• Journal of Korean Society of Transportation
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• v.32 no.4
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• pp.410-420
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• 2014

This research suggests a new tram signal priority model which determines signal timings and tram intersection waiting time using analytical method. This model can calculate the signal timings for Early Green and Green Extension among the active tram signal priority techniques by tram detection time of upstream detector. Moreover, it can determine the tram intersection waiting time that means tram intersection travel time delay from a vantage point of tram travel. Under the active tram signal priority condition, priority phases can bring additional green time from variable green time of non-priority phases. In this study, the signal timing and tram intersection waiting time calculation model was set up using analytical methods. In case studies using an isolated intersection, this study checks tram intersection waiting time ranged 12.7 to 29.4 seconds when variable green times of non-priority phases are 44 to 10 seconds under 120 seconds of cycle length.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.897-905
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• 2015

This research suggested the traffic signal calculation model of active transit signal priority using a shockwave model. Using this signal priority timing optimization model, the shockwave area is computed under the condition of Early Green and Green Extension among active transit signal priority techniques. This study suggested the speed estimation method of backward shockwave using average travel time and intersection passing time. A shockwave area change is calculated according to signal timing change of transit signal priority. Moreover, this signal timing calculation model could determine the optimal signal priority timings to minimize intersection delay of general vehicles. A micro simulation analysis using VISSIM and its user application model ComInterface was applied. This study checked that this model could calculate the signal timings to minimize intersection delay considering saturation condition of traffic flow. In case studies using an isolated intersection, this study checked that this model could improve general vehicle delay of more over ten percentage as compared with equality reduction strategy of non-priority phases. Recently, transit priority facilities are spreading such as tram, BRT and median bus lane in Korea. This research has an important significance in that the proposed priority model is a new methodology that improve operation efficiency of signal intersection.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.3
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• pp.25-37
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• 2014

Recently, our local governments are conducting the introduction of tram system because it is recognized as an effective public transit that can solve a traffic jam in downtown, decreasing public transit share and environmental issues in world wide cities. We developed the Active Priority Control Strategy to efficiently operate a tram in our existing traffic signal system. This study organized the tram system for operating the Active Priority Signal Control, developed the algorithm that calculates a tram-stop dwell time in order to pass the downstream intersection without a stop. The dwell time is determined by arrival time at tram-stop, downstream signal time, and the location of a opposite tram, it can be reduced by choosing the optimal one among Signal Priority Controls. Using the VISSIM and VISVAP model, we conducted a simulation test for the city of Chang-won that it is expected to install a tram system. It showed that a developed signal control strategy is effective to prevent a tram's stop in intersections, to reduce a tram's travel time.

• 한국ITS학회:학술대회논문집
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• 2010.05a
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• pp.109-113
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• 2010

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.15-25
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• 2014

Bus signal priority is a name for various techniques to speed up bus public transport services at intersections with traffic signals. In this study propose methodology to optimize signal times for Early green, Green extension out of the active bus signal priority using deterministic delay model in isolated intersection on median bus lane. Fluctuation is found in the vehicle delay and person delay in the event that using this methodology redistributed to green time and checking slack green time is correct value by sensitivity analysis. As a result of the study, car delay is increased a little and person delay is decreased. As a result of slack green time sensitivity, delay is not much in it if variation of slack green time under 30%. But this methodology effectiveness is under claimed capacity if variation of slack green time over 30%.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.107-116
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• 2011

In this paper, we implement an algorithm of transit signal priority control that not only maximizes service quality and efficiency of bus, but also minimizes the control delay of passenger cars using UTIS currently being deployed and operated in Seoul national capital area. For this purpose, we propose an algorithm that coordinates the strength of TSP by estimating bus demand. Typically, the higher the strength of TSP is on main street, the bigger the control delay is on the cross street. Motivated by this practical difficulty, we proposes an algorithm that coordinates TSP's strength by checking the degree of saturation of cross street. Also, we verify the possibility of field implementation via simulation analysis using CORSIM RTE based HILS (Hardware In the Loop Simulation). The result shows that travel time of bus improves about 10 percent without increasing control delay of passenger cars by TSP. We expect the result of this research to contribute to increasing the overall transit ridership in this country.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.3
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• pp.110-119
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• 2017

This study develops a passive traffic signal priority control algorithm for emergency vehicles. The passive priority control estimates and applies signal times for each signalized intersection on the emergency vehicle's route when an emergency call is received. As signals are controlled before the emergency vehicle leaves for its destination, it is possible to clear the queues at each intersection more effectively. Most of the previous studies applied preemption, which ends green time of cross streets when the emergency vehicle arrives at each intersection. This study applies green extension and early green in order not to shift the order of phases, and guarantees minimum green time for each phase. Simulation results show that the delay of emergency vehicles decreases when the signals are controlled. It is expected that delays can be decreased further by integrating the active priority control with the passive priority control algorithm presented in this study.

• Journal of Korean Society of Transportation
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• v.33 no.1
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• pp.70-80
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• 2015

In recent years, tram has been the focus of a new mode of public transportation that can solve traffic jams and decrease public transit usage and environmental problem. This research is in the works to develop a tram signal controller and signal control strategies, and aim to resolve the problem of what could happen if a tram system was installed in general road. We developed the hierarchical signal control strategies to obtain a minimum tram bandwidth and to minimize vehicle delay, in order to perform a priority control to include passive and active signal priority control strategies. The strategies was produced for S/W and H/W, it is based in standard traffic signal controller. We conducted a micro simulation test to evaluate the hierarchical signal control strategies, which showed that the developed optimization model is effective to prevent a tram's stop in intersection, to reduce a tram's travel time and vehicle's delay.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.4
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• pp.731-738
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• 2017

In this paper, we proposed a modified ML detector for generalized spatial modulation which is a method among Multiple-input Multiple-output. This proposed method detects signal applying modified channel statement information based on priority. Complexity in conventional methods increases as increasing the number of active antennas. To solve this problem, we proposed a new ML method using static channel information decided by the number of transmit antennas and the number of receive antennas. This method detects active antennas one by one through priority. The proposed method has proved benefit on complexity compared with conventional method through simulations. When the number of transmit antennas is equal to 10, there is approximately 45% complexity reduction.

• Journal of Communications and Networks
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• v.16 no.2
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• pp.110-120
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• 2014

This article proposes a spectrum sharing method which can avoid the mutual interference in both primary and secondary systems. The two systems make them a priority to use two single-dimension orthogonal signals, the real and imaginary pulse amplitude modulation signals, if the primary system is not in outage with this use. A secondary transmitter is selected to be the primary relay and the active secondary source to perform this. This allows a simultaneous spectrum access without any mutual interference. Otherwise, the primary system attempts to use a full two-dimensional signal, the quadrature amplitude modulation signal. If there is no outage with respect to this use, the secondary spectrum access is not allowed. When both of the previous attempts fail, the secondary system is allowed to freely use the spectrum two whole time slots. The analysis and simulation are provided to analyze the outage performance and they validate the considerable improvement of the proposed method as compared to the conventional one.