• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.73-81
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• 2008

The current electrical safety plan developed for the national electricity system has been playing an important role in handling a variety of electrical accidents. However, it can be more effective to prevent or reduce those accidents if a preventive electrical safety plan is available. In this paper, an approach to developing the safety plan is described. We first discuss the contents that should be included in the plan. Noting that an effective plan requires the system level consideration of all the factors affecting the safety issues, an operation concept document (OCD) is considered. The OCD can allow us to understand the behavior of the safety system based on the operation environment, the system functions, the performance requirements, all at the system level of the safety system. Thus, the OCD can be useful in developing the safety plan. A detailed description then follows on how the OCD is developed for the electrical safety system under study. Finally, we discuss how the developed OCD can be used in deriving the preventive electrical safety plan.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.152-161
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• 2011

The operation of vending machine system presents a decision-making problem which consists of determining the product allocation to vending-machine storage compartments, replenishment intervals of vending machines, and vehicle routes, all of which have critical effects on system profit. Especially, it becomes more difficult to determine the operation variables optimally when demand for a product that is out-of-stock spills over to another product or is lost. In this paper, we propose a heuristic for solving the operation problem of the vending machine system and evaluate it by comparing with Yang's algorithm on various test problems with respect to system profit via a computer simulation. The results of computational experiments show a substantial profit increase of the proposed heuristic over Yang's algorithm. Sensitivity analysis indicates that some input variables impact the profit increase significantly.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.3
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• pp.155-163
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• 2020

This paper conducted a study on the operation plan of the packaging system to enhance the logistics efficiency between the manufacturer and the distributor, whose prior research in the relevant field was insignificant. By identifying problems and improvements in the operation of the packaging system between domestic manufacturers and distributors through the Retail Ready Packaging. The institutional aspects were investigated to confirm that the mediation role of government and social organizations was required to resolve issues (χ2 = 148.916, p < 0.001), and that guidelines that gathered diverse opinions for the rational operation of the packaging system were essential, while institutional aspects are needed to be supplemented to be willing to improve logistics efficiency (χ2 = 95.781, p < 0.001). In this study, even though the difference in perception between manufacturers and distributors is clear and the issue related to the operation of the packaging system is ongoing, if there is no effort to grasp the issue, the opinions between manufacturers and distributors will be left at odds and could become a social problem. Unnecessary interference from government and social organizations should be excluded, but the level of mediation to support win-win management in order to promote logistics standardization and reduce CO2 and national logistics costs can be explained as a catalyst for improving logistics efficiency through reasonable operation of the packaging system.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2840-2851
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• 2022

Electric boilers (EBs) are the backup steam source for the auxiliary steam system of high-temperature gas-cooled reactor nuclear power plants. When the plant is in normal operations, the EB is always in hot standby status. However, the current hot standby operation strategy has problems of slow response, high power consumption, and long operation time. To solve these problems, this study focuses on the optimization of hot standby operations for the EB system. First, mathematical models of an electrode immersion EB and its accompanying deaerator were established. Then, a control simulation platform of the EB system was developed in MATLAB/Simulink implementing the established mathematical models and corresponding control systems. Finally, two optimization strategies for the EB hot standby operation were proposed, followed by dynamic simulations of the EB system transient from hot standby to normal operations. The results indicate that the proposed optimization strategies can significantly speed up the transient response of the EB system from hot standby to normal operations and reduce the power consumption in hot standby operations, improving the dynamic performance and economy of the system.

• New & Renewable Energy
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• v.6 no.1
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• pp.12-19
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• 2010

In Korea, experiences in wind farm operation are limited and the foundation for setting standards in electrical system connection is still weak in comparison to the operation experience in connection of wind power to the electrical system of other countries around the world. Therefore, standards that are being applied in various countries for connection and optimal operation in wind farms need to be examined, and in addition, procedures for the assessment of the effects on the system are needed for setting connection standards and optimal operation plans in accordance with Korean electrical system characteristics. In this study, procedures for the assessment of effects of wind power connection to the electrical system are presented.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2254-2256
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• 2004

Korea Water Resources Corporation (KOWACO), the only organization specialized in water resources management in Korea, is planning to establish a centralized control system for a related operation. in the central control room, of decision making as to water management and electric power generation. This plan is intended to convert the existing on-site operation system in each multi-purpose dam across the nation into a central operation system in the Corporations head office, for which Generation Integrated Operating System (GIOS) will be established control center in the Corporations head office and modernized nine (9) power stations. substations (RDAC). This article discusses realization of GTOS, especially real-time operation of hydropower plants and a specific architectural features for system communication.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.269-274
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• 1998

This paper describes a scaled model for PWM thyristor current-source inverter with a commutation circuit. The system consists of a 6-pulse thyristor bridge and an LC resonant circuit with thyristor switches, which offers thyristors to have turn-off capability for PWM operation with minimal switching losses. The proposed system can be used as a reactive power compensator with PWM operation for the utilitity application. There would be two advantages in the proposed system over the existing voltage source inverter. One is the low system cost due to using the conventional thyristors. Another is easy expansion of system operation voltage because th series operation of thyristor devices is already proven in HVDC system.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.900-905
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• 2006

5678SMRT (Seoul Metropolitan Rapid Transit Co) by a ATC/ATO system the other side which is operated with an automatic movement with a manual operation, the Seoul subway 1.2 lines ATS and 3.4 lines adopt a ATC method and they are operated. But it is improving progressively in SMRT railway ATO method. The ATO the operation method leads exchange of information of wayside and train system for and it is possible, the TWC system configuration is becoming wayside and train system and the radio antenna. It discussed the equipment for a TWC system and a automatic operation from the dissertation which it sees. It investigated a data exchange, a message format and an interface control method and it joined in and a system maintenance conservative method it discussed.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.964-967
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• 2006

Korea Railroad Research Institute (the following 'KRRI') built AGT test line in Gyeong San-city, Kyongsang-bukdo province, Korea on August, 2004. This test line is exclusively used for the test of the driverless rubber-tired AGT system, and applied with research result of AGT System Development Project like vehicles, power supply, control and signaling, track and infrastructure system. The test line is available for the test of rubber tired AGT system's performance, function, safety. In this paper, we described the operation system of test line for the test of performance, safety, reliability, and also system operation in emergency. Finally we present the operation result of test line.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.5
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• pp.664-668
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• 2012

This paper presents the operation strategy of KEPCO(Korea Electric Power COporation) ${\pm}80kV$ 60MW Bipole HVDC system that will be applied between Guemak C/S(converter station) and Hanlim C/S in Jeju island. Unlike intertie HVDC system, this system is located in AC power grid inside. Therefore, the enhancement of system security related with line flow and bus voltages can be major operation strategy. In this paper, in particular, the optimal operation algorithm in the abnormal(not steady state) power system is presented and simulated.