• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1612-1627
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• 2008

Dwelling time is one of the factors that influence in rail. Current research in dwelling time has been focusing on railways, the state of the research in high-speed rail's dwelling time is not complete. Dwelling time is consisted of time to open door, time to get into and out of vehicle and time of the departure it takes after the passenger's door was closed, it was affected by various factors such as congestion's degree in vehicle, the number of persons that get into and out of vehicle, congestion's degree in station. In order to analyze theses, we need data analysis such as the number of persons that get into and out of vehicle, congestion's degree in station, congestion's degree in vehicle, but the congestion's degree and passenger's distribution chart in vehicle is excluded in this research due to difficulty of gathering data, and thus we will develop forecasting models through high-speed rail's demand most affected by the dwelling time.

• Journal of Intelligence and Information Systems
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• v.15 no.3
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• pp.137-150
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• 2009

This paper proposes the hybrid heuristic method to apply the opportunity time to solve the vehicle routing and scheduling problem with time constraints(VRSPTW). The opportunity time indicates the idle time which remains after the vehicle performs the unloading service required by each customer's node. In this proposed heuristic, we add the constraints to VRSPTW model for the opportunity time. We also obtain the initial solution by applying the cost evaluation function to the insertion strategy considering the opportunity time. In addition, we improve the former result by applying the opportunity time to the tabu search strategy by swapping the customer's node. Finally, we suggest the construction strategies of initial routing which can efficiently acquire the nearest optimal solution from various types of data in terms of geographical condition, scheduling horizon and vehicle capacity. Our experiment show that our heuristic can get the nearest optimal solution more efficiently than the Solomon's I1 heuristic.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.1
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• pp.59-64
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• 2020

Scheduling of electric vehicles and optimizing for charging waiting time have been critical. Meanwhile, it is challengeable to exploit the fluctuating data from electric vehicles in real-time. We introduce an optimal routing algorithm and a simulator with electric vehicles obeying the Poisson distribution of the observed information about time, space and energy-demand. Electric vehicle routing is updated in every cycle even it is already set. Also, we suggest an electric vehicle routing algorithm for minimizing total trip time, considering a threshold of the waiting time. Total trip time and charging waiting time are decreased 34.3% and 86.4% respectively, compared to the previous algorithm. It can be applied to the information service of charging stations and utilized as a reservation service.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.4698-4716
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• 2017

Wireless signal transmission is influenced by environmental effects. These effects have also been challenging for Vehicular Ad hoc Network (VANET) in real-time communication. More specifically, in an urban environment, with high mobility among vehicles, a vehicle's status from the transmitter can instantly trigger from line of sight to non-line of sight, which may cause loss of real-time communication. In order to overcome this, a deterministic signal propagation model is required, which has less complexity and more feasibility of implementation. Hence, we propose a realistic path loss model which adopts ray tracing technique for VANET in a grid urban environment with less computational complexity. To evaluate the model, it is applied to a vehicular simulation scenario. The results obtained are compared with different path loss models in the same scenario based on path loss value and application layer performance analysis. The proposed path loss model provides higher loss value in dB compared to other models. Nevertheless, the performance of vehicle-vehicle communication, which is evaluated by the packet delivery ratio with different vehicle transmitter density verifies improvement in real-time vehicle-vehicle communication. In conclusion, we present a realistic path loss model that improves vehicle-vehicle wireless real-time communication in the grid urban environment.

• Journal of Mechanical Science and Technology
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• v.15 no.9
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• pp.1248-1256
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• 2001

In this study, a test bed for vehicle longitudinal control is developed using a chassis dynamometer and real time 3-D graphics. The proposed test bed system consists of a chassis dynamometer on which test vehicle can run longitudinally, a video system that shows virtual driver view, and computers that control the test vehicle and realize the real time 3-D graphics. The purpose of the proposed system is to test vehicle longitudinal control and warning algorithms such as Adaptive Cruise Control(ACC), stop and go systems, and collision warning systems. For acceleration and deceleration situations which only need throttle movements, a vehicle longitudinal spacing control algorithm has been tested on the test bed. The spacing control algorithm has been designed based on sliding mode control and road grade estimation scheme which utilizes the vehicle engine torque map and gear shift information.

• IEMEK Journal of Embedded Systems and Applications
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• v.12 no.2
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• pp.113-120
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• 2017

In this paper, we present a night-time vehicle detection method using CNN (Convolutional Neural Network) classification. The camera based night-time vehicle detection plays an important role on various advanced driver assistance systems (ADAS) such as automatic head-lamp control system. The method consists mainly of thresholding, labeling and classification steps. The classification step is implemented by existing CIFAR-10 model CNN. Through the simulations tested on real road video, we show that CNN classification is a good alternative for night-time vehicle detection.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.1-10
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• 2011

This paper addresses the analysis of the travel distance and order picking time of the vehicle in a aisle when items are picked by the batch in a warehouse system. Batching is to combine several orders in a single tour of the storage/retrieval machine. An advantage of batching is that the length of a tour for a batch of orders is shorter than the sum of the individual orders' tour lengths. The average travel distance and order picking time when a batch is picked in a aisle of the warehouse systems are analyzed for the batch size. And when the vehicle is idle, the dwell point of the vehicle to minimize to the response distance is analyzed. As the batch size is increased, average order picking time per item is decreased. The problem is analyzed and a numerical example is showed to explain the problem.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.4
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• pp.621-633
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• 1997

This paper is concerned with the multiobjective vehicle scheduling problem with time and area-dependent travel speeds(MVSPTD), in which two conflicting objectives are explicitly treated and the travel speed between two locations depends on the passing area and time of day. The two objectives are the minimization of total vehicle travel time and the minimization of total weighted tardiness. First, I construct a mixed integer linear programming formulation of the MVSPTD, and present o heuristic algorithm that builds the vehicle schedules based on the savings computed. The results of computational experiments showed that the heuristic performs very well. Finally, I propose an expert system for vehicle scheduling in the MVSPTD. Its whole process is executed under VP-Expert expert system environment.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1003-1008
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• 2007

Compliance effect consideration method for real-time multibody vehicle dynamics is proposed using quasi-static analysis. The multibody vehicle model without bush elements is used based on the subsystem synthesis method which provides real-time computation on the multibody vehicle model. Reaction forces are computed in the suspension subsystem. According to deformation from the quasi-static analysis using reaction forces and bush stiffness, suspension hardpoint locations and suspension linkage orientation are changed. To validate the proposed method, quarter car simulations of McPherson strut and multilink suspension subsystems. Full car bump run simulations are also carried out comparing with the ADAMS vehicle model with bush elements. CPU times are also measured to see the real-time capabilities of the proposed method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.2
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• pp.162-169
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• 2008

Compliance effect consideration method for real-time multibody vehicle dynamics is proposed using quasi-static analysis. The multibody vehicle model without bush elements is used based on the subsystem synthesis method which provides real-time computation on the multibody vehicle model. Reaction forces are computed in the suspension subsystem. According to deformation from the quasi-static analysis using reaction forces and bush stiffness, suspension hardpoint locations and suspension linkage orientation are changed. To validate the proposed method, quarter car simulations of McPherson strut and multilink suspension subsystems are performed. Full car bump run simulations and fish hook handling test simulations are also carried out comparing with the ADAMS vehicle model with bush elements. CPU times are also measured to see the real-time capabilities of the proposed method.