• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.13-23
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• 2016

Many traffic centers are highly hesitant in employing existing Automatic Incident Detection Algorithms due to high false alarm rate, low detection rate, and enormous effort taken in maintaining algorithm parameters, together with complex algorithm structure and filtering/smoothing process. Concerns grow over the situation particularly in Freeway Incident Management Area This study proposes a new algorithm and introduces a novel concept, the Displaced Flow Index (DiFI) which is similar to a product of relative speed and relative occupancy for every execution period. The algorithm structure is very simple, also easy to understand with minimum parameters, and could use raw data without any additional pre-processing. To evaluate the performance of the DiFI algorithm, validation test on the algorithm has been conducted using detector data taken from Naebu Expressway in Seoul and following transferability tests with Gyeongbu Expressway detector data. Performance test has utilized many indices such as DR, FAR, MTTD (Mean Time To Detect), CR (Classification Rate), CI (Composite Index) and PI (Performance Index). It was found that the DR is up to 100%, the MTTD is a little over 1.0 minutes, and the FAR is as low as 2.99%. This newly designed algorithm seems promising and outperformed SAO and most popular AIDAs such as APID and DELOS, and showed the best performance in every category.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.93-101
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• 2012

PURPOSES : Adverse weather conditions such as heavy rain, heavy snowfall, and thick fog and so on have highly affect on the change in traffic conditions on the road. In particular, heavy snowfall causes capacity reduction as well as crash occurrence. This study investigated the effects of snowfall on speed on a freeway. METHODS : Vehicle detection systems data were matched with corresponding weather station data by regression analysis. RESULTS : The results show that the travel speed is reduced by 6.7% under little snowfall and by 12.8% under heavy snowfall. Regarding the speed variation, 8.7% and 114.7% increases are observed under little snowfall and heavy snowfall, respectively. It is also found that 1 cm increase in snowfall leads to 0.4% decrease in travel speed. In addition, the travel speed increases by 0.4% when the temperature increases by $1^{\circ}C$. CONCLUSIONS : It is expected that the outcome of this study will be useful in establishing more effective strategies for winter operations and road maintenance in practice.

• Journal of Information Processing Systems
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• v.16 no.6
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• pp.1459-1478
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• 2020

In the last few years, quantum communication technology and services have been developing in various advanced applications to secure the sharing of information from one device to another. It is a classical commercial medium, where several Internet of Things (IoT) devices are connected to information communication technology (ICT) and can communicate the information through quantum systems. Digital communications for future networks face various challenges, including data traffic, low latency, deployment of high-broadband, security, and privacy. Quantum communication, quantum sensors, quantum computing are the solutions to address these issues, as mentioned above. The secure transaction of data is the foremost essential needs for smart advanced applications in the future. In this paper, we proposed a quantum communication model system for future ICT and methodological flow. We show how to use blockchain in quantum computing and quantum cryptography to provide security and privacy in recent information sharing. We also discuss the latest global research trends for quantum communication technology in several countries, including the United States, Canada, the United Kingdom, Korea, and others. Finally, we discuss some open research challenges for quantum communication technology in various areas, including quantum internet and quantum computing.

• International Journal of Highway Engineering
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• v.18 no.6
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• pp.69-76
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• 2016

OBJECTIVES : The objective of this study is to propose a capacity analysis methodology for riverside bike-exclusive roads. METHODS : Three steps were performed to develop a methodology to estimate bikeway capacity. First, we reviewed previous studies on the vehicle-road capacity analysis and proposed their applicability to bikeways. Second, two assumptions were made based on the traffic flow characteristics of bikeways: (1) the capacitated state in bikeways occur within a bicycle platoon, and (2) a bicycle platoon consists of more than three bicycles running in close proximity. In addition, it is assumed that the mean time headway of a bicycle platoon represents the characteristics of the platoon. The normality of the mean-time headway of a bicycle platoon calculated using the central limit theorem leads to the development of a method that estimates the riverside bikeway capacity using data collected from two different riverside bike-exclusive roads (Han-river and Anyangcheon). We used a location-fixed video camera to record videos of running bicycles and wrote a special-purpose software program to code the time-headway data from the videos. RESULTS : Time headways from 189 bicycle platoons were analyzed. The estimated mean-time headway of the capacitated bicycle flow is 1.01 s, from which the capacity of the bikeway is found to be 3578 vehicles/h. CONCLUSIONS : The proposed method that estimates bikeway capacity could be applicable to the analysis of short-range congested area rather than planning the number of lanes. In other words, it determines the sections that are temporarily highly congested and proposes appropriate strategies to mitigate the congestion.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.651-661
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• 2014

