• Title/Summary/Keyword: expansion algorithm

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On the Signal Power Normalization Approach to the Escalator Adaptive filter Algorithms

  • Kim Nam-Yong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.8C
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    • pp.801-805
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    • 2006
  • A normalization approach to coefficient adaptation in the escalator(ESC) filter structure that conventionally employs least mean square(LMS) algorithm is introduced. Using Taylor's expansion of the local error signal, a normalized form of the ESC-LMS algorithm is derived. Compared with the computational complexity of the conventional ESC-LMS algorithm employs input power estimation for time-varying convergence coefficient using a single-pole low-pass filter, the computational complexity of the proposed method can be reduced by 50% without performance degradation.

A CAPACITY EXPANSION STRATEGY ON PROJECT PLANNING

  • Joo, Un-Gi
    • ETRI Journal
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    • v.15 no.3
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    • pp.47-59
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    • 1994
  • A capacity expansion planning problem with buy-or-lease decisions is considered. Demands for capacity are deterministic and are given period-dependently at each period. Capacity additions occur by buying or leasing a capacity, and leased capacity at any period is reconverted to original source after a fixed length of periods, say, lease period. All cost functions (buying, leasing and idle costs) are assumed to be concave. And shortages of capacity and disposals are not considered. The properties of an optimal solution are characterized. This is then used in a tree search algorithm for the optimal solution and other two algorithms for a near-optimal solution are added. And these algorithms are illustrated with numerical examples.

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The method to produce GRM coefficient using single transform matrix (단일변수 변환 행렬을 이용한 GRM 상수 생성 방법)

  • 이철우;김영건
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.807-810
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    • 1998
  • This paper propose the method to produce GRM(Generalized Reed-Muller)expansion. The general method to obtain GRM expansion coefficient for p valued n variable is derivation of single variable transform matrix and expand it n times using Kronecker product. In this case the size of matrix increases depending on the augmentation of variables. In this paper we propose the simple algorithm to produce GRM coefficient using a single variable transform matrix.

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Time Discretization of the Nonlinear System with Variable Time-delayed Input using a Taylor Series Expansion

  • Choi, Hyung-Jo;Chong, Kil-To
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2562-2567
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    • 2005
  • This paper suggests a new method discretization of nonlinear system using Taylor series expansion and zero-order hold assumption. This method is applied into the sampled-data representation of a nonlinear system with input time delay. Additionally, the delayed input is time varying and its amplitude is bounded. The maximum time-delayed input is assumed to be two sampling periods. Them mathematical expressions of the discretization method are presented and the ability of the algorithm is tested for some of the examples. And 'hybrid' discretization scheme that result from a combination of the ‘scaling and squaring' technique with the Taylor method are also proposed, especially under condition of very low sampling rates. The computer simulation proves the proposed algorithm discretized the nonlinear system with the variable time-delayed input accurately.

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A Study on Constructing the Multiple-Valued Logic Systems over Finite Fields using by the Decision Diagram (결정도(決定圖)에 기초(基礎)한 유한체상(有限體上)의 다치논리(多値論理)시스템구성(構成)에 관한 연구(硏究))

  • Park, Chun-Myoung
    • Journal of IKEEE
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    • v.3 no.2 s.5
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    • pp.295-304
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    • 1999
  • This paper presents a method of constructing the Multiple-Valued Logic Systems(MVLS) over Finite Fields(FF) using by Decision Diagram(DD) that is based on Graph Theory. The proposed method is as following. First, we derivate the Ordered Multiple-Valued Logic Decision Diagram(OMVLDD) based on the multiple-valued Shannon's expansion theorem and we execute function decomposition using by sub-graph. Next, we propose the variable selecting algorithm and simplification algorithm after apply the each isomorphism and reodering vertex. Also we propose MVLS design method.

