• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1188-1195
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• 2014

This paper presents an analytical technique for reliability evaluation of electrical distribution network (EDN) containing distributed generation (DG). Based on hierarchical levels of circuit breaker controlling zones and feeder sections, a directed-relation-graph (DRG) for an END is formed to describe the hierarchical structure of the EDN. The reliability indices of EDN and load points can be evaluated directly using the formed DRG, and the reliability evaluation of an EDN containing DGs can also be done without re-forming the DRG. The proposed technique incorporates multi-state models of photovoltaic and diesel generations, as well as weather factors. The IEEE-RBTS Bus 6 EDN is used to validate the proposed technique; and a practical campus EDN containing DG was also analyzed using the proposed technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9A
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• pp.882-888
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• 2010

Vehicular Ad-Hoc Networks (VANETs) using inter-vehicle communication can potentially enhance traffic safety and facilitate many vehicular applications. Therefore, this paper proposes an inter-vehicle routing protocol called Junction-Assisted Routing (JAR) that uses fixed junction nodes to create the routing paths for VANETs in city environments. JAR is a proactive routing protocol that uses the Expected Transmission Count (ETC) for the road segment between two neighbor junctions as the routing paths between junction nodes. Simulation results showed that the proposed JAR protocol could outperform existing routing protocols in terms of the packet delivery ratio and average packet delay.

• Journal of Power Electronics
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• v.16 no.1
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• pp.388-397
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• 2016

An error-compensated pulse width modulator (ECPWM) is proposed to improve the baseband harmonic performance and the switching loss of voltage source inverters (VSIs). Selecting between harmonic distortion and switching loss is a design tradeoff in the conventional space vector pulse width modulation. In this work, an accumulated difference in produced and desired phase voltages is considered to adjust the reference signal. This mechanism can compensate for the voltage error in the previous carrier period. With error compensation every half-carrier period, the proposed ECPWM allows one-half reduction in carrier frequency without scarifying baseband harmonic distortion. The proposed modulator is applied to a three-phase VSI with R-L load and a motor-speed-control system for experiments. The measured efficiency and operating temperature of switches confirm the effectiveness of the proposed scheme.

• Transactions on Electrical and Electronic Materials
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• v.17 no.1
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• pp.33-36
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• 2016

In the present work, a Ni-doped indium zinc oxide (NIZO) film and its multilayers with Ag layers were investigated as transparent conducting electrodes for liquid crystal display (LCD) applications, as a substitute for indium tin oxide (ITO) electrodes. By interposing the Ag layer between the NIZO layers, the loss of the optical transmittance occurred; however, the Ag layer brought enhancement of electrical sheet resistance to the NIZO/Ag/NIZO multilayer electrode. The twisted nematic cell based on the NIZO/Ag/NIZO multilayer electrode exhibited superior electro-optical characteristics than those based on single NIZO electrode and was competitive compared to those based on the conventional ITO electrode. An LCD-based NIZO/Ag/NIZO multilayer electrode may allow new approaches to conventional ITO electrodes in display technology.

• Tribology and Lubricants
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• v.21 no.3
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• pp.130-135
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• 2005

Dry sliding wear resistance of DLC coated silicon disk with different surface roughness has been evaluated using a ball-on-disk sliding tester. It was found that the transfer layer formed on steel ball produced a low friction regime and the formation of transfer layer was more active with increasing the substrate surface roughness. Wear life of DLC coating was increased as increasing the real area of contact.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1235-1240
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• 2003

선박이 배출하는 안정수(ballast water)는 외부로부터 유해 생물들이 유입되어 전파해 오는 주요경로로써, 해양환경 변화를 초래하는 매우 중요하고 위험한 일중의 하나이다. 그러나 이에 대한 효과적인 처리방법은 아직까지도 미흡한 상태이다. 선박 안정수에 포함되어 타지역으로부터 옮겨지는 외래침입생물 처리방안의 하나로, 강 전리방전 기술을 적용하여 고 밀집 산소와 물분자로부터 고농도 수산자유기(OH: hydroxyl radical)를 전리, 발생시켜서 활성입자를 신속히 확산시켜 비교적 낮은 수산기농도하에서 유해성 침입생물을 소멸 처리하는 환경 친화적 녹색 청정처리방법을 제안하였다. 제안된 기술은 대상물의 처리 후 부수적으로 발생할 수 있는 처리잔류물이 전혀 발생하지 않으며, 화학 약제를 사용하지 않는 저렴한 처리방법으로 선박안정수의 침입생물을 안전하게 처리할 수 있는 자연치유적 신기술이다.

