To answer the problem of ambiguous design levels for large-scale distributed simulation systems, this paper proposes a hierarchical system model based on the quotient space theory. This model consists of a system glob...
详细信息
This paper investigates the synchronization problem of clock oscillators in nonlinear dynamical network with arbitrary time-delays. First, a dynamic synchronization algorithm based on consensus control strategy, named...
详细信息
This paper investigates the synchronization problem of clock oscillators in nonlinear dynamical network with arbitrary time-delays. First, a dynamic synchronization algorithm based on consensus control strategy, named fast averaging synchronization algorithm (FASA), is presented to find a solution to the synchronization problem. This algorithm can compensate the clock skew and offset differences between clock nodes, achieving the synchronization of clock nodes in a shorter time as compared to previous synchronization methods. Second, because of the dynamical performance of FASA, it is characterized from the perspective of compartmental dynamical system with arbitrary time-delays. In this case, the algorithm guarantees the states of all clock nodes in dynamical network converge to Lyapunov stable equilibria. Finally, numerical simulations and experimental results demonstrate the correctness and efficiency of the FASA, which means that the clock nodes can reach global consensus, and the synchronization error can reach nanosecond order of magnitude.
This paper deals with analysis and synthesis problems of spatially interconnected systems where communicated information may get lost between subsystems. Spatial shift operator and temporal forward shift operator are ...
详细信息
This paper deals with analysis and synthesis problems of spatially interconnected systems where communicated information may get lost between subsystems. Spatial shift operator and temporal forward shift operator are introduced to model the interconnected systems as discrete time-space multidimensional linear systems with Markovian jumping parameters which reflect the state of communication channels. To ensure the whole system s well-posedness and mean square stability for a given packet loss rate, a condition is derived through analysis. Then a procedure of designing distributed dynamic output feedback controllers is proposed. The controllers have the same structure as the plants and are solved within the linear matrix inequality (LMI) framework. Finally, we apply these results to study the effect of communication losses on the multiple vehicle platoon controlsystem, which further illustrates the effectiveness of the proposed model and method.
Model order selection and parameter estimation for Gaussian mixture model (GMM) are important issues for clustering analysis and density estimation. Most methods for model selection usually add a penalty term in the o...
详细信息
Model order selection and parameter estimation for Gaussian mixture model (GMM) are important issues for clustering analysis and density estimation. Most methods for model selection usually add a penalty term in the objective function that can penalize the models and choose an optimal one from a set of candidate models. This paper presents a simple and novel approach to determine the number of components and simultaneously estimate the parameters for GMM. By introducing the degenerating model, the proposed approach overcomes the drawback of likelihood estimate that is a non-decreasing function and can not be used to select the number of components. The degenerating model is a more general form of mixture component density and it can degenerate into the component density or a crater-like density when its parameter K varies from 1 to a bigger value. The likelihood of the crater-like density evaluated for the training data approximates to zero. This characteristic of the degenerating model forms the foundation of the proposed approach. The experimental results show robust and evident performance improvement of the approach.
The paper presents a theorem to show the relationship between the parameters of the Moving Average (MA) process and those of its inversed process. The theorem can be used for the parameter identification of the MA pro...
详细信息
The paper presents a theorem to show the relationship between the parameters of the Moving Average (MA) process and those of its inversed process. The theorem can be used for the parameter identification of the MA process. It is further shown in this paper that the parameter identification of autoregressive moving average with exogenous variable model (ARMAX), based on the identification of its MA part, can be easily achieved. The approach, at first, achieves the identification of the ARX part by directly using least-square estimations to find out a straightforward relationship between estimated parameters and observed data. Then, the inversed model of the MA part is identified in a similar way. Finally, the noise variance can be computed by using identified MA parameters. Numerical simulations validate the effectiveness and efficiency of the proposed approach.
In this paper, aimed at the problem of conventional image restore method faced to unknown reason of image degrading, a new IGA(improved GA) is brought out and applied to image restoration. And aimed at image restorati...
详细信息
ISBN:
(纸本)9787894631046
In this paper, aimed at the problem of conventional image restore method faced to unknown reason of image degrading, a new IGA(improved GA) is brought out and applied to image restoration. And aimed at image restoration problem, the operation of heredity, the group strategy, and maintenance the group variety are all improved as a whole. In this algorithm, the Chaos optimization, the mixed selection and elite reservation method are added, so the algorithm of this paper can give attention to both global search ability and convergence speed and it can give out satisfy restoration result.
Model linearization problem is studied for the longitudinal nonlinear dynamics of hypersonic vehicle. Based on parameter-dependent Lyapunov functions, static feedback controller which guarantees the robust tracking pe...
详细信息
ISBN:
(纸本)9787894631046
Model linearization problem is studied for the longitudinal nonlinear dynamics of hypersonic vehicle. Based on parameter-dependent Lyapunov functions, static feedback controller which guarantees the robust tracking performance is designed for the closed-loop system. Finally, the application to numerical example shows the validity of the proposed design approaches.
The error of Code Tracking Loop(CTL) of GPS receiver influences the error of carrier tracking loop in the presence of multipath. The error models of carrier tracking loop are established in the multipath environment w...
详细信息
ISBN:
(纸本)9787894631046
The error of Code Tracking Loop(CTL) of GPS receiver influences the error of carrier tracking loop in the presence of multipath. The error models of carrier tracking loop are established in the multipath environment when the non-coherent Early Minus Late(EML) power mode CTL and the non-coherent Dot-product(DOT) power mode CTL are used. The impacts of multipath parameters and correlator spacing on the error of carrier tracking loop are analyzed by simulation. The simulation results show that the two non-coherent CTLs have little difference in affecting the carrier tracking error. Furthermore, the narrow correlator technology cannot reduce the error of carrier tracking loop.
Angle random walk (ARW) is the noise component at the output of a fiber optic gyroscope (FOG) and it affects the FOG short-term accuracy. Using only the noise property described by random walk coefficient, we develope...
详细信息
ISBN:
(纸本)9787894631046
Angle random walk (ARW) is the noise component at the output of a fiber optic gyroscope (FOG) and it affects the FOG short-term accuracy. Using only the noise property described by random walk coefficient, we developed an unsupervised adaptive filter (UAF) for suppressing the noise. Theoretical analysis illuminates that UAF performs as good as the best FIR filter in the sense of means square. Experimental results both in stationary and non-stationary cases show that UAF is more effective than wavelet denoising and that based on fast fourier transform.
EEG data can be easily influenced by other components in the process of recording, which would thus interfere the analysis. Independent Component Analysis (ICA) is a valid method for blind source separation. It can es...
详细信息
ISBN:
(纸本)9787894631046
EEG data can be easily influenced by other components in the process of recording, which would thus interfere the analysis. Independent Component Analysis (ICA) is a valid method for blind source separation. It can estimate original signals' independent components from observed signals even the original signals and mixing model are unknown. Considering the shortcomings of the application of two ICA algorithms, FastICA and extended Infomax, to EEG artifacts removal, we propose a novel InfastICA algorithm by combing FastICA and extended Infomax. By appling to removal of the EOG artifacts from EEG, test results show that this new algorithm has no special requests to the matrix W's default values and study steps, and has a fast convergence speed, with simple operation and practical application.
暂无评论