• Title/Summary/Keyword: linear differential systems

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On-line parameter estimation of continuous-time systems using a genetic algorithm (유전알고리즘을 이용한 연속시스템의 온라인 퍼래미터 추정)

  • Lee, Hyeon-Sik;Jin, Gang-Gyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.1
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    • pp.76-81
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    • 1998
  • This paper presents an on-line scheme for parameter estimation of continuous-time systems, based on the model adjustment technique and the genetic algorithm technique. To deal with the initialisation and unmeasurable signal problems in on-line parameter estimation of continuous-time systems, a discrete-time model is obtained for the linear differential equation model and approximations of unmeasurable states with the observable output and its time-delayed values are obtained for the nonlinear state space model. Noisy observations may affect these approximation processes and degrade the estimation performance. A digital prefilter is therefore incorporated to avoid direct approximations of system derivatives from possible noisy observations. The parameters of both the model and the designed filter are adjusted on-line by a genetic algorithm, A set of simulation works for linear and nonlinear systems is carried out to demonstrate the effectiveness of the proposed method.

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IFS DECISION MAKING PROCESSES TO DIFFERENTIAL DIAGNOSIS OF HEADACHE

  • Kim, Soon-Ki
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.06a
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    • pp.264-267
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    • 1998
  • We are dealing with the preliminary diagnosis from the information of headache interview chart. We quantify the qualitative information based on the interview chart by dual scaling. Prototype of fuzzy diagnostic sets and the neural linear regression methods are established with these quantified data, These new methods can be used to classify new patient's tone of diseases with certain degrees of belief and its concerned symptoms. We call these procedures as neural Fuzzy Differential Diagnosis of Headache (NFDDH-1). Also we investigate three measures to medical diagnosis, where relations between symptoms and diseases are described by intutionistic fuzzy set (IFS) data. Two measures are described by nin-max and max-min IFS operators, respectively. Another measure is the similarity degree, i.e., IFS distance between patient's symptoms and prototypes of diseases. We consider some reasonable criteria for three measures in order to determine the label of headache, We will establish hree measures in NFDDH-2 and combine two packages as NFDDH

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Kinetic Measurements on Elastomer by Differential Scanning Calorimetry (Differential Scanning Calorimetry에 의(依)한 탄성체(彈性體)의 속도론적(速度論的) 연구(硏究))

  • Choi, Sei-Young
    • Elastomers and Composites
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    • v.22 no.4
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    • pp.333-339
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    • 1987
  • A modern kinetic evaluation method for nonisothermal reactions measured with Differential Scanning Calorimetry(DSC) is presented. It is based on multiple linear regression analysis using a number of curve points in a selectable range of conversion. The obtained kinetic data are the basis to compute a reaction process under any condition e.g. isothermal or adiabatic. The DSC measurements was performed on a Mettler TA3000 SYSTEM with the built in evaluation software. Mainly the following reactions are discussed: vulcanization of natural rubber compounds containing vulcanizing accelerators. The purpose of this work is to analyse the vulcanization kinetics of typical NR vulcanization systems using DSC. These systems were chosen because they are typically reactive elastomer and are commercially important.

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Using parametric reasoning to understand solutions to systems of differential equations

  • Allen, Karen
    • Communications of Mathematical Education
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    • v.18 no.2 s.19
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    • pp.79-92
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    • 2004
  • This paper offers an analysis of how students reasoned with the dynamic parameter time to support their mathematical activity and deepen their understandings of mathematical concepts. This mathematical thinking occurred as they participated in a differential equations class before, during, and instruction on solutions to linear systems of differential equations. Students participated in the following identified mathematical practices related to parametric reasoning during this time period: reasoning simultaneously in a qualitative and quantitative manner, reasoning by moving from discrete to continuous imaging of time, and reasoning by imagining the motion. Examples of this reasoning are provided in this report. Implications of this research include the possibility that instructional activities can build on this reasoning to help students learn about the mathematics of change at the middle school, high school, and the university.

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Nonlinear vibration of multi-body systems with linear and nonlinear springs

  • Bayat, Mahmoud;Pakar, Iman;Bayat, Mahdi
    • Steel and Composite Structures
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    • v.25 no.4
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    • pp.497-503
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    • 2017
  • In this paper, nonlinear vibration of multi-degree of freedom systems are studied. It has been tried to develop the mathematical model of systems by second-order nonlinear partial differential equations. The masses are connected with linear and nonlinear springs in series. A great effort has been done to solve the nonlinear governing equations analytically. A new analytical method called Variational Iteration Method (VIM) is proposed and successfully applied to the problem. The linear and nonlinear frequencies are obtained and the results are compared with numerical solutions. The first order of Variational Iteration Method (VIM) leads us to high accurate solution.

