• Journal of the Korean Professional Engineers Association
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• v.16 no.3
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• pp.41-53
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• 1983

The Dangri Crushed Stone Quarry is located in Dangridong, Busan City, and around the estuary of the Nagdong River. The quarry is considered to be a very promised one in the urban area from the standpoints of the assessment of the aggregate rank, the environmental impacts and the transportation distance. The crushed stones for aggregate of the quarry marks the higher rank in the gravity, the absorption ratio, the abrasion ratio, and the stability in comparison with the JISA 5005. The basement vibrations of the residential section in the vicinity of the quarry, which are arised by the millisecond blasting at the quarry site using the gelatin dynamites less than 39kg in weight, are measured to assess the vibration nuisance. The values of acceleration and the magnitudes are less than eight gals and O on the Richter scale respectively, the vibration nuisance thus can be ignored in such scales of the experiments. The traffic vibrations of the residential section are slightly susceptible. In the experiments, the traffic vibrations appears to be sensibler to the basement than the explosion vibration. The explosion noises in the experiments are not checked not only on the RION Sound Level Meter but also to our ears. The values of traffic noises also are in the safety values of the noise nuisance. The crush dust suspends in the air toward the upper valley in the opposite side of the residential area because of the influences of the sea breeze and the valley wind in the daytime, and the monsoon and the topographic disposition. the dust nuisance thus would not be remained in problem. The quarry is operated in the daytime only. The traffic dust in the residential area will be reduced by the faultless pavement and the careful driving. The elaborate survey on the ridges and peaks surrounded the quarry is recommended to prevent in advance the accidents of the rock slide. Moreover, it is required to make an advisory committee to develop the industry and to save the techniques. The most important matter is the accomodation between the attitude of the enterprising man for the social responsibility to the public nuisance and the cooperative spirit of the inhabitants for the industry.

• Journal of Korean Society of Forest Science
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• v.83 no.3
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• pp.400-409
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• 1994

To investigate the noise attenuation effects of various vegetation configurations, noise levels on 6 study sites along relatively heavy traffic roads were measured. The differences between noise level measures at 1m and 10m spots from the road range from 10 to 15dB depending upon the attributes of the vegetation. When flat grass land was set to control plot, the maximum noise attenuation at 10m spot was measured at the densely planted shrubs with 5dB difference. The areas on upward slope from the road showed the least attenuation effects. Based on the study results, an appropriate setting for low level residential area noise buffer belt would be densely planted shrubs with at least 3m width and 2m height. To be effective, 3m width soft areas covered with grasses are needed at the front and behind sides of the belt. More than 15dB of the noise level caused by the road traffic would be attenuated with the prescription.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.9 s.114
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• pp.964-970
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• 2006

Micro gas turbine(MGT) has received attention recently as small-scale distributed power sources. With characteristics such as their small size, lightweight, low maintenance cost and minimal vibrations during operation, they are expected to become widespread in a wide range of ' applications, including residential and small-scale industrial use. It is very easier to start-up and stop the MGT system which is the friendly environmental power system has just below the 9ppm NOx emmission and good quality of noise level. The exhaust heat emitted by the MGT is in the form of about $300^{\circ}C$ clean exhaust gas. The exhaust gas is suitable for absorption chiller/heater system. 1 has researched performance characteristics of the 60 kW class MGT-absorption chiller-heater system in the local condition. Variations of heat recovery from exhaust gas has measured according to micro gas turbine output of 15, 30, 45, 60kW. From those results, the performance of the MGT-absorption chiller/heater system has been evaluated.

• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.94-102
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• 1999

To estimate the effects of environmental noise on inhabitants' life in an apartment area at Taejon, noise levels and traffic volume of major roads were measured. 203 housewives were surveyed by questionaires including general factors, noise related factors and three items of life effects: subjective evaluations on the general environment, annoyance, and life disturbance due to environmental noise. At the boundary adjacent to the road with more traffic volume, noise level was higher; according to the time, the amount of noise level was in the morning, in the evening, at noon, and at night in order. Most of boundary noise levels were higher than those of recommended standard environmental noise levels in a residential area. The boundary noise level showed a very significant linear relationship with traffic volume of near roads. Noise level difference in the apartments adjacent to three roads was ranged 2.4~6.7dB between in windows open and close state. The apartments adjacent to 9 lane or 6 lane-road, which were protected by noise prevention wall and 20m or more distance from the roads, showed higher noise level at middle floors and high floors than those of low floors; but the buildings adjacent to 4 lane-road, with no protection, showed higher noise level at low and middle floors than those of high floors. Among 203 housewives, 120(59.1%) participated in this study, and 86(73.2%) of them answered that the most serious environmental noise was traffic noise from near roads. Comparing traffic noise levels with those of before-migration, 67.0% participants found the environmental noise became louder. Fifty eight(49.5%) of the participants wanted noise protection wall and 15(25.9%) of them were willing to charge the fee. Less perception on the present noise comparing to those before-migration, less traffic volume, and lower noise levels in the apartments were related to higher scores of self-evaluation on the environment. Higher susceptibility on the present noise, areas with more traffic volume, higher boundary noise levels, and higher noise levels showed higher scores of annoyance on environmental noise and life disturbance. Considering above all things, it was suggested that traffic noise in this area was the major problem of environmental noise, and its' effect was so serious that inhabitants needed some preventive measures for better life quality.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.847-854
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• 2012

