• Title/Summary/Keyword: Fixed-Point Algorithm

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Fixed Point Algorithm for GPS Measurement Solution (GPS 관측치 위치계산을 위한 부동점 알고리즘)

  • Lim, Samsung
    • Journal of Advanced Navigation Technology
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    • v.4 no.1
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    • pp.45-49
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    • 2000
  • A GPS measurement solution, in general, is obtained as a least squares solution since the measurement includes errors such as clock errors, ionospheric and tropospheric delays, multipath effect etc. Because of the nonlinearity of the measurement equation, we utilize the nonlinear Newton algorithm to obtain a least squares solution, or mostly, use its linearized algorithm which is more convenient and effective. In this study we developed a fixed point algorithm and proved its availability to replace the nonlinear Newton algorithm and the linearized algorithm. A nonlinear Newton algorithm and a linearized algorithm have the advantage of fast convergence, while their initial values have to be near the unknown solution. On the contrary, the fixed point algorithm provides more reliable but slower convergence even if the initial values are quite far from the solution. Therefore, two types of algorithms may be combined to achieve better performance.

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Improving the performance of PV system using the N-IC MPPT methods (N-IC MPPT방법을 이용한 태양광 발전시스템의 성능개선)

  • Seo, Tae-Young;Ko, Jae-Sub;Kang, Sung-Min;Kim, Yu-Tak;Chung, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.958-959
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    • 2015
  • This paper proposes adaptive incremental conductance(A-IC) algorithm for maximum power point tracking(MPPT) control of photovoltaic. Conventional Perturbation & Observation(PO) and IC MPPT control algorithm generally uses fixed step size. A small fixed step size will cause the tracking speed to decrease and tracking accuracy of the MPP will decrease due to large fixed step size. Therefore, this paper proposes N-IC MPPT algorithm that adjust automatically step size according to operating conditions. To improve tracking speed and accuracy, when operating point is far from maximum power point(MPP), step size uses maximum value and when operating point is near from MPP, step size uses variable step size that adjust according to slope of P-V curve. The validity of MPPT algorithm proposed in this paper prove through compare with conventional IC MPPT algorithm.

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GENERAL ITERATIVE ALGORITHMS FOR MONOTONE INCLUSION, VARIATIONAL INEQUALITY AND FIXED POINT PROBLEMS

  • Jung, Jong Soo
    • Journal of the Korean Mathematical Society
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    • v.58 no.3
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    • pp.525-552
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    • 2021
  • In this paper, we introduce two general iterative algorithms (one implicit algorithm and one explicit algorithm) for finding a common element of the solution set of the variational inequality problems for a continuous monotone mapping, the zero point set of a set-valued maximal monotone operator, and the fixed point set of a continuous pseudocontractive mapping in a Hilbert space. Then we establish strong convergence of the proposed iterative algorithms to a common point of three sets, which is a solution of a certain variational inequality. Further, we find the minimum-norm element in common set of three sets.

NEWTON SCHULZ METHOD FOR SOLVING NONLINEAR MATRIX EQUATION Xp + AXA = Q

  • Kim, Hyun-Min;Kim, Young-jin;Meng, Jie
    • Journal of the Korean Mathematical Society
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    • v.55 no.6
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    • pp.1529-1540
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    • 2018
  • The matrix equation $X^p+A^*XA=Q$ has been studied to find the positive definite solution in several researches. In this paper, we consider fixed-point iteration and Newton's method for finding the matrix p-th root. From these two considerations, we will use the Newton-Schulz algorithm (N.S.A). We will show the residual relation and the local convergence of the fixed-point iteration. The local convergence guarantees the convergence of N.S.A. We also show numerical experiments and easily check that the N.S. algorithm reduce the CPU-time significantly.

Fixed-Point Modeling and Performance Analysis of a Face Recognition Algorithm For Hardware Design (SoC 하드웨어 설계를 위한 얼굴 인식 알고리즘의 고정 소수점 모델 구현 및 성능 분석)

  • Kim, Young-Jin;Jeong, Yong-Jin
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.44 no.1
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    • pp.102-112
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    • 2007
  • This paper includes an analysis of face recognition algorithm to design hardware and presents fixed point model in accordance with it. Face recognition algorithm detects the positions of face and eyes to make use of their feature data to detect and verify human faces. It distinguishes a particular user by means of comparing them with registered face features. To implement the face recognition algorithm into hardware, we developed its fixed point model by analyzing face feature parameters, face acquisition data, and feature detection parameters and operation structure.

