• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1540-1548
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• 2010

KEPCO proposes enhanced voltage management system that is a coordinate voltage control system between the hierarchical voltage control system and the slow voltage control system. It has been installing in Jeju island. VMS consists of a master controller, CVC (Continuous Voltage Controller) and DVC (Discrete Voltage Controller). CVC consists of main controller, FDMU (Field Data Measurement Unit) and several RPDs (Reactive Power Dispatcher). CVC has a control scheme with AVRs of generator to maintain the voltage of a pilot bus in a power system, DVC has a control scheme with static reactive power sources, like a shunt capacitor, a shunt reactor, ULTC and so on, to maintain the reactive power reserve of a power system and a master controller is executed to recover reactive power margin of a power system through coordinated control between CVC and DVC.

• Journal of Electrical Engineering and Technology
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• v.4 no.4
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• pp.467-475
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• 2009

Congestion management is one of the technical challenges in power system deregulation. This paper presents single objective and multi-objective optimization approaches for optimal choice, location and size of Static Var Compensators (SVC) and Thyristor Controlled Series Capacitors (TCSC) in deregulated power system to improve branch loading (minimize congestion), improve voltage stability and reduce line losses. Though FACTS controllers offer many advantages, their installation cost is very high. Hence Independent System Operator (ISO) has to locate them optimally to satisfy a desired objective. This paper presents optimal location of FACTS controllers considering branch loading (BL), voltage stability (VS) and loss minimization (LM) as objectives at once using GA. It is observed that the locations that are most favorable with respect to one objective are not suitable locations with respect to other two objectives. Later these competing objectives are optimized simultaneously considering two and three objectives at a time using multi-objective Strength Pareto Evolutionary Algorithms (SPEA). The developed algorithms are tested on IEEE 30 bus system. Various cases like i) uniform line loading ii) line outage iii) bilateral and multilateral transactions between source and sink nodes have been considered to create congestion in the system. The developed algorithms show effective locations for all the cases considered for both single and multiobjective optimization studies.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.33-43
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• 2015

Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Light rail transit(LRT) with passenger capacity between bus and subway is driven by an unmanned control, so safety issues of LRT in emergency shall be considered more carefully than other rolling stock. Modern railway system is a complex system and many actions in emergency are required. In this view, interoperability approach is effective to identify the related elements in emergency. In this paper, we propose the method to generate the fire response scenario of unmann ed LRT based on the outputs of systems engineering architecture design methodology. The proposed method is could be contributed to establish more reliable and applicable fire response scenario.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.142-151
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• 1995

The trend of compact size, light weight, low power consumption in the portable telecommunication equipments demands large scale integration and low voltage operation of chips and the minimization of the number of the components in the telecommunication terminal. According to the trend, existing chip components are modulized and are integrated as a part into a bigger chip. This paper is about the development of the peripheral units of micro-controller for mobile telecommunication terminal. Peripherals consist of DMA controller, Interrupt controller, timer, watchdog timer, clock generator, and power management unit. They are designed to be integrated with EU(Execution Unit) and BIU(Bus Interface Unit) into a 16 bit micro-controller which will be used as a core of an ASIC for next generation digital mobile telecommunication terminal. At first, whole block of the micro-controller was described by VHDL behavioral model and simulated to verify its overall operation. Then, watchdog timer, clock generator and power management unit were directly synthesized by using VHDL synthesis tool. Rest of the pheriperal units were designed and simulated by using Compass Design Tool.

• Health Policy and Management
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• v.26 no.4
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• pp.382-389
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• 2016

Background: National cancer screening reduces mortality from stomach, colon, breast, and cervical cancer. However, cancer screening rates remain lower than 50% in Korea. This research was designed to make effective guidelines for cancer screening promotion to increase participation rate in cancer screening. Methods: Data was collected from Incheon regional cancer center's telephone survey 'Recognition of cancer prevention and control' of 861 Incheon citizens over age 40. Logistic regression was used to analyse a relationships between cancer screening rates and promotional methods. PASW SPSS ver. 18.0 program (SPSS Inc., Chicago, IL, USA) was used for statistical analysis. Results: About 27.4% of respondents (236 of 861 respondents) have recognized the promotional program of Incheon regional cancer center for cancer screening participation. Cancer screening rate was associated with age group, educational level for stomach cancer, age group, bus advertisement (odds ratio, 1.19 to 2.75) for colon cancer, educational level, residential area for breast cancer, and age group for cervical cancer. Conclusion: There was relationship between stomach cancer screening rates and promotional methods. Therefore, cancer screening promotion guidelines to increase participation rate should be considered.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.65-80
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• 2005

