• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.79-84
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• 2005

고속철도는 한번에 1천명에 달하는 승객을 태우고 시속 300km를 넘는 고속으로 주행하는 만큼 성능과 안전에 대한 철저한 사전 검증이 필수적이며, 특히 새로운 차량시스템의 개발은 철저한 성능검증 및 안전성을 확보하는 시험평가 과정을 반드시 거쳐야 한다. 본 논문에서는 최고속도 350km/h인 한국형 고속철도 차량시스템 개발사양의 성능요구 조건을 입증하기 위한 시험으로서, 핵심 개발품 단위별 구성품 시험, 개발품 단위간의 조합시험, 차량에서의 기능 동작 확인을 위한 완성차시험(단차시험 및 편성시험)및 전기신호 및 선로구축물 시스템과의 적합성 및 연계성을 확인하는 시운전 시험으로 구분하여 한국형 고속철도 차량시스템의 성능시험 체계 및 성능시험 기준(안)의 개발 내용을 소개하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.83-86
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• 1998

Ferroelectric PZT(40/67)/PZT(60/40)heterolayered thin films were Prepared by the alkoxide-based Sol-Gel method. PZT(40/60) and PZT(60/40) stock solutions were made and spin-coated on the P7Ti/Si02/Si substrate alternately. These PZT(40/60) and PZT(60/40) films were dried at 300$^{\circ}C$ for 30min to remove organic materials and were sintered at 650$^{\circ}C$ for 1 hour to crystalize into a perovskite structure. The coating and heating procedure were repeated 6 times to form heterolayered films. Increasing the number of coating, coercive field was decreased. The relative dielectric constant, loss, remanent polarization and coercive field of the 4-coated PZT heterolayered were 1200, 4.1[%], 30.794[${\mu}$C/㎡] and 147.22[kV/cm], respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.39-42
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• 2000

The effect of excess Pb contents on the etching of PZT thin films and their electrical properties has been investigated. Ferroelectric PZT(53/47) thin films were prepared by the metal alkoxide-based Sol-Gel method, in which they were spin-coating on P7Ti/Si02/Si substrate using the PZT(53/47) stock solutions with various excess Pb contents. Etching of PZT film was performed using planar inductively coupled Ar/Cl$_2$/BCl$_3$ plasma. The etch rate of PZT film was 2450 $\AA$/min at Ar(20)/BCl$_3$(80) gas mixing ratio and substrate temperature of 8$0^{\circ}C$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.1
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• pp.57-61
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• 1998

In this study, PLZT stock solutions were prepared by Sol-Gel processing after the compositions were selected in the memory region of PLZT bulk phase diagram. PLZT solutions were deposited on the ITO glass substrate by spin-coating method. The thin films were annealed by rapid thermal processing. The electric characteristics, hysteresis loop, C-V characteristics of thin films in the memory region were measured in order to investigate the electrical characteristics of PLZT thin films. In selected compositions the decrease in Zr/Ti ratio led to an increase in dielectric constant and the decrease in remanent polarization and coercieve field which brought about slim hysteresis loop.

• Journal of Technology Innovation
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• v.7 no.1
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• pp.176-186
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• 1999

This paper starts out by reviewing the literature that in different ways utilizes patent data as an output of Research ＆ Development (R&D) investment. The main focus, however, is an analysis of time-lag between industrial R&D input and its output. To achieve this research's purpose, the basic data associated with the industrial R&D input (expenditure, researchers) and output (applied patent and utilities) for the past 15 years, from 1980 to 1994, in the areas of electrical-electronic, mechanical and chemical industries have been collected. And the raw input data were altered into real flow data (but stock data) using Laspeyres approach and analyzed using multiple regression analysis, especially stepwise regression analysis. The result of this study can be summarized as follows: a) The time-lag; between industrial R&D input and its output is within 1 to 3 years. b) The time-lag: of patents was longer than that of utility models. c) The time-lag: in electrical-electronic, chemical industry was longer than that of the mechanical industry.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.129-138
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• 2017

