• Journal of Ocean Engineering and Technology
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• v.20 no.3 s.70
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• pp.45-53
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• 2006

Each year, the south coast of Korea is badly damaged from storm surge. The damages are greatly dependent upon the local peculiarities of the region where the storm surge occurs. So, in order to prevent/reduce recurrence of the disaster, it is very important to investigate the fluctuation characteristics of the storm surge height, related to the local peculiarities at each coastal area where occurrence of the disaster is expected. In this paper, using the numerical model, the storm surge was simulated to examine its fluctuation characteristics at the Gyeongnam coast (southeast coast of Korea). Typhoons of Sarah (5914), Thelma (8705) and Maemi (0314), which caused terrible damage to the coastal area in the southeast coast of Korea in the past, were used forstorm surge simulations. Moreover, the storm surge due to virtual typhoons, which were combined the characteristics of each proposed typhoons (Maemi, Sarah, Thelma)with the travel route of other typhoon, was predicted. As expected, the results revealed that the storm surge heights are enhanced at the coastal regions with the concavity like a long-shaped bay. Also, the storm surge heights, due to each typhoon, were compared and discussed at major points along the Gyeongnam coast, related to the local peculiarities, as well as the characteristics and the travel route of typhoon.

• Journal of Korean Society of Transportation
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• v.29 no.5
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• pp.121-138
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• 2011

More affordable and available cutting-edge technologies (e.g., wireless vehicle communication) are regarded as a possible alternative to the fixed infrastructure-based traffic information system requiring the expensive infrastructure investments and mostly implemented in the uninterrupted freeway network with limited spatial system expansion. This paper develops an advanced decentralized traveler information System (ATIS) using vehicle-to-vehicle (V2V) communication system whose performance (drivers' travel time savings) are enhanced by three complementary functions (autonomous automatic incident detection algorithm, reliable sample size function, and driver behavior model) and evaluates it in the typical $6{\times}6$ urban grid network with non-recurrent traffic state (traffic incident) with the varying key parameters (traffic flow, communication radio range, and penetration ratio), employing the off-the-shelf microscopic simulation model (VISSIM) under the ideal vehicle communication environment. Simulation outputs indicate that as the three key parameters are increased more participating vehicles are involved for traffic data propagation in the less communication groups at the faster data dissemination speed. Also, participating vehicles saved their travel time by dynamically updating the up-to-date traffic states and searching for the new route. Focusing on the travel time difference of (instant) re-routing vehicles, lower traffic flow cases saved more time than higher traffic flow ones. This is because a relatively small number of vehicles in 300vph case re-route during the most system-efficient time period (the early time of the traffic incident) but more vehicles in 514vph case re-route during less system-efficient time period, even after the incident is resolved. Also, normally re-routings on the network-entering links saved more travel time than any other places inside the network except the case where the direct effect of traffic incident triggers vehicle re-routings during the effective incident time period and the location and direction of the incident link determines the spatial distribution of re-routing vehicles.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.3
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• pp.72-86
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• 2018

Schedule-based public transit routing algorithm computes a single route that calculated minimum travel time using the departure and arrival times for each stop according to vehicle operation plan. However, additional factors such as transfer resistance and alternative route choice are not reflected in the path finding process. Therefore, this paper proposes a improved RAPTOR that reflected transfer resistance and multi-path searching. Transfer resistance is applied at the time of transfer and different values can be set according to type of transit mode. In this study, we analyzed the algorithm's before and after results compared with actual route of passengers. It is confirmed that the proposed algorithm reflects the various route selection criteria of passengers.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.111-122
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• 2004

The driver's decision making (e.g. route choice) is a typical decision making with an uncertainty. In this paper, we investigate the effect of route guidance information on driver's route choice and learning behavior and analyse the potential of information system in a road network in which traffic flows follow random walk. A Simulation performed focuses on the relationship among the network wide performance, message receiving rates and driver's learning mechanism. We know that at high levels of message receiving rates, the network-wide performance may get worse. However, at low levels of receiving rates, we found that the travel time when guidance information is provided decrease compared to the cases when no pubic information is provided. Also, we found that the learning parameter of the learning mechanism model always changes under nonstationary traffic condition. In addition, learning process of drivers does not converge on any specific value. More investigation is needed to enlarge the scope of the study and to explore more deeply driver's behavior.

• Journal of Korean Society of Transportation
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• v.33 no.2
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• pp.145-158
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• 2015

A network connectivity has been regarded as a key element to strengthen a business competitive power in the aviation industry, so many airport authorities try to attract the new airlines and scheme out new air routes. With this trend, a study for an induced travel demand estimation methodology is needed. This study introduces a demand estimation method, especially for a new air route to a promising destination. With the results of previous studies, the derived demand is classified into four types - Local, Beyond, Behind and Bridge. The explanatory variables are established for each type of demand and the main independent variables are composed of distance, ratio of detour, and relative capacity compared with other airports. The equations using such variables and statistically significant coefficients are suggested as the model to make an estimation of derived demand for a new route. Therefore this study will be expected to take an initial step for all related parties to be involved more deeply into developing new air routes to enhance network connectivity.

