Identification of system with distributed-order derivatives

2021 ◽  
Vol 24 (5) ◽  
pp. 1619-1628
Author(s):  
Jun-Sheng Duan ◽  
Yu Li
Keyword(s):  
Weight Distribution ◽  
Transfer Functions ◽  
Piecewise Linear ◽  
Identification Problem ◽  
Least Square ◽  
Linear Functions ◽  
Piecewise Linear Functions ◽  
Frequency Responses ◽  
Weight Distributions ◽  
Distributed Order

Abstract The identification problem for system with distributed-order derivative was considered. The order-weight distribution was approximated by piecewise linear functions. Then the discretized order-weight distribution was solved in frequency domain by using the least square technique based on the Moore-Penrose inverse matrix. Finally, five representative numerical examples were used to illustrate the validity of the method. The identification results are satisfactory, especially for the continuous order-weight distributions. In addition, the overlapped Bode magnitude frequency responses from the identified and exact transfer functions imply the effectiveness of the method.

Application of a Compensation Inspection Method in Geodynamic Monitoring

2015 ◽  
Vol 799-800 ◽  
pp. 989-993 ◽  
Author(s):  
Artem Bykov ◽  
Igor' Kurilov ◽  
Oleg Kuzichkin
Keyword(s):  
Transfer Functions ◽  
Block Diagram ◽  
Piecewise Linear ◽  
Linear Functions ◽  
Measuring System ◽  
System Of Equations ◽  
Piecewise Linear Functions ◽  
Geoelectric Section ◽  
Inspection Method ◽  
Geodynamic Monitoring

The paper proves the application of a compensation testing method for geodynamic monitoring when using multi-pole electrical systems. The transfer functions of a geoelectric section are presented as a system of equations, whose coefficients are determined at the initial setup of the measuring system. The block diagram of the compensation method application for geodynamic monitoring based on a multi-pole electrical system is given. Approximation in terms of continuous piecewise-linear functions will be used to distinguish the geodynamic offset vector of the geoelectric section. A system of equations for defining the geodynamic offset vector through the approximation vector by continuous piecewise-linear functions on a recorded geoelectric signal error is considered.

Modelling the single-electron transistor with piecewise linear functions

2009 ◽  
Author(s):  
Arturo Sarmiento-Reyes ◽  
Luis Hernandez-Martinez ◽  
Miguel Angel Gutierrez de Anda ◽  
Francisco Javier Castro Gonzalez
Keyword(s):  
Piecewise Linear ◽  
Linear Functions ◽  
Single Electron ◽  
Single Electron Transistor ◽  
Piecewise Linear Functions

Mesh duality and Legendre duality

1990 ◽  
Vol 428 (1875) ◽  
pp. 351-377 ◽  
Keyword(s):  
Piecewise Linear ◽  
Voronoi Tessellation ◽  
Tangent Plane ◽  
Linear Functions ◽  
Piecewise Linear Functions ◽  
Dual Transformation ◽  
Delaunay Mesh ◽  
Definition Of

We describe a sense in which mesh duality is equivalent to Legendre duality. That is, a general pair of meshes, which satisfy a definition of duality for meshes, are shown to be the projection of a pair of piecewise linear functions that are dual to each other in the sense of a Legendre dual transformation. In applications the latter functions can be a tangent plane approximation to a smoother function, and a chordal plane approximation to its Legendre dual. Convex examples include one from meteorology, and also the relation between the Delaunay mesh and the Voronoi tessellation. The latter are shown to be the projections of tangent plane and chordal approximations to the same paraboloid.

scholarly journals Polyhedral DC Decomposition and DCA Optimization of Piecewise Linear Functions

Algorithms ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 166 ◽  
Author(s):  
Andreas Griewank ◽  
Andrea Walther
Keyword(s):  
Piecewise Linear ◽  
Linear Representation ◽  
Local Minimizer ◽  
Descent Method ◽  
Linear Functions ◽  
Steepest Descent Method ◽  
Piecewise Linear Functions ◽  
Piecewise Linearization ◽  
Algorithmic Differentiation ◽  
Concave Part

For piecewise linear functions f : R n ↦ R we show how their abs-linear representation can be extended to yield simultaneously their decomposition into a convex f ˇ and a concave part f ^ , including a pair of generalized gradients g ˇ ∈ R n ∋ g ^ . The latter satisfy strict chain rules and can be computed in the reverse mode of algorithmic differentiation, at a small multiple of the cost of evaluating f itself. It is shown how f ˇ and f ^ can be expressed as a single maximum and a single minimum of affine functions, respectively. The two subgradients g ˇ and − g ^ are then used to drive DCA algorithms, where the (convex) inner problem can be solved in finitely many steps, e.g., by a Simplex variant or the true steepest descent method. Using a reflection technique to update the gradients of the concave part, one can ensure finite convergence to a local minimizer of f, provided the Linear Independence Kink Qualification holds. For piecewise smooth objectives the approach can be used as an inner method for successive piecewise linearization.

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