• Title/Summary/Keyword: Cascading

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Transient Stability Assessment Using Improved SIME (개선된 SIME법을 이용한 과도 안정도 평가)

  • Lee, Jong-Seock;Ahn, Tae-Hyung;Yang, Jung-Dae;Lee, Byong-Jun;Kwon, Sae-Hyuk
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.258-260
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    • 1999
  • The Single Machine Equivalent(SIME) is a hybrid method resulting from the coupling of a time-domain program with the equal-area criterion. This paper presents the efficient filtering algorithm using improved SIME for Transient Stability Assessment. The main feature of the method is cascading contingency filtering. First contingency filtering is conducted by using the first-swing stability of equivalent One Machine Infinite Bus(OMIB) system. This stability is evaluated by checking its time trajectory. Selected cases through the first step are assessed on the second step using SIME under the detailed model of power systems. The efficiency of the algorithm is tested on PSS/E test system.

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Design and Implementation of XLinking-based Web MapServer for Integrated Viewing of Spatial Data (공간 데이타 통합 뷰를 위한 XLinking 기반의 웹 맵서버의 설계 및 구현)

  • 이혜진;전봉기;홍봉희
    • Proceedings of the Korean Information Science Society Conference
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    • 2000.10a
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    • pp.240-242
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    • 2000
  • 기존의 통합 시스템은 이미 구축된 자원을 재활용하여 데이터의 구축 비용을 줄이고자 하는 의도에서 시작되었다. 최근 웹의 확산으로 인하여 웹 기반 분산 환경에서 공간 데이터의 제공을 위한 통합 시스템이 요구되고 있다. 이 논문에서는 XLinking을 기반으로 웹 환경에서 공간 데이터의 통합을 제공하는 시스템을 설계한다. 이는 기존 통합 시스템이 가지는 응용의 복잡성과 긴 사용자 응답 시간이라는 문제점을 해결 가능할 뿐만 아니라 표준 기술을 지원하여 상호 운용을 달성한다. 이 논몬에서는 OGC(OpenGIS Consortium)의 웹 매핑 표준 기술인 WMT(Web Mapping Testbed)의 중첩 맵서버(Cascading MapServer)와 GML(Geography Markup Language)을 사용하여 통합 시스템을 설계하고 구현한다.

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Design of 950~2150MHz tunable bandpass ilter by cascading low and high pass filters (저역 및 고역 통과필터 종속연결형 950~2150MHz 가변대역통과필터의 설계)

  • 신재준;구경헌
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.7
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    • pp.1385-1393
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    • 1997
  • In this paper, a systematic design method of brjoadband tunable bandpass filter is presented by using user defined varactor diode method. The tunable bandpass filter is constructed as the cascade connection of low pass filter and high pass filter. The designed filter shows the characteristeristics of 2.7.+-.0.2dB insertion loss and 37.1.+-.5.0dB insertion loss and 32.1.+-.2.2dB image rejection. The results of the research can be used fodr the broadband tunable filter of DBS tuner and communication instruments.

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A Study on the Performance Comparison Method of MTI Signal Processors Against Ground Clutter (지상클러터에 대한 MTI 신호처리기의 성능 비교 방법에 관한 연구)

  • 구연건;김두근
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.10 no.2
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    • pp.82-87
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    • 1985
  • The performance comparison method against ground clutter, when the trasnfer function of MTI filter or integrator is given, is considered for the MTI signal processors using a constant PRF. The MTI signal processors are modelled as the transversal filters, and the ground clutter power density spectrum as Gaussian type and the performance of the MTI signal processors are compared by calculating the MTI improvent factors. The MTI imrpovement factors versus normalized spectral width is depicted as examples for the MTI filters, the integrator using Hanning weighting function and the cascading of the two.

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Control Strategy against Undesirable Zone 3 Relay Operation in Voltage Instability

  • Lee Byong-Jun;Song Hwa-Chang
    • KIEE International Transactions on Power Engineering
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    • v.5A no.2
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    • pp.144-151
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    • 2005
  • This paper presents a framework for determining control strategies against unwanted tripping actions during relay operation that plays a very important role in cascading events leading to voltage collapse. The framework includes an algorithm for quick identification of possible zone 3 relay operation during voltage instability. Furthermore, it comes up with the control strategy of load shedding at the selected location with active power and relay margin criteria. In addition, Quasi Steady-State (QSS) simulation is employed to obtain time-related information that is valuable in the determination of control strategy. As a case study, an example applying the framework is shown with the modified New England 39-bus system.

