• Title/Summary/Keyword: road transportation

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Study on Enhancement of TRANSGUIDE Outlier Filter Method under Unstable Traffic Flow for Reliable Travel Time Estimation -Focus on Dedicated Short Range Communications Probes- (불안정한 교통류상태에서 TRANSGUIDE 이상치 제거 기법 개선을 통한 교통 통행시간 예측 향상 연구 -DSRC 수집정보를 중심으로-)

  • Khedher, Moataz Bellah Ben;Yun, Duk Geun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.249-257
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    • 2017
  • Filtering the data for travel time records obtained from DSRC probes is essential for a better estimation of the link travel time. This study addresses the major deficiency in the performance of TRANSGUIDE in removing anomalous data. This algorithm is unable to handle unstable traffic flow conditions for certain time intervals, where fluctuations are observed. In this regard, this study proposes an algorithm that is capable of overcoming the weaknesses of TRANSGUIDE. If TRANSGUIDE fails to validate sufficient number of observations inside one time interval, another process specifies a new validity range based on the median absolute deviation (MAD), a common statistical approach. The proposed algorithm suggests the parameters, ${\alpha}$ and ${\beta}$, to consider the maximum allowed outlier within a one-time interval to respond to certain traffic flow conditions. The parameter estimation relies on historical data because it needs to be updated frequently. To test the proposed algorithm, the DSRC probe travel time data were collected from a multilane highway road section. Calibration of the model was performed by statistical data analysis through using cumulative relative frequency. The qualitative evaluation shows satisfactory performance. The proposed model overcomes the deficiency associated with the rapid change in travel time.

Evaluation on the Applicability of the Conventional Roadbed Stiffness for High Speed Concrete Track (일반철도 노반 강성조건에서의 고속철도용 콘크리트 궤도의 적용성 검토)

  • Lee, Jin Wook;Lee, Seong Hyeok;SaGong, Myung;Lyu, Tae Jin
    • Journal of the Korean Society for Railway
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    • v.16 no.1
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    • pp.40-46
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    • 2013
  • Based on Korean railway design standards, the thicknesses of the reinforced roadbeds of conventional and high speed railways are different, and so too, for the size distribution of the ballast particles. Accordingly, considerable cost would be required to increase operating speeds of conventional lines, in particular related to changing from a ballasted track system to a ballastless one. In this study, applicability of a roadbed which supports conventional ballasted track, for use as a ballastless track for a high speed rail line was examined. A reinforced roadbed for a conventional railway is 20cm thick, and the type of material used for a conventional reinforced roadbed is M-40 (crushed gravel for road embankments). A dynamics test was conducted to evaluate the occurrence of the permanent settlement of the track substructure. These results suggest that, without changes to the track substructure, an operational speed of 400km/h is feasible with a ballastless track. This result; however, is from laboratory experiments. Further studies, such as numerical analyses or field validation, are required.

Bending Behavior of Preservative Treated Pitch Pine Stress-Laminated Timber (방부처리 리기다소나무 응력적층재의 휨거동 특성)

  • Kim, Kwang-Mo;Shim, Kug-Bo;Kim, Byoung-Nam
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.4
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    • pp.306-315
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    • 2010
  • The stress laminated timber, which could be manufactured by small dimension lumber on construction site, has high possibilities for bridges in remote area, such as recreation forest or forest road, because those bridges may be short span and low frequency in use. The stress laminated timber has merits of easiness for preservative treatment and transportation because it is manufactured with small dimension lumber. This study was carried out to analyze performances of stress laminated timber manufactured with preservative treated domestic pitch pine for developing structural design data for stress laminated timber bridges for vehicular traffic. Perpendicular to grain compressive performance by preservative treatment and bending performance by bored holes of pitch pine lumber was analyzed. Then, the effects of bending performance by pre-stress pressure, distance of bolts, number of laminations and planning were analyzed. Conclusively, planning of lumber was not necessary for manufacturing stress laminated timber, and 80% of bending stiffness criteria was maintained as pre-stress pressure was higher than 3.0 kg/$cm^2$. However, further researches are needed to define the effects of bolt distances and number of laminations. The results of this research would be basic data for design stress laminated timber bridges for vehicular traffic in Korea.

