• Title, Summary, Keyword: Time Weighted Algorithm

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Utilization of the Filtered Weighted Least Squares Algorithm For the Adaptive Identification of Time-Varying Nonlinear Systems (적응 FWLS 알고리즘을 응용한 시변 비선형 시스템 식별)

  • Ahn Kyu-Young;Lee In-Hwan;Nam Sang-Won
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.12
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    • pp.793-798
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    • 2004
  • In this paper, the problem of adaptively identifying time-varying nonlinear systems is considered. For that purpose, the discrete time-varying Volterra series is employed as a system model, and the filtered weighted least squares (FWLS) algorithm, developed for adaptive identification of linear time-varying systems, is utilized for the adaptive identification of time-varying quadratic Volterra systems. To demonstrate the performance of the proposed approach, some simulation results are provided. Note that the FWLS algorithm, decomposing the conventional weighted basis function (WBF) algorithm into a cascade of two (i.e., estimation and filtering) procedures, leads to fast parameter tracking with low computational burden, and the proposed approach can be easily extended to the adaptive identification of time-varying higher-order Volterra systems.

A Modified Dynamic Weighted Round Robin Cell Scheduling Algorithm

  • Kwak, Ji-Young;Nam, Ji-Seung;Kim, Do-Hyun
    • ETRI Journal
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    • v.24 no.5
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    • pp.360-372
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    • 2002
  • In this paper, we propose the modified dynamic weighted round robin (MDWRR) cell scheduling algorithm, which guarantees the delay property of real-time traffic and also efficiently transmits non-real-time traffic. The proposed scheduling algorithm is a variation of the dynamic weighted round robin (DWRR) algorithm and guarantees the delay property of real-time traffic by adding a cell transmission procedure based on delay priority. It also uses a threshold to prevent the cell loss of non-real-time traffic that is due to the cell transmission procedure based on delay priority. Though the MDWRR scheduling algorithm may be more complex than the conventional DWRR scheme, considering delay priority minimizes cell delay and decreases the required size of the temporary buffer. The results of our performance study show that the proposed scheduling algorithm has better performance than the conventional DWRR scheme because of the delay guarantee of real-time traffic.

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An Analysis and Comparison on Efficiency of Load Distribution Algorithm in a Clustered System (클러스터 시스템의 부하분산 알고리즘의 효율성 비교분석)

  • Kim, Seok-Chan;Rhee, Young
    • Journal of KIISE:Computing Practices and Letters
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    • v.12 no.2
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    • pp.111-118
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    • 2006
  • In this thesis, we analyze the efficiency of the algorithm to distribute the load in the clustered system, by comparing with the existed algorithm. PWLC algorithm detects each server's load in the system at weighted period, and following the detection of the loads, a set of weights is given to each server. The system allocates new loads to each server according to its weight. PWLC algorithm is compared with DWRR algorithm in terms of variance, waiting time by varying weighted Period. When the weighted period is too short, the system bears a heavy load for detecting load over time. On the other hand, when the weighted period is too long, the load balancing control of the system becomes ineffective. The analysis shows PWLC algorithm is more efficient than DWRR algorithm for the variance and waiting time.

Distributed Algorithm for Maximal Weighted Independent Set Problem in Wireless Network (무선통신망의 최대 가중치 독립집합 문제에 관한 분산형 알고리즘)

  • Lee, Sang-Un
    • The Journal of The Institute of Internet, Broadcasting and Communication
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    • v.19 no.5
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    • pp.73-78
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    • 2019
  • This paper proposes polynomial-time rule for maximum weighted independent set(MWIS) problem that is well known NP-hard. The well known distributed algorithm selects the maximum weighted node as a element of independent set in a local. But the merged independent nodes with less weighted nodes have more weights than maximum weighted node are frequently occur. In this case, existing algorithm fails to get the optimal solution. To deal with these problems, this paper constructs maximum weighted independent set in local area. Application result of proposed algorithm to various networks, this algorithm can be get the optimal solution that fail to existing algorithm.

Adaptive Identification of a Time-varying Volterra system using the FWLS (filtered weighted least squares) Algorithm (FWLS 적응 알고리듬을 이용한 시변 볼테라 시스템 식별)

  • Ahn, K.Y.;Jeong, I.S.;Nam, S.W.
    • Proceedings of the KIEE Conference
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    • pp.3-6
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    • 2004
  • In this paper, the problem of identifying a time-varying nonlinear system in an adaptive way was considered, whereby the time-varying second-order Volterra series was employed to model the system and the filtered weighted least squares (FWLS) algorithm was utilized for the fast parameter tracking capability with low computational burden. Finally, the performance of the proposed approach was demonstrated by providing some computer simulation results.

