• 제목/요약/키워드: GSC

검색결과 111건 처리시간 0.038초

CFAR 검파기법을 이용한 주파수 영역 부분적응 어레이 알고리듬 (Frequency Domain Partially Adaptive Array Algorithm Combined with CFAR Technique)

  • 문성훈;한동석
    • 대한전자공학회논문지SP
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    • 제38권2호
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    • pp.227-236
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    • 2001
  • 본 논문에서는 주파수 영역 적응 어레이의 계산량을 감소시키기 위한 주파수 영역 부분적응 어레이 알고리듬인 센서링(censoring) 알고리듬을 제안하고, 이를 공간평활(spatial smoothing) 기법과 결합하여 공간평활로 인한 계산량 문제를 해결할 수 있는 센서링 공간평활 알고리듬을 제안한다. 제안한 센서링 알고리듬은 CFAR(constant false alarm rate) 검파기법을 이용하여 각 주파수 대역에 간섭신호가 있는지를 판단하고 간섭신호가 있는 주파수 대역의 해당 가중치에 대해서만 적응 알고리듬을 적용한다. 모의실험을 통하여 제안한 알고리듬을 사용한 GSC(generalized sidelobe canceller)가 기존의 주파수 영역 LMS(least mean square) 알고리듬을 사용한 GSC에 비하여 크게 줄어든 계산량으로 빠르게 간섭신호를 제거함을 확인하였다.

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음극 전극 표면적과 메틸렌블루 염색이 스펀지 탄소나노 튜브 전극 미생물 연료전지의 전력수율에 미치는 영향 (Effects of anode surface area and methylene blue dye treatment on the power density of microbial fuel cell with sponge and carbon nano tube electrode)

  • 이채영;박수희;송영채;우정희;유규선;정재우;한선기
    • 상하수도학회지
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    • 제26권6호
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    • pp.883-888
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    • 2012
  • Anode electrode is one of the most important factors in microbial fuel cell (MFC). This study was conducted to investigate the effects of mediator as methylene blue (MB) and electrode surface area on the power density of MFC with sponge and carbon nano tube (CNT) electrode (SC). The SC electrode with MB (MC) showed the maximum power density increased from 74.0 $mW/m^2$ to 143.1 $mW/m^2$. The grid shaped sponge and CNT (GSC) electrode showed the maximum power density of 209.2 $mW/m^2$ due to the increase of surface area from 88.0 to 152.0 $cm^2$. The GSC electrode with MB (GMC) revealed the maximum power density of 384.9 $mW/m^2$ which was 5.2 times higher than that obtained from the MFC with SC. Therefore MB and increase of surface area led to enhance the performance of microbial fuel cell such as power density.

Optimal Operation for Green Supply Chain with Quality of Recyclable Parts and Contract for Recycling Activity

  • Kusukawa, Etsuko;Alozawa, Sho
    • Industrial Engineering and Management Systems
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    • 제14권3호
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    • pp.248-274
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    • 2015
  • This study discusses a contract to promote collection and recycling of used products in a green supply chain (GSC). A collection incentive contract is combined with a reward-penalty contract. The collection incentive contract for used products is made between a retailer and a manufacturer. The reward-penalty contract for recycling used products is made between a manufacturer and an external institution. A retailer pays an incentive for collecting used products from customers and delivers them to a manufacturer with a product order quantity under uncertainty in product demand. A manufacturer remanufactures products using recyclable parts with acceptable quality levels and covers a part of the retailer's incentive from the recycled parts by sharing the reward from an external institution. Product demand information is assumed as (i) the distribution is known (ii) mean and variance are known. Besides, the optimal decisions for product quantity, collection incentive of used products and lower limit of quality level for recyclable parts under decentralized integrated GSCs. The analysis numerically investigates how (1) contract for recycling activity, (ii) product demand information and (iii) quality of recyclable parts affect the optimal operation for each GSC. Supply chain coordination to shift IGSC is discussed by adopting Nash Bargaining solution.

Improved Grid Voltage Control Strategy for Wind Farms with DFIGs Connected to Distribution Networks

  • Zhang, Xueguang;Pan, Weiming;Liu, Yicheng;Xu, Dianguo
    • Journal of Power Electronics
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    • 제12권3호
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    • pp.495-502
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    • 2012
  • This paper presents an improved grid voltage control strategy for wind farms with doubly-fed induction generators (DFIGs) connected to distribution networks based on an analysis of the operation limits of DFIG systems. A modified reactive power limit calculation method in different operation states is proposed and a reactive power control strategy during grid voltage dips/rises is further discussed. A control strategy for compensating unbalanced grid voltage, based on DFIG systems, by injecting negative sequence current into the grid through the grid side converter (GSC) is proposed. In addition, the negative current limit of the GSC is discussed. The distribution principle of the negative sequence current among the different DFIG systems in a wind farm is also introduced. The validity of the proposed voltage control strategy is demonstrated by Matlab/Simulink simulations. It is shown that the stability of a wind farm and the power grid can be improved with the proposed strategy.

