• Title/Summary/Keyword: Road environment

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Using AHP to Analyze the Evaluation Factors Related to Wildlife Passage Management (AHP기법을 활용한 야생동물이동통로의 기능개선을 위한 평가항목 분석)

  • Lee, Jin-Young;Rho, Paik-Ho;Lee, Jang-Won
    • Korean Journal of Environment and Ecology
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    • v.24 no.6
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    • pp.763-771
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    • 2010
  • The rapid increase of wildlife passage installation since the late 2000s was aimed to reduce roadkill caused by habitat fragmentation and losses related to road construction, but wildlife-vehicle collisions are now still occurred even near the wildlife passage area. This is the reason that the effectiveness of wildlife passage have not been evaluated in combination with absence of monitoring data and management strategy of the wildlife passage. The AHP method are used, in this study, to identify the evaluation factors affecting the effectiveness of the present 367 wildlife passages in a mitigation measures to reduce road effects on wildlife species. Ten evaluation factors are derived from third levels in the AHP analysis. Priority setting to identify appropriate management strategies in first level is selected among four second levels on facility, environment, wildlife species and management tool. The AHP analysis suggested that neighboring environments are the most important factor at the second level, and passage structure, harmony with natural surroundings, wildlife occurrence and monitoring of the passage are also important factors at the third levels. In summary, effective measurements of wildlife passage management is based on managing the passage with neighboring topography and natural surrounding. This is useful to establish wildlife passage management strategy in order to reduce the negative effects of roads on wildlife species.

Physiological Responses of Roadside Trees by Regional Groups and Species in Daejeon City (대전광역시 가로수의 지역별·수종별 생리적 반응)

  • Kim, Dong Il;Park, Gwan Soo;Kim, Gil Nam;Lee, Hang Goo;Park, Beom Hwan
    • Journal of Korean Society of Forest Science
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    • v.100 no.1
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    • pp.88-94
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    • 2011
  • This study was conducted to provide on a basic information for maintenance of roadside trees and identify the links between environmental pollution and tree damages (Ginkgo biloba, Platanus occidentalis) in Daejeon City by analyzing photosynthetic characteristics, water use efficiency, chlorophyll fluorescence and chlorophyll contents by the regions and plants. The investigations were conducted at Chungnam national university(CNU) considered as the least air-polluted area compared to other study sites, Daedeok science town(DS) which a new road with little traffic recently was built around, Daehwa industry complex(DIC) and Daejeon station(DS) which an old road with heavy is located around. The photosynthetic capacity of the two species were highest in CNU and lowest in the DS. However the water use efficiency was highest on the contrary to the photosynthetic capacity in DS. Chlorophyll fluorescence and chlorophyll contents were highest in CNU and lowest in DS as the photosynthetic capacity. On all of the test, Ginkgo biloba shows the more favorable physiological responses than Platanus occidentalis.

A Numerical Study on the Characteristics of Flows and Fine Particulate Matter (PM2.5) Distributions in an Urban Area Using a Multi-scale Model: Part II - Effects of Road Emission (다중규모 모델을 이용한 도시 지역 흐름과 초미세먼지(PM2.5) 분포 특성 연구: Part II - 도로 배출 영향)

  • Park, Soo-Jin;Choi, Wonsik;Kim, Jae-Jin
    • Korean Journal of Remote Sensing
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    • v.36 no.6_3
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    • pp.1653-1667
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    • 2020
  • In this study, we coupled a computation fluid dynamics (CFD) model to the local data assimilation and prediction system (LDAPS), a current operational numerical weather prediction model of the Korea Meteorological Administration. We investigated the characteristics of fine particulate matter (PM2.5) distributions in a building-congested district. To analyze the effects of road emission on the PM2.5 concentrations, we calculated road emissions based on the monthly, daily, and hourly emission factors and the total amount of PM2.5 emissions established from the Clean Air Policy Support System (CAPSS) of the Ministry of Environment. We validated the simulated PM2.5 concentrations against those measured at the PKNU-AQ Sensor stations. In the cases of no road emission, the LDAPS-CFD model underestimated the PM2.5 concentrations measured at the PKNU-AQ Sensor stations. The LDAPS-CFD model improved the PM2.5 concentration predictions by considering road emission. At 07 and 19 LST on 22 June 2020, the southerly wind was dominant at the target area. The PM2.5 distribution at 07 LST were similar to that at 19 LST. The simulated PM2.5 concentrations were significantly affected by the road emissions at the roadside but not significantly at the building roof. In the road-emission case, the PM2.5 concentration was high at the north (wind speeds were weak) and west roads (a long street canyon). The PM2.5 concentration was low in the east road where the building density was relatively low.