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A Study on the Hardware Implementation of A 3${\times}$3 Window Weighted Median Filter Using Bit-Level Sorting Algorithm (비트 레벨 정렬 알고리즘을 이용한 3${\times}$3 윈도우 가중 메디언 필터의 하드웨어 구현에 관한 연구)

  • 이태욱;조상복
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.3
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    • pp.197-205
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    • 2004
  • In this paper, we studied on the hardware implementation of a 3${\times}$3 window weighted median filter using bit-level sorting algorithm. The weighted median filter is a generalization of the median filter that is able to preserve :,harp changes in signal and is very effective in removing impulse noise. It has been successfully applied in various areas such as digital signal and video/image processing. The weighted median filters are, for the most part, based on word-level sorting methods, which have more hardware and time complexity, However, the proposed bit-serial sorting algorithm uses weighted adder tree to overcome those disadvantages. It also offers a simple pipelined filter architecture that is highly regular with repeated modules and is very suitable for weighted median filtering. The algorithm was implemented by VHDL and graphical environment in MAX+PlusII of ALTERA. The simulation results indicate that the proposed design method is more efficient than the traditional ones.

Unrelated Parallel Processing Problems with Weighted Jobs and Setup Times in Single Stage (가중치와 준비시간을 포함한 병렬처리의 일정계획에 관한연구)

  • Goo, Jei-Hyun;Jung, Jong-Yun
    • Journal of Korean Institute of Industrial Engineers
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    • v.19 no.4
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    • pp.125-135
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    • 1993
  • An Unrelated Parallel Processing with Weighted jobs and Setup times scheduling prolem is studied. We consider a parallel processing in which a group of processors(machines) perform a single operation on jobs of a number of different job types. The processing time of each job depends on both the job and the machine, and each job has a weight. In addition each machine requires significant setup time between processing jobs of different job types. The performance measure is to minimize total weighted flow time in order to meet the job importance and to minimize in-process inventory. We present a 0-1 Mixed Integer Programming model as an optimizing algorithm. We also present a simple heuristic algorithm. Computational results for the optimal and the heuristic algorithm are reported and the results show that the simple heuristic is quite effective and efficient.

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An Efficient Load-Sharing Scheme for Internet-Based Clustering Systems (인터넷 기반 클러스터 시스템 환경에서 효율적인 부하공유 기법)

  • 최인복;이재동
    • Journal of Korea Multimedia Society
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    • v.7 no.2
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    • pp.264-271
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    • 2004
  • A load-sharing algorithm must deal with load imbalance caused by characteristics of a network and heterogeneity of nodes in Internet-based clustering systems. This paper has proposed the Efficient Load-Sharing algorithm. Efficient-Load-Sharing algorithm creates a scheduler based on the WF(Weighted Factoring) algorithm and then allocates tasks by an adaptive granularity strategy and the refined fixed granularity algorithm for better performance. In this paper, adaptive granularity strategy is that master node allocates tasks of relatively slower node to faster node and refined fixed granularity algorithm is to overlap between the time spent by slave nodes on computation and the time spent for network communication. For the simulation, the matrix multiplication using PVM is performed on the heterogeneous clustering environment which consists of two different networks. Compared to other algorithms such as Send, GSS and Weighted Factoring, the proposed algorithm results in an improvement of performance by 75%, 79% and 17%, respectively.

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Optimal Discrete Systems using Time-Weighted Performance Index with Prescribed Closed-Loop Eigenvalues

  • Gwon, Bong-Hwan;Yun, Myeong-Jung
    • Proceedings of the KIEE Conference
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    • pp.786-790
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    • 1987
  • An optimization problem minimizing n given time-weighted performance index for discrete-time linear multi-input systems is investigated for the prespecified closed-loop eigenvalues. Necessary conditions for an optimality of the controller that satisfies the specified closed-loop eigenvalues are derived. A computational algorithm solving the optimal constant feedback gain is presented and a numerical example is given to show the effect of a time-weighted performance index on the transient responses.

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Optimal Constant PIDM Feedback Controller using Time Weighted Performance Index for Linear Multivariable Systems (선형 다변수 시스템에 있어서 시간비중 성능지수를 이용한 최적 상수 PIDM 궤한 제어기)

  • 권봉환;윤명중
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.36 no.5
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    • pp.360-366
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    • 1987
  • The design problem of optimal constant PIDM (proportional-integral-derivative and measurable variable) feedback controller for linear time-invariannt systems is investigated with the time-weighted quadratic performance index. Necessary conditions for an optimality of the controller are derived and an algorithm for computing the optimal feedback gain is presented. It is shown via example that the design mithod using the time-weighted quadratic performance index improves the transient responses of the closed-loop system.

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