• Title/Summary/Keyword: Traffic estimation

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Investigation of Traffic Safety Requirements for Railway Bridge (철도교량 동적안정성 확보를 위한 거동한계기준에 대한 분석)

  • Kim, Sung-Il;Jeong, Han-Uk;Lee, Doo-Jae;Mun, Je-U;Kim, Jong-Tae
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1416-1423
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    • 2007
  • Dynamic instability of the railway bridge can cause track irregularities and be directly connected with unstable passenger comfort and derailment of the train. Europe and Japan had studied on this problem for a long time since 1960's, Results of those studies are reflected in recent Eurocode and the bridge design code of Japanese railway bridges. However, even though some traffic safety requirements were applied in Kyoung-bu highspeed railway by French engineers, we experienced many difficulties from insufficient information of criteria background and application procedures. In this paper, a investigation of recent traffic safety requirements of Europe and Japan for railway bridges will be introduced and application procedures for the estimation of dynamic performance will be proposed.

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Auditory and Visual Information Effect on the Loudness of Noise (시각 및 청각 정보가 소음의 인지도에 미치는 영향)

  • Shin, Hoon;Park, Sa-Gun;Song, Min-Jeong;Jang, Gil-Soo
    • KIEAE Journal
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    • v.6 no.4
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    • pp.69-76
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    • 2006
  • The effects of the additional visual and auditory stimuli on the loudness evaluation of road traffic noise was investigated by the method of magnitude estimation. As a result, it was shown that additional visual stimulus of noise barrier can influence on the loudness perception of road traffic noise. Also, additional auditory stimuli such as green music or sound of flowing water can influence on the loudness perception of road traffic noise, approximately 5~10% lower than the absence of stimuli. But this effect was disappeared in the range of over 65dB(A).

The Auditory and Visual Information Effects on the Loudness of Noises Perception (친환경적 시각 및 청각정보가 소음의 인지도에 미치는 영향)

  • Shin, Hoon;Song, Min-Jeong;Kook, Chan;Jang, Gil-Soo;Kim, Sun-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.970-973
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    • 2006
  • The effects of the additional visual and auditory stimuli on the loudness evaluation of road traffic noise was investigated by the method of magnitude estimation. As a result, it was shown that additional visual stimulus of noise barrier can influence on the loudness perception of road traffic noise. Also, additional auditory stimuli such as green music or sound of flowing water can influence on the loudness perception of road traffic noise. approximately $5{\sim}10%$ lower than the absence of stimuli. But this effect was disappeared in the range of over 65dB(A).

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A Genetic Algorithm for Trip Distribution and Traffic Assignment from Traffic Counts in a Stochastic User Equilibrium (사용자 평형을 이루는 통행분포와 통행배정을 위한 유전알고리즘)

  • Sung, Ki-Seok
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.11a
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    • pp.599-617
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    • 2006
  • A network model and a Genetic Algorithm(GA) is proposed to solve the simultaneous estimation of the trip distribution and traffic assignment from traffic counts in the congested networks in a logit-based Stochastic User Equilibrium (SUE). The model is formulated as a problem of minimizing the non-linear objective functions with the linear constraints. In the model, the flow-conservation constraints of the network are utilized to restrict the solution space and to force the link flows meet the traffic counts. The objective of the model is to minimize the discrepancies between the link flows satisfying the constraints of flow-conservation, trip production from origin, trip attraction to destination and traffic counts at observed links and the link flows estimated through the traffic assignment using the path flow estimator in the legit-based SUE. In the proposed GA, a chromosome is defined as a vector representing a set of Origin-Destination Matrix (ODM), link flows and travel-cost coefficient. Each chromosome is evaluated from the corresponding discrepancy, and the population of the chromosome is evolved by the concurrent simplex crossover and random mutation. To maintain the feasibility of solutions, a bounded vector shipment is applied during the crossover and mutation.

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A GIS-based Traffic Accident Analysis on Highways using Alignment Related Risk Indices (고속도로 선형조건과 GIS 기반 교통사고 위험도지수 분석 (호남.영동.중부고속도로를 중심으로))

  • 강승림;박창호
    • Journal of Korean Society of Transportation
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    • v.21 no.1
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    • pp.21-40
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    • 2003
  • A traffic accident analysis method was developed and tested based on the highway alignment risk indices using geographic information systems(GIS). Impacts of the highway alignment on traffic accidents have been identified by examining accidents occurred on different alignment conditions and by investigating traffic accident risk indices(TARI). Evaluative criteria are suggested using geometric design elements as an independent variable. Traffic accident rates were forecasted more realistically and objectively by considering the interaction between highway alignment factors and the design consistency. And traffic accident risk indices and risk ratings were suggested based on model estimation results and accident data. Finally, forecasting traffic accident rates, evaluating the level of risk and then visualizing information graphically were combined into one system called risk assessment system by means of GIS. This risk assessment system is expected to play a major role in designing four-lane highways and developing remedies for highway sections susceptible to traffic accidents.

