• Industrial Engineering and Management Systems
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• v.9 no.2
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• pp.178-194
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• 2010

To improve the ship operation in automated container terminals, it is important to schedule different types of handling equipment to operate synchronously. For example, a vehicle with container receiving and lifting capabilities is used to transport containers from a storage yard to a vessel and vice versa, while a triple quay crane (QC) can handle up to three 40-ft containers simultaneously. This paper discusses the manner in which vehicles should be assigned to containers to support such multi-lifts of QCs by using information about the locations and times of deliveries. A mixed-integer programming model is introduced to optimally assign delivery tasks to vehicles. This model considers the constraint imposed by the limited buffer space under each QC. A procedure for converting buffer-space constraints into time window constraints and a heuristic algorithmfor overcoming the excessive computational time required for solving the mathematical model are suggested. A numerical experiment is conducted to compare the objective values and computational times of the heuristic algorithm with those of the optimizing method to evaluate the performance of the heuristic algorithm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.297-300
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• 2005

This paper presents vibration control of an engine mount for a passenger vehicle utilizing ER fluid and piezoelectric actuator. The proposed engine mount can be isolated the vibration of wide frequency range with many types of amplitude. The main function of ER fluid is to attenuate vibration for low frequency with large amplitude, while the piezoelectric actuator is activated in hish frequency range with small amplitude. A mathematical model of the engine mount is derived using Hydraulic model and mechanical model. After formulating the governing equation of motion, then field-dependent dynamic stiffness of the engine mount is evaluated for various engine speed and excitation amplitude conditions. Then robust controller is designed to attenuate vibration of wide range frequency component. Computer simulation is undertaken in order to evaluate the vibration control performance such as transmissibility magnitude in frequency domains.

• Journal of Information Processing Systems
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• v.20 no.3
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• pp.296-306
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• 2024

Traditional ecological driving (Eco-Driving) evaluations often rely on mathematical models that predominantly offer subjective insights, which limits their application in real-world scenarios. This study develops a robust, data-driven Eco-Driving evaluation model by integrating dynamic and distributed multi-source data, including vehicle performance, road conditions, and the driving environment. The model employs a combination weighting method alongside K-means clustering to facilitate a nuanced comparative analysis of Eco-Driving behaviors across vehicles with identical energy consumption profiles. Extensive data validation confirms that the proposed model is capable of assessing Eco-Driving practices across diverse vehicles, roads, and environmental conditions, thereby ensuring more objective, comprehensive, and equitable results.

• Journal of the military operations research society of Korea
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• v.34 no.3
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• pp.1-12
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• 2008

Design of supply chain network (SCN) is required to optimize every factor in SCN and to provide a long-term and strategic decision-making. A mathematical model can not reflect the real world because design of SCN contains variables and stochastic factors according to status of its system. This paper presents the designing methodology of military SCN using the mathematical model and the simulation model. It constructs SCN to minimize its total costs using the Mixed Integer Programming (MIP) model. And we solve problems of a vehicle assignment and routing through adaptation of experiment parameters repeatedly in the simulation model based on the results from the MIP model. We implement each model with CPLEX and AutoMod, and experiment to reconstruct SCN when the Logistic Support Unit is restricted to support military units. The results from these experiments show that the proposed method can be used for a design of military SCN.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.3-4
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• 2011

In this study, the nonlinear mathematical model of Manta type UUV is derived the hydrodynamic derivatives and the sliding mode controller of Manta type UUV test bed is designed. The sliding mode control scheme is used for robust control on the nonlinear motion. The designed controller is used the depth and heading control. It is based on the 6 DOF mathematical model with effect of the ocean currents. As a result, the performance of the designed controller is confirmed by computer simulation.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.201-204
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• 2002

