共查询到20条相似文献，搜索用时 218 毫秒
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Noriaki Suetake Go Tanaka Hayato Hashii Eiji Uchino 《Journal of The Franklin Institute》2012,349(8):2570-2584
As the filter which can effectively remove the small amplitude noises on digital images, the has been proposed. In order to effectively use this filter, a smoothing parameter should be appropriately estimated before applying it. To address this problem, the authors proposed the parameter estimation method based on Hellinger distance (HD). In the method, HD between a residual signal and assumed noise distribution was evaluated, and a parameter of the was estimated by finding the value giving minimum distance. However, the enough discussion on use of HD has not been made.In this paper, it is attempted to utilize not only the HD, but also various distribution distances in the parameter estimation, and their performances and characteristics are compared and analyzed experimentally. Furthermore, the parameter estimation method is extended to be applicable for the vector for the color images. Consequently, through the experiments, it is shown that L1-norm or maximum norm is appropriate as the distribution distance used in the parameter estimation methods from the view points of the simplicity of the calculation and MSE performance in the filtering. 相似文献
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Akbar Zada Bakht Zada Jinde Cao Tongxing Li 《Journal of The Franklin Institute》2017,354(14):6247-6257
Let {Πτ(m, n): m?≥?n?≥?0} be the family of periodic discrete transition matrices generated by bounded valued square matrices Λτ(n), where is an arbitrary switching signal. We prove that the family {Πτ(m, n): m?≥?n?≥?0} of bounded linear operator is uniformly exponentially stable if and only if the sequence is bounded. 相似文献
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Shen Kang Jianan Wang Chaoyong Li Jiayuan Shan 《Journal of The Franklin Institute》2018,355(16):8027-8048
This paper presents an optimal solution to asteroid soft landing problem, on the base of control technique and disturbance rejection mechanism. The control objective is to drive a probe to reach the surface of an asteroid with a desirable line-of-sight angle and zero velocity, eliminating the influence of external disturbance. Firstly, elementary technique is applied in the absence of disturbance to tackle the nonlinear optimal control problem. Secondly, the disturbance is estimated in the fast-estimation framework with explicitly bounded estimation error. Afterwards, an integrated control protocol is presented in a feed-forward structure by the aid of an additional variable-structure term to ensure stability under time-varying disturbance. Simulation results of the proposed approach compared with the results of elementary method and robust method are presented at the end of this paper, demonstrating the effectiveness of the proposed control protocol. 相似文献
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Xiongping Dai Tingwen Huang Yu Huang Yi Luo Gang Wang Mingqing Xiao 《Journal of The Franklin Institute》2017,354(10):4126-4155
Given any finite family of real d-by-d nonsingular matrices by extending the well-known Li–Yorke chaos of a deterministic nonlinear dynamical system to a discrete-time linear inclusion or hybrid or switched system:
we study the chaotic dynamics of the state trajectory (xn(x0, σ))n ≥ 1 with initial state governed by a switching law . Two sufficient conditions are given so that for a “large” set of switching laws σ, there exhibits the scrambled dynamics as follows: for all This implies that there coexist positive, zero and negative Lyapunov exponents and that the trajectories (xn(x0, σ))n ≥ 1 are extremely sensitive to the initial states . We also show that a periodically stable linear inclusion system, which may be product unbounded, does not exhibit any such chaotic behavior. An explicit simple example shows the discontinuity of Lyapunov exponents with respect to the switching laws. 相似文献
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Fengxia Zhang Musheng Wei Ying Li Jianli Zhao 《Journal of The Franklin Institute》2018,355(3):1296-1310
In this paper, by applying the real representations of complex matrices, the particular structure of the real representations and the Moore–Penrose generalized inverse, we obtain the explicit expression of the minimal norm least squares Hermitian solution of the complex matrix equation . And we also derive the minimal norm least squares Hermitian solution of the complex matrix equation . Our proposed formulas only involve real matrices, and therefore are more effective and portable than those reported in Yuan and Liao (2014). The corresponding algorithms only perform real arithmetic which also consider the particular structure of the real representations of complex matrices. Two numerical examples are provided to demonstrate the effectiveness of our algorithms. 相似文献