• 전기화학회지
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• 제12권1호
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• pp.1-10
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• 2009

This article reviewed transport behaviours of electroactive species in ionic compounds, focusing on chemical diffusion of Li through the transition metal oxide in a current flowing condition. For this purpose, a distinction has been first briefly made between migration and diffusion with respect to current, driving force and charge of electroactive species considered. Then, the equations for chemical diffusion are derived theoretically in open-circuit and current flowing conditions. Finally, the experimental methods such as ac impedance spectroscopy and current (potential) transient techniques are described in details for characterising chemical diffusion. In addition, the role of the thermodynamic enhancement factor in chemical diffusion is discussed.

• 동력기계공학회지
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• 제9권4호
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• pp.110-117
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• 2005

Underwater wet arc welds were experimentally performed on 11mm thick KR-RA steel plate using six different types of flux coated electrodes of 4.0mm diameter, KSKR, KSKT, USBL, JPUW, UWEA and UWEB. From analysis of bead appearance, detachability of weld slag, spatter occurrence and arc stability, JPUW gives the best result, and UWEB is superior to KSKR and KSKT. By experimental result of hardness distribution on the weld bonds, UWEB weld has the narrowest bond structure which is probable condition to get the best mechanical properties of weld. UWEB and JPUW welds have more even hardness distribution across weld deposit and base metal. Upon polarization test to measure the respondency of corrosion, the electrode of UWEB shows the most excellent degree due to the low open circuit potential difference.

• Journal of Communications and Networks
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• 제9권4호
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• pp.368-376
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• 2007

The large potential bandwidth available in wavelength-division multiplexed optical networks makes this technology of crucial importance for satisfying the ever increasing capacity requirements of the next-generation Internet. In this scenario, the routing and wavelength assignment(RWA) problem that concerns determining the optical paths and wavelengths to be used for connection establishment in a wavelength-routed network, is still one of the most important open issues. In this paper we propose a new online dynamic grooming-capable RWA heuristic scheme working on wavelength division multiplexing(WDM) networks as a multistage selection process. The proposed algorithm is transparent with respect to the presence of wavelength converters, achieves very low connection rejection ratios with minimal computational complexity and is appropriate for the modern multilayer optical circuit and wavelength switched networks with sparse wavelength conversion capability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1409-1412
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• 1994

The electrodes for Phosphoric Acid Fuel Ceil were fabricated as a condition of PTFE contents in electrocatalyst layer and sintering temperature in the range of 25 -- 65 wt% and 310 -- $390^{\circ}C$, respectively. For the fabricated electrode, the accelation testing of cathode half cell at open circuit potential was investigated. While the performance of electrode showed maximum at the low level of PTFE contents in the initial stage of accelation testing, the maximum performance was shifted to higher PTFE contents of 45wt% after 24hrs accelation testing.

• 전기학회논문지
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• 제59권7호
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• pp.1259-1264
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• 2010

This paper was researched about effectiveness of the electrochemical cell which is composed of the sea water and the Cu/Zn electrode. The electric potential difference between copper and zinc finally reached 0.51 volts. Short current decreased with time. It might depend on the electromotive force decreasing. Confirmed the load resistance and electrode affect in electromotive force and electric current. The resistance which shows a maximum output power was 20[$\Omega$], and the maximum output power from this resistance was evaluated as 0.736mW. In order to calculate the energy which creates from electrochemical cell, charging voltage of the capacitor with various capacitance was investigated. It was found that energy harvesting possibility of the cell which is made of a sea water electrolyte and the copper/the zinc.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.262-263
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• 2019

In this study, a sensor for detecting corrosion of rebar embedded in reinforced concrete structures was fabricated and its performance was verified. In order to monitor the open circuit potential(OCP) of the rebar embedded in reinforced concrete, a concrete embedded solid electrode was constructed as a sensor using MnO2. The OCP of the rebar could be observed using a sensor and a data logger. The decrease of the OCP to -510mV (vs.MnO2) or less was judged to be corrosion of the rebar. Since it is a solid-mediated sensor, it is more stable and durable than an electrode using an aqueous solution, and it is considered that the corrosion state of the rebar can be monitored for a long period of time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1064-1066
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• 2004

This paper deals with analysis of a 3-phase high speed machine with diametrically magnetized rotor. The field equations due to magnet and stator windings are established in terms of vector potential and 2-d polar coordinate systems and then, characteristic equation of torque and back emf are derived by using field equations. Finally, this paper predicts open-circuit field, armature reaction field distributions, field distributions on load, torque and back emf distributions from those of equations. Results are compared with predictions from corresponding finite element analyses.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권12호
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• pp.576-585
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• 2005

This paper deals with the electromagnetic field analysis of slotless brushless permanent magnet machines with three different magnetization patterns such as Halbach, parallel and radial magnetization. The magnetization modeling of Halbach, parallel and radial magnetization is performed analytically. And then, analytical solutions for open-circuit field distributions, armature reaction field distributions, flux linkages due to PMs and stator windings, torque, back-emf and inductance are derived in terms of magnetic vector potential and two-dimensional (2-d) polar coordinate systems. The analytical results are validated extensively by finite element (FE) analyses. The magnet volume required in order to produce identical flux density is compared with each magnetization. Finally, analytical solutions and derivation procedures of those presented in this paper can be applied to slotless and slotted brushless permanent magnet AC and DC machines.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.202-205
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• 1997

We investigated grain boundary effect for terrestrial applications of solar cell\ulcorner with low cost, large area, and high efficiency. Grain boundaries are known as potential barriers and recombination centers for the photo-generated charge carriers, which make it difficult to achieve a high efficiency cell. To reduce these effects of grain boundaries, we investigated various influencing factors such as thermal treatments, various grid patterns, selective wet etchings for grain boundaries, buried contact metallizations along grain boundaries, and use of metallic thin films. From the various grid patterns we learned that the series resistance of solar cell reduced open circuit voltage and consequently decreased the cell efficiency. This paper describes the effect of various grid patterns and the employment of metallic thin films for a top electrode.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2007년도 추계학술대회 논문집
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• pp.87-88
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• 2007

무전해 구리 도금 공정에서 첨가제로 사용되는 HIQSA 화합물이 Damascene 공정을 이용한 60nm급 trench 패턴 내 무전해 구리 배선 형성 과정에 미치는 효과를 전기 화학적 기법과 광학적 기법을 이용하여 관찰하였다. HIQSA 농도별 open circuit potential의 변화를 관측한 결과, 3ppm 수준으로 첨가되었을 때, 무전해 도금 과정 중 가장 안정한 전위가 유지됨을 볼 수 있었다. 무전해 도금액 내 HIQSA 농도가 높아짐에 따라 구리 도금층의 두께는 지수적으로 감소하였으며, 표면의 결정 크기도 감소하였다. 60nm급 trench 내 무전해 구리 도금 시, 용액 내 침적 시간 60초가 무결함 superconformal copper filling을 얻기 위한 최적 시간이었다.