ACCELERATED STRONGLY CONVERGENT EXTRAGRADIENT ALGORITHMS TO SOLVE VARIATIONAL INEQUALITIES AND FIXED POINT PROBLEMS IN REAL HILBERT SPACES

  • Nopparat Wairojjana;Nattawut Pholasa;Chainarong Khunpanuk;Nuttapol Pakkaranang
    • Nonlinear Functional Analysis and Applications
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    • v.29 no.2
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    • pp.307-332
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    • 2024
  • Two inertial extragradient-type algorithms are introduced for solving convex pseudomonotone variational inequalities with fixed point problems, where the associated mapping for the fixed point is a 𝜌-demicontractive mapping. The algorithm employs variable step sizes that are updated at each iteration, based on certain previous iterates. One notable advantage of these algorithms is their ability to operate without prior knowledge of Lipschitz-type constants and without necessitating any line search procedures. The iterative sequence constructed demonstrates strong convergence to the common solution of the variational inequality and fixed point problem under standard assumptions. In-depth numerical applications are conducted to illustrate theoretical findings and to compare the proposed algorithms with existing approaches.

Verification method for 4x4 MIMO algorithm implementation and results (4x4 MIMO 알고리즘 구현 및 결과에 대한 검증 방법)

  • Choi, Jun-su;Hur, Chang-wu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.5
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    • pp.1157-1162
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    • 2015
  • This paper is the design and implementation to the 4x4 MIMO algorithm based on OFDM, and presented how to verify the implemented result. Algorithm applied the MRVD and QRM-MLD. Matlab and Simulink are used to design channel presumption & MIMO algorithm by Floating-point and Fixed-point model. After then implement VHDL using Modelsim. Performance of algorithm is checked by comparing Simulink model, Modelsim simulation, ISE ChipScope with the result measured by oscilloscope. This method is useful to verify an algorithm with uncompleted system. Conformance between the result of ChipScope and the result of oscilloscope is confirmed, it could be applied on the Backhaul system.

Fixed-point Processing Optimization of MPEG Psychoacoustic Model-II Algorithm for ASIC Implementation (MPEG 심리음향 모델-ll 알고리듬의 ASIC 구현을 위한 고정 소수점 연산 최적화)

  • Lee Keun-Sup;Park Young-Cheol;Youn Dae Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.11C
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    • pp.1491-1497
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    • 2004
  • The psychoacoustic model in MPEG audio layer-III (MP3) encoder is optimized for the fixed-point processing. The optimization process consists of determining the data word length of arithmetic unit and the algorithm for transcendental functions that are often used in the psychoacoustic model. In order to determine the data word length, we defined a statistical model expressing the relation between the fixed-point operation errors of the psychoacoustic model and the probability of alteration of the allocated bits doe to these errors. Based on the simulations using this model, we chose a 24-bit data path and constructed a 24-bit fixed-point MP3 encoder. Sound quality tests using the constructed fixed-point encoder showed a mean degradation of -0.2 on ITU-R 5-point audio impairment scale.

Fixed-point performance analysis and implementation of the FS-CELP vocoder (FS-CELP 음성 부호화기의 고정 소수점 성능 분석 및 구현)

  • 손종서;김시현;강지양;성원용
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.2
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    • pp.365-374
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    • 1996
  • Finite wordlength effects of the FS-1016 CELP(Code Excite Linear Prediction) vocoder algorithm) is analyzed, and a block floating-Point implementation method is employed to improve the fixed-point performance. An efficient run-time integer wordlength estimation algorithm is developed, and the overall system performance. An efficient run-time integer wordlength estimation algorithm is developed, and the overall system performance is verified in real-time using a TMS320C50 emulation board. Autoscaler software that conducts simulation-based automatic scaling to provide a floating-point like programming environment is used for this application development.

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A NEW ALGORITHM FOR SOLVING MIXED EQUILIBRIUM PROBLEM AND FINDING COMMON FIXED POINTS OF BREGMAN STRONGLY NONEXPANSIVE MAPPINGS

  • Biranvand, Nader;Darvish, Vahid
    • Korean Journal of Mathematics
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    • v.26 no.4
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    • pp.777-798
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    • 2018
  • In this paper, we study a new iterative method for solving mixed equilibrium problem and a common fixed point of a finite family of Bregman strongly nonexpansive mappings in the framework of reflexive real Banach spaces. Moreover, we prove a strong convergence theorem for finding common fixed points which also are solutions of a mixed equilibrium problem.