• Title/Summary/Keyword: LS-design

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A Study on Shielding characteristics of Cable used in High-efficiency Automobile (고효율 자동차용 고전압 케이블의 차폐특성에 관한 연구)

  • Lee, Bong-Yi;Lee, Sang-Seon;Yoon, Seung-Hoon;Park, Kyung-Hoon;Youn, Bok-Hee
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1892-1893
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    • 2007
  • Because High efficiency electric vehicles use electrical energy by an power source, radiated noise at high voltage cable bring on problems at other electric/electronic components. But, in order to insure shielding effectiveness increasing braid density infinitely, it is possible that the cost is more than one third of cost of manufacturing cable. Accordingly in this paper, we studied design of cost-effective and light shield cable using dual shielding system of braid and al-foil.

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A Strategy for Developing a Platform-based PCS (Platform 기반의 PCS 개발전략)

  • Joe, Injoon;Kang, Hohyun;Koh, Kwangsoo;Kim, Heejung;Kim, Younggeun
    • Proceedings of the KIPE Conference
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    • 2019.07a
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    • pp.435-436
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    • 2019
  • 본 논문은 Platform 기반의 PEBB(Power Electronics Building Block)을 이용한 계통연계형 에너지저장시스템(ESS) PCS의 개발전략과 효율적인 운용 방법에 대해 제안한다. Platform Design이란 표준제조 공정을 통해 다양한 제품을 만들어 내는 기술을 뜻한다. 이 Platform으로 생산되는 Modular PEBB(Power Electronics Building Block)을 이용하여 다양한 용량대의 제품에 대응할 수 있으며, 이를 통해 125kW에서부터 2MW제품까지 병렬확장이 가능하다. PCS의 Platform화로 시스템 용량 확장이 용이하며, 대량 생산이 가능하기 때문에 비용 측면에서의 장점이 있다. 그리고 부분 운전을 통해 운영 효율 향상과 PCS 수명을 늘릴 수 있다. 본 논문에서는 Platform 기반의 PCS의 물리적 및 제어적 구조를 설명하고, 개발전략의 방법에 대해 소개하고자 한다.

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Effect of inclusion of different levels of Leucaena silage on rumen microbial population and microbial protein synthesis in dairy steers fed on rice straw

  • Nguyen, Thien Truong Giang;Wanapat, Metha;Phesatcha, Kampanat;Kang, Sungchhang
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.2
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    • pp.181-186
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    • 2017
  • Objective: Leucaena leucocephala (Leucaena) is a perennial tropical legume that can be directly grazed or harvested and offered to ruminants as hay, silage, or fresh. However, Leucaena contain phenolic compounds, which are considered anti-nutritional factors as these may reduce intake, digestibility and thus animal performance. Therefore, the objective of this experiment was to determine effects of Leucaena silage (LS) feeding levels on rumen microbial populations, N-balance and microbial protein synthesis in dairy steers. Methods: Four, rumen fistulated dairy steers with initial weight of $167{\pm}12kg$ were randomly assigned to receive dietary treatments according to a $4{\times}4$ Latin square design. Treatments were as followings: T1 = untreated rice straw (RS; Control), T2 = 70% RS+30% LS, T3 = 40% RS+60% LS, and T4 = 100% LS. Dairy steers were fed rice straw and LS ad libitum and supplemented with concentrate at 0.2% of body weight/d. Results: Results revealed that the rumen microbial population, especially cellulolytic, proteolytic bacteria and fungal zoospores were enhanced in steers that received 60% of LS (p<0.05), whereas the amylolytic bacteria population was not affected by treatments (p>0.05). Protozoal population was linearly decreased with increasing level of LS (p<0.05). Moreover, N-balance and microbial protein synthesis were enhanced by LS feeding (p<0.05) and were the highest in 60% LS group. Conclusion: Based on this study, it could be concluded that replacement of RS with 60% LS significantly improved microbial population and microbial protein synthesis in diary steers.

Field Bus communication design in HVDC System (HVDC 시스템의 프로피버스 통신 디자인)

  • JIANG, LILI;LEE, YILHWA;MOON, JUNMO
    • Proceedings of the KIPE Conference
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    • 2013.11a
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    • pp.243-244
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    • 2013
  • This paper introduces the application of Profibus field bus communication in HVDC power system. Discusses about the configuration of HVDC system and the structure of control and protection system. Analyzes and designs the network configuration of field device level. Using OPAS engineering tool to config IO system and at the same time monitor data in SCADA HMI.

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A Study on the Simulation of Grounding of Double Hull Tanker using LS/DYNA3D (LS/DYNA3D를 이용한 이중선체 유조선의 좌초에 관한 연구)

  • 이상갑
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.4 no.2
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    • pp.1-12
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    • 1998
  • This paper descirbes a series of numberical simulations of grounding accidents of four 40,000 DWT Conventional and Advanced Double Hull tanker bottom structures using LS/DYNA3D. The overall objective of this study is no understand the structural failure and energy absorbing mechanisms during grounding events for candidate double hull tanker bottom structures, which lead to the initiation of inner shell rupture and cause the kinetic energy dissipation to bring the ship to a stop. These nuberical simulations of the grounding events will contribute to future improvements in tanker safety at the design stage.

