• Title/Summary/Keyword: shed amount

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An Adaptive Undervoltage Load Shedding Against Voltage Collapse Based Power Transfer Stability Index

  • Nizam, Muhammad;Mohamed, Azah;Hussain, Aini
    • Journal of Electrical Engineering and Technology
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    • v.2 no.4
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    • pp.420-427
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    • 2007
  • This paper highlights the comparison of a proposed methods named adaptive undervoltage load shedding based PTSI techniques for undervoltage load shedding and two previous methods named Fixed Shed Fixed Delay (FSFD) and Variable Shed Variable Delay (VSVD) for avoiding voltage collapse. There are three main area considerations in load shedding schemes as the amount of load to be shed, the timing of load shedding event, and the location where load shed is to be shed. The proposed method, named as adaptive UVLS based PTSI seem to be most appropriate among the uncoordinated schemes. From the simulation result can be shown the Adaptive UVLS based PTSI give faster response, accurate and very sensitive control for the UVLS control technique. This technique is effectively when calculating the amount to be shed. Therefore, it is possible to bring the voltage to the threshold value in one step. Thus, the adaptive load shedding can effectively reduce the computational time for control strategy.

The development of frequency relaying algorithm considering a transient stability (과도 안정도를 고려한 주파수 계전 알고리즘 개발)

  • Lee, B.H.;Kim, C.H.
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.282-283
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    • 2006
  • A frequency relaying algorithm which is used system separation and load shedding to improve transient stability is proposed. The algorithm can trip the generator and shed load in the abnormal frequency condition. The computer simulations of load flow analysis is used to determine the amount of load to be shed in an under frequency condition. Furthermore dynamic brake energization in the simulation is performed for the control of overfrequency.

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Efficacy of Fipronil-applied Canine Hair against House Dust Mites (Fipronil 적용 개 피모의 집먼지 진드기의 살진드기에 대한 효과)

  • 강선미;이충호;박옥지;임지혜;윤희정;권오경
    • Journal of Veterinary Clinics
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    • v.19 no.2
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    • pp.215-218
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    • 2002
  • It is known that house dust mites which settle on sofa, carpet, and dust in the house ignite asthma and allergic rhinitis. Dermatophagoides farinae and Dermatophagoides pteronyssinus distribute widely and densely in Korea. In this study we carried out to identify that shed hair of dogs which was applied topically with fipronil ($\Frontline^{circledR}$) kill house dust mites. We co-cultured house dust mites with fipronil-applied hair of dog during 12 hours, and then compared the death rate of mites here with that cultured without hair. The larger amount of hair, the more mites were killed. The death rate of mites was higher than control significantly until 2 weeks after $\Frontline^{circledR}$ application. Hair which had been shed at 3 days after $\Frontline^{circledR}$ application always killed the smaller number of mites than not shed. The present study suggested that the use of $\Frontline^{circledR}$ to our pets control house dust mites effectively.

Effects of Weaving Machine Characteristics on the Physical Properties of PET Fabrics (I) (직기 특성이 PET직물 물성에 미치는 영향(I))

  • 김승진;손준혁;강지만;박명환
    • Textile Coloration and Finishing
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    • v.16 no.4
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    • pp.26-35
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    • 2004
  • This study surveys the tension differences between Korean domestic and foreign looms and analyses fabric mechanical properties due to warp and weft tension differences using KES-FB system. Paper is divided by two parts. In this 1st paper, fabric is designed as 5 harness satin weave using 75d/36f warp and 100d/192f weft polyester filaments, and is woven by $Omega^\circledR$ rapier loom by Textec Co.Ltd and Picanol$-GTX^\circledR$ rapier loom by Picanol Co.Ltd respectively. These grey fabrics are processed on the same dyeing and finishing processes. Weavability is also analysed by measuring warp tension variation according to the warp position, the relationship between shed amount and the warp tension on one fixed heald frame is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

Effect of the Projectile and the Air-jet Weaving Machine Characteristics on the Physical Properties of Worsted Fabrics for Garment(I) -Tension Characteristics & Loom Mechanism- (프로젝타일과 에어제트 직기특성이 의류용 모직물 물성에 미치는 영향(I) - 장력특성과 직기 메커니즘 -)

  • Kim, Seung-Jin;Jung, Gee-Jin
    • Fashion & Textile Research Journal
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    • v.7 no.1
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    • pp.101-105
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    • 2005
  • This study surveys the warp and weft tension differences between projectile and air-jet looms and analyses the mechanical properties of worsted fabrics for garment with relation of these loom characteristics using KES-FB system. The paper is divided by two parts. In the 1st paper, the worsted fabric is woven as 5 harness satin weave using 1/40 Nm sirofil worsted warp yarn and 1/30 Nm worsted weft yarn by projectile(Sulzer) and air-jet looms(Picanol PAT and OMNI), respectively. The weavability is also analysed by measuring warp tension variation according to the warp position and weft tension of 3 kinds of looms. The relationship between shed amount and the warp tension is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

Effects of Rapier Weaving Machine Characteristics on the Physical Properties of Worsted Fabrics for Garment (I) - Tension Characteristics & Loom Mechanism - (래피어 직기 특성이 의류용 모직물 물성에 미치는 영향(I) - 장력특성과 직기 매카니즘 -)

