• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.3
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• pp.286-292
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• 2017

The Coastal VTS will be continuously constructed to prevent marine traffic accidents in the coastal waters of the Republic of Korea. In order to provide the best traffic information service to the ship operator, it is important to understand the navigation risk factor. In this study, we analyzed the navigational hazards of Gunsan coastal area where the coastal VTS will be constructed until 2020. For this purpose, major traffic flows of merchant ships and density of vessels engaged in fishing were analyzed. This study was conducted by Automatic Identification System (AIS) and Vessel Pass (V-PASS) data. The grid intervals are 10 minute ${\times}$ 10 minute (latitude ${\times}$ longitude) based on the section of the sea. A total of 30 sections were analyzed by constructing a grid. As a result of the analysis, the major traffic flows of the merchant vessels in the coastal area of Gunsan were surveyed from north to south toward Incheon, Pyeongtaek, Daesan, Yeosu, Pusan and Ulsan, and from east to west in the port of Gunsan Port, 173-3, 173-6, 173-8, 183-2, 183-5, 183-8, 183-3, 184-1 and 184-2. As a result of the study, the fishing boats in Gunsan coastal area mainly operated in spring and autumn. On the other hand, the main traffic flow of merchant ships and the distribution of fishing vessels continue to overlap from March to June, so special attention should be paid to the control during this period.

• Korean Institute of Interior Design Journal
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• v.17 no.1
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• pp.138-145
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• 2008

This study is conducted to formulate various spatial compositions for mixed-use elementary schools in order to use them as community centers. Accordingly, this study is conducted to analyze currently operating community-use elementary schools to find out about the current condition of mixed-use facilities, and the types of mixed-use facilities will be derived from the analysis. In addition, a more effective method of planning mixed-use elementary schools is investigated. By incorporating various educational curricula and teaching/learning activities, major points, which should be considered when planning elementary schools, will be suggested to effectively respond to the changes of educational environment in the future. The results show that in terms of inner traffic flow type, 9 schools out of the schools under study showed a unificated traffic flow type or a cross traffic flow type. When traffic overlaps, problems of noise, visual distraction, and decreased learning performance can appear. To prevent the conflict between areas and to manage areas effectively, each area should be differentiated by installing doors and shutters and by marking guides, and the facility used for community residents and students should also be scheduled separately to avoid time conflict. In addition, to accommodate the changes of users, flexible space planning options should be considered.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.42-60
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• 2024

This study analyzed the characteristics of mixed traffic flows with autonomous vehicles on highway weaving sections and assessed the safety of vehicle-following pairs based on surrogate safety indicators. The intelligent driver model (IDM) was utilized to emulate the driving behavior of autonomous vehicles, and the weaving sections were divided into lengths of 300 and 600 meters for analysis within a micro-traffic simulation (VISSIM). Although significant differences were found in the average speed, density, and headway between the two sections through t-test results, no significant differences were observed when comparing the number of conflicts per indicator and the vehicle-following pair. Four safety indicators were selected for the mixed traffic evaluation based on their ability to represent risk levels similar to those perceived by drivers. The safety analysis, based on the selected four indicators, determined that autonomous vehicles following other autonomous vehicles were the safest pairing. Future research should focus on integrating these indicators into a single comprehensive index for analysis.

• Journal of Korean Society of Transportation
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• v.27 no.3
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• pp.141-148
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• 2009

An inappropriate evaluation of capacity leads to the incorrect and impractical result due to the transfer of error to the analysis and the evaluation on highway system. The traffic accident which reduces the capacity of road temporarily generates unpredictable congestion, causing difficulties in congestion management. Therefore, this research aims on the measurement of the capacity of the road in accordance to the speed at the accident which is a basic factor when performing analysis. Based on the given approach, the behavior of a vehicle in highway is understood to develop model of critical gap and model of maximum flow rate with respect to the speed of traffic flow. With the established model, the reduction rate of the capacity in highway system at the accident is measured. The result shows that the capacity is reduced by 37% when the speed of the traffic flow is 40km/h. Although the developed model can't be verified clearly, this research has shown that the reduction rate of the capacity in road system has a close relation to the speed.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.31-41
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• 2012

Due to growing interests in the distribution of traffic volume through information dissemination such as VMS and traffic broadcasting system, the research on the driver's reaction and effect of the traffic report has continued. In this study, we propose a methodology, which estimates the traffic volume of diversion and the consequential diversion rate using FTMS data and TCS data, and the estimation is based on the analysis of the national highway and IC, in which real-time FTMS and TCS data are established. We also calculate the diversion rate of actual targeted sections and analyze the changes in time and spatial diversion rate. In this study, we define a deviation (considering a deviation due to dynamic properties of traffic conditions) found when the outflow traffic volume is temporarily higher than the average outflow traffic volume on a relevant time slot after providing traffic information. The diverting volume is considered to be caused by the traffic information, and the study determines the ratio of traffic volume on highways to that of route diversion as the diversion rate. The analysis on changes in the diversion rate in accordance with the time flow, the initial change in the diversion rate on upstream IC that first acquires the report on the traffic congestion is significant. After that, the change in the diversion rate on upstream IC affects the route diversion on downstream IC with spatial and time flow, and this again leads the change in upstream IC. Thereby, we confirmed that there is a feedback-control circulation system in the route diversion.