Construction of Molecular Genetic Linkage Map Using RAPD Markes in Cowpea

  • Chung, Jong-Il;Shim, Jung-Hyun;Go, Mi-Suk
    • 한국작물학회지
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    • 제46권4호
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    • pp.341-343
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    • 2001
  • Molecular markers have become fundamental tools for crop genome study. The objective of this study was to construct a genetic linkage map for cowpea with PCR-based molecular markers. Five hundred and twenty random RAPD primers were screened for parental polymorphism. Ninety RAPD markers from sixty primers was segregated in 75 F2 mapping population derived from the cross of local cultivars GSC01 and GSC02. 70 RAPD markers were found to be genetically linked and formed 11 linkage groups. Linkage map spanned 474.1 cM across all 11 linkage groups. There are six linkage groups of 40 cM or more, and five smaller linkage groups range from 4.9 to 24.8 cM. The average linkage distance between pairs of markers among all linkage groups was 6.87 cM. The number of markers per linkage group ranged from 2 to 32. The longest group 1 spans 190.6 cM, while the length of shortest group 11 is 4.9 cM. This map is further needed to be saturated with the various markers such as RFLP, AFLP, SSR and more various populations and primers. In addition, morphological markers and biochemical markers should be united to construct a comprehensive linkage map.

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Double Opportunistic Transmit Cooperative Relaying System with GSC in Rayleigh Fading Channels

  • Kim, Nam-Soo;Lee, Ye-Hoon
    • Journal of electromagnetic engineering and science
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    • 제10권4호
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    • pp.270-275
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    • 2010
  • In a conventional opportunistic transmit (COT) cooperative relaying system, only the relays that receive signal-to-noise ratio (SNR) from the source and that exceed the threshold transmit to the destination. The COT system, however, only considers the SNR of the source-relay (S-R) path regardless that the SNR of the relay-destination (R-D) path is the opportunistic transmission condition. For that reason, it is not guaranteed that all the transmitted signals from relays exceed the threshold at the destination. Therefore we propose a double opportunistic transmit (DOT) cooperative relaying system - when both of the received SNR from a source and from a destination exceed the threshold, the relay transmits to the destination. It is shown that the proposed DOT system reduces power consumption by 6.9, 20.9, 32.4, and 41.4 % for K =3, 5, 7, and 9, respectively under the given condition of $P_{out}=1{\times}10^{-3}$ and $\overline{\gamma}_{SR}/\Gamma_{SR}$=30 dB, compared to the COT system. We noticed that the performance of the DOT system is superior to that of the COT system for the identical number of active transmit relays under the same condition of the normalized average SNR of $\overline{\gamma}_{RD}/\Gamma_{RD}$.

Study on Genetic Evaluation for Linear Type Traits in Holstein Cows

  • Lee, Deukhwan;Oh, Sang;Whitley, Niki C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권1호
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    • pp.1-6
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    • 2010
  • The objectives of this study were to i) investigate genetic performance for linear type traits of individual Holstein dairy cows, especially focusing on comparative traits, and to estimate genetic variances for these traits using actual data, and ii) compare genetic performance and improvement of progeny by birth country of the cows. Linear type traits defined with five comparative traits on this study were general stature composite (GSC), dairy capacity composite (DCC), body size composite (BSC), foot and leg composite (FLC), and udder composite (UDC). These traits were scored from 1 to 6 with 1 = poor, 2 = fair, 3 = good, 4 = good plus, 5 = very good and 6 = excellent. Final scores (FS) were also included in this study. Data used was collected from the years 2000 to 2004 by the Korea Animal Improvement Association (KAIA). Only data of more than five tested cows by herd appraisal date and by sires having more than ten daughters were included to increase the reliability of the data analyses. A total of 30,204 records of the selected traits, which was collected from 26,701 individuals having pedigree information were used. Herd appraisal date, year of age, lactation stage (grouped by month), and time lagged for milking (in hours) were assumed as fixed effects on the model. Animal additive genetic effects considering pedigree relationship and residual errors were assumed with random effects. Year of age at appraisal date was classified from one to nine years of age, assigning the value of nine years of age for animals that were greater than or equal to nine years of age. From our results, the estimate for heritability was 0.463, 0.346, 0.473, 0.290, and 0.430 on GSC, DCC, BSC, FLC and UDC, respectively. The estimate for FS heritability was 0.539. The greatest breeding values for GSC were estimated for Canada, with the breeding values for American lines increasing for 10 years starting in 1989 but tending to decrease after that until 2004. For DCC, the breeding values for American and Canadian lines showed similar patterns until 1999, after which the breeding values for the American lines declined sharply. For BSC, data from Korea, Canada and the USA followed similar trends overall except when the breeding values of the American lines decreased starting in 1999. Overall, the methods used to evaluate genetic performance in this study were acceptable and allowed for the discovery of differences by country of genetic origin, likely due in part to the American use of selection indexes based primarily on milk yield traits until methods for evaluating other traits began to emerge.