• 제목/요약/키워드: Distributed Algorithm

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분산전원의 Fault Ride Through를 고려한 방향성 과전류 계전기 최적 정정법에 관한 연구 (A Study on the Optimal Setting Method of Directional Overcurrent Relay Considering Fault Ride Through of Distributed Generation)

  • 송진솔;조규정;김지수;신재윤;김동현;김철환
    • 전기학회논문지
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    • 제67권8호
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    • pp.1002-1008
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    • 2018
  • Fault Ride Through(FRT) requirement prevents disconnections of distributed generations during the specific time on disturbance condition for system stability. However, since there is a limitation to the FRT capability of distributed generation, and the protection system needs to clear the fault quickly before the distributed generation is disconnected. Therefore, this paper proposes a novel optimal setting method of directional overcurrent relay considering FRT of distributed generation. The proposed method reduces the probability of disconnections of the distributed generation in disturbance without additional equipment considering the FRT capability of the distributed generation by calculating the optimal relay setting through the Genetic Algorithm(GA).

WiMedia Distributed MAC 통신 시스템을 위한 UWB 링크에 적응적인 릴레이 통신 프로토콜 (UWB Link-Adaptive Relay Transmission Protocol for WiMedia Distributed MAC Systems)

  • 허경
    • 한국통신학회논문지
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    • 제37권3A호
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    • pp.141-150
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    • 2012
  • 본 논문에서는 UWB 기술 기반 WiMedia Distributed Medium Access Control (D-MAC) 표준 프로토콜에 적용할 수 있는 릴레이 자원 예약 프로토콜을 제안한다. 그리고, 무선 채널 상태에 따라 변화하는 UWB 링크 전송속도에 적응적인 릴레이 노드 선정 알고리즘을 제안한다. 본 논문에서 제안하는 UWB 링크에 적응적인 릴레이 통신 프로토콜은 분산적인 D-MAC 표준 기술과 호환성을 갖고, 각 디바이스에서 독립적으로 실행되는 Satisfaction of QoS (SoQ) 기준에 따라 실행된다.

순간전압강하를 고려한 분산전원 최적위치 선정 (Optimal Placement of Distributed Generation Units Considering Voltage Sags)

  • 송영원;이계병;박창현
    • 전기학회논문지
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    • 제62권11호
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    • pp.1505-1510
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    • 2013
  • This paper presents a method for determining the optimal placement of distributed generation units considering voltage sags. In general, the existing methods for distributed generation placement do not consider power quality problems such as voltage sags. In this paper, a novel method based on both genetic algorithm and voltage sag assessment is proposed for determining the placement of distributed generation unit. In the proposed method, the optimal placement is determined to minimize voltage sag effects and system losses.

Distributed Decision-Making in Wireless Sensor Networks for Online Structural Health Monitoring

  • Ling, Qing;Tian, Zhi;Li, Yue
    • Journal of Communications and Networks
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    • 제11권4호
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    • pp.350-358
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    • 2009
  • In a wireless sensor network (WSN) setting, this paper presents a distributed decision-making framework and illustrates its application in an online structural health monitoring (SHM) system. The objective is to recover a damage severity vector, which identifies, localizes, and quantifies damages in a structure, via distributive and collaborative decision-making among wireless sensors. Observing the fact that damages are generally scarce in a structure, this paper develops a nonlinear 0-norm minimization formulation to recover the sparse damage severity vector, then relaxes it to a linear and distributively tractable one. An optimal algorithm based on the alternating direction method of multipliers (ADMM) and a heuristic distributed linear programming (DLP) algorithm are proposed to estimate the damage severity vector distributively. By limiting sensors to exchange information among neighboring sensors, the distributed decision-making algorithms reduce communication costs, thus alleviate the channel interference and prolong the network lifetime. Simulation results in monitoring a steel frame structure prove the effectiveness of the proposed algorithms.

