• Corrosion Science and Technology
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• v.10 no.3
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• pp.95-100
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• 2011

Protective coatings play an important role in the protection of metallic structures against corrosive environment. The main function of anticorrosive coating is to prevent the materials from corrosive agents, such as water, oxygen and ions. In the study, the corrosion protection properties of urethane and epoxy coating systems were evaluated using EIS methods exposed to the corrosion acceleration test such as Norsok M501, Prohesion and hygrothermal cyclic test. AFM analysis of the coating systems was carried out to monitor the change of roughness of coatings. Urethane coating system was more stable than the epoxy coating under given cyclic conditions. Water uptake into the urethane coatings was less than that into the epoxy coating. The urethane coating system showed better corrosion protection than epoxy coating system based on the changes of the impedance modulus at low frequency region with exposure time. Consequently, the corrosion protection properties of the epoxy and urethane coatings was well correspond with their surface roughness changes and water uptakes.

• Journal of Environmental Impact Assessment
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• v.1 no.1
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• pp.21-30
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• 1992

Environmental Impact Assessment(EIA) is developing as a tool for environmentally sound and sustainable development in Korea. For more effective implementation of it, we try to apply Environmental Information System (EIS) to EIA process. EIS is composed of geographic and attribute data related to environment and Geographic Information System(GIS), and it will be applied to scoping, prediction, and alternative assessment, etc. in EIA. This study focuses on application of geographic data using GIS in suitability analysis of alternative assessment. We use TIN, buffering, and overlaying in GIS functions.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.683-686
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• 1996

본 연구는 P사의 사례를 바탕으로 사용중인 중역정보시스템(EIS : Excutive Informaiton System. 이하 "EIS"라함)에서 차별화된 회장전용 시스템의 개선에 대한 연구방법을 소개한다. EIS는 80년대 후반에서 90년도 초반에 이르기까지 급격한 성장을 이룩한 정보시스템이다. 그동안의 EIS가 도입과 보급 단계에서 양적인 성장을 이루었다면, 이제부터는 개선과 발전의 질적인 성장을 이룩하여야 할 필요성들이 점차 커지고 있다. 이러한 시점에서 P사의 EIS가 보다 더 나은 시스템으로 발전하기 위한 토대로, 본 연구는 회장전용의 차별화 된 시스템의 프로토타입을 구성하였다. 또한 본 연구에서는 멀티미디어 기술, 하이퍼미디어 및 슬라이드쇼를 이용하여 차별화된 EIS를 구축하였다. 시스템 구축을 위하여 다양한 아이디어의 도입을 통한 아이디어 기반의 시스템 개발과, 기존 EIS의 정보 전달 형태의 입체화 방안, 갱신 주기별 정보제공 및 전략차별 방안과 정보의 체계적 제공 방안을 근본 연구 추진 방향으로 하여 시스템을 개발하였다. 따라서 본 연구는 현재 개발계획중이거나, 개발중인 EIS에 새로운 접근 방법으로 도움을 줄 수 있을 것이다. 수 있을 것이다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.344-354
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• 1994

In the development of executive information systems (EIS) the selection of an appropriate software package as a system building tool is regarded as a key technology. This paper attempts to shed some light on the evolving field of EIS software packages and provides a helpful Guideline for selecting the most suitable product by addressing significant considerations. A framework is presented that includes a six-step evaluation process: need analysis, team building, vendor survey, identification of decision criteria, and building an evaluation model and its verification. The major evaluation criteria of the full-featured software include: special functionality, reporting, graphics. decision support capability user friendliness, general functionality physical requirements, communication linkage, vendor support, cost related factors, performance, and documentation capability. An illustrative model using the analytic hierarchy process (AHP) method is also discussed to prove the appropriateness of our approach.

• Journal of Electrochemical Science and Technology
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• v.4 no.4
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• pp.157-162
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• 2013

First of all, we express our deepest sympathies for the passing of Professor Su-Moon Park. In the present paper, an electrochemical impedance spectroscopy (EIS), which Professor Su-Moon Park also used frequently for the investigation of electroconducting polymer, is introduced as a recent evaluation tool for a commercially available lithium-ion battery (LIB). The paper surveys how to design equivalent circuits while explaining physical and chemical phenomena in the LIB and how to get more accurate impedance spectra with varying the measuring temperatures. Additionally, a square current EIS (SC-EIS) technique, which we have suggested, is introduced for the larger LIB system as a promising technique for the future.