Audio Transcoding for Audio Streams from a T-DTV Broadcasting Station to a T-DMB Receiver

  • Bang, Kyoung-Ho;Park, Young-Cheol;Seo, Jeong-Il
    • ETRI Journal
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    • v.28 no.5
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    • pp.664-667
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    • 2006
  • We propose an efficient audio transcoding algorithm that can convert audio streams from terrestrial digital television broadcasting service stations to those for terrestrial digital multimedia broadcasting hand-held receivers. The proposed algorithm avoids the complicated psychoacoustic analysis by calculating the scalefactors of the bit-sliced arithmetic coding encoder directly from the signal-to-noise ratio parameters of the AC-3 decoder. The bit-allocation process is also simplified by cascading the nested distortion control loop. Through subjective evaluation, it is shown that the proposed algorithm provides comparable audio quality to tandem coding but it requires much smaller complexity.

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Design of Expandable 32x32 MBAM Neuro-chip (확장 가능한 32X32 MBAM Neuro-chip의 설계)

  • 최윤경;박정배;이수영
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.6
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    • pp.86-92
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    • 1993
  • In this paper, we present a VLSI chip design of Multi-layer Bidirectionsl Associative Memory with good error-correction performance. The MBAM neural chip utilizes inner product implementation schems with binary storage and analog calculation.. Multi-layer can be constructed by direct cascading of these chips, and the number of neurons is expandable by parallel connection of these chips. We made proto-type chips and interface board to test the expansion. Currently the Chip has 32 input nodes, 32 output nodes, and can store up to 48 patterns, 32x48x2 SRAMs are included in the chip.

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A Study on the Magnetic Bubble Logic Circuit (자기바블 논리회로에 관한 연구)

  • 전경일;민태홍
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.11 no.1
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    • pp.40-47
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    • 1986
  • In this paper, the principles of cascade realization of 3-3CLC(3input-3out put Conservative Logic Circuit)using magnetic bubble are exlpored and the problem of realizing arbitary 3-3lofic circuit with minimal number of logic elements is handled. The five primitives classes 5, 15, 21, 24 and 29 are selected to realize all of the 3 equivatlent class by cascading only two of them. The crossoreres of lines are permitted in this realization and the upper bound of crossorers is three. The composition results are computed in MV 4000 minicomputer.

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Blind Adaptive Multiuser Detection for the MC-CDMA Systems Using Orthogonalized Subspace Tracking

  • Ali, Imran;Kim, Doug-Nyun;Lim, Jong-Soo
    • ETRI Journal
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    • v.31 no.2
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    • pp.193-200
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    • 2009
  • In this paper, we study the performance of subspace-based multiuser detection techniques for multicarrier code-division multiple access (MC-CDMA) systems. We propose an improvement in the PASTd algorithm by cascading it with the classical Gram-Schmidt procedure to orthonormalize the eigenvectors after their sequential extraction. The tracking of signal subspace using this algorithm, which we call OPASTd, has a faster convergence as the eigenvectors are orthonormalized at each discrete time sample. This improved PASTd algorithm is then used to implement the subspace blind adaptive multiuser detection for MC-CDMA. We also show that, for multiuser detection, the complexity of the proposed scheme is lower than that of many other orthogonalization schemes found in the literature. Extensive simulation results are presented and discussed to demonstrate the performance of the proposed scheme.

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Quad-Band Bandpass Filter Using Quad-Mode Stub-loaded Resonators

  • Liu, Haiwen;Wang, Xiaomei;Wang, Yan;Li, Shen;Zhao, Yulong;Guan, Xuehui
    • ETRI Journal
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    • v.36 no.4
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    • pp.690-693
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    • 2014
  • Compact multi-band bandpass filters using quad-mode stub-loaded resonators are proposed in this letter. Firstly, a novel approach about the mode-splitting characteristics of the quadruple-mode resonator is investigated, which can provide dual-band behavior. Secondly, a quad-band filter is proposed and designed by cascading two quadruple-mode resonators; the upper one operates at 1.8/2.4 GHz (GSM- and WiMax-band) and the lower one at 1.57/2.1 GHz (GPS- and WCDMA-band). Finally, the proposed filters have been fabricated. Respectable agreement between simulation and measurement verifies the validity of this design methodology.