• Title/Summary/Keyword: street ratio

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An Investigation of Flow and Pollutant Dispersion in Three-Dimensional Asymmetric Street Canyons Using a CFD Model (CFD 모형을 이용한 3차원 비대칭 도로 협곡에서의 흐름 및 오염물질 분산 연구)

  • Park, Seung-Bu;Baik, Jong-Jin
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.2
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    • pp.214-224
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    • 2007
  • A three-dimensional computational fluid dynamics (CFD) model with the renormalization group (RNG) $k-{\varepsilon}$ turbulence model is used to examine the effects of difference in building height on flow and pollutant dispersion in asymmetric street canyons. Three numerical experiments with different street canyons formed by two isolated buildings are performed. In the experiment with equal building height, a portal vortex is formed in the street canyon and a typical recirculation zone is formed behind the downwind building. In the experiment with the downwind building being higher than the upwind building, the ambient flow comes into the street canyon at the front of the downwind building and incoming flow diverges strongly in the street canyon. Hence, pollutants released therein are strongly dispersed through the lateral sides of the street canyon. In the experiment with the upwind building being higher than the downwind building, a large recirculation zone is formed behind the upwind building, which is disturbed by the downwind building. Pollutants are weakly dispersed from the street canyon and the residue concentration ratio is largest among the three experiments. This study shows that the difference in upwind and downwind building height significantly influences flow and pollutant dispersion in and around the street canyon.

A Study on the image evaluation of Street Landscape -Focused on an Analysis of Psychological and Physical Factors which Creates a Busy Street (가로경관의 이미지 평가에 관한 연구 - 번화한 가로를 만드는 심리적, 물리적 인자의 분석을 중심으로)

  • 이재원
    • Archives of design research
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    • v.17 no.2
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    • pp.135-146
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    • 2004
  • The street landscape image is through complex experience of psychological factor by the visionary experience and physical factor by recognize a street's structure. Therefore, the need for analyz-ing and evaluating the psychological and physical aspect of street view was aroused, and how much it has an effect on the outcome. Above all, a definite street standard of a region in its characteristics was selected to analyze the street characteristics of a region (commercial, business, and complex area). A questionnaire was used to measure psychological information felt in a street area. As a result, the street image holds similar characteristics according to regional characteristics and the amenity and busy condition play a major role in having the effect. To know of the effect of street of a region that is known to cause the busy in a region, the discriminant analysis was made between the selected regions to analyze the difference. As a result, the difference of the width of street, ratio of widths of sidewalk and driveway, the ratio of height of a building and width of street, and the difference of tree-planting ratio were main factors which helped to feel more of the contrary of street in a region. Current research has helped to make more precise analysis and evaluation of all kinds of street images, and suggested different means of having more live image in a street region through physical factors. To create more the busy in a region, it is considered that analyzing the image of a street would be used more.

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Verification of Computational Fluid Dynamics Model Using Observation Data in Artificial Street Canyon (인공 도로협곡 관측 자료를 활용한 전산유체역학모델 검증)

  • Kim, Do-Hyoung;Hong, Seon-Ok;Lee, Dae-Geun;Lee, Young-Gon;Kim, Baek-Jo
    • Atmosphere
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    • v.26 no.3
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    • pp.423-433
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    • 2016
  • In this study, performance of a computational fluid dynamics (CFD) model is assessed from analysis on air flow pattern which is observed in the artificial street canyon. Field observations focusing on flows were conducted at an artificial street canyon in Magok region. For the observation of three-dimensional airflow structures, twelve three-dimensional wind anemometers (hereafter, CSAT3) were installed inside the street canyon. The street canyon was composed of two rectangular buildings with 35-m length, 4-m width, and 7-m height. The street width (distance between the buildings) is 7 m, making the street aspect ratio (defined by the ratio of building height to street width) of 1. For the observation of above-building wind, a CSAT3 was installed above the northwest-side building. Southwesterly, westerly and northwesterly were dominant in the street canyon during the observations. Because wind direction is parallel to the street canyon in the southwesterly case, westerly and northwesterly were selected as inflow directions in numerical simulations using a computational fluid dynamics model developed through the collaborative research project between National Institute of Meteorological Sciences and Seoul National University (CFD_NIMR_SNU). The observations showed that a well-structured vortex flow (skimming flow) and an evidence of a small eddy at the corner of the downwind building and ground appeared. The CFD_NIMR_SNU reproduced both the observed flow patterns reasonably well, although wind speeds inside the street canyon were underestimated.

