• Title/Summary/Keyword: Urban median

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The Effect of Urban Road Vegetation on a Decrease of Road Surface Temperature (도시도로 녹지의 도로 표면온도 져감 효과에 관한 연구)

  • Cha, Hye-Jin;Lim, Ji-Hyun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.3
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    • pp.107-116
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    • 2011
  • One of the major factors which increase urban temperature is roads. This paper is aimed to investigate the effect of urban roadside vegetation on the road surface temperature. For this, surface temperature was measured at 18 spots using the thermal imaging camera in terms of road components including use of roadside land use, roadway, sidewalk, roadside vegetation and vegetation median barrier. The size of the roadside vegetation and related urban road characteristics were also measured. In terms of the effect of roadside vegetation on a decrease in road surface temperature, the roadside land use as a green area or open space was the highest, followed by the size of vegetation median barrier and the size of roadside vegetation. Besides road surroundings, an increase in the green zone such as roadside vegetation and median strip vegetation has a significant impact on lowering road surface temperature. Therefore, a good solution for reducing urban heat island effects would be to increase the area of roadside vegetation and green areas along roads.

Wind Fragility for Urban Street Tree in Korea (강풍 발생 시 국내 가로수의 취약성 분석)

  • Sim, Viriyavudh;Jung, WooYoung
    • Journal of Wetlands Research
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    • v.21 no.4
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    • pp.298-304
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    • 2019
  • In this paper, the analytical method to derive wind fragility for urban street tree in Korea was shown. Monte Carlo Simulation method was used to determine the probability of failure for urban street tree. This probability result was used to determine wind fragility parameters for four types of tree based on the study of street tree species in urban area in Daegu, Korea. Wind fragility for street tree was presented in terms of median capacity and standard deviation of the natural logarithm of the capacity. Results showed that the dominant factor affecting the probability of failure of tree under wind load was their diameter. Moreover, amongst the four types of tree chosen, the tree with height 7m and diameter 35cm had the lowest probability of failure under wind loading, whereas the tree with height 8m and diameter 30cm could resist the least wind loading. The median failure wind speed for urban street tree with height 7m were 43.8m/s and 50.6m/s for diameter 30cm and 35cm, respectively. Also, for tree with height 8m, their median failure wind speeds were 38.7m/s and 45.4m/s for tree with diameter 30cm and 35cm, respectively.

Analysis of Traffic Accident by Circular Intersection Type in Korea Using Count Data Model (가산자료 모형을 이용한 국내 원형교차로 유형별 교통사고 분석)

  • Kim, Tae Yang;Lee, Min Yeong;Park, Byung Ho
    • Journal of the Korean Society of Safety
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    • v.32 no.5
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    • pp.129-134
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    • 2017
  • This study aims to develop the traffic accident models by circular intersection type using count data model. The number of accident, the number of fatal and injured persons(FSI), and EPDO are calculated from the traffic accident data of TAAS. The circular intersection accident models are developed through Poisson and negative binomial regression analysis. The main results of this study are as follows. First, the null hypotheses that there are differences in the number of traffic accidents, FSI and EPDO by type of circular intersections are rejected. Second, the scale of intersection(median, large), number of approach road, mean width and length of exit road, area of the circulating roadway and central island are selected as factors influencing the number of traffic accidents, FSI and EPDO in rotary. Third, the scale of intersection(median), guide signs(limited speed, direction, roundabout), number of approach road, entry angle, area of the intersection and central island are adopted as factors influencing the number of traffic accidents, FSI and EPDO in roundabout. Finally, transferring from rotary to roundabout could be expected to make the accident decrease.

