• Proceedings of the KSR Conference
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• 2002.10b
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• pp.969-974
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• 2002

Recently, many studies are performed according to increased interests about factory or room acoustics. In this study, the inside and environmental noise conditions of Diesel-locomotive load test building were investigated by multi-channel noise measurement system. In addition to this, the mitigation effects of environmental noise from this test building were analyzed using commercial software.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.395-408
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• 2021

In this study, we investigated the effects of wind speed and direction on building fires using GIS and a CFD model. We conducted numerical simulations for a fire event that occurred at an apartment in Ulsan on October 8, 2020. For realistic simulations, we used the profiles of wind speeds and directions and temperatures predicted by the local data assimilation and prediction system (LDAPS). First, using the realistic boundary conditions, we conducted two numerical simulations (a control run, CNTL, considered the building fire and the other assumed the same conditions as CNTL except for the building fire). Then, we conducted the additional four simulations with the same conditions as CNTL except for the inflow wind speeds and direction. When the ignition point was located on the windward of the building, strong updraft induced by the fire had a wide impact on the building roof and downwind region. The evacuation floor (15th floor) played a role to spread fire to the downwind wall of the building. The weaker the wind speed, the narrower fire spread around the ignition point, but the higher the flame above the building reaches. When the ignition point was located on the downwind wall of the building, the flame didn't spread to the upwind wall of the building. The results showed that wind speed and direction were important for the flow and temperature (or flame) distribution around a firing building.

• Journal of the Korean Solar Energy Society
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• v.34 no.4
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• pp.31-38
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• 2014

This study makes three apartment building complex an object of analyzing representative building types and energy consumption rate of house holds, and effect of outdoor air cooling. Recently created apatrment complex is composed of very various types of building, plan, and orientation etc. But, it is difficult to remark conclusively that these various types of buildings are designed energy-effectively. Because architects are hard to find useful energy design guideline for decision making. By the preceding study, the present condition and problem about this subject is grasped, apartment building types were examined and representative types were extracted. In this study, energy simulation was conducted, and the effect to outdoor air cooling was analyzed about representative types of the subject apartment complex. It is expected that this analysed results will be basic data for the more integrated study. Research consequence can be summarized as follow: 1) Besides solar gain, household layout of building, orientation, and plan etc. effects compositively on energy consumption rate. 2) The effect of ourdoor air cooling in building of tower type can be improved by arranging households appropriately.

• KIEAE Journal
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• v.17 no.3
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• pp.69-74
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• 2017

Purpose: The apartment complex constructed recently is composed of very various types of building, plan, and orientation etc. However, it is difficult to remark conclusively that these various types of buildings are designed energy-effectively, since it is difficult for architects to find useful energy design guideline for decision making. By the preceding study, the present condition and problem about this subject was grasped, apartment building types were examined and representative types were extracted. Method: Large apartment building complex having 1940 households, located in haengbok-dosi, sejong city, Korea is used as an example to conduct this study. Representative building types are extracted first. Then, heating and cooling load of households is analyzed. Lastly, effect of outdoor air cooling is investigated by computer simulation. Result: Results of this research are summarized as follows: 1. Besides solar gain, household layout of building, orientation, and plan have compositive effects on heating and cooling load. 2. The effect of outdoor air cooling in apartment can be improved by arranging windows of households.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.10
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• pp.639-645
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• 2011

The object of this study is to analyze and evaluate outdoor wind pressure effect in a high-rise residential building when seasonal wind blow on coast area. The target building consists of 3 tower buildings over 250m in height. For the evaluation of the outdoor wind effect, CFD simulation was performed. The results of the simulations are as follows : 1) In that case of high-rise building, horizontal stream is more affected than vertical stream. 2) In case of summer season northeasterly wind, building pressure distributions are unstable and surface pressures of outside are effected respectively. 3) In case of winter season westerly wind, building preassure differentiations are not so much because of screening effects of the B, and the C buildings. 4) In case of winter season northwesterly wind, front wind affects on the A building directly because of no obstacles.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.10
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• pp.960-968
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• 2004

One of the most important functions of a building is to provide thermally comfortable indoor environmental conditions for the occupants. Therefore, a great deal of energy is consumed for heating and cooling to satisfy those thermal requirements. In order to provide thermal comfort with minimum heating and cooling energy consumption, optimal design of building affecting indoor climate is required. This study used the TRNSYS for modeling and simulation of the energy flows of residential building types, and examined the energy efficient measures to reduce the thermal loads. The residential building types are classified into the detached house, apartment house and high-rise residential complex. The results of the simulation show that the heating energy consumption in the detached house is especially high, whereas the cooling load is an important determinant in the apartment house and high-rise residential complex. The measures examined are the insulation thickness, various types of glazing, infiltration, natural and controlled ventilation, solar shading, orientation and etc. Comparative evaluations and sensitivity analyses revealed the effects of these variables and identified their energy efficient building design strategies.

