The Experts below are selected from a list of 163131 Experts worldwide ranked by ideXlab platform

Thomas Kämpke - One of the best experts on this subject based on the ideXlab platform.

  • Constrained quantization
    Signal Processing, 2003
    Co-Authors: Thomas Kämpke
    Abstract:

    Discrete Functions over a continuous domain are approximated by Discrete Functions with fewer levels. These quantizations are endowed with different types of constraints such as monotonicity and variational constraints. Quantization Functions exactly or approximately minimize the squared error to a given Discrete Function. Exact algorithms are derived from dynamic programming with finite horizon. All algorithms have polynomial run time.

Yuriy Ivanov - One of the best experts on this subject based on the ideXlab platform.

  • partial blur model detection deblurring
    DepCoS-RELCOMEX, 2014
    Co-Authors: Dmytro Peleshko, Mariya Rashkevych, Andriy Klyuvak, Yuriy Ivanov
    Abstract:

    Physical process of blurring emergence has been analyzed. It has been proved through conducted experiments that image blurring formation is adequately described by the model based on convolution, i. e. wrapping. It is shown that blurring center or Discrete Function of point scattering comprises information about trajectory and uniformity of motion, which has caused an image distortion. It determined that extreme values number of averaged normalized column values of Fourier image is distorted by artificial blurring correlates with parameters of blurring.

  • DepCoS-RELCOMEX - Partial Blur: Model, Detection, Deblurring
    Proceedings of the Ninth International Conference on Dependability and Complex Systems DepCoS-RELCOMEX. June 30 – July 4 2014 Brunów Poland, 2014
    Co-Authors: Dmytro Peleshko, Mariya Rashkevych, Andriy Klyuvak, Yuriy Ivanov
    Abstract:

    Physical process of blurring emergence has been analyzed. It has been proved through conducted experiments that image blurring formation is adequately described by the model based on convolution, i. e. wrapping. It is shown that blurring center or Discrete Function of point scattering comprises information about trajectory and uniformity of motion, which has caused an image distortion. It determined that extreme values number of averaged normalized column values of Fourier image is distorted by artificial blurring correlates with parameters of blurring.

Vladimir Gurvich - One of the best experts on this subject based on the ideXlab platform.

  • Separable Discrete Functions: recognition and sufficient conditions
    Discrete Mathematics, 2019
    Co-Authors: Endre Boros, Ondrej Cepek, Vladimir Gurvich
    Abstract:

    Abstract A Discrete Function of n variables is a mapping g : X 1 × … × X n → A , where X 1 , … , X n , and A are arbitrary finite sets. Function g is called separable if there exist n Functions g i : X i → A for i = 1 , … , n , such that for every input x 1 , … , x n the Function g ( x 1 , … , x n ) takes one of the values g 1 ( x 1 ) , … , g n ( x n ) . Given a Discrete Function g , it is an interesting problem to ask whether g is separable or not. Although this seems to be a very basic problem concerning Discrete Functions, the complexity of recognition of separable Discrete Functions of n variables is known only for n = 2 . In this paper we will show that a slightly more general recognition problem, when g is not fully but only partially defined, is NP-complete for n ≥ 3 . We will then use this result to show that the recognition of fully defined separable Discrete Functions is NP-complete for n ≥ 4 . The general recognition problem contains the above mentioned special case for n = 2 . This case is well-studied in the context of game theory, where (separable) Discrete Functions of n variables are referred to as (assignable) n -person game forms. There is a known sufficient condition for assignability (separability) of two-person game forms (Discrete Functions of two variables) called (weak) total tightness of a game form. This property can be tested in polynomial time, and can be easily generalized both to higher dimension and to partially defined Functions. We will prove in this paper that weak total tightness implies separability for (partially defined) Discrete Functions of n variables for any n , thus generalizing the above result known for n = 2 . Our proof is constructive. Using a graph-based Discrete algorithm we show how for a given weakly totally tight (partially defined) Discrete Function g of n variables one can construct separating Functions g 1 , … , g n in polynomial time with respect to the size of the input Function.