Empirical Analysis on Radio Communication Range and Vehicle Ratio in V2X Environment (무선 통신 가능 범위와 V2X 차량 비율에 관한 경험적 분석)

  • Park, Sang-Ung;Kim, Joo-Young;Na, Sung-Yong;Lee, Seung-Jae
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.15 no.5
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    • pp.29-41
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    • 2016
  • V2X environment is the most popular part of the C-ITS based on the high technologies. To evaluate V2X environment technologies, radio communication range and market penetration rate of V2X vehicle are used. This paper studies the V2X environment considering various traffic congestion level, radio communication range and market penetration rate of V2X vehicle using the microscopic simulation (VISSIM) based on proper parameters and algorithm. In conclusion, V2X environment can reduce the congestion in proper traffic volume. However, if traffic volume is almost near the capacity, even V2X environment can't relieve the road condition. Furthermore, increase of the radio communication range does not always mean the decrease of the congestion and even with the small market penetration rate, it can also have an impact on the V2X environment. This result will be the foundation for the V2X environment much better.

Analysis of the Relationship between Three-Dimensional Built Environment and Urban Surface Temperature (도시의 3차원 물리적 환경변수와 지표온도의 관계 분석)

  • Li, Yige;Lee, Sugie;Han, Jaewon
    • Journal of Korea Planning Association
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    • v.54 no.2
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    • pp.93-108
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    • 2019
  • This study examines the relationship between three-dimensional urban built environment and urban surface temperature using LANDSAT 8 satellite image data in Seoul city. The image was divided into 600m×600m grid units as an unit of analysis. Due to the high level of spatial dependency in surface temperature, this study uses spatial statistics to take into account spatial auto-correlation. The spatial error model shows the best goodness of fit. The analysis results show that the three-dimensional built environment and transport environment as well as natural environment have statistically significant associations with surface temperature. First, natural environment variables such as green space, streams and river, and average elevation show statistically significant negative association with surface temperature. Second, the building area shows a positive association with surface temperature. In addition, while sky view factor (SVF) has a positive association with surface temperature, surface roughness (SR) shows a negative association with it. Third, transportation related variables such as road density, railway density, and traffic volume show positive associations with surface temperature. Moreover, this study finds that SVF and SR have different effects on surface temperature in regard to the levels of total floor areas in built environment. The results indicate that interactions between floor area ratio (FAR) and three-dimensional built environmental variables such as SVF and SR should be considered to reduce urban surface temperature.

Design and Fabrication of Base Station Antenna for ETCS based on DSRC (DSRC 기반의 ETCS 기지국 안테나 설계 및 제작)

  • Ko Jin-Hyun;Kim Nam-Ki;Ha Jae-Kwon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.3 no.1 s.4
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    • pp.75-83
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    • 2004
  • This paper describes the design, fabrication, and measurement of a low side lobe antenna for RSE base station of the ETCS which is one of the ITS services. The antenna is installed on the gantry of road side and provides the wireless communication lint between vehicles and RSE. The required characteristics of ETCS base station antenna are low sidelobe and specific beam pattern by the road and install environment and installed place of OBU. To minimize the affects of multipath signal by reflection, Circular polarization is required. To get low sidelobe of antenna, array configuration and weighting factor by Taylor distribution in radiator elements are applied. The measured results of fabricated antenna are as follows; return loss of 130MHz by -10dB, an axial ratio of 2.6dB, and a gain of 17dBi. It is found that the measured beam patterns are similar to design results.