Experimental Investigation of Macroscopic Analysis of Traffic Safety Using Meta Analysis Focused on Busan Metropolitan City (메타분석을 이용한 교통안전성의 거시적 분석에 대한 실험적 고찰 : 부산광역시를 중심으로)

  • Park, Jongseo;Oh, Yun Pyo;Kim, Hoe Kyoung;Ahn, Woosung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.6
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    • pp.1339-1345
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    • 2015
  • Korean government annually estimates and reports the traffic safety index to evaluate the traffic safety of 228 Gu Gun. However, since the traffic safety index is derived from the spatially macroscopic perspective based on collected relative data, there are a couple of problems such as inability to investigate the individual traffic accidents on the spot, insecurity of accuracy and reliability of traffic safety index estimation method, and absence of establishing temporal relationship of traffic accidents. Thus, this study investigated temporal traffic safety in macroscopic manner for Gu Gun in Busan depending on the installation of the traffic safety facility (i.e., urban median), employing meta analysis. As a result, all Gu Gun in Busan except Saha, Buk, Dong, and Busanjin experienced more traffic accidents after installing the urban median, indicating that there are more rooms for improvement of macroscopic traffic safety evaluation.

Characterization of Air Quality in Various Types of Indoor Environments in Urban Areas - Focusing on Homes, Offices, and Restaurants - (도시지역 실내환경 유형별 공기질 특성 평가 -가정, 사무실 및 식당을 중심으로-)

  • 백성옥;김윤신
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.4
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    • pp.343-360
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    • 1998
  • In this study, comprehensive air quality monitoring was undertaken with a variety of objectives to collect data on the levels of various indoor and ambient air quality parameters in the urban areas of Seoul and Taegu. The sampling sites were comprised of six offices, six residences and six restaurants in each city. The ambient air adjacent to the indoor sites was also simultaneously sampled for the same constituents. The sampling was conducted in two phases: summer of 1994 and winter of 1994/95. A range of air quality parameters were measured simultaneously, which include RSP, CO, COB, NOB, a range of VOC, airborne microbials, temperature, and relative humidity. The indoor and ambient levels of the pollutants measured in this study varied widely between the three types of environments studied. Comparison of median values for the three groups revealed that restaurants had higher indoor levels of most pollutants than homes or offices. There was also a clear pattern of the indoor levels of target pollutants being higher than those outdoors, particularly in restaurants. Concentrations of CO and most of the VOC were found to be significantly higher in the commercial districts, indicating the influence of vehicle exhaust emissions. A very wide range of VOC levels was documented in this study. Although median indoorloutdoor ratios indicated a generally increasing level of VOC indoors when compared to those outdoors, no statistically significant differences were found between indoor and outdoor VOC levels in homes and offices, implying the importance of ambient air quality in determining the quality of indoor air for homes and offices in urban areas. In addition, there was a general pattern of increasing concentrations from summer to winter, and similarly from outdoor to indoor air for nearly all target compounds. The seasonal differences in median levels were very clearly seen for fuel combustion related pollutants such as RSP, CO and VOC, this being attributed to the effects of increased fuel consumption during the cold season and to meteorological factors.

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Correlation Analysis between Median Household Income and LEED-Certified Public Transportation Access

  • Han, Hee Su;Kim, Boo-Young;Park, Young Jun;Son, Kiyoung
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.3
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    • pp.266-272
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    • 2014
  • The Leadership in Energy and Environmental Design (LEED) Green Building Rating System provides third-party verification for environmentally sustainable construction. But while LEED-certified buildings provide healthier work and living environments, Previous studies have shown that LEED certification does not provide any direct economic incentives to owners and developers. To address this issue, this study aims to investigate the economic benefits of LEED criteria. The objective of this study is to examine whether or not there is a significant correlation between median household income and the number of bus stops and light rail stations for a given parcel that meet LEED sustainable site criteria for public transportation access. The findings showed that the number of bus stops had a positive correlation with median household income, which means that more bus stops a given parcel had that met LEED criteria, the greater the median household income of a block group where the given parcel was located would be, though this positive correlation was very weak.