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Improved Contrast for Threshold Random-grid-based Visual Cryptography

  • Hu, Hao;Shen, Gang;Fu, Zhengxin;Yu, Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.7
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    • pp.3401-3420
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    • 2018
  • Pixel expansion and contrast are two major performance parameters for visual cryptography scheme (VCS), which is a type of secret image sharing. Random Grid (RG) is an alternative approach to solve the pixel expansion problem. Chen and Tsao proposed the first (k, n) RG-based VCS, and then Guo et al., Wu et al., Shyu, and Yan et al. significantly improved the contrast in recent years. However, the investigations on improving the contrast of threshold RG-based VCS are not sufficient. In this paper, we develop a contrast-improved algorithm for (k, n) RG-based VCS. Theoretical analysis and experimental results demonstrate that the proposed algorithm outperformers the previous threshold algorithms with better visual quality and a higher accuracy of contrast.

Anisotropic continuum damage analysis of thin-walled pressure vessels under cyclic thermo-mechanical loading

  • Surmiri, Azam;Nayebi, Ali;Rokhgireh, Hojjatollah;Varvani-Farahani, Ahmad
    • Structural Engineering and Mechanics
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    • v.75 no.1
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    • pp.101-108
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    • 2020
  • The present study intends to analyze damage in thin-walled steel cylinders undergoing constant internal pressure and thermal cycles through use of anisotropic continuum damage mechanics (CDM) model coupled with nonlinear kinematic hardening rule of Chaboche. Materials damage in each direction was defined based on plastic strain and its direction. Stress and strain distribution over wall-thickness was described based on the CDM model and the return mapping algorithm was employed based on the consistency condition. Plastic zone expansion across the wall thickness of cylinders was noticeably affected with change in internal pressure and temperature gradients. Expansion of plastic zone over wall-thickness at inner and outer surfaces and their boundaries demarking elastic and plastic regions was attributed to the magnitude of damage induced over thermomechanical cycles on the thin-walled samples tested at various pressure stresses.

Economic Design for Expanding Computer Networks Using Scatter Search (Scatter Search를 이용한 컴퓨터 네트워크 확장의 경제적 설계)

  • Lee, Han-Jin;Yum, Chang-Sun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.33 no.2
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    • pp.81-88
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    • 2010
  • This paper presents an application of heuristic approach to problem of designing reliable network expansion. The problem essentially consists in finding the network topology that satisfies given set of reliability constraints. To efficiently solve the problem, a scatter search approach is proposed. The results of the two experiments show that scatter search is a more suitable approach for finding a good solution or near optimal solution in comparison with genetic algorithm.

Digital Simulation of Narrow-Band Ocean Systems (협대역 해양시스템의 Digital simulation)

  • 김영균
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.18 no.2
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    • pp.22-26
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    • 1981
  • Truncated expansions based upon the sampling theorem but containing only a few terms can be very useful for practical interpolations of band-limited or narrow-band random signals. The major goal of this work is to find and coiupare efficient and "statistically accurate" algorithms for the dynamic analysis of the ocean systems. The stalistical accuracy of truncated sampling interpolations is investicated, and one simple ocean systems, which yields a Runge-Kutta simulation algorithm of improved accuracy with very little increase in computation, is indicated.indicated.

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Development of Visual Servo Control System for the Tracking and Grabbing of Moving Object (이동 물체 포착을 위한 비젼 서보 제어 시스템 개발)

  • Choi, G.J.;Cho, W.S.;Ahn, D.S.
    • Journal of Power System Engineering
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    • v.6 no.1
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    • pp.96-101
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    • 2002
  • In this paper, we address the problem of controlling an end-effector to track and grab a moving target using the visual servoing technique. A visual servo mechanism based on the image-based servoing principle, is proposed by using visual feedback to control an end-effector without calibrated robot and camera models. Firstly, we consider the control problem as a nonlinear least squares optimization and update the joint angles through the Taylor Series Expansion. And to track a moving target in real time, the Jacobian estimation scheme(Dynamic Broyden's Method) is used to estimate the combined robot and image Jacobian. Using this algorithm, we can drive the objective function value to a neighborhood of zero. To show the effectiveness of the proposed algorithm, simulation results for a six degree of freedom robot are presented.

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