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Development of Vehicle and/or Obstacle Detection System using Heterogenous Sensors (이종센서를 이용한 차량과 장애물 검지시스템 개발 기초 연구)

  • Jang, Jeong-Ah;Lee, Giroung;Kwak, Dong-Yong
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.5
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    • pp.125-135
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    • 2012
  • This paper proposes the new object detection system with two laser-scanners and a camera for classifying the objects and predicting the location of objects on road street. This detection system could be applied the new C-ITS service such as ADAS(Advanced Driver Assist System) or (semi-)automatic vehicle guidance services using object's types and precise position. This study describes the some examples in other countries and feasibility of object detection system based on a camera and two laser-scanners. This study has developed the heterogenous sensor's fusion method and shows the results of implementation at road environments. As a results, object detection system at roadside infrastructure is a useful method that aims at reliable classification and positioning of road objects, such as a vehicle, a pedestrian, and obstacles in a street. The algorithm of this paper is performed at ideal condition, so it need to implement at various condition such as light brightness and weather condition. This paper should help better object detection and development of new methods at improved C-ITS environment.

A Study on the Road Facilities Use Characteristics of the Transportation Vulnerable by AHP Analysis (AHP분석을 통한 교통약자의 도로시설 이용특성에 관한 연구)

  • KIM, Min Je;LEE, Young Woo
    • Journal of Korean Society of Transportation
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    • v.33 no.3
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    • pp.276-283
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    • 2015
  • Pedestrians have been exposed to dangerous traffic environments, in which walking spaces in a city decrease without improved facilities even though cars increase. Such poor walking environments are deadly dangerous to the vulnerable as well as the non-vulnerable. This study analyzed the road facilities use characteristics according to a type of vulnerability in order to improve traffic safety and walking environment for vulnerable pedestrians. This study surveyed the vulnerable in terms of issues that they encountered on existing walkways and conducted the analytic hierarchy process (AHP), which took all quantitative and qualitative variables into account. The results of Level-3 analysis were showed that the elderly and the disabled were partially similar; both felt most inconvenient at enter-exit sections, steep walkway and bad paved walkway. Unlike those results, people with children and/or infants answered that overpass or underpass walkways without lifting facilities were most inconvenient walking environments.

Field Application of High Strength Concrete by Cement Types Using Maturity (적산온도를 이용한 시멘트 종류별 고강도 콘크리트의 현장 적용성)

  • Kim, Dong Baek
    • Journal of the Society of Disaster Information
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    • v.16 no.3
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    • pp.472-478
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    • 2020
  • Purpose: The purpose of the study is to help economic and safe construction by accurately predicting the initial strength of high-strength concrete (70MPa) for each type of cement, securing reliability of concrete quality, and drawing accurately the timing of form deformed, tensioning time of PS concrete, and openning of traffic after road repair with maturity. Method: Calculate the maturity by measuring the hydration heat with cement type for each age, and measure the strength of concrete with age to predict the strength corresponding to the any maturity. Result: In estimating the time required for traffic opening in road repair, ASTM C1074 was theoretically estimated at 16.4 hours for high-strength concrete, but in this study, maturity was calculated at 307, 14.4 hours for OPC and maturity at 2700, 34 hours for LHPC and maturity 200, 8 hours for ESPC. Conclusion: The timing of form deformed of structures using high-strength concrete and the opening of traffic of road repair may be much faster than in the case of concrete using OPC below the design basis strength 40MPa applied by ACI Committee 347.

Development of Korean RDE Routes for On-road Emissions Measurement of Light Duty Vehicles (소형자동차 실제도로 주행 배출가스 측정을 위한 국내 주행경로 개발)

  • Kang, Gunwoo;Lee, Jongtae;Park, Junhong;Cha, Junepyo;Chon, Mun Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.3
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    • pp.287-296
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    • 2017
  • Although emission regulations have been gradually strengthened in the past decade, the road transport section remains the most important source of NOx emission in air pollution. One reason is that there has been an increase in the proportion of diesel vehicles and in the volume of traffic. In addition, the certification procedure for standard emission limit does not sufficiently reflect real traffic condition and various driving patterns. Therefore, the European Commission(EC) has recently come up with the RDE-LDV(Real driving emissions-light duty vehicle) regulations, and the Ministry of Environment in Korea has been conducting research on evaluating RDE-LDV with PEMS(Portable Emission Measurement Systems). According to the trip requirements of the 2nd RDE package announced by the EC, the objectives of the present study include the development of Korean RDE routes to reflect domestic traffic and road conditions. Based on the results, both RDE routes are in correct compliance with RDE-LDV regulations, including trip requirements and trip dynamics. KOR-NIER Route 1, in particular, has a higher driving load in rural driving with regard to excessive gradient of elevation compared to KOR-NIER Route 2, including relatively plane rural driving.