• Title/Summary/Keyword: Matrix function

Search Result 1,758, Processing Time 0.022 seconds

The description of wigner function and density matrix by computer tomograph (전산 시늉에 의한 위그너 함수와 밀도 행렬이 기술)

  • 강장원;조기현;윤선현
    • Korean Journal of Optics and Photonics
    • /
    • v.11 no.6
    • /
    • pp.441-446
    • /
    • 2000
  • Wigner functions and density matrices are computer simulated for various quantum mechanical states of light. Wigner function and density matrices are evaluated by filtered back projection which includes inverse Radon transform from the distribution function of the photocurrents, which are calculated in the balanced homodyne detection scheme. The density matrix is also directly obtained by using the pattern function from the simulated phase independent photocurrent distribution function. ction.

  • PDF

An Efficient Design Method of RF Filters via Optimized Rational-Function Fitting, without Coupling-Coefficient Similarity Transformation (무 결합계수-회전변환의, 최적화된 유리함수 Fitting에 의한 효율적인 RF대역 여파기 설계기법)

  • Ju Jeong-Ho;Kang Sung-Tek;Kim Hyeong-Seok
    • 한국정보통신설비학회:학술대회논문집
    • /
    • 2006.08a
    • /
    • pp.202-204
    • /
    • 2006
  • A new method is presented to design RF filters without the Similarity Transform of their coupling coefficient matrix as circuit parameters which is very tedious due to pivoting and deciding rotation angles needed during the iterations. The transfer function of a filter is directly used for the design and its desired form is derived by the optimized rational-function fitting technique. A 3rd order Coaxial Lowpass filter and an 8th order dual-mode elliptic integral function response filter are taken as an example to validate the proposed method.

  • PDF

Unbalance Control Strategy of Boost Type Three-Phase to Single-Phase Matrix Converters Based on Lyapunov Function

  • Xu, Yu-xiang;Ge, Hong-juan;Guo, Hai
    • Journal of Power Electronics
    • /
    • v.19 no.1
    • /
    • pp.89-98
    • /
    • 2019
  • This paper analyzes the input side performance of a conventional three-phase to single-phase matrix converter (3-1MC). It also presents the input-side waveform quality under this topology. The suppression of low-frequency input current harmonics is studied using the 3-1MC plus capacitance compensation unit. The constraint between the modulation function of the output and compensation sides is analyzed, and the relations among the voltage utilization ratio and the output compensation capacitance, filter capacitors and other system parameters are deduced. For a 3-1MC without large-capacity energy storage, the system performance is susceptible to input voltage imbalance. This paper decouples the inner current of the 3-1MC using a Lyapunov function in the input positive and negative sequence bi-coordinate axes. Meanwhile, the outer loop adopts a voltage-weighted synthesis of the output and compensation sides as a cascade of control objects. Experiments show that this strategy suppresses the low-frequency input current harmonics caused by input voltage imbalance, and ensures that the system maintains good static and dynamic performances under input-unbalanced conditions. At the same time, the parameter selection and debugging methods are simple.

Frequency-Dependent Element Matrices for Vibration Analysis of Piping Systems (배영계의 진동해소를 위한 주파수종속 요표행렬)

  • 양보석;안영홍;최원호
    • Journal of Ocean Engineering and Technology
    • /
    • v.6 no.2
    • /
    • pp.125-132
    • /
    • 1992
  • This paper presents an approach for the derivation of frequency-dependent element matrices for vibration analysis of piping systems containing a moving medium. The dynamic stiffness matrix is deduced from transfer matrix, and, in turn, the frequency-dependent element matrices are derived. Numerical examples show that method gives more accurate results than those obtained using the conventional static shape function based element matrices.

  • PDF

Pole Placement Method to Move a Equal Poles with Jordan Block to Two Real Poles Using LQ Control and Pole's Moving-Range (LQ 제어와 근의 이동범위를 이용한 조단 블록을 갖는 중근을 두 실근으로 이동시키는 극배치 방법)

