• Journal of Korean Society of Transportation
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• v.36 no.3
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• pp.169-183
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• 2018

Aggressive driving leads to a greater crash potential because it threatens surrounding vehicles. This study conducted traffic simulation experiments using driving behavior data obtained from multi-agent driving simulations. VISSIM traffic simulator and surrogate safety assessment model (SSAM) were used to identify the impacts of aggressive driving on traffic stream in terms of safety and operational efficiency. Market penetration rates (MPR) of aggressive driving vehicle, coupled with various traffic conditions, were taken into consideration in analyzing the impacts. As expected, it was identified that aggressive driving vehicles tended to deteriorate the traffic safety performance. From the perspective of operational efficiency, interesting results were observable. Under level of service (LOS) A, B, and C, it was observed that the average travel speed increased with greater MPRs. Conversely, the average travel speed decreased with under LOS D and E conditions. The outcome of this study would be effectively used for developing safety-related policies for reducing aggressive driving behavior.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.244-257
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• 2017

Traffic congestion occurs from drivers' human factors such as driver reaction time, reckless lane change, and inexperienced driving. When Automated Vehicles are introduced, human factors are excluded, resulting in increased average vehicle speed, stabilizing traffic flow, and increasing road capacity. This study analyzed traffic flow changes through traffic volume-speed-density plots, and increased road capacity due to Automated Vehicles. As a result of the analysis, when rate of automated vehicles gests higher, the traffic flow became stable. Additionally, it was analyzed that when all vehicles were automated, the road capacity increased by about 120 %. It is expected that there will be a positive expectation in terms of traffic congestion and traffic demand management due to the introduction of Automated Vehicles.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.7-15
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• 2011

Emerged in early 1990s, so called 'Quick service' industry that provides faster delivery of small parcels than regular mail service accelerated use of motorcycles. As the economic grows, use of large bicycles (more than 250CC displacement) for leisure purpose has also rapidly increased. Traffic crash data clearly shows the increasing trend in motorcycle crashes. The ratio of motorcycle involved crashes out of total has increased from 5.7% in 2005 to 8.3% in 2008, and similar trend can be found in fatalities ratio as well. In this study, we assess the level of risk when motorcycles operate on motorways by analyzing traffic rule violation ratio, lane change behaviour, driving speed behaviors of motorcycles in Uninterrupted Traffic Flow Facilities and using PC-CRASH simulation we also calculate car shock impulses occurred when an accident happens. Analysis result shows that the motorcycle is different from the car in terms of lane change timing and average speed, and also shows motorcycle drivers tends to conduct more improper driving behavior particularly when traffic is congested. The results from this study could be usefully applied when the law enforcement agent decides whether bicycles shall be allowed to use motorways. The result could be also utilized as fundamental information for further study of bicycles' driving behavior.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.3
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• pp.580-592
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• 1997

Since an ATM network consists of a number of VPC/VCC requiring various QoS requirements, the end-to-end QoS for each VPC/VCC should be guaranteed. Although many research works on the traffic control are under study to guarantee the QoS, there have been research efforts to reflect the results of network management functions into the traffic control mechanism. To effectively make use of the performance management functions into the VPC/VCC management, threre is a need for the network manager to rapidly retrieve the relevant information. In this research, the mechanism to effectively retrieve the management information using SNMP is suggested. First of all, we construct the MIBs in the agent for the corresponding VPC/VCC. Also, we suggest the way to retrieve MIB with minimum cost. Mathematical analysis shows that the proposed technique has better performance than that using the existing SNMP.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.2057-2067
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• 2013

Traffic demand forecasting for pavement management in the present can be estimated using the past trends or subjective judgement of experts instead of objective methods. Also future road plans and local development plans of a target region, for example new road constructions and detour plans cannot be considered for the estimate of future traffic demands. This study, which is the fundamental research for developing objective and accurate decision-making support system of maintenance management for the national highway, proposed the methodology to predict future traffic demands according to 4-step traffic forecasting method using EMME in order to examine significance of future traffic demands affecting pavement deterioration trends and compare existing traffic demand forecasting methods. For the case study, this study conducted the comparison of traffic demand forecasting methods targeting Daejeon Regional Construction and Management Administration. Therefore, this study figured out that the differences of traffic demands and the level of agent costs as well as user costs between existing traffic demand forecasting methods and proposed traffic demand forecasting method with considering future road plans and local development plan.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.91-99
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• 2013