Designation of Logical Bicycle Accident Dangerous Zone by Digital Map-Based Accident Characteristics Analysis (디지털 맵 기반 사고특성 분석을 통한 자전거 사고 논리 위험존 설정 연구)

  • Sung, Kwang-mo;Kim, Ki-cheol;Lee, Choul-ki;Kim, Sung-jin;Lee, Jung-uck
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.1
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    • pp.117-130
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    • 2017
  • Bicycles are leading to serious accidents in the event of a side collision, and it is very important to prevent accidents in advance because it is difficult to actively deal with them in a dangerous situation. As a part of the bicycle safety driving support technology, this study establishes bicycle accidents dangerous zone based on bicycle accident data and road property information of digital map nationwide and provides timely safety information to cyclists. The point selected by using actual accident data was called 'dangerous zone', and the potential accident occurrence point generated by modeling based on this 'dangerous zone' was called 'logical dangerous zone'. As a result of the research on the Designation of Logical Bicycle Accident Dangerous Zone, the regional specificity of the bicycle accident points across the nation was generalized to the form of the logical dangerous zone through the network data.

Spacio-temporal Analysis of Urban Population Exposure to Traffic-Related air Pollution (교통흐름에 기인하는 미세먼지 노출 도시인구에 대한 시.공간적 분석)

  • Lee, Keum-Sook
    • Journal of the Economic Geographical Society of Korea
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    • v.11 no.1
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    • pp.59-77
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    • 2008
  • The purpose of this study is to investigate the impact of traffic-related air pollution on the urban population in the Metropolitan Seoul area. In particular, this study analyzes urban population exposure to traffic-related particulate materials(PM). For the purpose, this study examines the relationships between traffic flows and PM concentration levels during the last fifteen years. Traffic volumes have been decreased significantly in recent year in Seoul, however, PM levels have been declined less compare to traffic volumes. It may be related with the rapid growth in the population and vehicle numbers in Gyenggi, the outskirt of Seoul, where several New Towns have been developed in the middle of 1990's. The spatial pattern of commuting has changed, and thus and travel distances and traffic volumes have increased along the main roads connecting CBDs in Seoul and New Towns consisting of large residential apartment complexes. These changes in traffic flows and travel behaviors cause increasing exposure to traffic-related air pollution for urban population over the Metropolitan Seoul area. GIS techniques are applied to analyze the spatial patterns of traffic flows, population distributions, PM distributions, and passenger flows comprehensively. This study also analyzes real time base traffic flow data and passenger flow data obtained from T-card transaction database applying data mining techniques. This study also attempts to develop a space-time model for assessing journey-time exposure to traffic related air pollutants based on travel passenger frequency distribution function. The results of this study can be used for the implications for sustainable transport systems, public health and transportation policy by reducing urban air pollution and road traffics in the Metropolitan Seoul area.

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Development of Network Equipment Based on V2X System for Automatic Intersection Traffic Signal Control (V2X 시스템 기반 교차로 네트워크 자동 신호시스템 개발에 관한 연구)

  • Oh, Jeakon;Kim, Hyungjin;Kang, JeongJin
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.5
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    • pp.173-177
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    • 2016
  • Korea, the traffic and transportation problems are significant because private cars are increasing constantly. Therefore, it is imperative to improve traffic condition so as to solve the problems such as traffic congestion and accidents which may occur due to the increase of vehicles in a limited area through the signal control. However, the current operating system for traffic control cannot provide car users the optimal signal but it generates a time delay of vehicles, traffic congestions etc. In this paper, we propose and implement the system based on V2X based automatic controller, which reduces the waste of time and the driver's psychological stress on the road intersection.

A Study on Estimation of the Greenhouse Gas Emission from the Road Transportation Infrastructure Using the Geostatistical Analysis -A Case of the Daegu- (공간통계기법을 이용한 도로교통기반의 온실가스 관한 연구 -대구광역시를 대상으로-)

  • Lee, Sang Woo;Lee, Seung Wook;Lee, Seung Yeob;Hong, Won Hwa
    • Spatial Information Research
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    • v.22 no.1
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    • pp.9-17
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    • 2014
  • This study was intended to reliably predict the traffic green house gas emission in Daegu with the use of spatial statistical technique and calculate the traffic green house gas emission of each administrative district on the basis of the accurately predicted emission. First, with the use of the traffic actually surveyed at a traffic observation point, and traffic green house gas emission was calculated. Secondly, on the basis of the calculation, and with the use of Universal Kriging technique, this researcher set a suitable variogram modeling to accurately and reliably predict the green house gas emission at non-observation point suitable through spatial correlation, and then performed cross validation to prove the validity of the proper variogram modeling and Kriging technique. Thirdly, with the use of the validated kriging technique, traffic green gas emission was visualized, and its distribution features were analyzed to predict and calculate the traffic green house gas emission of each administrative district. As a result, regarding the traffic green house gas emission of each administration, it was found that Bukgu had the highest green house gas emission of $291,878,020kgCO_2eq/yr$.