• Bulletin of the Korean Chemical Society
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• v.13 no.1
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• pp.30-32
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• 1992

The apparent depth of space charge region on the ZnO $(10{\bar{1}}0)$ surface in chemisorption of oxygen has been estimated from the capacitance of two contacting faces. When the sample (donor concentration: $2.4{\times}10^{22}\;m^{-3}$) was evacuated at 773 K for 1 hr the depth reached to 40-100 ${\AA}$ depending on sample assembly. Admission of oxygen to the sample resulted in an increase of the depth to 3600 ${\AA}$ where the increment was greater at higher oxygen pressure between 6.6-1600 $N/m^2$. Admission of CO to the sample previously exposed to oxygen yields a decrease in the depth. The results of the measurement support that oxygen is adsorbed as an acceptor on ZnO $(10{\bar{1}}0)$.

• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.625-628
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• 1991

Using uniform flat plate-like samples of ZSM-5 zeolites, diffusion coefficients were measured volumetrically for the diffusion of xylene, ethyltoluene and diethylbenzene by direct measurement of sorption rate. Toluene disproportionation over H(100)-, K(72)-and Cs(82)-ZSM-5 at 773 K and toluene methylation, toluene ethylation and ethylbenzene ethylation over Cs(75)-ZSM-5 at 623 K were carried out. The selective formation of para xylene during the toluene disproportionation, presumably due to the increased tortuosity over Cs-ZSM-5, could be explained by smaller diffusion coefficient in Cs-ZSM-5 than in K-and H-ZSM-5. The para selectivity increased in the order; toluene methylation < toluene ethylation < ethylbenzene ethylation. As the chain length of the alkyl substituent in dialkylbenzenes is increased, the para selectivity of the products was improved. It may be attributed to the differences in the ratios of diffusion coefficient of para products to that of ortho ones. Diffusion coefficient of m-xylene was about 1 order of magnitude smaller than that of o-xylene.

• Computers and Concrete
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• v.16 no.2
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• pp.275-285
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• 2015

This paper reports the results of an experimental study on the compressive strength and the stress-strain curve (SSC) of recycled fine glass aggregate concrete with different replacement percentages of recycled fine glass aggregate. The results show that the recycled fine glass aggregate contents have significant impact on the workability, compressive strength, the elastic modulus, the peak and the ultimate strains of recycled fine glass aggregate concrete. Analytical expressions for the stress-strain relationship of recycled fine glass aggregate concrete are given, which can satisfactorily describe the effect of the recycled fine glass aggregate on the SSC.

• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.67-76
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• 2001

The "crescent-egg" a new spontaneous mutant was detected in a white egg strain k37. Studies were carried out the linkage analysis, to investigate phenotypic characteristics and biochemical analysis of haemolymph and ovarian protein. The mutant, ore was independent from 20 linkage groups P(2), Ze(3),L(4), oc(5), sn8), Ia(9), w-1(10), K(11), ch(13), U(14), bl(15), cts(16), bts(17), mln(18), nb(19), oh(20),Lan(21), or(22), tub(23) and Xan(27). The fertilization, hatchability and larval growth were not different from the those of normal eggs. The content and composition of yolk protein were similared to normal eggs. Scanning electron microscopy revealed the areal specific structure in dorsal region of egg-shell of cre mutant. Analysis of chorion protein by isoelectrofocusing(IEF), was resolved no difference in the composite of the chorion protein. We conclude that the egg mutant ere is expressed only in the egg-shape formation and region specific determination.