Energy Efficiency of Distributed Massive MIMO Systems

  • He, Chunlong;Yin, Jiajia;He, Yejun;Huang, Min;Zhao, Bo
    • Journal of Communications and Networks
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    • 제18권4호
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    • pp.649-657
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    • 2016
  • In this paper, we investigate energy efficiency (EE) of the traditional co-located and the distributed massive multiple-input multiple-output (MIMO) systems. First, we derive an approximate EE expression for both the idealistic and the realistic power consumption models. Then an optimal energy-efficient remote access unit (RAU) selection algorithm based on the distance between the mobile stations (MSs) and the RAUs are developed to maximize the EE for the downlink distributed massive MIMO systems under the realistic power consumption model. Numerical results show that the EE of the distributed massive MIMO systems is larger than the co-located massive MIMO systems under both the idealistic and realistic power consumption models, and the optimal EE can be obtained by the developed energy-efficient RAU selection algorithm.

고속 WALSH 변환에 의한 분포정수계의 최적제어 (Optimal Control of Distributed Parameter Systems Via Fast WALSH Transform)

  • 김태훈;김진태;이승;안두수
    • 대한전기학회논문지:시스템및제어부문D
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    • 제50권10호
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    • pp.464-472
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    • 2001
  • This study uses distributed parameter systems as the spatial discretization technique, modelling in lumped parameter systems, and applies fast WALSH transform and the Picard's iteration method to high order partial differential equations and matrix partial differential equations. This thesis presents a new algorithm which usefully exercises the optimal control in the distributed parameter systems. In exercising optimal control of distributed parameter systems, excellent consequences are found without using the existing decentralized control or hierarchical control method. This study will help apply to linear time-varying systems and non-linear systems. Further research on algorithm will be required to solve the problems of convergence in case of numerous applicable intervals.

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A Distributed Stock Cutting using Mean Field Annealing and Genetic Algorithm

  • Hong, Chul-Eui
    • Journal of information and communication convergence engineering
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    • 제8권1호
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    • pp.13-18
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    • 2010
  • The composite stock cutting problem is defined as allocating rectangular and irregular patterns onto a large composite stock sheet of finite dimensions in such a way that the resulting scrap will be minimized. In this paper, we introduce a novel approach to hybrid optimization algorithm called MGA in MPI (Message Passing Interface) environments. The proposed MGA combines the benefit of rapid convergence property of Mean Field Annealing and the effective genetic operations. This paper also proposes the efficient data structures for pattern related information.

분산전원을 고려한 재폐로 기법 (A Reclosing Technique considering the Distributed Generation)

  • 서훈철;김철환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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    • pp.270-271
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    • 2006
  • This paper presents the reclosing algorithm considering the DG(Distributed Generation). The algorithm consists of angle oscillation's judgment, EEEAC(Emergency Extended Equal-Area Criterion), calculation of optimal reclosing time and reconnection algorithm. The simulation is implemented for the three different DG technologies by using EMTP MODELS.

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Virtual Back-off를 사용한 변형된 DCF 알고리즘 제안 (Proposal of Modified Distributed coordination function (DCF) using Virtual Back-off)

  • 송경희;김태환;박동선
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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    • pp.49-52
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    • 2003
  • IEEE 802.11 MAC uses a distributed coordination function (DCF) known as carrier sense multiple access with collision avoidance (CSMA/CA) for medium access. Random back-off algorithm helps to avoid the collision. This paper proposes virtual back-off and modified back-off algorithm for reduce a waiting time by back-off and reduce the collision. The modified DCF is consisted of these two algorithms. We expect to reduce the average waiting time of each transmission by using the modified DCF algorithm.

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Distributed Scheduling Scheme for Optimal Performance in Wireless Networks

  • Tran, Nguyen H.;Hong, Choong-Seon
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(D)
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    • pp.232-233
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    • 2011
  • We propose a randomized distributed scheduling algorithm which can achieve the optimal throughput under the general interference model. The proposed algorithm is analyzed to show an attractive performance in that it can return a maximal schedule with high probability and has a low time-complexity. We also provide the simulation results to validate performance analysis of our algorithm.