• ETRI Journal
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• v.42 no.1
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• pp.7-16
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• 2020

Assuming omnidirectional antenna reception, the ITU-R recently developed a new propagation model on building entry loss (BEL) for 5G millimeter-wave frequency sharing and compatibility studies, which is a simplified outdoor-to-indoor path loss model. Considering the utilization of high-gain narrow-beamwidth beamforming, the omnidirectional-based ITU-R BEL model may not be appropriate to predict propagation characteristics for directional beamforming scenarios. This paper studies the effects of beamwidth on the ITU-R BEL model. This study is based on field measurements collected with four different beamwidth antennas: omnidirectional, 10° horn, 30° horn, and 60° horn. The measurement campaigns were conducted at two types of building sites: traditional and thermally efficient buildings. These sites, as well as the measurement scenarios, were carefully chosen to comply with the ITU-R BEL measurement guidelines and the ITU-R building types. We observed the importance of accurate beam alignment from the BEL variation range. We were able to quantify the beamwidth dependency by fitting to a model that is inversely proportional to the beamwidth.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.114-115
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• 2019

When concrete is exposed to fire, the decomposition of Portland cement paste results in critical damage to the concrete structure of a building. Although the behavior of cement pastes after heating provides crucial information with respect to the reuse of the building exposed to fire, the recovery process of the damaged concrete structure has not yet been fully elucidated. In addition, research on appropriate additives such as carbon nanotube (CNT) has been increasing recently, however, investigation of CNT incorporated cement paste after decomposition of CNT by high temperature is not fully investigated. In this study, we investigated the physicochemical properties of CNT incorporated cement paste under different temperatures (200℃, 500℃ and 800℃). Also, the effects of different rehydration conditions (20℃ 60% RH and in water for different curing times) on the recovery of the paste were studied. The changes in tensile and compressive strength, surface observation of the specimens were characterized. In addition, the decomposition and formation of hydrates in the paste due to the heating process were studied using X-ray diffraction.

• Proceeding of KASS Symposium
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• 2006.05a
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• pp.102-109
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• 2006

The effects of wind fence on the pressure characteristics around low-rise building model were investigated experimentally. Flow characteristics of turbulences behind wind fence were measured using hot-wire anemometer. The wind fence characterize by varying the porosity of 0 %, 40 % and the distances from the wind fence from 1 H to 6 H with maintaining the uniform flow velocity of 6 m/s. We investigated the overall characterization of the low-rise building by measuring pressure seventy four on model. The effects of porosity fences varied with the porosity of the fence and measurement locations(1H-6H). The 0% porosity proved to be effective for the protection area of 4H to 6H, but the 40% porosity proved to be effective for the protection area of 1H to 6H. The low-rise building of front face was found to be best wind fence for decreasing the mean, maximum and minimum pressure fluctuation.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.1136-1144
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• 2022

The effects of nearby residents and the public by the residual contamination from the decommissioning of nuclear facilities should comply with the dose criteria, and whether additional remediation action is necessary from the ALARA perspective must be determined. Therefore, we analyzed the requirements of ALARA action levels and performed preliminary ALARA evaluation. The ratio of residual contamination concentration to DCGL was calculated for the basement fill and the building occupancy mode. The results showed that the additional remediation actions below DCGL are not justified. In addition, we analyzed the effect of remediation area. It was noted that the increase of the remediation area showed a positive correlation with the Conc/DCGL value in the basement fill mode. On the other hand, in the building occupancy mode, since the floor area of the building is the target of remediation and has the effect of increasing the same as the evaluation area of the building occupants, but due to the difference in the amount of increase, the Conc/DCGL showed a negative correlation. We expect the approach and method of ALARA evaluation can be utilized for concrete cost-benefit calculation during the decommissioning or at the time of remediation.