• Journal of Intelligence and Information Systems
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• v.12 no.3
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• pp.47-65
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• 2006

These days, the number of automated container terminals is increasing to encourage the productivity of the container terminal inside and outside of the country. So far, there have been a lot of researches on the operating one type of equipments in a container terminal. However, there is still room for further improvement as none of equipment works itself but cooperate each other to finish a job, which means synchronization among the equipments is necessary. Among lots of equipments in a terminal, this paper concerns with the operation of ATCs (Automated Transfer Crane) and YTs (Yard Truck). The purpose of this paper is to find the efficient heuristic methods for operating ATCs and YTs that can set up a schedule in a real time. Moreover, using simulation this paper shows the efficient stacking strategy to decide the location of containers to be put and the proper selection range of YTs.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.555-563
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• 2016

Line capacity of railways is a core criterion to decide maximum trips in accordance with traffic demand and a priority in railway investment to improve transportation capability. Particularly, because two operators will start revenue services in the HSR from mid-2016, the line capacity should be carefully calculated and controlled to avoid conflicts between the maximum number of KTXs, and the number needed to guarantee the effective competition of the operators. Meanwhile, there have been many arguments about calculating the line capacity, because this number is affected by the number of trips by train types, stopping pattern and dwell time in each station, journey time, crossing or passing, safety headway between trains, etc. To deal successfully with these kinds of problems, this study proposes a simulation method to calculate the line capacity that considers train operation according to the operator's service policies.

• Korean Journal of Construction Engineering and Management
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• v.22 no.6
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• pp.131-137
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• 2021

Since many resources are put into the work of changing the railway operation within limited time, it is important to have a specific work plan and safety management. For this reason, the work schedule is shared in advance, and parallel work is being carried out simultaneously by rail system, such as tracks, trolly wires, and signals. However, due to the nature of the transfer work, the work is carried out at night when the railway operation is finished, and many resources are put into the limited area of the operating line, so the risk of safety accidents and failure to change the operating line is recognized as high. Nevertheless, there is still not enough research done in korea regarding the operation line change construction. Therefore, this study is conducted a survey on the track exchange work of railroad for working people, and analyzed the results of the survey. Finally, a standard work process was suggested to reduce the risk of track exchange work.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.601-611
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• 2017

This paper proposes a simultaneous control of frequency deviation and electric vehicles (EVs) battery state of charge (SOC) using load frequency control (LFC) and EV controllers. In order to provide both frequency stabilization and SOC schedule near optimal performance within the whole operating regions, a multiple-input multiple-output model predictive control (MIMO-MPC) is employed for the coordination of LFC and EV controllers. The MIMO-MPC is an effective model-based prediction which calculates future control signals by an optimization of quadratic programming based on the plant model, past manipulate, measured disturbance, and control signals. By optimizing the input and output weights of the MIMO-MPC using particle swarm optimization (PSO), the optimal MIMO-MPC for simultaneous control of the LFC and EVs, is able to stabilize the frequency fluctuation and maintain the desired battery SOC at the certain time, effectively. Simulation study in a two-area interconnected power system with wind farms shows the effectiveness of the proposed MIMO-MPC over the proportional integral (PI) controller and the decentralized vehicle to grid control (DVC) controller.

• Journal of the Korea Society of Computer and Information
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• v.23 no.8
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• pp.133-142
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• 2018

Subway metro scheduling is one of the most important problems impacting passenger convenience today. To operate efficiently, the Seoul metro uses regular, periodic schedules for all lanes, both north and southbound. However, many past studies suggest that non-periodic scheduling would better optimize costs. Since the Seoul metro is continuously facing a deficit, adopting a non-periodic schedule may be necessary. Two objectives are presented; the first, to minimize the average passengers' waiting time, and the second, to minimize total costs, the sum of the passenger waiting time, and the operational costs. In this paper, we use passenger smart card data and a precise estimation of transfer times. To find the optimal time-table, a genetic algorithm is used to find the best solution for both objectives. Using Python 3.5 for the analysis, for the first objective, we are able to reduce the average waiting time, even when there are fewer trains. For the second objective, we are able to save about 4.5 thousand USD with six fewer trains.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.5
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• pp.421-429
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• 2004

In Korea, the radiant heating system has been widely used as a residential heating method, which has been modernized to use hot water running into the tubes embedded in the floor structure. According to the recent improvement of living standard of residential buildings, the requirement of the thermal comfort and energy saving in heating system has been raised. Until now, the radiant floor heating system has been controlled by room thermostat installed in the living room, but for better thermal comfort, an individual room control method is adopted as an alternative. Therefore, it is necessary to evaluate the control performance between the current control method and the individual room control method. In this study, the control performance between the two systems is evaluated through the field experiment. And the control performances of room air temperature and energy performances are analyzed through the simulation using TRNSYS. Firstly, the simulations are performed in the various outdoor conditions and the flow rates and the simulation results are analyzed for the control performances. Also, to evaluate the energy performance, the simulations are performed under the operating conditions in which the set-point of the room air temperature is fixed or changed according to the schedule of occupancy, and the simulation results are analyzed between the two methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1910-1917
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• 2011

In this paper, a cloud computing platform is designed and implemented based on an open source cloud platform, OpenNebula, and Xen hypervisor on each node for efficient computer lab system. For the purpose of convenient management, a web-based user interface has been developed for the cloud virtualization system. Once individual virtual machine is allocated to a user based upon class schedule, each user can access the virtual machine remotely and use appropriate operating system and application programs. The developed system can reduce computer lab upgrade cost, management cost, and administration time considerably.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.160-163
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• 2000

Due to the complexities of the real-world system, a water resource management program has to deal with various types of data. It appears that management personnel who has to use the program usually suffers from the technical burdens of handling large amount of data and understanding the optimization theory when they try to interpret the results. By combining the capabilities of database technology and modeling technique with optimization procedure we can develop a reliable decision supporting tool for multi-reservoir operation planning, which yields operating schedule for each dam in a river basin. We introduce two special data handling methodology for the real world application. First, by treating dams, hydro-electric power generating facilities and demand sites as separate database tables, the proposed data handling scheme can be applied to general water resource system in Korea. Second, by assigning variable names using predetermined key words, we can save searching time for identifying the moaning of the variables, so that we can quickly save the results of the optimization run to the database.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.11-17
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• 2012

In this study, a simulation program was developed with heat transfer model in the thermal storage tank for a solar collector and burner combined heating and hot water supply system. Analysis was conducted with variation of operating condition and schedule to analyze performance of a hot water supply and panel heating system with a solar collector and burner combined thermal storage tank. The simulation program is divided two sections. One part is calculation of temperature variation of water which flows through the panel in the floor for heating of the residential house during 24 hours, and the other part is heat transfer calculation for the reaction time to get desired water temperature in the thermal storage tank. As results, light oil consumption and system performance during operation period were analyzed with variation of climate condition and with or without solar collector. Most of the case, oil could be saved about from 24 to 41% with installing the solar collector. The performance of the system is more dependent on radiation time of the solar collector rather than the intensity of the solar radiation which was adopted for the climate analysis.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.638-641
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• 2004

This study suggests the optimum deconstruction management system for minimizing construction waste and increasing reuse and recycle rate of material to be different from traditional demolition. The purpose of this system is to minimize environmental damages and reduce construction waste quantity of a country by planning and operating preliminarily estimation of demolition quantity, demolition methods of each structural elements and reuse or recycle methods of C&D waste. This system is consist of four modules such as planning of preliminary demolition survey, estimating of demolition quantity, planning of demolition schedule and planning of construction waste management, and these all modules can be used individually module according to user's utilization purpose.