• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.672-678
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• 2020

The parallel-feeding operation of an AC traction power supply system has the advantages of extending the power supply section and increasing the power supply capacity by reducing the voltage drop and peak demand caused by a train operation load. On the other hand, the parallel-feeding operation is restricted because of the circulating power flow induced from the phase difference between substations. Moreover, the power supply capacity is limited because of the unbalanced substation load depending on the trainload distribution, which can be changed by the train operation along the railway track. This paper suggests a Thyristor-controlled Phase Angle Regulator (TCPAR) to reduce the circulating power flow and the unbalanced substation load, which depends on the phase difference and the trainload distribution and provides a feasibility study. A dedicated control model of TCPAR is also provided, which uses substation power supplies as the input to control the circulating power flow and an unbalanced substation load depending on the phase difference and the trainload distribution. Simulation studies using PSCAD/EMTDC shows that the proposed TCPAR control model can reduce the circulating power flow and the unbalanced substation load depending on the phase difference and the trainload distribution. The proposed TCPAR can extend the parallel-feeding operation of an AC traction power system and increase the power supply capacity.

• Korean Journal of Construction Engineering and Management
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• v.16 no.1
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• pp.74-81
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• 2015

As one of urban infrastructure system, the electricity substation is critical for urban life and industrial activity as the electricity demands get higher than ever. However the substation is generally regarded as unpleasant or dangerous facility, which finally results in the continuous opposition movement by resident due to the belief of unidentified negative effect in apartment prices. Accordingly, as the scientifically objective and quantitative analysis is required to solve the social conflict, this study intends to examine the variation affected by urban infrastructure system, expecially for substation. After the independent variable defining the price of apartment and the dependent variable, which is apartment price, are identified and their spatial data has been filed, the forecasting model has been developed through the hedonic price function as well as artificial neural networks system. The research finding indicated that the spatial range affected by substation is not notable and the range of some case was applicable for less than 600m. It is expected that these research findings can be applied for establishing the one of solid cases for the analysis of economical effect to local housing market by the urban infrastructure system.

• Journal of Life Science
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• v.19 no.6
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• pp.793-798
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• 2009

This study was undertaken to reveal the relationship between genetic variations and inheritance patterns and the development of a systemic white coat color frequently observed in Jeju horses. It was determined that the white coat color occurred in all basic coat colored (black, bay and chestnut) horses by combining the phenotype and MC1R genotypes. There were no polymorphisms found in Jeju horses tested for mutational loci in the KIT gene, which were previously reported as potential mutations of the congenital dominant white coat color in other horse breeds in heterogeneity. The horses that had the 4.6-kb duplication in the STX17 intron 6 specifically showed the depigmented white coat color. Based on observation and STX17 genotypes, this depigmented whitening is defined as 'Chongma' (whitening, progressive graying with age-Gray) in Jeju horses. Pedigrees showed that this is an autosomal dominant inheritance pattern distinct from the bovine albinism caused by an autosomal recessive passion eye color. Because the gray phenotype is generally not completely expressed early in Jeju horses, it often makes them indistinguishable from other horses. Further studies are recommended for classification between the gray coat color and its similar phenotypes, such as the roan with its mixed hair colors appearing since neonatal period, acquired white hairs on wounded skin by veterinary treatment, and vitiligo-like skin pigmentation. However, study results revealing the relationship between the gray phenotype and genetic background suggested that useful information may be provided in regards to molecular breeding of Jeju horses.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.3
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• pp.201-220
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• 2023

Power cable tunnels is one of the underground structures meant for electricity transmission and are constructed using shield TBM method when transitting across urban and subsea regions. With the increasing shaft depth for tunnels excavation when the shield TBM excavated the rock mass, the review of selecting closed-type shield TBM in rocks becomes necessary. A simplified shield TBM design method is also necessary based on conventional geotechnical survey results. In this respect, design method and related design program are developed based on combined results of full-scale tests, considerable amount of accumulated TBM data, and numerical simulation results. In order to validate the program results, excavation data of a completed power cable tunnel project are utilized. Thrust force, torque, and power of shield TBM specification are validated using Kernel density concept which estimates the population data. The robustness of design expertise is established through this research which will help in stable provision of electricity supply.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.255-258
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• 2009

This paper gives a feasibility reference of integrating power automation for digital substation. An overview and techno-economical potential of IEC61850 are introduced. The result of economic analysis is shown to save up to one-third of the total cost of automation installation. The gained benefits can be used to increase the economy and reliability of electrical power system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.151-156
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• 2001

Performance-based course design on the job of receiving substation installations is presented to achieve a work based curriculum development. It includes a job analysis method called ISD(Instructional Systems Design & Development) and DACUM(Developing a Curriculum) which is designed to accept various requirements of industrial fields. It is provided with course profile, key contents, terminal learning objectives, intermediate learning objectives, instruction strategy, instruction sequence, case study, action learning and lesson plan.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.408-410
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• 2005

It is important to identify and correct bad data for maintaining the security and the reliability of data acquisition and management in a substation. This paper presents a bad data processing method based on rules acquired by analysis of cause and effect of bad data. The proposed method verified by the case study in a typical substation model.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.301-303
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• 2005

IEC 61850 is an international standard for substation communications. It introduces function that provide a substation with autonomous behavior of IEDs. The paper presents the model which is for change and modification of the IED setting values with analyzing IEC 61850.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.5
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• pp.224-226
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• 2005

In this paper, the secular changes of buried grounding electrodes was investigated; the electrodes are such facilities as grounding grid, grounding connector, grounding terminal and grounding rod etc.. The corrosiveness of removed substation grounding electrodes after commercial operation more than 50 years was measured and its conductivity deterioration trend was analyzed. The measuring results using three experimental methods were compared, finally the consideration for safe and economic grounding design were shown. As the result, it shows the maintenance necessity of grounding systems.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.151-153
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• 2002

This paper proposes a concept for fault diagnosis system based on the relay coordination to deal with unavoidable uncertainties imposed on fault dignosis of substation. This system uses information on the relay setting values and tripped data to identify the faulted element of power system. The proposed concept will be very useful and efficient for substation and control center operator.