The demand for noise barriers and necessity for the installation are highly growing because residential areas have become diverse and locational priority is changed to consider how to approach highway easily. However, public annoyance to the noise generated from highway is continued despite lots of noise barrier are installed. Moreover, there are growing concerns to maintain noise barriers to be free from losing transparency, dust stack, and shock fracture. To resolve these issues, it is suggested to develop new polymer materials and conceptually new noise barrier. In this study, as a first step to develop a new noise barrier to overcome current technological challenges as well as economic issues, recent research trends have been analyzed and found the direction for the future research in terms of material, supplementary function, and patterning.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.29-38
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• 2009

In Korea, large.scale housing complexes and residential areas began to appear in urban regions through urban plan projects from the 1970s. In addition, with the increase in the percentage of apartments in developed areas, road traffic noise at roadside apartments was raised as a new problem. Furthermore, since the late 1980s, apartments, which had been no taller than 15 stories, have grown higher to 20-30 stories and recently 40.story or higher apartments are being constructed, and as a result, residences are growing denser and road traffic noise is increasing in urban areas. Thus, the present study made a noise map using variables 'traffic volume' and 'mean spot speed' among factors influencing roadside apartments, and examined the noise reduction efficiency of the variables. According to the results, traffic volume and speed limit were found to have an effect on a limited space, and the median bus lane system was found to have a slight effect on the roadside.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.47-55
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• 2008

According to the increase of power demand and expansion of downtown, it is necessary to install transformers additionally in operating substations and construct substations in residential area. But the public complaint has been increased due to the transformer noise of the substation. KEPCO has used a vibration preventing pad, various soundproof walls and an enclosure to transformers in outdoor substations, and a soundproof door, shutter and wind-path soundproof equipment in indoor substations to block the sound propagation from the transformers. But these noise reduction methods are not satisfied. It should be considered to reduce transformer noise itself. To shut out sound emitted from transformers, we developed a soundproof technology that wall up reinforcing bar by steel sheet. For the practical application of it, we analyzed the vibration characteristics of a transformer tank and reduction of noise according to soundproof plate. As a result, it is confirmed that the technology can reduce 11 [dB] of transformer noise.

• Land and Housing Review
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• v.13 no.4
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• pp.13-26
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• 2022

This study analyzes housing choice determinants of the youth and newlyweds households by using housing survey data in Incheon. A multinomial logit model is employed for analysis with the following variables: housing characteristics, housing market characteristics, and residential and neighborhood environment characteristics. The findings from the analysis are as follows. First, for the continued residence of the youth, the important factors were the relief assistance of housing maintenance costs. For the newlyweds, the important factors were the quality improvement of residential environments to ensure residential stability. Second, the housing choice factors to attract the youth were residential support for rent, maintenance costs, and relocation, and the improvements of residential environments such as security, noise levels, and medical facilities. For the newlyweds, the important factors were housing loan assistance for a home purchase or a cheonsei deposit and residential quality improvements for air pollution and parking facilities. Third, the youth were likely to move out due to high rental costs, and the newlyweds were likely to move out for the purchase of a new apartment or higher-quality housing.

• Land and Housing Review
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• v.15 no.1
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• pp.39-55
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• 2024

The aim of this study is to analyse housing satisfaction among residents of different types of public rental housing-permanent, national, and happy housing-following the integration of housing types upon the full-scale supply of integrated public rental housing. By identifying key factors that influence residential satisfaction, our goal is to inform the planning of public rental housing complexes and derive policy implications. The study focuses on analysing discrepancies in residential satisfaction among residents of different types of public rental housing and comparing the factors influencing this satisfaction. Microdata from the Ministry of Land, Infrastructure, and Transport's 'Housing Situation Survey' in 2021 is utilized for analysis, employing one-way ANOVA and binomial logistic regression methods. Empirical analysis reveals variations in residential satisfaction levels between residents of permanent and national rental housing, with national rental housing residents exhibiting higher satisfaction. The influencing factors of overall condition satisfaction are consistent for permanent and national rental residents but differ for happy housing residents. Additionally, the influencing factors of overall residential environmental satisfaction vary across all three housing types. Nonetheless, common factors across all types include housing noise and facility accessibility, highlighting their significance in complex planning. Subsequent studies may involve time series analysis to assess changes in influencing factors over time.

• The KSFM Journal of Fluid Machinery
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• v.13 no.2
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• pp.18-23
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• 2010

This paper presents a procedure for the aerodynamic and aeroacoustic characteristics of a sirocco fan. For the aerodynamic and aeroacoustic analyses of the sirocco fan, three-dimensional steady and unsteady Reynolds-averaged Navier-Stokes equations are solved with a shear stress transport turbulence model for turbulence closure. The flow analyses were performed on a hexahedral grid using a finite-volume solver. The validation of the numerical results is performed by comparing with experimental data for the pressure, efficiency and power. The internal flow analyses of the sirocco fan are performed to understand the unstable flow phenomenon on the casing for the wall pressure and internal flow characteristics at each position. It was found that fluctuation of pressure and locally concentrated noise source are observed near the cut-off and expansion regions of the casing.