• Title/Summary/Keyword: protection ability

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A Study on Ulraviolet-cut Ability of Silk Fabric Dyed with Natural Dyestuffs (천연염재의 자외선 차단성능 연구)

  • 김월순;최인려
    • The Research Journal of the Costume Culture
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    • v.12 no.1
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    • pp.1-11
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    • 2004
  • This study was carried out on the process of natural dye substances which can flock ultraviolet rays without producing harmful substances by pollution, germs, etc. While making human body safe in contact, extracting Gardenia, Sappan wood, Radix scutellariae, Cromwell, Mugwort, Gallnut, Lac. Those are used for curing diseases, dyeing silk cloth with those extracts, and examining the color fastness, Ultraviolet protection. From this study, the following conclusion was produced. Brightness was lower in pre-mordanting than in post. And color difference showed that Radix scutellariae was the highest. Aluminum-mordanting showed a higher color difference than Fe. Colorfastness to washing was high in all samples, and the degree of color-changing by washing was the highest in the sample dyed by gardenia, pre-mordanted gallnut showed the highest degree. Colorfastness to perspiration was the highest in gardenia. UV-A test showed that all samples a high rate of 85% or higher compared with test white cloth. Especially, post-mordanted radix scutellariae, pre-mordanted gallnut and post-mordanted sappanwood showed a superior blocking rate.

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Development of TCAD calibration methodology for ESD simulation and TLP measurement analysis (ESD 시뮬레이션과 TLP 측정해석을 위한 TCAD calibration methodology 개발)

  • 염기수
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.11a
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    • pp.538-542
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    • 1999
  • New methodology of parameter calibration is proposed for TCAD simulation of nMOSFET in ESD(Electro-Static Discharge) protection circuits. Recently, TLP(Transmission Line Pulsing) measurement has received great interest due to the ability of analyzing device characteristics when ESD pulse is applied to the ESD pulse is applied to the ESD protection circuits. This paper describes new methodology of analyizing TLP measurement, TCAD simulation, and parameter calibration.

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Optimal protection by using Parametric Protection Ability Index (파라미터를 이용한 배전계통 보호능력 평가 및 최적화)

  • Shin, J.H.;Hyun, S.H.;Lim, S.I.;Lee, S.J.;Choi, I.S.;Jin, B.G.
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.202-204
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    • 2003
  • This paper suggests an optimal parameter setting method by use of parametric protectability index, as the objective function. In this paper, a gradient based optimization method is used under the assumption that the initial values of a parameter is in a convex set including the optimal value, which is verified by a plenty of simulation studies. The proposed method is applied to a sample distribution network to shows its effectiveness.

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Circuit Improvement of 345kV Bus bar protection panel for Human Error Prevention in the event of Field Test (전력설비 시험시 인적실수 방지를 위한 345kV 모선보호 배전반 회로개선)

  • Kim, In-Sup;Lee, Jong-Seok;Jung, Si-Hwan;Kang, Dae-Eon;Seung, Jae-Hyeun
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.675-676
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    • 2007
  • This Paper presents circuit improvement of 345kV Bus bar protection panel by using VDD (Voltage disturbance detection) relay with distinctive ability between human error in the field test and real facility faults. Therefore, We expect that this improvement of circuit helps decrease of blackout coming from human error. In order to guarantee electric power system reliability, consistent study of human error prevention in the event of field test is necessarily required

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Characteristics of Interruption Ability in DC Circuit Breaker using Superconducting Coil (초전도 코일을 이용한 DC 회로 차단기의 차단 능력 특성)

  • Jeong, In-Sung;Choi, Hye-Won;Youn, Jeong-Il;Choi, Hyo-Sang
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.68 no.1
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    • pp.215-219
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    • 2019
  • Development of DC interruption technology is being studied actively for enhanced DC grid reliability and stability. In this study, coil type superconductor DC circuit breaker was proposed as DC interruption. It is integration technology that combined current-limiting technique using superconductor and cut-off technique using mechanical DC circuit breaker. Superconductor was applied to the coil type. In simulation, Mayr arc model was applied to realize the arc characteristic in the mechanical DC circuit breaker. PSCAD/EMTDC had used to model and perform the simulation. To find out the protection range of coil type superconductor DCCB, the working operation have analyzed based on the rated voltage of DCCB. The results confirmed that, according to apply the limiting device, the protection range was increased in twice. Therefore, the probability of failure of interruption has lowered significantly.

Current Source ZCS PFM DC-DC Converter for Magnetron Power Supply

  • Kwon, Soon-Kurl
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.7
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    • pp.20-28
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    • 2009
  • This paper presents the design of zero current switching ZCS pulse frequency modulation type DC-DC converter for magnetron power supply. A magnetron serving as the microwave source in a microwave oven is driven by a switch mode power supply (SMPS). SMPSs have the advantages of improved efficiency, reduced size and weight, regulation and the ability to operate directly from the converter DC bus. The demands of the load system and the design of the power supply required to produce constant power at 4[kV]. A magnetron power supply requires the ability to limit the load current under short circuit conditions. The current source series resonant converter is a circuit configuration which can achieve this. The main features of the proposed converter are an inherent protection against a short circuit at the output, a high voltage gain and zero current switching over a large range of output power. These characteristics make it a viable choice for the implementation of a high voltage magnetron power supply.