• International Journal of Highway Engineering
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• v.18 no.1
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• pp.119-129
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• 2016

PURPOSES : The purpose of this study is to develop a methodology for estimating additional carbon emissions due to freeway incidents. METHODS : As our country grows, our highway policy has mainly neglected the environmental and social sectors. However, with the formation of a national green growth keynote and an increase in the number of people interested in environmental and social issues, problems related to social issues, such as traffic accidents and congestion, and environmental issues, such as the impact of air pollution caused by exhaust gases that are emitted from highway vehicles, are beginning to be discussed. Accordingly, studies have been conducted on a variety of environmental aspects in the field of road transport, and for the quantitative calculation of greenhouse gas emissions, using various methods. However, in order to observe the effects of carbon emissions, microscopic simulations must use many difficult variables such as cost, analysis time, and ease of analysis process. In this study, additional greenhouse gas emissions that occur because of highway traffic accidents were classified by type (incident handling time, number of lanes blocked, freeway level of service), and the annual additional emissions based on incidents were calculated. According to the results, congestion length and emissions tend to increase with an increase in incident clearance time, number of occupied lanes, and worsening level of service. Using this data, we analyzed accident data on the Gyeong-bu Expressway (Yang-Jae IC - Osan IC) for a year. RESULTS : Additional greenhouse gas emissions that occur because of highway traffic accidents were classified by type (incident handling time, number of lanes blocked, freeway level of service) and annual additional emissions caused by accidents were calculated. CONCLUSIONS : In this study, a methodology for estimating carbon emissions due to freeway incidents was developed that incorporates macroscopic flow models. The results of the study are organized in the form of a look-Up table that calculates carbon emissions rather easily.

• Wind and Structures
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• v.27 no.4
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• pp.255-267
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• 2018

This paper investigated the wind-snow flow around the bogie region of a high-speed train under crosswinds using a coupled numerical method of the unsteady Realizable $k-{\varepsilon}$ turbulence model and discrete phase model (DPM). The flow features around the bogie region were discussed and the influence of bogie fairing height on the snow accumulation on the bogie was also analyzed. Here the high-speed train was running at a speed of 200 km/h in a natural environment with the crosswind speed of 15 m/s. The mesh resolution and methodology for CFD analysis were validated against wind tunnel experiments. The results show that large negative pressure occurs locally on the bottom of wheels, electric motors, gear covers, while the positive pressure occurs locally on those windward surfaces. The airflow travels through the complex bogie and flows towards the rear bogie plate, causing a backflow in the upper space of the bogie region. The snow particles mainly accumulate on the wheels, electric motors, windward sides of gear covers, side fairings and back plate of the bogie. Longer side fairings increase the snow accumulation on the bogie, especially on the back plate, side fairings and brake clamps. However, the fairing height shows little impact on snow accumulation on the upper region of the bogie. Compared to short side fairings, a full length side fairing model contributes to more than two times of snow accumulation on the brake clamps, and more than 20% on the whole bogie.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.3
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• pp.8-14
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• 2014

Arrival management is a tool which provides efficient flow of traffic and reduces ATC workload by determining aircraft's sequence and schedules while they are in cruise phase. As a decision support tool, arrival management should advise on air traffic control service based on the understanding of human factor of its user, air traffic controller. This paper proposed a prediction model for air traffic controller sequencing strategy by analyzing the historical trajectory data. Statistical analysis is used to find how air traffic controller decides the sequence of aircraft based on the speed difference and the airspace entering time difference of aircraft. Logistic regression was applied for the proposed model and its performance was demonstrated through the comparison of the real operational data.

• Journal of information and communication convergence engineering
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• v.20 no.4
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• pp.273-279
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• 2022

Owing to the need to establish a cooperative-intelligent transport system (C-ITS) environment in the transportation sector locally and abroad, various research and development efforts such as high-tech road infrastructure, connection technology between road components, and traffic information systems are currently underway. However, the current central control center-oriented information collection and provision service structure and the insufficient road infrastructure limit the realization of the C-ITS, which requires a diversity of traffic information, real-time data, advanced traffic safety management, and transportation convenience services. In this study, a network construction method based on the existing received signal strength indicator (RSSI) selected as a comparison target, and the experimental target and the proposed intelligent edge network compared and analyzed. The result of the analysis showed that the data transmission rate in the intelligent edge network was 97.48%, the data transmission time was 215 ms, and the recovery time of network failure was 49,983 ms.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.10
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• pp.995-999
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• 2010

Every year, traffic accidents and traffic congestion have been rapidly increasing, Although the roadway design and signal system have been improved to relieve traffic accidents, traffic casualties and property damage do not decrease. This paper develops a real-time traffic accident detection and analysis system (RTADAS): In the proposed system, we aim to precisely detect traffic accidents at different design and flow of intersections, However, because the data collected from intersections have uncertainty and complicated causal dependency between them, we construct probability-based networks for correct accident detection.