This paper describes the hydrodynamic characteristics of a test-bed AUV SNUUV-I constructed at Seoul National University. The main purpose of the AUV is to carry out fundamental control and hydrodynamic experiments. Its configuration is basically a long cylinder of 1.35m in length and 0.25m in diameter with delta-type wings near its rear end. On the edge of each wing, a thruster of 1/4HP is mounted, which is used for both drive and turn the vehicle for horizontal movement as the output control power is varied. A pair of control surfaces installed near its font part generates pitch moments for vertical movement. The 6 DOF mathematical model of SNUUV-I contains hydrodynamic forces and moments expressed in terms of a set of hydrodynamic coefficients. These coefficients can be classified into linear damping coefficients, linear inertial coefficients and nonlinear damping coefficients. It is important to estimate the exact value of these coefficients to control the vehicle precisely. Among these, the linear coefficients are known to affect the motion of the vehicle dominantly. The linear damping coefficients are estimated by using Extended Kalman Filter. The responses of the vehicle to input signals are used to estimate the hydrodynamic coefficients, which can be inferred from output signals measured from an IMU (inertial motion unit) sensor, while the linear inertial coefficients are calculated by a potential code. By using these coefficients estimated as described above, a simulation program is constructed using Matlab.

• Journal of Sensor Science and Technology
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• v.5 no.6
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• pp.35-42
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• 1996

In this paper, a development of model based battery SOC indicator is described. The proposed method is independent upon initial SOC, is reliable on the sudden change of load, and could estimate the available driving distance. The mathematical model of battery which has relation of the current, voltage and SOC estimates the SOC by least square estimation to minimize the error between measured voltage and estimated voltage. For experiment, the charging and discharging system using computer was designed to acquire the current and voltage data for model. The feasibility in electric vehicle was confirmed by variable load testing using the developed SOC indicator by stand-alone type microcontroller.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.107-117
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• 2004

The growing demand for customer-response, made-to-order manufacturing and satisfactory delivery are stimulating the importance of commercial fleet management problem. Moreover, the rapid transformation to the customer-oriented multi-frequency, relatively small fleet, such as home delivery and Perishable goods, requiring prompt delivery and advanced real-time operation of vehicle fleets. In this paper we consider the vehicle routing problem(VRP) to minimize delivery completion time which is equal to the time that last customer wait for the vehicle in fleet operation. The mathematical formulation is different from those for the classical VRP which is minimizing cost/distance/time by running vehicles in manager's point of view. The key aspect of this model is not considering the return time from the last customer to depot in every vehicle path. Thereby, the vehicle dispatcher can afford to dynamically respond to customer demand and vehicle availability. The customer's position concerned with minimizing waiting time that may be applied for the delivery of product required freshness or delivery time. Extensive experiments are carried out to compare the performance of minimizing delivery completion time by using the ILOG Solver which has the advantage of solving quickly an interim solution very near an optimal solution. The experimental results show that the suggested model can easily find near optimal solution in a reasonable computational time under the various combination of customers and vehicles.

• The Journal of Information Systems
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• v.21 no.3
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• pp.99-116
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• 2012

As a way to allocate lots of orders to many participants for vehicle allocation problem, this study has used an agent negotiation based reverse auction model. This agent negotiation provides coordination functions allowing all participants to make a profit, and accomplishing Pareto optimum solution from the viewpoint of a whole trucking cargo transportation network. In order to build a strategic cooperation relationship based on information sharing, this agent negotiation provides a coordination mechanism in which all the participants including consignors, brokerage firms, and car owners are able to attain their own profits, and also that ensure a competitive market. This study has tried to prove that the result of an agent-based negotiation is the Pareto optimal solution under the present market environment. We established a mathematical formulation for a comparison with the Integer Programming model, and analysing e-Marketplace, structure of shipping expenses and brokerage system in the trucking cargo transportation industry.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.1
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• pp.1-9
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• 2011

This paper presents a new method that can solve the integrated problem of combined location routing and inventory problem (CLRIP) efficiently. The CLRIP is used to establish facilities from several candidate depots, to find the optimal set of vehicle routes, and to determine the inventory policy in order to minimize the total system cost. We propose a mathematical model for the CLRIP with budget constrained. Because this model is a nonpolynomial (NP) problem, we propose a endosymbiotic evolutionary algorithm (EEA) which is a kind of symbiotic evolutionary algorithm (SEA). The heuristic method is used to obtaining the initial solutions for the EEA. The experimental results show that EEA perform very well compared to the existing heuristic methods with considering inventory control decisions.