Wavelet-based Analysis for Singularly Perturbed Linear Systems Via Decomposition Method (웨이블릿 및 시스템 분할을 이용한 특이섭동 선형 시스템 해석)

  • Kim, Beom-Soo;Shim, Il-Joo
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.12
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    • pp.1270-1277
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    • 2008
  • A Haar wavelet based numerical method for solving singularly perturbed linear time invariant system is presented in this paper. The reduced pure slow and pure fast subsystems are obtained by decoupling the singularly perturbed system and differential matrix equations are converted into algebraic Sylvester matrix equations via Haar wavelet technique. The operational matrix of integration and its inverse matrix are utilized to reduce the computational time to the solution of algebraic matrix equations. Finally a numerical example is given to demonstrate the validity and applicability of the proposed method.

NUMERICAL SOLUTION OF STOCHASTIC DIFFERENTIAL EQUATION CORRESPONDING TO CONTINUOUS DISTRIBUTIONS

  • Amini, Mohammad;Soheili, Ali Reza;Allahdadi, Mahdi
    • Communications of the Korean Mathematical Society
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    • v.26 no.4
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    • pp.709-720
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    • 2011
  • We obtain special type of differential equations which their solution are random variable with known continuous density function. Stochastic differential equations (SDE) of continuous distributions are determined by the Fokker-Planck theorem. We approximate solution of differential equation with numerical methods such as: the Euler-Maruyama and ten stages explicit Runge-Kutta method, and analysis error prediction statistically. Numerical results, show the performance of the Rung-Kutta method with respect to the Euler-Maruyama. The exponential two parameters, exponential, normal, uniform, beta, gamma and Parreto distributions are considered in this paper.

Symbolic Algorithm for a System of Differential-Algebraic Equations

  • Thota, Srinivasarao;Kumar, Shiv Datt
    • Kyungpook Mathematical Journal
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    • v.56 no.4
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    • pp.1141-1160
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    • 2016
  • In this paper, a symbolic algorithm for solving a regular initial value problem (IVP) for a system of linear differential-algebraic equations (DAEs) with constant coeffcients has been presented. Algebra of integro-differential operators is employed to express the given system of DAEs. We compute a canonical form of the given system which produces another simple equivalent system. Algorithm includes computing the matrix Green's operator and the vector Green's function of a given IVP. Implementation of the proposed algorithm in Maple is also presented with sample computations.

A New BISON-like Construction Block Cipher: DBISON

  • Zhao, Haixia;Wei, Yongzhuang;Liu, Zhenghong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.5
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    • pp.1611-1633
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    • 2022
  • At EUROCRYPT 2019, a new block cipher algorithm called BISON was proposed by Canteaut et al. which uses a novel structure named as Whitened Swap-Or-Not (WSN). Unlike the traditional wide trail strategy, the differential and linear properties of this algorithm can be easily determined. However, the encryption speed of the BISON algorithm is quite low due to a large number of iterative rounds needed to ensure certain security margins. Commonly, denoting by n is the data block length, this design requires 3n encryption rounds. Moreover, the block size n of BISON is always odd, which is not convenient for operations performed on a byte level. In order to overcome these issues, we propose a new block cipher, named DBISON, which more efficiently employs the ideas of double layers typical to the BISON-like construction. More precisely, DBISON divides the input into two parts of size n/2 bits and performs the round computations in parallel, which leads to an increased encryption speed. In particular, the data block length n of DBISON can be even, which gives certain additional implementation benefits over BISON. Furthermore, the resistance of DBISON against differential and linear attacks is also investigated. It is shown the maximal differential probability (MDP) is 1/2n-1 for n encryption rounds and that the maximal linear probability (MLP) is strictly less than 1/2n-1 when (n/2+3) iterative encryption rounds are used. These estimates are very close to the ideal values when n is close to 256.

A Study on the Deadbeat Response Attribute of Nonlinear Systems (비선형시스템의 데드비트응답 특성 연구)

  • Song, Ja-Youn
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.1993-1995
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    • 2001
  • The subject of nonlinear control is an important area of automatic control. The behavior of nonlinear systems is much more complex. If the operating range of a control system is small, and if the involved nonlinearities are smooth, then the control system may be resonably approximated by a set of linear differential equations. This paper presents the deadbeat response attribute of some nonlinear systems, e.g., magnetic levitation, pendulum, van der pol oscillator etc.. The studied results through the computer simulation are shown a promising attribute of deadbeat response that the outputs of the systems are reached relatively fast the steady state.

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