  • Kim, Seung-Jin;Kang, Ji-Man
    • Fashion & Textile Research Journal
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    • v.6 no.6
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    • pp.765-771
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    • 2004
  • This study surveys the warp and weft tension differences among 3 types of rapier looms and analyses the mechanical properties of worsted fabrics for garment with relation of these looms characteristics using KES-FB system. Raper is divided by two parts. In the 1st paper, the worsted fabric is woven as 5 harness satin weave using 1/40 Nm sirofil worsted warp yam and 1/30 Nm worsted weft yam by rapier looms such as FAST-R, THEMA-11-E and PICANOL-GTX respectively. The weavability is also analysed by measuring warp tension variation according to the warp position and weft tension of 3 kinds of looms. The relationship between shed amount and the warp tension is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

Effects of Weaving Machine Characteristics on the Physical Properties of PET Fabrics (III) (직기 특성이 PET직물 물성에 미치는 영향(III))

  • Kim Seung Jin;Jin Young Dae;Kang Ji man;Jung Gee Jin
    • Textile Coloration and Finishing
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    • v.16 no.5
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    • pp.48-53
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    • 2004
  • This study surveys the tension differences between Textec and Vamatex looms and analyses fabric mechanical properties using KES-FB system according to warp and weft tension differences. Fabric is designed as 5 harness satin weave using 150d/48f warp and 200d/384f weft polyester filaments, and is woven by $Omega^{\circledR$-Panter rapier loom by Textec Co.Ltd and P1001es rapier loom by Vamatex Co.Ltd., respectively. These grey fabrics are processed on the same dyeing and finishing processes. Weavability is also analysed by measuring warp tension variation according to the warp position. The relationship between shed amount and the warp tension on one fixed heald frame is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

Analysis of Ultimate Rockfall Energy Resistance of CFT Rock Shed Main Frame (CFT 피암터널 주구조체의 극한 낙석에너지 저항능력 분석)

  • Moon, Jiho;Lee, Juho;Song, Jong-Keol
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.3
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    • pp.129-135
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    • 2021
  • Rock sheds are a type of rockfall protection facility that is installed on the road near steep slopes, where large amount of rockfall is expected. Rock sheds are generally designed to resist approximately 200 kJ to 3,000 kJ of rockfall energy. In a previous study, a new type rock shed structure having a concrete-filled tube (CFT) main frame was proposed. By using CFT as the main frame in a rock shed, rapid construction is possible. Additionally, high load carrying capacity and ductility can be achieved. The behavior of the proposed rock shed structure was studied via elastic analysis with the equivalent static load of rockfall energy as in a previous study. However, it is necessary to investigate the behavior of the proposed rock shed in more detail with a full 3D finite element (FE) model considering realistic rockfall load. The FE model for the CFT rock shed main frame was developed first in this study. Then, the resistance of the CFT rock shed main frame Under ultimate rockfall energy was investigated.

Studies on Botrytis cinerea Density in Packing Shed and Gray Mold Incidence Following Storage-Temperature in Exported Strawberry (수출딸기 선별장에서 잿빛곰팡이병원균 밀도조사와 저장온도에 따른 잿빛곰팡이병 발생 연구)

  • Kim, Da-Ran;Jeon, Chang Wook;kwak, Youn-Sig
    • The Korean Journal of Pesticide Science
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    • v.19 no.3
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    • pp.295-300
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    • 2015
  • Currently, amount of export strawberry has been continuously increased to ship many south Asia countries, including Hong Kong and Singapore. In the distribution process, significant damage to the quality has been caused depending on the environmental conditions. Gray mold disease caused by Botrytis cinerea has been known as major damage to the export strawberry, and the disease was caused during shipping and distribution to the final consumers. This study was performed to assess the relationship between pathogen density in packing shed and disease incidence of gray mold during storage period. Maximum gray mold disease incidence in storage period was up to 16% with low temperature condition ($4^{\circ}C$). At room temperature condition, the disease incidence reached up to 100% even densities of the pathogen spore were recorded relatively low in the packing shed. As results of the study, the correlation between pathogen density in the air and disease occurrence clearly clarified.

Measurement of R-134a Leakage from Vehicle Equipped Mobile Air Conditioning(MAC) System (실차를 이용한 자동차 에어컨 냉매 누출량 평가)

  • Kim, Ji Young;Seo, Chungyoul;Lee, Sangeun;Kim, Jeongsoo
    • Journal of Climate Change Research
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    • v.3 no.2
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    • pp.153-159
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    • 2012
  • CFC-12 used in mobile air conditioning(MAC) system has been replaced by R-134a, a type of HFC refrigerant, from 1991 to 1994. R-134a has since been widely used as a refrigerant of a mobile air conditioner. However, it is one of the six main green house gases listed in Kyoto Protocol, which makes it imperative to regulate its emission and develop alternative refrigerants. In this study, the concentration of leaked R-134a was measured using VT(Variable Temperature) shed and Running loss test shed to analyze the level of air conditioner refrigerant leaked in a vehicle. According to the analysis of the concentration of R-134a leaked from a vehicle parked, annual leakage amount of R-134a was in the range of 6.46~13.28 g/yr. The figure was similar with the leakage from the mobile air conditioning system currently used. In a study using the same vehicle model, a vehicle equipped with dual evaporation system had a higher leakage rate of refrigerant than a vehicle with a single evaporation system. It appears that the added fittings and joints of the dual evaporator system led to higher leakage rate. Besides, the analysis of the change in R-134a concentration under various car speed found that more refrigerant leaked under high speed(100km/hr) and but the volume of the wind did not affect to the variation of refrigerant leakage.