  • Park, Minho
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.2
    • /
    • pp.608-616
    • /
    • 2018
  • If a general nonlinear system is linearized by the successive multiplication of the 1st and 2nd order systems, then there are four types of poles in this linearized system: the pole of the 1st order system and the equal poles, two distinct real poles, and complex conjugate pair of poles of the 2nd order system. Linear Quadratic (LQ) control is a method of designing a control law that minimizes the quadratic performance index. It has the advantage of ensuring the stability of the system and the pole placement of the root of the system by weighted matrix adjustment. LQ control by the weighted matrix can move the position of the pole of the system arbitrarily, but it is difficult to set the weighting matrix by the trial and error method. This problem can be solved using the characteristic equations of the Hamiltonian system, and if the control weighting matrix is a symmetric matrix of constants, it is possible to move several poles of the system to the desired closed loop poles by applying the control law repeatedly. The paper presents a method of calculating the state weighting matrix and the control law for moving the equal poles with Jordan blocks to two real poles using the characteristic equation of the Hamiltonian system. We express this characteristic equation with a state weighting matrix by means of a trigonometric function, and we derive the relation function (${\rho},\;{\theta}$) between the equal poles and the state weighting matrix under the condition that the two real poles are the roots of the characteristic equation. Then, we obtain the moving-range of the two real poles under the condition that the state weighting matrix becomes a positive semi-finite matrix. We calculate the state weighting matrix and the control law by substituting the two real roots selected in the moving-range into the relational function. As an example, we apply the proposed method to a simple example 3rd order system.

Switching Function Implementation based on Graph (그래프에 기초한 스위칭함수 구현)

  • Park, Chun-Myoung
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.15 no.9
    • /
    • pp.1965-1970
    • /
    • 2011
  • This paper proposes the method of switching function implementation using switching function extraction based on graph over finite fields. After we deduce the matrix equation from path number of directional graph, we propose the switching function circuit algorithm, also we propose the code assignment algorithm for nodes which is satisfied the directional graph characteristics with designed circuits. We can implement more optimal switching function compare with former algorithm, also we can design the switching function circuit which have any natural number path through the proposed switching function circuit implementation algorithms. Also the proposed switching function implementation using graph theory over finite fields have decrement number of input-output, circuit construction simplification, increment arithmetic speed and decrement cost etc.

Class function table matrix of finite groups

  • Park, Won-Sun
    • Journal of the Korean Mathematical Society
    • /
    • v.32 no.4
    • /
    • pp.689-695
    • /
    • 1995
  • Let G be a finite group with k distinct conjugacy classes $C_1, C_2, \cdots, C_k$ and F an algebraically closed field such that char$(F){\dag}\left$\mid$ G \right$\mid$$. We denoted by $Irr_F$(G) the set of all irreducible F-characters of G and $Cf_F$(G) the set of all class functions of G into F. Then $Cf_F$(G) is a commutative F-algebra with an F-basis $Irr_F(G) = {\chi_1, \chi_2, \cdots, \chi_k}$.

  • PDF

Controller Design for Affine T-S Fuzzy System with Parametric Uncertainties (파라미터 불확실성을 갖는 어핀 T-S 퍼지 시스템의 제어기 설계)

  • Lee, Sang-In;Park, Jin-Bae;Joo, Young-Hoon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • 2004.04a
    • /
    • pp.133-136
    • /
    • 2004
  • This paper proposes a stability condition in affine Takagi-Sugeno (T-S) fuzzy systems with parametric uncertainties and then, introduces the design method of a fuzzy-model-based controller which guarantees the stability. The analysis is based on Lyapunov functions that are continuous and piecewise quadratic. The search for a piecewise quadratic Lyapunov function can be represented in terms of linear matrix inequalities (LMIs).

  • PDF

Block-decomposition of a Linear Discrete Large-scale systems Via the Matrix Sign Function (행렬부호 함수에 의한 선형 이산치 대단위 계토의 블럭-분해)

  • 천희영;박귀태;권성하;이창훈
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.35 no.11
    • /
    • pp.511-518
    • /
    • 1986
  • An algorithm for block-decomposition of a linear, time-invariant, discrete large-scale systems is presented, based upon the matrix sign function on Z-plane. The block-decomposition is performed by defining a reference circle, a circular stripe and projection operators. Simulation study shows that the presented algorithm is very useful for multivariable control system's analysis and design.

  • PDF

Influence Measures for the Likelihood Ratio Test on Independence of Two Random Vectors

  • Jung, Kang-Mo
    • 한국데이터정보과학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.13-16
    • /
    • 2001
  • We compare methods for detecting influential observations that have a large influence on the likelihood ratio test statistics that the two sets of variables are uncorrelated with one another. For this purpose we derive results of the deletion diagnostic, the influence function, the standardized influence matrix and the local influence. An illustrative example is given.

  • PDF