Popular Celebrity and Adolescent Fashion - With a Focus on Popular Singers Appearing on Domestic TV in 2005 to 2009 - (대중스타와 청소년패션 - 05~09년도 국내 TV매체 속 대중가수를 중심으로 -)

  • Yoon, Jin-Ah
    • Journal of the Korea Fashion and Costume Design Association
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    • v.11 no.3
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    • pp.59-72
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    • 2009
  • The purpose of this study was to establish objective data for marketing of industries and product development design by researching popular singer fashion of Korea, investigating the preference for popular singer design in street fashion among adolescents on the basis of the research, and drawing an conclusion. To analyze street fashion, total 190 young men and women in their 20s, including teenagers, were surveyed mainly in downtowns around Daehakro, Gangnam and Hongik University. First, in relation to the upper garment, men were found to wear T-shirts and hood T-shirts the most, while women were found to wear T-shirts and one-piece dress the most. Second, in relation to the lower garment, the ratio of those who wore skinny clothes was high both among men and women. Third, in relation to the outer apparel, the ratio of men who wore casual jacket and hood zip-up was high, while the ratio of women who wore tailored jacket and leather jacket was high. Fourth, in relation to shoes, the ratio of men who wore sports shoes was high, while the ratio of women who wore heeled-shoe was high. Fifth, it was found that plane pattern was preferred the most. As it was stated above, the findings of this study on the effect of entertainers' fashion on adolescents through street fashion indicated that the number of adolescents who imitate the fashion of entertainers increased.

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A study on the activating factors of street spaces - Focused on the analysis of the component factors of streets in Korea and Japan - (가로공간의 활성화 인자에 관한 연구 - 한국과 일본의 가로구성인자분석을 중심으로 -)

  • Rhee, Jae-Won
    • Archives of design research
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    • v.19 no.2 s.64
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    • pp.99-108
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    • 2006
  • Based on the results from the already published 'A study on factors that make busy of street space' and 'A study on street the image evaluation of streetscape', this study is an attempt to explore factors, other than the structural factors, that compose the street space and affect the image of street to be more lively. First of all, this study was mainly concentrated on the structure of street space that fits the theory of the previous two theses, stating that the structural ratio ($D/H=0.5{\sim}2$) gives the street an interesting image. The next study subject was the street space that exhibits the amenity and busy of image according to the space structure ratio. I defined that exhibiting amenity and busy means the activation of the street space, and I attempted to extract the activation factors from the component elements. The street space that shows amenity and busy image after the activation was named as 'lively street space' in this study. Furthermore, I selected 20 street spaces, after classifying the whole, according to nations and local characteristics as the previous theses had done and looked for the 'lively street space', whose structural ratio was not in the range of $D/H=0.5{\sim}2$ and the factors that contributed to the Image. As the result, I founded that in case of the business areas with the ratio of $D/H=0.5{\sim}2$, street activation factors were hydroponic facilities, sidewalks, and wayside buildings and In case of the commercial areas, the factors were sidewalk, wayside buildings, hydroponic facilities, and illumination facilities. Especially, 5 commercial areas in Korea and 1 business areas in Japan did not have the structural ratio of $D/H=0.5{\sim}2$, but still exhibited lively image as streets. This was because aside from the structural element, other street activation factors such as facilities also had major contribution in these streets. In other words, in commercial areas in Korea have wayside buildings, sidewalks, and hydroponic facilities as activating factors, whereas in street spaces in business areas in Japan, hydroponic facilities, wayside buildings, and sidewalk factors are influential to the activation of street spaces.

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The Present Conditions and Remedial Measures of Street Trees in Miryang City (밀양시 가로수 현황과 개선방안)

  • 백재봉;조재우;최송현
    • Journal of Environmental Science International
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    • v.12 no.6
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    • pp.565-572
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    • 2003
  • The aim of this research is to survey the census of street trees and to provide remedial measures for street trees management to Miryang City. To do this, survey was carried out 16 region units in Miryang City. Through the survey, the current status of street trees’ map was made using automated map. From the results, it is turned out that 17,079 trees have been planted in Miryang City. The major species of street trees are Prunus serrulata var. spontanea(41.6%), Ginkgo biloba(26.1%), Pinus thunbergiana(13.3%) and the others are 12 species(19.0%). By the region units, Samrangjin-Eub is the most that 2,308 street trees are planted, and the next is Chodong-Myon(2,206 trees). The littlest street trees planted region is Cheongdo-Myon. In the results of comparison the component of street trees with other municipal cities, e.g. Seoul, Incheon, Kwangyang etc., only a few street trees have been planted so many in Miryang City. So, Miryang City indicated high proportionate street trees planting ratio. The suggested remedial measures are consisted with identifying the each street, increasing the green area by accepting the suitable street tree planting model, improving the physiological growth condition and systematic management with GIS.

A Study on the Characteristics of Flow and Reactive Pollutants' Dispersion in Step-up Street Canyons Using a CFD Model (CFD 모델을 이용한 체승 도시협곡의 흐름과 반응성 대기오염물질 확산 특성 연구)