PURPOSES : This study aims at proposing the methodology for benefit evaluations in pavement maintenance methods and timings using KoPMS(Korean Pavement Management System) software which was developed for efficient pavement management. METHODS : This study classified pavement sections into 4 clusters considering AADT(Annual Average Daily Traffic) and ESAL(Equivalent Single-Axle Load) using cluster analysis and used the deterioration models in each cluster. Increased user costs due to pavement deterioration as time goes by and agent costs for maintenance were estimated. Based on deterioration model and KoPMS software, Methodology for benefit evaluation was proposed in pavement maintenance methods and with/without implementation using real pavement section data. RESULTS : This study verified that considering agent costs only would be constrained to decide pavement maintenance methods and timings, and ascertained that decision making with agent and user costs would be effective. In addition, this study revealed that pavement maintenance methods and timings can be affected by AADT and ESAL and frequent pavement maintenances can be more efficient for benefits in pavement sections with more AADT and ESAL. Also this study found that user costs would be more affected to decision making than agent costs. Moreover, Delay of conducting pavement maintenance caused increased vehicle operating costs and environmental costs because of poor conditions of pavements. CONCLUSIONS : This study proposed LCCA and benefit estimation methodology of pavement with considering agent and user costs. The results of this study can be used for baseline data of efficient pavement asset management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6B
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• pp.608-617
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• 2011

ubiquitous network management system (u-NMS) is the network management system based on smartphone which are recently of wide use. The purpose of the u-NMS is to provide convenience for network administrator utilizing the mobility of smartphone and to manage the network efficiently. This paper proposes the smart NMS agent and the mobility management server (MMS). The smart NMS agent enables to use the monitoring web server and remote control application on the smartphone in wireless network. The MMS is developed to reduce the problems such as handover latency and packet loss, which can be taken place in wireless network. The network manager can monitor traffic in real time through the smart NMS agent and remotely control the network efficiently when sudden failures happen in the u-NMS. In this paper, performance evaluation is carried out with our test-bed system implemented. We focus on the measurement of the MMS performance. When the MMS is compared to previous mobility management protocol, our mobility management server reduces the average latency up to 65% in initial access, handover latency and processing delay to the network management center.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.465-470
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• 2015

The curing of epoxy asphalt mixture depends on the chemical reaction of epoxy resin and the curing agent. The curing level of epoxy asphalt mixture needs to be predicted in order to decide traffic opening time and to establish further construction plans. In this study, chemical analysis of the prediction model was executed to expand the applicability of the previous prediction model. Consequently, the curing level prediction model of epoxy asphalt concrete mixture was proposed using the concentration ratio and the acid value ratio. According to the results of outdoor curing experiments, the final prediction model showed that the correlation coefficient is greater than 0.971. Precise prediction results of different composition epoxy asphalt were obtained by reflecting the chemical composition ratios in the curing level prediction model.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.2
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• pp.304-313
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• 2012

Uncertainty increases as a result of environment change and change of individual decision-making in extreme weather. This study consider individual decision-making which has been not covered until now. The purpose of this study is making Agent-Based Model to predict it more accurate that how much change travel demand in heavy rain and heavy snow. Through this model, it can be utilized to forecast travel demand, changes in travel behavior and traffic patterns. It will be also possible to predict discomfort index and risk of accidents.

• Convergence Security Journal
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• v.8 no.2
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• pp.41-50
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• 2008

Recently amount of traffic into the network rapidly increase since multimedia streaming services is generally adopted for application. In addition, various network management systems have been suggested for providing a stable service and QoS guarantee. It is necessary for such systems to have QoS monitoring module in order to evaluate acceptance or violation of QoS requirements by analogizing a state information of each node within network. In this paper, we suggest a network management system to evaluate QoS level between end-to-end agents and analysis traffics transmitted between them. The proposed system is implemented for the purpose of collecting network traffic information and monitoring of the view. The proposed system makes user easily understand information of QoS parameters such as throughput, delay and jitter by adopting a method of visual and numerical representation. To achieve this, we purportedly generate test packet into network for confirming acceptance or violation of QoS requirements from point of view of multimedia application service.