• Title/Summary/Keyword: recursive-structure

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Evaluation and Optimal Arrangement of Multi-Dimensional Consecutive System

  • 안해일
    • Proceedings of the Korean Reliability Society Conference
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    • 2000.11a
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    • pp.397-397
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    • 2000
  • There exists an increasing need of study for generalized consecutive k-out-of-n systems. This paper demonstrates that a recursive formula for multi-dimensional consecutive k-out-of-n systems can be systematically developed by means of conventional structure function analysis. By taking advantage of notational convenience, the formulae expressed in the same recursive fashion just as the one dimensional consecutive k-out-of-n system. With the aids of the recursive formulae, not only the exact reliability of the system, but also the optimal arrangement of components is obtainable in a straightforward way.

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Recursive approximate overdetermined ARMA spectral estimation (순환 근사 과결정 ARMA 스펙트럼 추정)

  • 이철희;이석원;양흥석
    • 제어로봇시스템학회:학술대회논문집
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    • 1987.10b
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    • pp.446-450
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    • 1987
  • In this paper, overdetermined method is used for high resolution spectral estimation in case of short data record length. To reduce the computational effort and to obtain recursive form of estimation algorithm, we modify data matrix to have near-Toeplitz structure. Then, new recursive algorithm is derived in the form of fast Kalman algorithm. Two stage procedure is used for the estimation of ARMA parameters. First AR parameters are estimated by using overdetermined modified Yule-walker equation, and then MA parameters are implicitly estimated by estimating numerator spectral coefficients(NS).

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Least-squares Lattice Laguerre Smoother

  • Kim, Dong-Kyoo;Park, Poo-Gyeon
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1189-1191
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    • 2005
  • This paper introduces the least-squares order-recursive lattice (LSORL) Laguerre smoother that has order-recursive smoothing structure based on the Laguerre signal representation. The LSORL Laguerre smoother gives excellent performance for a channel equalization problem with smaller order of tap-weights than its counterpart algorithm based on the transversal filter structure. Simulation results show that the LSORL Laguerre smoother gives better performance than the LSORL transversal smoother.

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Pretension process control based on cable force observation values for prestressed space grid structures

  • Zhou, Zhen;Meng, Shao-Ping;Wu, Jing
    • Structural Engineering and Mechanics
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    • v.34 no.6
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    • pp.739-753
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    • 2010
  • Pointing to the design requirement of prestressed space grid structure being the target cable force, the pretension scheme decision analysis method is studied when there's great difference between structural actual state and the analytical model. Based on recursive formulation of cable forces, the simulative recursive system for pretension process is established from the systematic viewpoint, including four kinds of parameters, i.e., system initial value (structural initial state), system input value (tensioning control force scheme), system state parameters (influence matrix of cable forces), system output value (pretension accomplishment). The system controllability depends on the system state parameters. Based on cable force observation values, the influence matrix for system state parameters can be calculated, making the system controllable. Next, the pretension scheme decision method based on cable force observation values can be formed on the basis of iterative calculation for recursive system. In this way, the tensioning control force scheme that can meet the design requirement when next cyclic supplemental tension finished is obtained. Engineering example analysis results show that the proposed method in this paper can reduce a lot of cyclic tensioning work and meanwhile the design requirement can be met.

Parallelization of Recursive Functions for Recursive Data Structures (재귀적 자료구조에 대한 재귀 함수의 병렬화)

  • An, Jun-Seon;Han, Tae-Suk
    • Journal of KIISE:Software and Applications
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    • v.26 no.12
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    • pp.1542-1552
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    • 1999
  • 자료 병렬성이란 자료 집합의 원소들에 대하여 동일한 작업을 동시에 수행하므로써 얻어지는 병렬성을 말한다. 함수형 언어에서 자료 집합에 대한 반복 수행은 재귀적 자료형에 대한 재귀 함수에 의하여 표현된다. 본 논문에서는 이러한 재귀 함수를 자료 병렬 프로그램으로 변환하기 위한 병렬화 방법을 제시한다. 생성되는 병렬 프로그램의 병렬 수행 구조로는 일반적인 형태의 재귀적 자료형에 대하여 정의되는 다형적인 자료 병렬 연산을 사용하여 트리, 리스트 등과 같은 일반적인 재귀적 자료 집합에 대한 자료 병렬 수행이 가능하도록 하였다. 재귀 함수의 병렬화를 위해서는, 함수를 이루는 각각의 계산들의 병렬성을 재귀 호출에 의해 존재하는 의존성에 기반하여 분류하고, 이에 기반하여 각각의 계산들에 대한 적절한 자료 병렬 연산을 사용하는 병렬 프로그램을 생성하였다.Abstract Data parallelism is obtained by applying the same operations to each element of a data collection. In functional languages, iterative computations on data collections are expressed by recursions on recursive data structures. We propose a parallelization method for data-parallel implementation of such recursive functions. We employ polytypic data-parallel primitives to represent the parallel execution structure of the object programs, which enables data parallel execution with general recursive data structures, such as trees and lists. To transform sequential programs to their parallelized versions, we propose a method to classify the types of parallelism in subexpressions, based on the dependencies of the recursive calls, and generate the data-parallel programs using data-parallel primitives appropriately.

