results, for non-fire evacuation, there was only a little difference of evacuation time for both conditions. However, for fire emergency evacuation, the evacuation time for the condition with door increased more 110 seconds than for the condition without door. When the auto door not opened, the evacuation time was increased more 670 seconds than for the condition without door. Consequently, in case of fire, the automatic door should be operating by the signal of fire detector and keep open when the fire accidents. To lead the evacuees well to the escape route the luminaries for an emergency exit sign have to be reinforced to the wall and floor around the exit.

• Wind and Structures
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• v.39 no.3
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• pp.223-242
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• 2024

Wind comfort in cold climates is one of the most essential factors for urban planners. This issue is particularly important for sidewalks that are in line with the prevailing wind flow and surrounded by high-rise buildings. Imam Street near the University Square in Tabriz is one of the passages that struggle with uncomfortable wind speeds. The aim of this study is to investigate the role of sidewalk walls on pedestrian wind comfort. These multifunctional walls not only serve as street furniture, but also reduce wind speed at pedestrian level. In this work, all simulations are performed using the RWIND tool and validated by wind tunnel experiments at the Architectural Institute of Japan. The main objective of this study is to evaluate the effects of the angle, height and spacing of the walls on wind attenuation at pedestrian level. The results show the effect of multifunctional walls on pedestrian-level wind mitigation. By rotating the windbreak walls from 0 to 60 degrees along the street, the average wind speed decreases by 30% to 46% compared to a situation without this type of wall. Increasing the wall height from 1.5 to 2 meters reduces the urban wind speed by 39-46%. However, increasing the distance between the sidewalk walls from 3.5-9.5 meters reduces the speed in the models from 46% to 32.7%. Finally, it has been demonstrated that sidewalk walls with a height of 2 meters, a rotation angle of 60° and a distance of 3.5 meters are the optimal choice for wind attenuation at pedestrian level.

• Korean Institute of Interior Design Journal
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• v.20 no.6
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• pp.200-207
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• 2011

This study aims to understand the unique housing culture and decoration style in traditional Thai houses. Literature review and site visit were applied for the research method. A steep gable roof, a lifted floor structure on the pillars, a semi-enclosed central flatform(charn) and a outdoor staircase are important plastic elements of exterior decoration in Thai traditional houses. 'Panlom(windbreak on gable)' and 'fa loog fak(wall panel)' are the most unique elements which determine Thai traditional style. In Thai traditional style decoration, the beautifully carved wooden panels and decorations are also the most important factors. The decorations can be analyzed in the aspect of following perspectives. ; The characteristics of Thai traditional house decorations have been developed and evolved as result of influences from regional climate and local material. And also the social-cultural factors such as religion, social and family relationship and life style controlled the forms and culture of traditional housing form and culture. As a result, this study summarises and defines the outstanding and unique meaning and definition of the decoration in Thai traditional houses focused on central region in Thailand.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2011.04a
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• pp.103-108
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• 2011

This study aims to understand the unique housing culture and decoration style in traditional Thai houses. Literature review and site visit were applied for the research method. A steep gable roof, a lifted floor structure on the pillars, a semi-enclosed central flatform(charn) and a outdoor staircase are important plastic elements of exterior decoration in Thai traditional houses. 'Panlom(windbreak on gable)' and 'fa loog fak(wall panel)' are the most unique elements which determine Thai traditional style. In Thai traditional style decoration, the beautifully carved wooden panels and decorations are also the most important factors. The decorations can be analyzed in the aspect of following perspectives. ; The characteristics of Thai traditional house decorations have been developed and evolved as result of influences from regional climate and local material. And also the social-cultural factors such as religion, social and family relationship and life style controlled the forms and culture of traditional housing form and culture. As a result, this study summarises and defines the outstanding and unique meaning and definition of the decoration in Thai traditional houses focused on central region in Thailand.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.4
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• pp.20-36
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• 2022

This study aims to provide basic data for high-quality street tree management by setting reasonable management items and appropriate unit prices by reviewing the adequacy of current street tree management. Currently, street tree management items, except for street tree pruning, use general landscape tree quantity per unit for the street tree management quantity per unit. KEPCO (Korea Electric Power Corporation) applied pruning items from standard electric production infrastructure and carried out the activities at an average unit price of 51% lower for heavy pruning and 39% lower for light pruning than the standard estimate. This was judged to be a level that could not maintain or increase the quality of street tree management. It was determined that an appropriate standard unit price for street tree management was necessary. To improve the quantity per unit for the proper management of street trees, it was necessary to review costs in the field. However, due to the absence of data on actual construction costs in the domestic landscape field, detailed items of the US RSMeans Building Construction Cost Data (RSMeans) were reviewed, and the actual construction costs were calculated by applying personal domestic expenses. As a result, the standard of the estimated unit showed a good ratio of 107% for heavy pruning of street tree pruning compared to the actual construction cost, but light pruning was underestimated with a 59% ratio. Shrub pruning was 82%, weeding was 92%, tree fertilization was 87%, and windbreak wall installation was 91% under-engineered. In addition, it was also confirmed that the watering by sprinkler trucks and chemical spraying were over-designed compared to the actual construction cost at the rates of 118% and 124%, respectively. Due to the specificity of the street trees, the increase in personal expenses and the input cost of equipment, such as road safety controls, were judged to be the main cause of the underestimation of items. Therefore, it is necessary to add items related to street trees and general landscape trees to the landscape maintenance items of the standard of the estimated unit.