• International Journal of Highway Engineering
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• v.11 no.1
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• pp.25-36
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• 2009

Everyday congestion length (distance) and duration (time) data are collected and recorded in Expressway Traffic Information Center. These records are based on the information that the operators watch CCTV and decide traffic condition in order to present information about congestion on VMS. Using VMS message has some merits like that it doesn't need a great lot of cost to construct hardware such like FTMS because operators can check traffic condition by watching CCTV only. Of cause in the aspect of accuracy, using VMS message has the limitation that it is based on subject decision compared with FTMS. However, it can be said that the value of using VMS message is very large. The object of this study is to use the VMS information record (log file) usefully to provide information of traffic condition on expressway for users (drivers) without keeping the VMS information record in dead storage. To do so, in this research, congestion calculation method able to understand traffic congestion condition on expressway was developed.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.85-87
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• 2004

In the past, TR-cost was collected the combination of energy cost. When power market is restructured. TR-cost is collected the separated form of loss-cost, congestion-cost and maintenance-cost. One of thorn, loss-cost is computed by using TR loss-factor. We need correct and fair standards of loss factor to offer economical signal and to protect against confusions of investment and bidding. Therefore, we propose the method of minimizing system loss-cost that is based on fair and correct loss-factor.

• Journal of Korean Society of Transportation
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• v.18 no.2
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• pp.91-101
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• 2000

The optimal congestion charge in transportation economics corresponds to the solution to the welfare maximization Problem for users of a certain road link where congestion takes Place. This congestion charge is in nature the optimal Price of the transportation facility, which is derived by the Partial equilibrium analysis on that facility. Therefore it is not certain that this congestion charge can maximize the well-being of all the users of the total transportation network, since the analysis does not count the impact of the congestion charge on traffic volumes of other links. This study suggests an alternative approach to estimate the optimal congestion charge. The key difference of this study from Previous ones is to derive the solution through the general equilibrium analysis on a market where several transportation facilities as well as Private goods are available to consumers. This approach shows a set of solutions a little different from the Previous one, which are explained below. The optimal congestion charge is derived for two different cases. One is the situation of which the congestion charge is levied on every transportation facility In this case, the optimal solution of each facility should equate the marginal utility of every user to the marginal cost of the corresponding facility. This analysis result in general equilibrium coincides with the Previous analysis result in partial equilibrium. However this result cannot apply to another case of which the charge is imposed only on a certain transportation facility. In this case, the optimal charge on a certain transportation facility should be less than the optimal congestion charge of partial equilibrium analysis.

• Journal of the Korean Professional Engineers Association
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• v.46 no.1
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• pp.49-54
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• 2013

The total estimated socioeconomic logistics cost in transportation sector, including traffic congestion, household travel expenses, national macroeconomic logistics and traffic accident related cost, amount to approximately 240 trillion won a year in 2009. The amount is in increasing trend every year due to the inefficient infrastructure system in urban city roads and in intercity highways. The Government adopts the 4th National Spatial Planning (Revised) which is in progress in order to build a new physical environment ensuring people's welfare by providing the efficient and sustainable transportation networking system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1969-1980
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• 2013

The Traffic congestion is caused by the increasing traffic demand. Thus, economic losses have been increasing every year. To solve these problems, car sharing and rental car systems that are equipped with IT technologies emerge. Car sharing has many advantages-the alleviation of the traffic congestion, the saving of maintenance cost for cars, the reduction of car possessiveness, the solution for the hassle of car ownership, for business and personal duty, and the improvement of connectivity between public transportations-. The goal of the car sharing is to achieve low-carbon and eco-friendly transportation. In this study, we review papers related to the car sharing system and the cost system of traffic systems. We estimate the optimal cost of the cloud traffic system that is one of the car sharing services. We suggest a methodology to estimate operational cost and use cost through the analysis of cost system between similar traffic means. The range of the maximum and minimum cost was determined through the comparison and analysis of similar traffic means. Expected demand and the cost that people are willing to pay were estimated through optimized value pricing. The minimum cost per hour that was compared to the cost of rental car was estimated at 5,333 won and the maximum cost per hour that was compared to taxi cost was estimated at 17,700 won. The cost for users was estimated at 6,930 won. The cost of 50% demands was estimated at 6,550won. Future studies should analyze service hours of users, weather, demand pattern and trend and consider them into the cost estimation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.63-82
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• 2010