Construction of an Estimation Model for Intersection Queue Length (교차로의 대기행렬 예측모형구축에 관한 연구)

  • Cho, Hyung K.;Min, Joon H.;Choi, Jong U.
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.5
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    • pp.1070-1081
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    • 1996
  • In this research, a model was developed for estimating the queue length of vehicles, based on occupancy time of each vehicle collected by loop detectors which were setup at the upstream of urban street. The estimation model suggestes a method which minimizes architectural effects of the street, such as existence of pedestrian crossing, for future applications to the field. The estimation model suggested in this research was established based on real traffic data collected at up-stream detectors in Kangnam Subway station, Seoul, and the formula of the model is based on Multi-Polynomial equations. Consequence of the experiments showed that the model can adequately and in real-time mode measure length of the queue which were constructed at the 80 to 90 meters away from the upstream detectors. The estimation accuracy of the model was verified in statistical analysis conducted by regressing analysis and test results in real traffic situation.

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Social Cost Comparison of Air-Quality based on Various Traffic Assignment Frameworks (교통량 배정 방법에 따른 대기질의 사회적 비용 비교분석)

  • Lee, Kyu Jin;Choi, Keechoo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.1087-1094
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    • 2013
  • This study aims at enhancing the objective estimation of social cost of air quality due to mobile emission. More specifically, it examines the difference between the daily oriented and hourly oriented estimation results of social air quality cost and draws implications from the comparative analysis. The result indicates that the social cost of air quality differs up to approximately 24 times depending on the analysis time period. Moneywise, the difference between daily and hourly assignments amounts to the average of 653.5 billion won whereas only 1% of error occurred in the estimation result based on peak and nonpeak based hourly assignment. This study reaffirms the need for time-based travel demand management for emission reduction, and confirms the feasibility of emission estimation by travel demand forecasting method over the conventional method employed by the CAPSS.

Structure damage estimation due to tunnel excavation based on indoor model test

  • Nam, Kyoungmin;Kim, Jungjoo;Kwak, Dongyoup;Rehman, Hafeezur;Yoo, Hankyu
    • Geomechanics and Engineering
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    • v.21 no.2
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    • pp.95-102
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    • 2020
  • Population concentration in urban areas has led traffic management a central issue. To mitigate traffic congestions, the government has planned to construct large-cross-section tunnels deep underground. This study focuses on estimating the damage caused to frame structures owing to tunnel excavation. When constructing a tunnel network deep underground, it is necessary to divide the main tunnel and connect the divergence tunnel to the ground surface. Ground settlement is caused by excavation of the adjacent divergence tunnel. Therefore, predicting ground settlement using diverse variables is necessary before performing damage estimation. We used the volume loss and cover-tunnel diameter ratio as the variables in this study. Applying the ground settlement values to the settlement induction device, we measured the extent of damage to frame structures due to displacement at specific points. The vertical and horizontal displacements that occur at these points were measured using preattached LVDT (Linear variable differential transformer), and the lateral strain and angular distortion were calculated using these displacements. The lateral strain and angular distortion are key parameters for structural damage estimation. A damage assessment chart comprises the "Negligible", "Very Slight Damage", "Slight Damage", "Moderate to Severe Damage", and "Severe to Very Severe Damage" categories was developed. This table was applied to steel frame and concrete frame structures for comparison.

Analyzing Relationship between Road Traffic Flows and Noise Trend using Korea Highway Traffic Noise Model (KHTN을 이용한 교통류 특성과 교통소음추이 분석)

  • Choi, Yoon Hyuk;Kim, Cheol Hwan
    • Journal of Environmental Policy
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    • v.11 no.3
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    • pp.49-65
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    • 2012
  • Road traffic noise is closely related to road traffic environment, including traffic volumes by type and travel speed. In this study, we stated some issues and analyzed the relationships between road traffic noise and traffic flow characteristics. First, in attempt to find the answer to the question "When does the loudest traffic noise occur?" we reviewed the issue in the terms of traffic flow. As a result of analyzing level of service through Korea Highway Traffic Noise model, the actual maximum noise occurred in level of service D rather than level of service E, on the capacity state. It shows that maximum noise would be most likely to occur right before and after the peak hours. Second, this paper was looking for the method of a more easy and accurate traffic speed estimation to predict traffic noise. This paper proposed sketch planning techniques of speed-volume curve by level of service on Korea Highway Capacity Manual. As a result of trend line modeling, it was judged that quadratic form is a suitable function, and coefficient of determination ($R^2$) was higher than 0.96, respectively.