• Journal of Korean Society of Transportation
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• v.17 no.3
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• pp.47-60
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• 1999

In this study, the dynamic route choice behavior of driver is assumed to be affected by the current conditions of traffic environments as well as the Past traffic environments and activities. The repeated survey of multi-timed to owner drove in Chon-ju city by the virtual traffic information system was performed by the stated preference method. And the LISREL(An analysis of linear structural relationship) model was used. As the results. the variable Parameter and t-value of travel time information on applied model was high and their results have an effect greatly to the route choice. After all, the route choice was negative from Kirin-ro, which Penetrates the downtown, and positive from Chunbyun-ro which was a roundabout way was confirmed. Estimated result of the reasonability, the highest suitable model was ode which applied the concept of serial correlation and stated dependence and was shown applying rightfulness to dynamic model. As the serial correlation and stated dependence parameter value, when time interval was large, parameter value was small and the serial correlation and stated dependence was in inverse proportion ratio to the time interval.

• The Journal of the Korea Contents Association
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• v.11 no.2
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• pp.135-141
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• 2011

Mobile communication technology in the field of ubiquitous computing is one of important technologies. The development of GPS technology in mobile communications technology and PDA, the vast majority of mobile devices such as smart phones also being equipped with GPS functionality. This user where they are located where they are based on the number of through services were able to receive information. In this paper, mounted on a mobile device user's location using GPS capabilities to track the migration routes and the accumulated user to determine the migratory path of the system used to recommend the proposed route of the proposed method and system Designs. The services offered by tracking the location of the user to move the user to route data to create and upload to the server. Upload a migration path to move data from where they currently reside to the user is recommended to go to your destination. The services offered by the users do not know where to travel or go to your destination, etc. If you do not remember the path can be useful.

• Journal of Navigation and Port Research
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• v.38 no.5
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• pp.493-501
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• 2014

An automated lifting vehicle(ALV) used in an automated container terminal is a type of unmanned vehicle that can self-lift a container as well as self-transport it to a destination. To operate a fleet of ALVs efficiently, one needs to be able to determine a minimum-time route to a given destination whenever an ALV is to start its transport job. To find a route free from any collision or deadlock, the occupation time of the ALV on each segment of the route should be carefully scheduled to avoid any such hazard. However, it is not easy because not only the travel times of ALVs are uncertain due to traffic condition but also the operation times of cranes en route are not predicted precisely. In this paper, we propose a routing method based on an ant colony optimization algorithm that takes into account these uncertainties. The result of simulation experiment shows that the proposed method can effectively find good routes under uncertainty.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.67-75
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• 2020

This paper proposes a methodology for gantry route optimization in order to maximize the productivity of a odd-type surface mount device (SMD). A odd-type SMD is a machine that uses a gantry to mount electronic components on the placement point of a printed circuit board (PCB). The gantry needs a nozzle to move its electronic components. There is a suitability between the nozzle and the electronic component, and the mounting speed varies depending on the suitability. When it is difficult for the nozzle to adsorb electronic components, nozzle exchange is performed, and nozzle exchange takes a certain amount of time. The gantry route optimization problem is divided into the mounting order on PCB and the allocation of nozzles and electronic components to the gantry. Nozzle and electronic component allocation minimized the time incurred by nozzle exchange and nozzle-to-electronic component compatibility by using an mixed integer programming method. Sequence of mounting points on PCB minimizes travel time by using the branch-and-price method. Experimental data was made by randomly picking the location of the mounting point on a PCB of 800mm in width and 800mm in length. The number of mounting points is divided into 25, 50, 75, and 100, and experiments are conducted according to the number of types of electronic components, number of nozzle types, and suitability between nozzles and electronic components, respectively. Because the experimental data are random, the calculation time is not constant, but it is confirmed that the gantry route is found within a reasonable time.

• Journal of Korean Society of Transportation
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• v.21 no.3
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• pp.85-96
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• 2003

To build traffic information providing services by ITS technology should be carried out effect analysis in the first step for social and individual advantages. The propose on this study is to make clear what influences of highway network by traffic information are, and what differences between drivers who use traffic information and drivers who do not use that for route choice are. For these propose. travel time and forecast error of travel time on network and traffic information dependence of driver are analyzed by simulation. As a result of analysis travel time and forecast error of travel time is that the efficiency and reliability of travel time were increased when getting more drivers using traffic information in network. Drivers who using traffic information had advantage of decrease of travel time and forecast error in only definite situation. traffic information dependence analysis presented that drivers are dependent upon information and reliability of traffic information is also increased when drivers using traffic information become on increasing in network. In conclusion, considering the range of the traffic information user ratio in this simulation, this study presents that the traffic information service provides an advantage to the highway network and the drivers, and increases the dependence of information.