In spite of continuous road construction, traffic congestion has been worsening by radical vehicle's increase and development of surroundings near expressway. Thus, the necessity of traffic management and the needs of provision of traffic information to drivers are raised. In order to solve traffic problems, such as traffic congestion, search for optimal congestion management technique and evaluation of the effect of optimal solution should be examined prior to practice of optimal alternative. However, existing traffic analysis model and simulation programs as tools to search and evaluate optimal alternative are not sufficient to reflect traffic flow characteristics, domestic road and traffic conditions and to link up to Freeway Traffic Management Systems (FTMS). Hence, to use existing traffic analysis and simulation tools are followed by hard work to need a lot of time and cost. Therefore, in this research, Expressway TRaffic Analysis Model (ExTRAM) based on Freeway Traffic Management Systems (FTMS) was developed to apply it into congestion management easily.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.6
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• pp.1881-1900
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• 2014

Since 802.11 wireless LANs are so widely used, it has become common for numerous access points (APs) to overlap in a region, where most of those APs are managed individually without any coordinated control. This pattern of wireless LAN usage is called the private OBSS (Overlapping Basic Service Set) environment in this paper. Due to frame collisions across BSSs, each BSS in the private OBSS environment suffers severe performance degradation. This study approaches the problem from the perspective of congestion control rather than noise or collision resolution. The retry limit, one of the 802.11 attributes, could be used for traffic control in conjunction with TCP. Reducing the retry limit causes early discard of a frame, and it has a similar effect of random early drops at a router, well known in the research area of congestion control. It makes the shared link less crowded with frames, and then the benefit of fewer collisions surpasses the penalty of less strict error recovery. As a result, the network-wide performance improves and so does the performance of each BSS eventually. Reducing the retry limit also has positive effects of merging TCP ACKs and reducing HOL-like blocking time at the AP. Extensive experiments have validated the idea that in the OBSS environment, reducing the retry limit provides better performance, which is contrary to the common wisdom. Since our strategy is basically to sacrifice error recovery for congestion control, it could yield side-effects in an environment where the cost of error recovery is high. Therefore, to be useful in general network and traffic environments, adaptability is required. To prove the feasibility of the adaptive scheme, a simple method to dynamically adjust the value of the retry limit has been proposed. Experiments have shown that this approach could provide comparable performance in unfriendly environments.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.697-702
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• 2018

Recently, the number of private cars has increased sharply due to the increase in national income. The sudden increase in the number of vehicles in limited territory has caused serious traffic congestion and the traffic congestion cost wasted on the road due to such traffic congestion is increasing every year. To solve this problem, we propose a traffic signal control system using image processing. In this paper, we use the camera installed at the intersection to measure the amount of traffic flowing in and out of each road simultaneously. We propose a traffic signal control system that can prevent traffic congestion before it happens. In the case of applying the traffic signal control system proposed in this paper to the daytime, the traffic volume could be measured accurately. However, the result of the experiment with the night-time general camera and the headlight with the infrared camera at the night-time of 72.8% was 86.6%.

• Journal of the Korean Professional Engineers Association
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• v.42 no.2
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• pp.49-53
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• 2009

The Kyung-In Canal is to protect Gulpo Stream Area from recursive flooding and to relief inland transportation congestion, in the Seoul Metropolitan Area. Enlarging and extending the Gulpo stream Drainage Canal operated only during rainy season. Kyung-in Canal will serve not only for preventiong flood, but for reducing logistics cost also in the Seoul Metropolitan Area

• ETRI Journal
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• v.27 no.6
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• pp.725-732
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• 2005

The reconfiguration management scheme changes a logical topology in response to changing traffic patterns in the higher layer of a network or the congestion level on the logical topology. In this paper, we formulate a reconfiguration scheme with a shared buffer-constrained cost model based on required quality-of-service (QoS) constraints, reconfiguration penalty cost, and buffer gain cost through traffic aggregation. The proposed scheme maximizes the derived expected reward-cost function as well as guarantees the required flow's QoS. Simulation results show that our reconfiguration scheme significantly outperforms the conventional one, while the required physical resources are limited.