Prevalence and Age, Gender and Geographical Area Distribution of Esophageal Squamous Cell Carcinomas in North China from 1985 to 2006

  • Feng, Xiao-Shan;Yang, Yan-Tong;Gao, She-Gan;Ru, Yi;Wang, Gong-Ping;Zhou, Bo;Wang, Yu-Feng;Zhang, Peng-Fei;Li, Pu-Yu;Liu, Yong-Xuan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.1981-1987
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    • 2014
  • Objective: To establish the prevalence and distribution profile of esophageal squamous cell carcinomas (ESCCs) over a 22-yr period in North China. Methods: Using endoscopy for primary diagnosis and histological analysis for the further confirmation, a total of 74,854 ESCC patients aged 20-89 between January 1985 and December 2006 were investigated to analyze the epidemiological profile including prevalence rates, distribution of age-of-onset, gender and geographical area of ESCC in Luoyang, the highest incidence area of North China. Results: A total of 4092 cases of ESCC were finally diagnosed among 74,854 patients who had their first endoscopies. The prevalence among males was higher than that among females (p<0.01), resulting in an overall male:female OR of 1.2 (95%CI, 1.2-1.3). The prevalence in rural areas was higher than in urban areas (p<0.01), resulting in an overall rural:urban OR of 2.6 (95%CI, 2.4-2.9). The rural:urban ORs and the 95% CI increased continuously from 2.6, 2.3-3.0 to 2.7, 2.2-3.3, respectively, for 4 consecutive periods during the 22-yr study period. Moreover, the median age of onset among females was higher than that among males (p<0.01). For both sexes and in both areas, the prevalence rates declined and the median age of onset rose for 4 consecutive periods in the 22-yrs time frame (p<0.01). Conculsions: These data reveal the epidemiological profile of ESCC in the area of North China, and suggest that urban areas and rural people account for a growing proportion of the ESCC patients although the prevalence of ESCC significantly declined and the median age-of-onset postponed over the 22-yrs period. Moreover, the prevalence status of ESCC in rural areas also underlines the need for public health initiatives aimed at reducing risk factors of this fatal disease.

Analysis of Traffic Accident Severity by Aging Level (고령화 수준별 교통사고 심각성 분석)

  • Kim, Tae Yang;Park, Byung Ho
    • Journal of the Korean Society of Safety
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    • v.33 no.4
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    • pp.105-110
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    • 2018
  • Korea has entered to 'aged society', which the elderly people over 65 years old is over 14% of total population. This paper aims to analyze the traffic accident by aging level. In pursuing the above, this paper focuses on modeling the traffic accident severity based on three aging levels. The main results are as follows. First, the ratio of fatal and serious injured persons (FSI) is judged to increase according to increasing aging level. Second, the null hypothesis that there is no difference in FSI among three aging levels (aging, aged, and super-aged) is rejected. Four accident severity generalized linear models which are all statistically significant have been developed. Third, the common variables are analyzed to be median age, the number of hospital beds per persons, and turn signal usage ratio. Fourth, the differentiated traffic safety policies fitted to aging levels are required. The enforcement of traffic law violation and safety enhancement of motorcycle in the region of 'aging society', improvement of traffic facilities in the region of 'aged society', and expansion of transportation facilities in the region of 'super-aged society' are evaluated to be indispensable.

A Study on the Factors Affecting Air Temperature on Roadside : Focusing on Road Conditions and Traffic Characteristics (도로 주변부 기온에 영향을 미치는 요인에 관한 연구: 도로조건과 교통특성을 중심으로)

  • Lee, Yuhwa;Yang, Inchul;Kim, Do-Gyeong;Lim, Ji Hyun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1619-1629
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    • 2013
  • It turned out that there was a direct or an indirect relationship among global warming, urban heat island effects, urban and traffic environments, and public's health. In particular, unusual climate phenomena such as frequent heavy rainfall and scorching heat in a row that had rarely happened before have a negative effect on quality of life for people living in urban areas. This study focuses on the effects of roadway geometric design and traffic conditions on air temperature of roadside in Seoul Metropolitan Areas, controlling of roadway micro-climate environment. Five roadway segments containing different roadway and traffic conditions in terms of traffic median with trees, street trees, traffic volume and average travel speeds were surveyed. According to statistical results(t-test) from three roadway air temperature regression model estimations, air temperature is found to be different from one another in three periods-morning, afternoon and evening. Regarding roadway geometric design, air temperature of urban roads with vegetated median strips is lower about 1.3~2.2 degrees in celcius. Higher traffic volumes per lane and lower average travel speeds will tend to increase roadside air temperature, and efficient traffic operation policies can protect from increasing roadside air temperature in urban areas.