Recently, many studies have been undertaken regarding the of introduction at roundabout in Korea. The studies related to roundabout capacity, however, is insufficient. Thus, the goal of this study is to develop a capacity model based on real data. The main results are as follows. First, roundabout capacity in Korea was analyzed using HCM capacity model based on critical gap and following time estimated by Probit model. Entry capacity in Korea was evaluated to be similar to that of the U.S in the case of low circulating flow($Q_c$), but higher in the case of high circulating flow($Q_c$). Second, the basic capacity models in Korea were newly developed based on real traffic data. Third, models that consider geometric structure were developed based on the basic models. Finally, all of the developed models mentioned above were analyzed to be statistically significant.

• Journal of Korea Water Resources Association
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• v.33 no.6
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• pp.815-825
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• 2000

In the present work Einstein's(l942) suspended load equation IS refined in vanous aspects. After checking the flow characteristics a new method is presented for the estimation of zero velocity point at the condition of smooth turbulent flow, and non-dimensional number of suspended load is introduced for the clear representation of suspended load equation. And a recent equation of bed load is employed in order to calculate accurately the sediment concentration at a reference point. Several approximation equations are also developed to compute directly or explicitly two integrals introduced in the equations. The refined equation has been tested against the measurement data collected by Brownlie(l981) in comparison with Einstein's original equation.uation.

• KIISE Transactions on Computing Practices
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• v.23 no.5
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• pp.310-315
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• 2017

In a centralized control structure, the software defined network controller manages all openflow enabled switched in a data plane and controls the telecommunication between all hosts. In addition, the network manager can easily deploy the network function to the application layer with a software defined network controller. For this reason, many methods for network management using a software defined network concept have been proposed. The main policies for network management are related to traffic Quality of Service and resource management. In order to provide Quality of Service and load distribution for network users, we propose an efficient routing method using a naive bayesian algorithm and transmission delay estimation module. In this method, the forwarding path is decided by flow class and estimated transmission delay result in the software defined network controller. With this method, the load on the network node can be distributed to improve overall network performance. The network user also gets better dynamic Quality of Service.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.431-437
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• 2005

In korea, Freight generation models developed in korea were estimated by spatial unit method which predict freight flow by traffic zone. But it is difficult to predict freight generation using these models, because there are the difference of the totality method of sampling data on freight volume and the variability of the variables by these models on each case study, This study developed new estimation model to predict freight flow which is generated from each company using the characteristics of each company such as the freight outbound & inbound volume, the number of employee, sales, gross area, land area. This model is simpler than the that of spatial unit and can apply to the other region. The subjects of study were companies in metropolitan area and types of model were exponential regression models. The adequate explanatory variable in the models were sales. this study have a uniqueness apply micro research method to estimate freight generation not use spatial unit method but use flow unit method by each company unit.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.13-21
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• 2015

This study focuses on operational analysis of 2 types of intersection shared lanes. First, the analysis showed that a through & right-turn shared lane is always less used than the adjacent through-only lanes and as a result, operational efficiency deteriorates. To improve the efficiency fine-tuning in signal timing optimization using lane-by-lane traffic volume data is required. Further improvement can be achieved by guiding drivers to equally use the shared lane. For left-turn & U-turn shared lanes, it was found that saturation flow rate is affected by interference between U-turn and conflicting right-turn movements. However, since such interference does not occur in every cycle, a statistical model must be established to develop realistic adjustment factor for saturation flow rate of the shared lane.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1099-1104
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• 2020

In order to provide various types of application services based on the Internet, it is ideal to guarantee the quality of service(QoS) for each flow. However, realizing these ideas is not an easy task.. It is effective to classify multiple flows having the same or similar service quality requirements into same group, and to provide service quality for each group. The queue management mechanism in the router plays a very important role in order to efficiently transmit data and to support differentiated quality of service for each service. In order to efficiently support various multimedia services, an intelligent and adaptive queue management mechanism is required. This paper proposes an intelligent queue management mechanism based on deep reinforcement learning that decides whether to deliver packets for each group based on the traffic information of each flow group flowing in for a certain period of time and the current network state information.