A Study on Intelligent Mobility Enhancement System for the Mobility Handicapped (첨단 교통약자 보호시스템에 대한 연구)

  • Han, Woong-Gu;Shin, Kang-Won;Choi, Kee-Choo;Kim, Nam-Sun;Sohn, Sang-Hyun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.5
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    • pp.25-37
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    • 2010
  • This study is aimed at enhancing mobility rights for the transportation underprivileged that has been made light of relatively compared to normal people. In order to do this, we've suggested having ITS (Intelligent Traffic System) built and improving satisfaction through the test operation of its main system. The existing sound signal device for the visually handicapped has one problem with managing it. Because, the people in charge of it had to visit each problematic site directly to maintain and fix some problems every time it was out of order. Moreover, it couldn't provide sustainable services about voice guidance and the visually handicapped had to control it by either confirming the location of buttons that were installed on the pillar of traffic light and then pressing one of them or using a remote controller on their own. In order to improve such inconveniences, we have created a new typed sound signal device for the visually handicapped by applying the cutting-edge wireless technology based on ergonomics considering actual road situations. Such technology enables it report the status of signal device and light to them by using its voice guidance system automatically every time they have access to it. Additionally, we've already introduced it to a couple of test areas and then known the fact that they recognized traffic situation more conveniently and safely compared to the existing sound signal device. That is above average in terms of satisfaction. In addition to that, we've provided LTS (Location Tracking System - Location-based service intended for elementary students) by utilizing the existing wireless infrastructure and founded the fact that about 87% of their parents were satisfied with the service based on LTS.

CO2 Emission Structure Analysis of Industrial Sector with Environmental Input-Output Table 2005 (환경산업연관표 2005를 이용한 산업부문의 이산화탄소(CO2) 배출 분석)

  • Kim, Yoon Kyung
    • Environmental and Resource Economics Review
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    • v.20 no.1
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    • pp.1-31
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    • 2011
  • By employing Environmental Input-Output Table 2005, which has 76 intermediate sector and 21 energy sources, this paper analyses the flow of energy demand and $CO_2$ after estimating an induced $CO_2$ emissions from 76 industrial sectors. Index of $CO_2$ intensity($CO_2/GDP$) and other index of $CO_2$ intensity($CO_2/calory$) showed that final demand sector uses more high calory energy source. Intermediate sector used less environmental friendly energy source and emit more $CO_2$ at same calory. Industries those has high induced $CO_2$ emissions are Thermal Power($32.587CO_2-g/Won$), Cement($10.370CO_2-g/Won$), Road Transportation($7.255CO_2-g/Won$), Cokes and Other Coal Products($5.791CO_2-g/Won$), Steam and Hot water supply, Sewage, Sanitary services($4.575CO_2-g/Won$). It is shown that industry such as Iron and Steel which has low $CO_2$ intensity, high backward linkage effect and high forward linkage effect makes high induced $CO_2$ emissions. Environmental load and $CO_2$ emissions in overall economy will decrease when not high $CO_2$ intensity industry but also low $CO_2$ intensity industry makes lower $CO_2$ intensity.

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An Origin and Diffusion of the Bibo in Youngnam Region (영남지방 비보(裨補)의 기원(起源)과 확산(擴散)에 관한 일고찰(一考察))

  • Choe, Won-Suk
    • Journal of the Korean association of regional geographers
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    • v.7 no.4
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    • pp.48-64
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    • 2001
  • In the dissertation, Bibos are discussed as landscape features in the geographical context of Youngnam Region. The bibo tradition in Youngnam Region began with the incorporation of temple structures in Shilla and Kaya kingdoms, and spread throughout the country during the period of Unified Shilla. In Korea Dynasty, the diffusion of temple Bibo gained momentum, because Buddhism was worshipped as national religion. Then came a sea change in the Bibo repertoire with the replacement of Buddhism by Confucianism as an ideological prop for Chason Korea. The retreat of Buddhism led to the popularization of feng-shui motifs in Bibo strategy. The centers of the diffusion of the logic of bibo were major towns such as Kyongju, Ahndong, Sangju, and Chinju. The diffusion process continued top-down to mid-sized towns, and to the bottom of small villages. What sustained the hierarchical diffusion of Bibo attributes was myriad of transportation lines. The main artery of the diffusion in Korea Dynasty was that connecting Kaegyong to Kyongju. That same function was performed by the royal road running from Seoul through Sangju, Milyang, and to Tongrae. In the age of modernization, the feng-shui and Bibo landscapes have lost their original aura. They have suffered from the ruthless attacks of the Enlightenment logic of science. However, the elan vital of feng-shui and Bibo are still visible and strongly felt in the countryside. From field experiences, one can notice that the Bibo landscapes are tightly integrated into the rural way of life. The durability of the traditional geomancy shows us the beauty of the harmonious interplay between Youngnam people and the nature.

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