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Development of the replaced Eco-friendly SIS with GIS for 25.8kV class (25.8kV $SF_6$가스절연 스위치기어(GIS)를 대체한 친환경 고체절연 스위치기어(SIS) 개발)

  • Ma, Ji-Hoon;Zheng, Meng-Lei;Yoo, Lyun;Won, Sung-Yoen;Lee, Seog-Won;Kim, Young-Keun
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1219_1220
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    • 2009
  • In recent years, the companies of electric power equipment for MV, HV class trend to develop that the eco-friendly insulated(solid, eco-gas, air etc.) switchgear replace with existent SF6 gas insulated switchgear by environmental problems such as global warming and soon. This paper introduces the Solid Insulated Switchgear(SIS) which is the epoxy of eco-friendly insulation material. The characteristic of SIS to introduce in this paper is as following. 1) Eco-friendly. (SF6 gas free) 2) The structure of flexible system. (Expansion) 3) The optimum design. (The Analysis of electrical & mechanical) 4) An Interface treatment between epoxy and insert. (Molding technology) This paper described about some technology for development of SIS.

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The Effect of Different Flaked Lupin Seed Inclusion Levels on the Growth of Growing Korean Native Bulls

  • Kwak, B.O.;Kim, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.14 no.8
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    • pp.1129-1132
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    • 2001
  • Seventy-two Korean native bulls, with an average initial body weight of $247.2{\pm}2.34kg$ were used to determine the effect of different flaked lupin seed inclusion levels (0%, 15% and 30%; Control, LS15, LS30, respectively) on growth with a $3{\times}3$ randomized complete block design at the experimental farm of TS Corporation in Korea for 150 days. There were no significant differences in average daily gain (ADG) and feed:gain among treatments, However, LS30 increased concentrate intake and total feed intake (p<0.05) and decreased rice straw intake compared with Control and LS 15 (p<0.05), With inclusion of flaked lupin seeds, concentrate intake and total feed intake increased (p<0.01) and rice straw intake decreased (p<0.05) compared with Control. There were no specific changes in the health status of animals used in this experiment with inclusion of flaked lupin seeds in concentrates. Inclusion of flaked lupin seeds in the concentrates showed a tendency of reduced average daily total feed cost per kg weight gain compared with Control by 1.6% and 3.4%, respectively, in LS15 and LS30.

Estimating uncertainty in limit state capacities for reinforced concrete frame structures through pushover analysis

  • Yu, Xiaohui;Lu, Dagang;Li, Bing
    • Earthquakes and Structures
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    • v.10 no.1
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    • pp.141-161
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    • 2016
  • In seismic fragility and risk analysis, the definition of structural limit state (LS) capacities is of crucial importance. Traditionally, LS capacities are defined according to design code provisions or using deterministic pushover analysis without considering the inherent randomness of structural parameters. To assess the effects of structural randomness on LS capacities, ten structural parameters that include material strengths and gravity loads are considered as random variables, and a probabilistic pushover method based on a correlation-controlled Latin hypercube sampling technique is used to estimate the uncertainties in LS capacities for four typical reinforced concrete frame buildings. A series of ten LSs are identified from the pushover curves based on the design-code-given thresholds and the available damage-controlled criteria. The obtained LS capacities are further represented by a lognormal model with the median $m_C$ and the dispersion ${\beta}_C$. The results show that structural uncertainties have limited influence on $m_C$ for the LSs other than that near collapse. The commonly used assumption of ${\beta}_C$ between 0.25 and 0.30 overestimates the uncertainties in LS capacities for each individual building, but they are suitable for a building group with moderate damages. A low uncertainty as ${\beta}_C=0.1{\sim}0.15$ is adequate for the LSs associated with slight damages of structures, while a large uncertainty as ${\beta}_C=0.40{\sim}0.45$ is suggested for the LSs near collapse.

Nutritional Evaluation of Lentil (Lens culinaris) Straw and Urea Treated Wheat Straw in Goats and Lactating Buffaloes

  • Dutta, Narayan;Sharma, K.;Naulia, Uma
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.11
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    • pp.1529-1534
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    • 2004
  • The nutritive value of lentil straw (Lens culinaris) relative to 4% urea treated wheat straw (w/w) was assessed in adult bucks and milking buffaloes on-station and on-farm, respectively. A digestion-cum-nitrogen balance experiment was conducted with three bucks (24.35 kg) fed ad libitum lentil straw (LS), urea treated wheat straw (UTS) and a 1:1 (w/w DM basis) mixture of LS and UTS (LS:UTS) in a 3$\times$3 Latin square design. Though daily dry matter intake (g kg $W^{0.75}$ or % LW) of bucks fed LS and UTS did not differ significantly, that of LS:UTS was significantly (p<0.05) low. Similarly, digestibility of nutrients (DM, OM and CP) and nitrogen balance (g/day) did not differ significantly for bucks given LS or UTS although a significant positive improvement was evident in these parameters for LS:UTS. The digestibility of fibre fractions (NDF and ADF) was significantly (p<0.05) lower in LS as compared to UTS or LS:UTS. Except for the significantly (p<0.05) lower intake of DCP (g kg$W^{0.75}$), the bucks fed LS had statistically similar nutrient intake as compared to UTS. Feeding of LS:UTS resulted in significantly higher nutrient (DCP, TDN) intake by bucks. The important blood-biochemical parameters (haemoglobin,packed cell volume, glucose, urea nitrogen, total protein) and activity of serum enzymes (alanine aminotransferase and aspartate aminotransferase) did not differ significantly in goats irrespective of dietary treatment. In the onfarm study, eighteen multiparous milking buffaloes were randomly assigned into three equal groups to assess the relative effect of feeding untreated wheat straw (WS), UTS and LS:UTS ad libitum as basal feed with a supplement. The study continued for 3 months and revealed that daily dry matter intake and average milk production (liters/day) by buffaloes offered LS:UTS and UTS was statistically similar but it was significantly higher compare to WS. However, milk composition did not differ significantly among the dietary treatments. It may be concluded that the nutritive value of lentil straw appeared to be no different to UTS, however, a positive synergistic effect was evident by feeding a mixture of LS and UTS on performance of goats and lactating buffaloes.