• Corrosion Science and Technology
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• v.11 no.5
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• pp.165-172
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• 2012

The corrosion resistance of epoxy-coated carbon steel was evaluated. The carbon steel surface was subjected to different treatment methods such as steel grit blasting with different size, steel shot ball blasting and power tool treatment. To study the effect of the treatments, the topology of the treated surface was observed by optical 3D microscopy and a pull-off adhesion test was conducted. The corrosion resistance of the epoxy-coated carbon steel was further examined by electrochemical impedance spectroscopy (EIS) combined with hygrothermal cyclic testing. The results of EIS indicated that the epoxy-coated carbon steel treated with steel grit blasting showed an improved corrosion resistance compared to untreated epoxy-coated surfaces or surfaces subjected to shot ball blasting and power tool treatments.

• Journal of Power Electronics
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• v.16 no.2
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• pp.695-703
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• 2016

A fuel cell power conditioning system for online diagnosis and load leveling under the condition of varying load is developed in this study. The proposed system comprises a unidirectional boost converter and a bidirectional buck-boost converter with a battery. The system operates in two different modes. In normal mode, the bidirectional converter is utilized for load leveling; in diagnostic mode, it is utilized to control load voltage while the boost converter generates perturbation current to implement the online diagnosis function through in-situ electrochemical impedance spectroscopy (EIS). The proposed method can perform EIS for a fuel cell under varying-load conditions with no influence on the load. The validity and feasibility of the proposed system are verified by experiments, and the design procedure of the proposed system is detailed.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.224-224
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• 2014

최근 기존의 아연 도금 강판의 성능을 향상시키기 위하여 다른 금속과의 합금 박막의 연구가 활발히 진행 중에 있다. 기존 아연 도금 강판에 비해 Mg를 함유한 Zn-Mg 합금 박막이 내식성이 우수하다고 알려져 있으며, 본 연구에서는 다양한 Mg 함량의 Zn-Mg 합금 타겟을 사용하여 Zn-Mg 박막을 합성하였다. 합성된 박막들의 내식성을 평가하기 위해서 Electrochemical Impedance Spectroscopy (EIS) 분석을 실시하였으며, 도출된 Nyquist plot 과 Bode phase angle plot 결과를 등가회로 피팅과 시뮬레이션을 실시하여 Mg 함량에 따른 Zn-Mg 박막의 내식성을 비교 분석하였다. Zn-Mg 박막은 Mg 함량이 증가할수록 내식성 또한 증가하였으며, 이는 Mg 함량에 따라 치밀해지는 미세구조에 의한 것으로 판단된다.

• Corrosion Science and Technology
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• v.5 no.1
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• pp.15-22
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• 2006

The introduction of two-grid inside a conventional process system produces a reactive coating deposition and increases metal ion ratio in the plasma, resulting in denser and smoother films. The corrosion behaviors of TiN coatings were investigated by electrochemical methods, such as potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) in deaerated 3.5% NaCl solution. Electrochemical tests were used to evaluate the effect of microstructure on the corrosion behavior of TiN coatings exposed to a corrosive environment. The crystal structure of the coatings was examined by X-ray diffractometry (XRD) and the microstructure of the coatings was investigated by scanning electron microscopy (SEM) and transmission electron spectroscopy (TEM). In the potentiodynamic polarization test and EIS measurement, the corrosion current density of TiN deposited by two grid-attached magnetron sputtering was lower than TiN deposited by conventional magnetron type and also presented higher Rct values during 240 h immersion time. It is attributed to the formation of a dense microstructure, which promotes the compactness of coatings and yields lower porosity.

• Corrosion Science and Technology
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• v.15 no.2
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• pp.69-77
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• 2016

In the present study, polyester-melamine coating systems with natural wood fiber (NWF) were prepared and the effects of NWF on the corrosion protectiveness of the polyester-melamine coating were examined using EIS analysis. From the results, higher average surface roughness was observed with increase of NWF content. Water diffusivity and water uptake into the polyester-melamine coatings with NWF were much higher than that into the pure polyester-melamine coating. The decrease in the impedance modulus |Z| was associated with the localized corrosion on carbon steel, confirming that corrosion protection of the polyester-melamine coatings with NWF well agrees with its water transport behavior.