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Intelligent Optimal Route Planning Based on Context Awareness (상황인식 기반 지능형 최적 경로계획)

  • Lee, Hyun-Jung;Chang, Yong-Sik
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.117-137
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    • 2009
  • Recently, intelligent traffic information systems have enabled people to forecast traffic conditions before hitting the road. These convenient systems operate on the basis of data reflecting current road and traffic conditions as well as distance-based data between locations. Thanks to the rapid development of ubiquitous computing, tremendous context data have become readily available making vehicle route planning easier than ever. Previous research in relation to optimization of vehicle route planning merely focused on finding the optimal distance between locations. Contexts reflecting the road and traffic conditions were then not seriously treated as a way to resolve the optimal routing problems based on distance-based route planning, because this kind of information does not have much significant impact on traffic routing until a a complex traffic situation arises. Further, it was also not easy to take into full account the traffic contexts for resolving optimal routing problems because predicting the dynamic traffic situations was regarded a daunting task. However, with rapid increase in traffic complexity the importance of developing contexts reflecting data related to moving costs has emerged. Hence, this research proposes a framework designed to resolve an optimal route planning problem by taking full account of additional moving cost such as road traffic cost and weather cost, among others. Recent technological development particularly in the ubiquitous computing environment has facilitated the collection of such data. This framework is based on the contexts of time, traffic, and environment, which addresses the following issues. First, we clarify and classify the diverse contexts that affect a vehicle's velocity and estimates the optimization of moving cost based on dynamic programming that accounts for the context cost according to the variance of contexts. Second, the velocity reduction rate is applied to find the optimal route (shortest path) using the context data on the current traffic condition. The velocity reduction rate infers to the degree of possible velocity including moving vehicles' considerable road and traffic contexts, indicating the statistical or experimental data. Knowledge generated in this papercan be referenced by several organizations which deal with road and traffic data. Third, in experimentation, we evaluate the effectiveness of the proposed context-based optimal route (shortest path) between locations by comparing it to the previously used distance-based shortest path. A vehicles' optimal route might change due to its diverse velocity caused by unexpected but potential dynamic situations depending on the road condition. This study includes such context variables as 'road congestion', 'work', 'accident', and 'weather' which can alter the traffic condition. The contexts can affect moving vehicle's velocity on the road. Since these context variables except for 'weather' are related to road conditions, relevant data were provided by the Korea Expressway Corporation. The 'weather'-related data were attained from the Korea Meteorological Administration. The aware contexts are classified contexts causing reduction of vehicles' velocity which determines the velocity reduction rate. To find the optimal route (shortest path), we introduced the velocity reduction rate in the context for calculating a vehicle's velocity reflecting composite contexts when one event synchronizes with another. We then proposed a context-based optimal route (shortest path) algorithm based on the dynamic programming. The algorithm is composed of three steps. In the first initialization step, departure and destination locations are given, and the path step is initialized as 0. In the second step, moving costs including composite contexts into account between locations on path are estimated using the velocity reduction rate by context as increasing path steps. In the third step, the optimal route (shortest path) is retrieved through back-tracking. In the provided research model, we designed a framework to account for context awareness, moving cost estimation (taking both composite and single contexts into account), and optimal route (shortest path) algorithm (based on dynamic programming). Through illustrative experimentation using the Wilcoxon signed rank test, we proved that context-based route planning is much more effective than distance-based route planning., In addition, we found that the optimal solution (shortest paths) through the distance-based route planning might not be optimized in real situation because road condition is very dynamic and unpredictable while affecting most vehicles' moving costs. For further study, while more information is needed for a more accurate estimation of moving vehicles' costs, this study still stands viable in the applications to reduce moving costs by effective route planning. For instance, it could be applied to deliverers' decision making to enhance their decision satisfaction when they meet unpredictable dynamic situations in moving vehicles on the road. Overall, we conclude that taking into account the contexts as a part of costs is a meaningful and sensible approach to in resolving the optimal route problem.