翻訳と辞書
Words near each other
・ Tensor (disambiguation)
・ Tensor (intrinsic definition)
・ Tensor algebra
・ Tensor calculus
・ Tensor contraction
・ Tensor Contraction Engine
・ Tensor density
・ Tensor derivative (continuum mechanics)
・ Tensor fasciae latae muscle
・ Tensor field
・ Tensor glyph
・ Tensor network theory
・ Tensor operator
・ Tensor product
・ Tensor product bundle
Tensor product model transformation
・ Tensor product network
・ Tensor product of algebras
・ Tensor product of fields
・ Tensor product of graphs
・ Tensor product of Hilbert spaces
・ Tensor product of modules
・ Tensor product of quadratic forms
・ Tensor rank decomposition
・ Tensor software
・ Tensor Trucks
・ Tensor tympani muscle
・ Tensor veli palatini muscle
・ Tensor-hom adjunction
・ TensorFlow


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

Tensor product model transformation : ウィキペディア英語版
Tensor product model transformation
In mathematics, the tensor product (TP) model transformation was proposed by Baranyi and Yam

for quasi-LPV (qLPV) control theory. It transforms a function (which can be given via closed formulas or neural networks, fuzzy logic, etc.) into TP function form if such a transformation is possible. If an exact transformation is not possible, then the method determines a TP function that is an approximation of the given function. Hence, the TP model transformation can provide a trade-off between approximation accuracy and complexity.
A free MATLAB implementation of the TP model transformation can be downloaded at () or at MATLAB Central (). A key underpinning of the transformation is the higher-order singular value decomposition.〔
Besides being a transformation of functions, the TP model transformation is also a new concept in qLPV based control which plays a central role in the providing a valuable means of bridging between identification and polytopic systems theories. The TP model transformation is uniquely effective in manipulating the convex hull of polytopic forms, and, as a result has revealed and proved the fact that convex hull manipulation is a necessary and crucial step in achieving optimal solutions and decreasing conservativeness in modern LMI based control theory. Thus, although it is a transformation in a mathematical sense, it has established a conceptually new direction in control theory and has laid the ground for further new approaches towards optimality. Further details on the control theoretical aspects of the TP model transformation can be found here: TP model transformation in control theory.
The TP model transformation motivated the definition of the "HOSVD canonical form of TP functions", on which further information can be found here. It has been proved that the TP model transformation is capable of numerically reconstructing this HOSVD based canonical form.〔 Thus, the TP model transformation can be viewed as a numerical method to compute the HOSVD of functions, which provides exact results if the given function has a TP function structure and approximative results otherwise.
The TP model transformation has recently been extended in order to derive various types of convex TP functions and to manipulate them. This feature has led to new optimization approaches in qLPV system analysis and design, as described here: TP model transformation in control theory.
==Definitions==
;Finite element TP function: A given function f(\in R^N, is a TP function if it has the structure:
:: f(\mathbf)=\sum_^ \sum_^ \ldots \sum_^ \prod_^N w_(x_n) s_,
that is, using compact tensor notation (using the tensor product operation \otimes of ):
:: f(\mathbf)=\mathcal\mathop_^N\mathbf_n(x_n),
where core tensor \mathcal\in \mathcal^ is constructed from s_, and row vector \mathbf_n(x_n), (n=1 \ldots N) contains continuous univariate weighting functions w_(x_n),(i_n=1 \ldots I_n). The function w_(x_n) is the i_n-th weighting function defined on the n-th dimension, and x_n is the n-the element of vector \mathbf. Finite element means that I_n is bounded for all n . For qLPV modelling and control applications a higher structure of TP functions are referred to as TP model.
;Finite element TP model (TP model in short): This is a higher structure of TP function:
:: \mathcal(\mathbf)=\mathcal\boxtimes_^N\mathbf_n(x_n).
Here \mathcal=\mathcal(\in \mathcal^, thus the size of the core tensor is \mathcal\in \mathcal^. The product operator \boxtimes has the same role as \otimes , but expresses the fact that the tensor product is applied on the L_1\times L_2\times ... \times L_O sized tensor elements of the core tensor \mathcal. Vector \mathbf is an element of the closed hypercube \Omega=()\times()\times ... \times()\subset R^N.
;Finite element convex TP function or model: A TP function or model is convex if the wighting functions hold:
:: \forall n : \sum_^ w_(x_n) = 1 and w_(x_n) \in () .
This means that f(\mathbf) is inside the convex hull defined by the core tensor for all \mathbf \in \Omega .
;TP model transformation: Assume a given TP model \mathcal = \mathcal(\mathbf) , where \mathbf\in \Omega \subset R^N, whose TP structure maybe unknown (e.g. it is given by neural networks). The TP model transformation determines its TP structure as
:: \mathcal(\mathbf)=\mathcal\boxtimes_^N\mathbf_n(x_n) ,
namely it generates the core tensor \mathcal and the weighting functions \mathbf_n(x_n) for all n=1 \ldots N . Its free MATLAB implementation is downloadable at () or at MATLAB Central ().
If the given \mathcal(\mathbf) does not have TP structure (i.e. it is not in the class of TP models), then the TP model transformation determines its approximation:〔
:: \mathcal(\mathbf) \approx \mathcal\boxtimes_^N\mathbf_n(x_n),
where trade-off is offered by the TP model transformation between complexity (number of components in the core tensor or the number of weighting functions) and the approximation accuracy. The TP model can be generated according to various constrains. Typical TP models generated by the TP model transformation are:
* HOSVD canonical form of TP functions or TP model (qLPV models),
* Various kinds of TP type polytopic form or convex TP model forms (this advantage is used in qLPV system analysis and design).

抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)
ウィキペディアで「Tensor product model transformation」の詳細全文を読む



スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース

Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.