대부분의 국가들이 노선버스의 운영을 공공부문에서 담당하고 있으나 우리나라를 비롯한 일부에서만 민간이 운영하고 있어 시민들을 위한 공익성만을 추구 할 수는 없는 입장이며 노선의 선정 또한 사업자와 공공이 협의하여 시행할 수밖에 없다. 이를 개선하기 위하여 버스노선 개편, 공동배차제 등 개선방안을 많은 지자체에서 시행하였지만 시민${\cdot}$업체${\cdot}$공공부문에서의 합의 도출은 지난한 상황이며 실행력이 없는 계획이 되고 있음을 여러 사례에서 볼 수 있다. Internet등 통신기술의 급속한 발달에 따라 통신을 통한 의사표출이 자유롭고 용이해지면서 일반지자체의 경우에 전체 민원 중 교통부문이 차지하는 민원이 $50\%$를 상회하고 있으며, 교통민원 중 $45.3\%$가 노선버스의 정시성 확보 및 운전기사의 불친절, 무정차 통과 등에 관한 것으로써 시민들이 가장 알고싶어 하는 사항이 버스의 실시간 운행상황임을 알 수 있었다. 따라서 본 연구에서는 실시간 버스정보제공을 통해 노선버스 이용자들의 대기시간 감소 및 이용편의를 증진시키고, 이를 통해 승용차 이용자를 대중교통수단으로 유도하여 대중교통을 활성화시키는 버스정보시스템(BIS ; Bus Information System)을 정립하며, 충주시 교통여건을 감안한 버스정보시스템 도입전략을 수립하고, 도입에 따른 기대효과를 분석하여 합리적이고 효과적으로 적용할 수 있는 지방자치단체 특히 충주시의 지능형 교통정보 시스템을 마련하는데 그 목적이 있다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.2
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• pp.242-247
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• 2010

This paper introduces a real-time load flow program for Korean energy management system(EMS). This study is concentrated on the following aspects. First, we propose the model of the real-time database and power system equipment for the real-time load flow. These models are extracted from the needs of load flow functions and are designed to the application common information. Second, several techniques are applied for the efficient convergence and computational speed. The generation/load mismatch is redistributed using generator participation factors which are separated to the reference bus. For the voltage control, the jacobian matrix is composed with the basic Y matrix elements and the voltage control elements. Through the optimally ordering, jacobian row and column for a column is changed. However all jacobian matrix entries have same order with the Y matrix. The proposed program is tested using the Korea Electric Power Corporation(KEPCO) system. Through the test, we verified that the proposed program can be effectively used to accomplish the Korean EMS system.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3347-3352
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• 2022

In 2013, the International Atomic Energy Agency (IAEA) changed the recommended maximum range of the Emergency Planning Zone (EPZ) to 30 km, and the Kori Nuclear Power Plant in Republic of Korea has also expanded the EPZ to 30 km, following the recommendation. As a result, metropolitan cities with a high population density are contained within the EPZ, and evacuating millions of people should be considered if the 30 km range of evacuation is to take place. This study proposes an evacuation plan using buses (public transportation) to transport people outside of the EPZ, quickly and efficiently. To verify the appropriate mode share ratio of buses that can guarantee the right of vulnerable road users and reduce traffic congestion, a model was built simulating the Kori Nuclear Power Plant in Ulsan Metropolitan City. The scenarios were established by changing the mode share ratio of buses and passenger cars by 10%. Considering a large-scale network analysis at the city level, a cell transmission model was applied to calculate the evacuation time in each scenario. The result shows that the optimal mode share ratio of buses is 40%, with a total evacuation time of 132 min, considering feasible bus fleets in Ulsan Metropolitan City.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.1
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• pp.80-93
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• 2024

This study attempted to analyze the factors that influence the participation of beneficiary companies in the government's defense industry promotion support project. To this end, experimental data were analyzed by constructing a prediction model consisting of highly important variables in beneficiary company decisions among various company information using the decision tree model, one of the data mining techniques. In addition, various rules were derived to determine the beneficiary companies of the government's support project using the analysis results expressed as decision trees. Three policy measures were presented based on the important rules that repeatedly appear in different predictive models to increase the effect of the government's industrial development. Using the analysis methods presented in this study and the determinants of the beneficiary companies of the government support project will help create a sustainable future defense industry growth environment.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1309-1312
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• 2002

The electric power network paralleled with wind turbine generator may have the negative impacts on the protection, operation, and management caused by the operation of wind turbine generator. Therefore, it is necessary to investigate the operating characteristic of wind turbine generator. This paper describes model of a squirrel-cage type wind turbine induction generator and the soft cut-in connection method for reducing the transient state on power network, and simulates various cases of wind turbine operations. The radial distribution network of IEEE 13-bus are modeled and tested by PSCAD/EMTDC.