Meta-elliptical copulas are often proposed to model dependence between the components of a random vector. They are specified by a correlation matrix and a map g, called density generator. While the latter correlation ...
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Meta-elliptical copulas are often proposed to model dependence between the components of a random vector. They are specified by a correlation matrix and a map g, called density generator. While the latter correlation matrix can easily be estimated from pseudo-samples of observations, the density generator is harder to estimate, especially when it does not belong to a parametric family. We give sufficient conditions to non parametrically identify this generator. Several nonparametric estimators of g are then proposed, by M-estimation, simulation-based inference, or by an iterative procedure available in the R package ElliptCopulas. Some simulations illustrate the relevance of the latter method. (C) 2022 Elsevier Inc. All rights reserved.
The purpose of this paper is to study the boundedness of the tracking position error of robot controls based on the computed-torque method. It is seen that the nature of the input vector bears heavily on the results: ...
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The purpose of this paper is to study the boundedness of the tracking position error of robot controls based on the computed-torque method. It is seen that the nature of the input vector bears heavily on the results: only resolved-acceleration input permits to null the error. The later part of the Paper deals with the robustness of the conventional computed-torque structure and in particular, with a robust recursive control algorithm for robots proposed in a previous paper
Image segmentation is a key part in image processing field Though traditional threshold methods based on maximum entropy principle could sometimes divide the image into object and background, the size of search space ...
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ISBN:
(纸本)9781424417339
Image segmentation is a key part in image processing field Though traditional threshold methods based on maximum entropy principle could sometimes divide the image into object and background, the size of search space increase very rapidly when the number of parameters needed to determine the membership function increase, so it's time-consuming is often an obstacle. In this paper, based on the traditional threshold methods, the membership function is simplified and a new recursive scheme is introduced which decreases the computation complexity of the traditional method. The approach does not need the calculation of the membership function and increases the calculated speed. The experiments prove this novel approach is not only segment accuracy, but also decrease the computation time. Comparing with the traditional methods, the new method shows better real timing and noise restraining performance.
The function-valued Pade-type approximant(FPTA) was defined in the inner product *** this work,we choose coefficients in the Neumann power series to make the inner product with both sides of a function-valued system o...
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The function-valued Pade-type approximant(FPTA) was defined in the inner product *** this work,we choose coefficients in the Neumann power series to make the inner product with both sides of a function-valued system of equations to yield a scalar *** we express an FPTA in the determinant *** avoid the direct computation of the determinants,we expand the Sylvester theorem to the function-valued case called the Sylvester-type algorithm (FPTAVSA).The numerical experimentation for a typical integral equation illustrates that the method of FPTAVSA is simpler and more effective for obtaining the characteristic values and the characteristic function than all previous methods.
The growing complexity of computational modelling and its applications demands the simplicity of mathematical equations and techniques for solving today's scientific problems and challenges. This paper presents a ...
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The growing complexity of computational modelling and its applications demands the simplicity of mathematical equations and techniques for solving today's scientific problems and challenges. This paper presents a model of iterative computation that deals with design and optimization of recursive formulae related to series and summability with real-time function.
Bidirectional hindsight options are a kind of exotic options. In the constant elasticity of variance (CEV) model, a combining binomial tree was built up to approximate the non- constant volatility that is a function o...
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Bidirectional hindsight options are a kind of exotic options. In the constant elasticity of variance (CEV) model, a combining binomial tree was built up to approximate the non- constant volatility that is a function of the underlying asset. On this basis, a simple and efficient recursive algorithm was developed to compute the risk-neutral probability of each different node for the underlying asset reaching maximum or minimum price and the total number of maxima (minima) in the binomial tree. With help of it, the computational problems can be effectively solved arising from the inherent complexities of different types of bidirectional hindsight options when the underlying asset evolves as the CEV model. Numerical results demonstrate the validity and the convergence of the binomial approach for the different parameter values set in CEV model.
The key point of robot dynamics is optimal design and control. The efficiency of robot dynamics has been the goal of researchers in recent years. Lie Algebra and Screws are used to describe dynamic problems in this pa...
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The key point of robot dynamics is optimal design and control. The efficiency of robot dynamics has been the goal of researchers in recent years. Lie Algebra and Screws are used to describe dynamic problems in this paper, and an O(N) recursive robot forward dynamic algorithm is given on this. The results show that dynamics described with screws are helpful in high efficient dynamics modeling. The dynamical expressions based on screws are concise and clear. The computed torque control law is used to simulate with the results of dynamics. Compared with the simulation result of PID control law, the computed torque control law has better performance.
Analyzed in detail the storage structures of tree, forest and binary tree, introduced the design ideas of the recursive algorithms about transformation between the forests and the corresponding binary trees, gave the ...
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Analyzed in detail the storage structures of tree, forest and binary tree, introduced the design ideas of the recursive algorithms about transformation between the forests and the corresponding binary trees, gave the descriptions of the recursive algorithms in C, and then analyzed the algorithms and evaluated them from the two aspects of time complexity and space complexity.
A new method of global optimal planning for mobile robot navigation in environment with random obstacles is proposed using the first local then global path planning strategy. This method includes three main algorithms...
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A new method of global optimal planning for mobile robot navigation in environment with random obstacles is proposed using the first local then global path planning strategy. This method includes three main algorithms: the first one utilizes the global path planning method based on target direction angle tracking modeling;the second is the evaluation sub-target point method based on recursive algorithm;the third one makes use of the local trajectory planning method based on quantum-behaved particle swarm optimization. The results from simulation experiments show that the proposed method is effective and can be used in the real-time path planning of mobile robots. It also demonstrates that current method performs better than the method based on the first global followed by local path planning modeling.
Some modifications of the algorithm of image construction with a high sampling frequency are proposed. These modifications multiply reduce the computational costs with an almost unchanged quality of the result. Softwa...
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Some modifications of the algorithm of image construction with a high sampling frequency are proposed. These modifications multiply reduce the computational costs with an almost unchanged quality of the result. Software implementation of the proposed modifications of the algorithm allows the latter to be used in video surveillance systems for real-time formation of high-quality image fragments.
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