The aim of this paper is to suggest methodology for local governments when discovering locally customized future promising industries with regard to policies of central government, regional competencies, and industrial promising. Firstly, key industries by region specified in '5-years regional industrial development master plan(2014)' were utilized. Secondly, science and technology competency by region was calculated with analyzing patent data in each key industries. Thirdly, industrial promising was verified by calculating Knowledge Stock and Activity Index based on measuring industry-IPC linkage. Based on the methodology proposed above, case study(case of Busan city) was done. Finally, 7 core industries and 94 candidates of future promising industries were extracted on the basis of 5 digit of KSIC subdivision. The methodology is expected to contribute local governments to establish evidence-based, efficient, and future-oriented local R&D roadmapping.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05a
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• pp.74-77
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• 2000

The main objective of this paper is to design and test a new type of polymer ZnO surge arrester for AC power system of railroad vehicles. Metal oxide surge arrester for most electric power system applications, electric train and must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of ZnO elements in a surge arrester occurs due to flashover, fault short current flows through the arrester and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock. pressure rise, etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion. The main research works are focused on the structure design by finite element method, pressure relief of module, and studies of performance of surge arrester for electric railway vehicle.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1445-1456
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• 2011

This paper presents the research of Low Pass Filter(hereinafter called "LPF") which is the part of Chopper Gate Control Unit on the electric rolling stock. Chopper Gate Control Unit controling the propulsive equipments of electric rolling stock consists of several electronic parts, PCB, Power Supply, Gate Circuit Amp, Freon Cooling Device, and has been used the parts made by japan manufacturer Mitsubish. But these parts recently have been more broken down and slow down performance because of long-term use, deterioration. Most of the malfunctions are low performance of LPF. Furthermore, it is physically impossible to repair LPF. Because it is molding type part and no longer manufactured. Also it needs high cost for custom-building. Therefore, it is now making up for through self-developed LPF and operating on Busan metro 1st after on-board testing. This research performed the PS Pice simulation testing, analysis of self-developed LPF performance and the wave form characteristic by multi-function synthesizer, spectrum analyzer, oscilloscope.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.227-230
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• 2013

Financial transactions using a mobile terminal and the Internet is activated, it is a stock exchange enabled using mobile devices and the Internet. Koscom in charge of IT operations of securities transaction-related in (securities ISAC), to analyze the vulnerability of information security related to securities transactions, which corresponds to running the integrated security control system. Online stock trading is a subject to the Personal Information Protection Act, electronic systems of related, has been designated as the main information and communication infrastructure to, damage financial carelessness of the user, such as by hacking is expected to are. As a result, research on the key vulnerabilities of information security fields related to securities business cancer decoding of the Securities and Exchange packet, through the analysis of security events and integrated security control is needed.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.335-346
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• 2020

This study aims to describe the role of corporate governance as a moderator in electronic financial disclosure that adopts Extensible Business Reporting Language (XBRL) and Company Characteristics on value relevance. The population in this study was all manufacturing companies listed on the Indonesia Stock Exchange from 2017 to 2018, totaling 166 companies. The sampling technique used purposive sampling method, namely, manufacturing companies that publish fully audited financial statements by December 31 of the year 2017-2018. The method used in this research is a quantitative description using the financial statements of manufacturing companies listed on the Indonesia Stock Exchange that have adopted XBRL during the 2017-2018 period. The data analysis method used is multiple regression analysis with moderating variables. The results of this study show a negative and insignificant effect of XBRL on value relevance, a significant negative effect of size on value relevance, a positive and insignificant effect of growth on value relevance, and a significant positive effect of profit on value relevance; meanwhile, corporate governance moderation variable has an insignificant effect in all hypotheses. Suggestions are to increase the number of variables that have an important role in value relevance and expand the number of research objects to be compared.