  • Kim, Eun-Ryoung;Park, Rokjin J.;Lee, Dae-Geun;Kim, Jae-Jin
    • Atmosphere
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    • v.25 no.3
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    • pp.473-482
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    • 2015
  • In this study, street canyons with a higher downwind building (so called, step-up street canyons) are considered for understanding characteristics of flow and reactive pollutants' dispersion as a basic step to understand the characteristics in wider urban areas. This study used a CFD_NIMR_SNU coupled to a chemistry module just including simple $NO_X-O_3$ photochemical reactions. First, flow characteristics are analyzed in step-up street canyons with four aspect ratios (0.33, 0.47, 0.6, 0.73) defined as ratios of upwind building heights to downwind building height. The CFD_NIMR_SNU reproduced very well the main features (that is, vortices in the street canyons) which appeared in the wind-tunnel experiment. Wind speed within the street canyons became weak as the aspect ratio increased, because volume of flow incoming over the upwind building decreased. For each step-up street canyon, chemistry transport model was integrated up to 3600 s with the time step of 0.5 s. The distribution patterns of $NO_X$ and $O_3$ were largely dependent on the mean flow patterns, however, $NO_X$ and $O_3$ concentrations were partly affected by photochemical reactions. $O_3$ concentration near the upwind lower region of the street canyons was much lower than background concentration, because there was much reduction in $O_3$ concentration due to NO titration there. Total amount of $NO_X$ in the street canyons increased with the aspect ratio, resulting from the decrease of mean wind intensity.

Study of Construction Costs in South and North Korea: Focusing on Construction Cost in Ryomyong Street Project, Pyongyang (남북 건축공사비 연구: 평양 려명거리 사업 건설조립액을 중심으로)

  • Kim, Jang-Han
    • Journal of the Korea Institute of Building Construction
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    • v.22 no.4
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    • pp.371-378
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    • 2022
  • The Ryomyong Street project is the only construction project for which the construction cost is known, but its scale cannot be estimated because it is marked in North Korean Won. In this paper, the construction cost per m2 of North Korean apartment building construction was calculated based on the construction and assembly amount of the Ryomyong Street project. 160 to 1 was calculated as the ratio of the building construction cost per m2 between South and North Korea based on the Ryomyong Street project in Pyongyang and Seoul Housing & Communities Corporation. This ratio can be used to assume the construction size presented in North Korean won as there is no official exchange rate between the two Koreas.

Effects of Building-roof Cooling on Scalar Dispersion in Urban Street Canyons (도시 협곡에서 건물 지붕 냉각이 스칼라 물질 확산에 미치는 영향)

  • Park, Soo-Jin;Kim, Jae-Jin
    • Atmosphere
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    • v.24 no.3
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    • pp.331-341
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    • 2014
  • In this study, the effects of building-roof cooling on scalar dispersion in three-dimensional street canyons are investigated using a computational fluid dynamics (CFD) model. For this, surface temperature of building roof is systematically changed and non-reactive pollutants are released from street bottom in urban street canyons with the aspect ratio of 1. The characteristics of flow, air temperature, and non-reactive pollutant dispersion in the control experiment are analyzed first. Then, the effects of building-roof cooling are investigated by comparing the results with those in the control experiment. In the control experiment, a portal vortex which is a secondary flow induced by ambient air flow is formed in each street canyon. Averaged air temperature is higher inside the street canyon than in both sides of the street canyon, because warmer air is coming into the street canyon from the roof level. However, air temperature near the street bottom is lower inside the street canyon due to the inflow of cooler air from both sides of the street canyon. As building-roof temperature decreases, wind speed at the roof level increases and portal vortex becomes intensified (that is, downdraft, reverse flow, and updraft becomes stronger). Building-roof cooling contributes to the reduction of average concentration of the non-reactive pollutants and average air temperature in the street canyon. The results imply that building-roof cooling has positive effects on improvement of thermal environment and air quality in urban areas.

An Analysis on the Color Trend of Street Fashion in Dalian, China(paper no.1) - Focused on 2010 Summer -

  • Kim, Eun-Sil;Bae, Soo-Jeong
    • Journal of Fashion Business
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    • v.15 no.3
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    • pp.51-66
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    • 2011
  • The purpose of this study is to investigate the effect of the traditional color sentiment on the contemporary clothing color by studying the pictures of street fashion of Dalian in China, in view of the clothing color of women in their 20-30 years of age having highest purchasing power, along with traditional Chinese color. The clothing color is various in frequency depending on the items in street fashion. Due to the seasonal impact of summer, the most frequent item was one-piece dress with the Multi of various color patterns, followed by White, Black, PB, R and B category. In the top color, the White was most prevalent color due to the seasonal factor, followed by Black, Grey, Multi, R, Y, RP category. Achromatic color is more dominant with the ratio of 7:3, comparing with its counterpart, which consists of R and Y category of V, B, P, VP tone. In the bottom color, Dp tone of PB shows most high frequency, followed by Black. This results illustrate that Chinese women prefer blue jeans and to be looked as slimmer by using of the dark colors. In the accessories, colors of bags and shoes show different results. The bag colors show the high frequency of Dk tone, YR category, and the chromatic colors are little bit dominant than achromatic ones with the ratio of 5.3:4.7. On the contrary, the shoes colors show the highest frequency in Black, the achromatic colors are more dominant than chromatic ones with the ratio of 6.6:3.4. These results somewhat diverge from the international color trend. Color trend in Dalian street fashion in which the high frequency of V tone is observed through all the colors of the items followed by P, VP, Lgr tone in sequence. In the light of Chinese traditional color preference, this result denotes that the traditional color preferences of red, yellow are still affecting the contemporary color choices of clothing in Chinese women. The high incidence of PB category in the bottom and one-piece dress does not seem to have its origin form traditional Chinese color sentiment.