Single Stage PFC Flyback Converter Using Top Switch (Top 스위치를 이용한 단일 전력단 역률개선 플라이백 컨버터)

  • Lim Chang Seob;Kwon Soon Kurl;Lee Hyun Woo;Kim Eun Soo
    • Proceedings of the KIPE Conference
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    • 2001.07a
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    • pp.669-672
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    • 2001
  • Generally, previous converter is divided into two categories to get high power factor and good output regulation. These two categories can be combined a category with a main switch. These converter is called Single Stage PFC Converter. This approach has good electrical characteristics of high power factor and fast output voltage regulation. The cost and size are important factor to design the converter in low power system. Even single stage can reduce the size and cost, but this approach needs to have additional circuit like control, PWM circuit. To improve these demerits, Top switch is one of good choice In reduce and size in low power single stage converter. Because it has the ability of current limit, thermal protection, oscillator, control circuit as well as a main switch ability.

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Application of Fault Location Method to Improve Protect-ability for Distributed Generations

  • Jang Sung-Il;Lee Duck-Su;Choi Jung-Hwan;Kang Yong-Cheol;Kang Sang-Hee;Kim Kwang-Ho;Park Yong-Up
    • Journal of Electrical Engineering and Technology
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    • v.1 no.2
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    • pp.137-144
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    • 2006
  • This paper proposes novel protection schemes for grid-connected distributed generation (DG) units using the fault location algorithm. The grid-connected DG would be influenced by abnormal distribution line conditions. Identification of the fault location for the distribution lines at the relaying point of DG helps solve the problems of the protection relays for DG. The proposed scheme first identifies fault locations using currents and voltages measured at DG and source impedance of distribution networks. Then the actual faulted feeder is identified, applying time-current characteristic curves (TCC) of overcurrent relay (OCR). The method considering the fault location and TCC of OCR might improve the performance of the conventional relays for DG. Test results show that the method prevents the superfluous operations of protection devices by discriminating the faulted feeder, whether it is a distribution line where DG is integrated or out of the line emanated from the substation to which the DGs are connected.

Development of ACL Modul For Agent Communication in Auto-Adaptive OCR Agent (자율적응형 과전류계전기 에이전트의 통신을 위한 ACL모듈 개발)

  • Oh, T.W.;Lee, S.J.;Choi, M.S.;Kim, K.H.;Lim, S.I.;Min, B.W.;Lee, H.W.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.193-195
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    • 2002
  • In this paper, a communication module is proposed to be applied to communication between over current relay (OCR) agents in multi agent protection system. A multi agent system can achieve a global goal beyond the ability of each individual agent by working together, in which it is the prerequisite for each agent to be able to exchange or share information or processing status with other agent. The proposed communication module is purposed to enable not only each agent to bring about its own goal, but also the whole protective system to provide much improved coordinated protection. It is applied to a self adaptive protection system for a distribution network using multi agent concept to show its effectiveness.

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Antagonistic Potential of Fluorescent Pseudomonads and Control of Crown and Root Rot of Cucumber Caused by Phythophtora drechsleri

  • Shirzad, Akbar;Fallahzadeh-Mamaghani, Vahid;Pazhouhandeh, Maghsoud
    • The Plant Pathology Journal
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    • v.28 no.1
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    • pp.1-9
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    • 2012
  • In this study, 200 isolates of fluorescent pseudomonads were isolated from different fields of East and West Azarbaijan and Ardebil provinces of Iran. These bacterial isolates were screened on the basis of a dual culture assay, the presence of known antibiotic genes, and their ability to successfully colonize roots and to promote plant growth. Twelve isolates exhibited 30% or more inhibition of mycelia growth of $P.$ $drechsleri$. Genes encoding production of the antibiotics 2,4-diacetylphloroglucinol, phenazine-1-carboxylic acid, and pyoluteorin were detected in some strains but none of the strains possessed the coding gene for production of antibiotic pyrrolnitrin. In an $in$ $vitro$ test for root colonization, the population density on roots of plants treated with most of the above strains was more than 6 $\log_{10}$ CFU $g^{-1}$ roots, with a maximum of 7.99 $\log_{10}$ CFU $g^{-1}$ roots for strain 58A. Most of the strains promoted significant plant growth in comparison to non-treated controls. In green house studies, the percentage of healthy plants in pots treated with strains 58A and 8B was 90.8% and 88.7%, respectively. The difference between these treatments and treatment with the fungicide metalaxyl was not significant.