Two-Stage Estimator Design Using Stable Recursive FIR Filter and Smoother

  • Kim, Jong-Ju;Kim, Jae-Hun;Lyou, Joon
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2532-2537
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    • 2005
  • FIR(Finite Impulse Response) filter is well known to be ideal for the finite time state-space model, but it requires much computation due to its inherent non-recursive structure especially when the measurement interval grows to a large extent. And often a fixed-lag smoother based on the finite time interval is needed to monitor the soundness of the system model and the measurement model, but the computation burden of FIR-type smoother imposes much restriction of its usage for real-time application. Conventional recursive forms of FIR estimator[1]-[4] could not be used for real time applications, since they are numerically unstable in their recursive equations. To cope with this problem, we suggest a stable recursive form FIR estimator(SRFIR) and its usefulness is demonstrated for designing the real-time fixed-lag smoother on the finite time window through an example of detection of rate bias in the anti-aircraft gun fire control system.

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Model Structuring Technique by A Knowledge Representation Scheme: A FMS Fractal Architecture Example (지식 표현 기법을 이용한 모델 구조의 표현과 구성 : 단편구조 유연생산 시스템 예)

  • 조대호
    • Journal of the Korea Society for Simulation
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    • v.4 no.1
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    • pp.1-11
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    • 1995
  • The model of a FMS (Flexible Manufacturing System) admits to a natural hierarchical decomposition of highly decoupled units with similar structure and control. The FMS fractal architecture model represents a hierarchical structure built from elements of a single basic design. A SES (System Entity Structure) is a structural knowledge representation scheme that contains knowledge of decomposition, taxonomy, and coupling relationships of a system necessary to direct model synthesis. A substructure of a SES is extracted for use as the skeleton for a model. This substructure is called pruned SES and the extraction operation of a pruned SES from a SES is called pruning (or pruning operation). This paper presents a pruning operation called recursive pruning. It is applied to SES for generating a model structure whose sub-structure contains copies if itself as in FMS fractal architecture. Another pruning operation called delay pruning is also presented. Combined with recursive pruning the delay pruningis a useful tool for representing and constructing complex systems.

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A Study on Progressive Removing Radar Clutter by Wavelet and Recursive Mathematical Morphology (Wavelet과 반복적 수리형태학을 이용한 레이더 클러터의 점진적 제거에 관한 연구)

  • Jeong, Gi-Ryong
    • Journal of Navigation and Port Research
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    • v.26 no.2
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    • pp.209-213
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    • 2002
  • MRA(Multi-resolution analysis) algorithm by Wavelet and morphology with $3{\times}3$ SQ(square) SE(structure element) is efficient to remove ship's radar clutter progressively and enhances detecting performance. Smoothing efficiency of RMM (Recursive mathematical Morphology) is better than that of Morphology. So, to get a better result than that of old algorithms, this paper proposes a new MRA algorithm which uses Wavelet and Recursive mathematical Morphology with $3{\times}3$ RHR(rhombus) SE. Simulation result of the proposed algorithm shows that PSNR is 0.65~1.50db better than that of old method.

Multiuser Channel Estimation Using Robust Recursive Filters for CDMA System

  • Kim, Jang-Sub;Shin, Ho-Jin;Shin, Dong-Ryeol
    • Journal of Communications and Networks
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    • v.9 no.3
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    • pp.219-228
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    • 2007
  • In this paper, we present a novel blind adaptive multiuser detector structure and three robust recursive filters to improve the performance in CDMA environments: Sigma point kalman filter (SPKF), particle filter (PF), and Gaussian mixture sigma point particle filter (GMSPPF). Our proposed robust recursive filters have superior performance over a conventional extended Kalman filter (EKF). The proposed multiuser detector algorithms initially use Kalman prediction form to estimated channel parameters, and unknown data symbol be predicted. Second, based on this predicted data symbol, the robust recursive filters (e.g., GMSPPF) is a refined estimation of joint multipaths and time delays. With these estimated multipaths and time delays, data symbol detection is carried out (Kalman correction form). Computer simulations show that the proposed algorithms outperform the conventional blind multiuser detector with the EKF. Also we can see it provides a more viable means for tracking time-varying amplitudes and time delays in CDMA communication systems, compared to that of the EKF for near-far ratio of 20 dB. For this reason, it is believed that the proposed channel estimators can replace well-known filter such as the EKF.

RECURSIVE FIR FILTERS FOR DISCRETE TIME-INVARIANT STATE-SPACE MODELS (순환형 FIR 필터)

  • Gwon, O-Gyu;Gwon, Uk-Hyeon
    • Proceedings of the KIEE Conference
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    • 1986.07a
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    • pp.140-144
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    • 1986
  • In this paper an FIR(finite impulse response) filter and smoother are introduced for discrete time-invariant state-space models with driving noises. The FIR structure not only quarantees the BIBO stability and the robustness to parameter changes but also improves the filter divergence problem. It is shown that the impulse responses of the FIR filter and the smoother are obtained by Riccati-type difference equations and that they are to be time-invariant and reduced to very simple forms. For implementational purpose, recursive forms of the FIR filler and smoother are derived with each other used as the adjoint variable.

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