  • Separable Discrete Functions: recognition and sufficient conditions
    arXiv: Combinatorics, 2017
    Co-Authors: Endre Boros, Ondrej Cepek, Vladimir Gurvich
    Abstract:

    A Discrete Function of $n$ variables is a mapping $g : X_1 \times \ldots \times X_n \rightarrow A$, where $X_1, \ldots, X_n$, and $A$ are arbitrary finite sets. Function $g$ is called {\em separable} if there exist $n$ Functions $g_i : X_i \rightarrow A$ for $i = 1, \ldots, n$, such that for every input $x_1, \ldots ,x_n$ the Function $g(x_1, \ldots, x_n)$ takes one of the values $g_1(x_1), \ldots ,g_n(x_n)$. Given a Discrete Function $g$, it is an interesting problem to ask whether $g$ is separable or not. Although this seems to be a very basic problem concerning Discrete Functions, the complexity of recognition of separable Discrete Functions of $n$ variables is known only for $n=2$. In this paper we will show that a slightly more general recognition problem, when $g$ is not fully but only partially defined, is NP-complete for $n \geq 3$. We will then use this result to show that the recognition of fully defined separable Discrete Functions is NP-complete for $n \geq 4$. The case $n = 2$ is well-studied in the context of game theory, where (separable) Discrete Functions of $n$ variables are referred to as (assignable) $n$-person game forms. There is a known sufficient condition for assignability (separability) of two-person game forms (Discrete Functions of two variables) called (weak) total tightness of a game form. This property can be tested in polynomial time, and can be easily generalized both to higher dimension and to partially defined Functions. We will prove in this paper that weak total tightness implies separability for (partially defined) Discrete Functions of $n$ variables for any $n$, thus generalizing the above result known for $n=2$. Keywords: separable Discrete Functions, totally tight and assignable game forms

Wei Yong - One of the best experts on this subject based on the ideXlab platform.

  • Optimize an Optimal GM(1,1) Based on the Discrete Function with Exponential Law Once Again
    Mathematics in Practice and Theory, 2009
    Co-Authors: Wei Yong
    Abstract:

    This paper analyzes the reason why there exist a error during structuring a new background value in an optimal GM(1,1) based on the Discrete Function with exponential law,although it has improved the modeling precision greatly,and put forward a further optimization method for this reason.Then,obtain a new GM(1,1) model and improve the model precision further.The new model has been proven strictly to have the property of white exponential law coincident,so it not only to be suitable for the low growth sequence,but also suitable for the high growth sequence.Through simulation to a large number of data,and compared with the original GM(1,1) model and the optimal GM(1,1) based on the Discrete Function with exponential law,then we discovered that the new optimized model in this paper has very high simulation and forecasting precision.

Dmytro Peleshko - One of the best experts on this subject based on the ideXlab platform.

  • partial blur model detection deblurring
    DepCoS-RELCOMEX, 2014
    Co-Authors: Dmytro Peleshko, Mariya Rashkevych, Andriy Klyuvak, Yuriy Ivanov
    Abstract:

    Physical process of blurring emergence has been analyzed. It has been proved through conducted experiments that image blurring formation is adequately described by the model based on convolution, i. e. wrapping. It is shown that blurring center or Discrete Function of point scattering comprises information about trajectory and uniformity of motion, which has caused an image distortion. It determined that extreme values number of averaged normalized column values of Fourier image is distorted by artificial blurring correlates with parameters of blurring.

  • DepCoS-RELCOMEX - Partial Blur: Model, Detection, Deblurring
    Proceedings of the Ninth International Conference on Dependability and Complex Systems DepCoS-RELCOMEX. June 30 – July 4 2014 Brunów Poland, 2014
    Co-Authors: Dmytro Peleshko, Mariya Rashkevych, Andriy Klyuvak, Yuriy Ivanov
    Abstract:

    Physical process of blurring emergence has been analyzed. It has been proved through conducted experiments that image blurring formation is adequately described by the model based on convolution, i. e. wrapping. It is shown that blurring center or Discrete Function of point scattering comprises information about trajectory and uniformity of motion, which has caused an image distortion. It determined that extreme values number of averaged normalized column values of Fourier image is distorted by artificial blurring correlates with parameters of blurring.