• Journal of Electrochemical Science and Technology
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• v.13 no.2
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• pp.167-176
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• 2022

Electrochemical impedance spectroscopy (EIS) is a unique non-destructive technique employed to analyze various devices in different energy storage applications. It characterizes materials and interfaces for their properties in heterogeneous systems employing equivalent circuits as models. So far, it has been used to analyze the performance of various photovoltaic cells, fuel cells, batteries, and other energy storage devices, through equivalent circuit designing. This review highlights the diverse applications of EIS in fuel cells and specific parameters affecting its performance. A particular emphasis has been laid on the challenges faced by this technique and their possible solutions.

• Corrosion Science and Technology
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• v.8 no.2
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• pp.53-61
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• 2009

In this study, both evaluations by visual imaging for exterior view of coating and by EIS were executed for epoxy primer coated specimens deteriorated by accelerated test, and comparison and analysis were carried out for 2 evaluation methods. In the comparison between total damaged area ratio acquired by image processing method and deterioration point, higher deterioration points were appeared for rusted specimens than for non-rusted specimens. It is attributed that deterioration point per unit area ratio given for rust is higher than for peeling. In the comparison between total damaged area ratio and EIS result, impedance of coating was largely decreased as about TEX>$10^4{\Omega}{\cdot}cm^2$ or less when rust area ratio is more than about 0.1%, and blistering area ratio is more than about 3%. Charge transfer resistance ($R_{ct}$) and double layer capacitance ($C_{dl}$) values were appeared for all specimens except 2 ones, which shows that water is accumulated and steel substrate is corroded at coated film-steel interface. In the comparison between deterioration point and EIS result, more than 10 points as deterioration point were given for specimens of below $10^6{\Omega}{\cdot}cm^2$ of impedance at low frequency. For specimens deteriorated by NORSOK cyclic test, impedance was lowest of all, though deterioration point was not high. It is thought to be attributed that coating system and accelerated deterioration condition of cyclic tested specimens were different from those of main specimens. From the result, it is thought that coating resistance can be relatively more decreased than deterioration degree estimated from exterior view under more severe corrosion environment or in the present of more complex deterioration factors.

• Journal of the Korean Society for Library and Information Science
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• v.38 no.2
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• pp.239-259
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• 2004

The purpose of this study is to review the established research practices and managerial methods on the range of Knowledge that have been independently studied from the conventional information system (libraries) and the managerial information system (MIS, DSS and EIS) within the quantitative and the non-quantitative perspective. The information systems were developed through their own purpose since the 1950s and these days the corporate environments have become integrated due to the rapid creation and expansion of information. Therefore, to make fast decisions in this situation it is appropriate that these two systems, Library and the managerial information system, should be dealt within the same category. In other words, not only the quantitative data that become main sources of DSS or EIS, but also the qualitative data such as the text documents, video and audio data, which have been managed in the libraries and information centers and not extracted from the former, can be used as the new knowledge source. Also BSS/EIS can provide the splendid infrastructure for Knowledge Management(KM) while libraries/information centers manage the comprehensive range of explicit and tacit knowledge, which can be a facilitator or main driver for KM.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.12
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• pp.124-133
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• 2015

Electro interstitial scan shows potential as a non-invasive screening method. It can discriminate some diseases based on electric current response to induce low intensity direct current to limbs or local area of body. DDFAO was invented in France and it is claimed that multi-channel EIS(Electro Interstitial Scan) is useful for various diseases, especially, diagnoses of endocrine system such as diabetics are very effective. In this study, we verified the repeatability and sensitivity of DDFAO by using a RC phantom model and its clinical usefulness using data obtained from normal and diabetes subject groups. As a result, it showed the repeatability and the output change according to change of phantom characteristic, but it was hard to distinguish normal and patient groups non-invasively with just six surface electrodes of DDFAO. The repeatability and the clinical accuracy was not sufficient for screening or diagnostic purposes, as well. In spite of the results with low repeatability and accuracy conducted in this study, we still need further investigations to improve the EIS-based measurement method; EIS is very convenient and simple and it shows potential as a screening tool of the whole body health conditions rather than localized disease diagnosis.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.4
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• pp.164-168
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• 2003

The initial stage of copper electrodeposition has been known to be very important role for morphology and physical properties after final growth. The factors affecting the nucleation are electrode, current density, electrolyte and temperature. Current studies has illuminated the initial nucleation of copper electrodeposition in the viewpoint of the surface status of electrode and analyzed using EIS and SEM observation

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.675-678
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• 1996

While a large number of firms have already developed and use an executive information system (EIS) effectively, some firms are reluctant to build one for lack of appropriate and well-organized guidance on how to achieve their own project. In this paper we suggest an EIS development methodology by testing five research hypotheses. As a result, we can conclude that prototyping should be applied to be combined with the SDLC. Moreover the preliminary stage accomplished the highest score in the eight-stage process.

• Communications of Mathematical Education
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• v.18 no.2 s.19
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• pp.441-451
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• 2004

수학의 내용을 학생에게 지도할 때 기계적인 계산법칙을 가르치는 것보다 개념을 이해할 수 있도록 돕는 것은 교사의 중요한 역할이다. 그 동안 연구를 통해 정수를 지도하기 위한 모델들은 꽤 많이 알려져 왔으나 이 모델들을 학생에게 직접 적용하였을 때 일어나는 현상을 파악한 연구는 그리 많지 않다. 따라서 본 연구는 상위, 중위권 초등학교 5학년을 대상으로 EIS이론에 바탕을 둔 정수의 모델을 통해 학생들이 정수의 개념을 어떻게 형성하고 그 과정에서 어떤 오류를 나타내는지, 또 무엇을 가장 어려워하는지 등 그 학습과정을 조사하였다.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.341-343
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• 2002

According to the computerization of railway signalling equipments, the need of communication protocol for interface between these equipments is increasing. In this paper the research results on communication protocol structure for interface between LDTS(Local Data Transmission System) and EIS(Electronic Interlocking System) is represented.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.907-913
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• 1998

Corrosion behavior of steel reinforcements embedded in concrete containing various chloride ion concentrations was investigated by an electrochemical impedance spectroscopy(EIS). Chloride ions were introduced into the concrete by dissolving the NaCl and $CaCl_2$ in the water with a given weight of cement. Based on the impedance parameters measured by EIS, more complete equivalent circuit, a schematic physical model, and the mechanism of concrete reinforcement corrosion were suggested. By the implement of experimental impedance parameters obtained from the model with corresponding CNLS-fitting data, the corrosion rate of steel reinforcement with chloride ions could be predicted.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2425-2430
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• 2009

Dye-sensitized solar cell(DSC) is composed of a dye-adsorbed nanoporous $TiO_2$ layer on fluorine-doped tin oxide(FTO) glass substrate, electrolyte, and platinium doped counter electrode. Among these, a dye-absorbed nanoporous $TiO_2$ layer plays an important role in the performance of the DSC because the injected electrons from excited dye molecules move through this layer. And the condition of $TiO_2$ layer such as the morphology and thickness affects on the electron movement. Therefore, the performances and the efficiency of DSC change as the thickness of $TiO_2$ layer is different. Electrochemical Impedance Spectroscopy(EIS) is the powerful analysis method to study the kinetics of electrochemical and photoelectrochemical processes occurring in the DSC especially the injected electron movements. So we analyzed the DSCs with different $TiO_2$ thicknesses by using EIS to understand the influence of the $TiO_2$ thickness to the performance of the DSC clearly. Finally, we got the EIS analysis on the DSC with different $TiO_2$ thickness from the internal resistance of the DSC, the electron life time and the amount of dye molecules.