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 ...
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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...
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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...
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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.
As the trend of future space based information system, networked space based information system can acquire and process all sorts of information more quickly and continuously under the user task scheduling. In the bac...
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ISBN:
(纸本)9787894631046
As the trend of future space based information system, networked space based information system can acquire and process all sorts of information more quickly and continuously under the user task scheduling. In the background of earthquake relief for applications, working flow and main tasks of the system are analyzed, and continuity effectiveness evaluation index system is constructed in multi-task level. The continuity effectiveness is a measurement of intensive degree of information returned. Evaluation model based on grey evaluation method is constructed and different reference indexes are used for different tasks. Examples are given by using statistical data in simulation, and the integrative evaluation results are obtained. Detailed evaluation results in every specific task level are offered, which are helpful to find out the effectiveness bottleneck factors meanwhile provide guidance in system design and development.
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...
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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...
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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...
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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.
Algorithm based on NMI feature matching and Position Prediction for automatic target tracking are develop for realize an DSP based real-time target tracking system. The target is firstly detected with a improved frame...
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ISBN:
(纸本)9787894631046
Algorithm based on NMI feature matching and Position Prediction for automatic target tracking are develop for realize an DSP based real-time target tracking system. The target is firstly detected with a improved frame-difference method, and then the target area is segmented based on threshold segmentation and region growth. The NMI feature is used for matching. Finally a combining forecast algorithm is used in the tracking system. This tracking system is implemented with a DSP controller and software is accomplished on DSP/BIOS operation system. It is proved that it can be meet the needs of real-time stably tracking and overcome the disturbance brought by attitude variances and short time occlusion.
In order to utilize the repetitive information among the video sequence more reasonably, this paper proposes an image mosaicing approach based on space-time manifolds for the video sequence taking the properties of hi...
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ISBN:
(纸本)9787894631046
In order to utilize the repetitive information among the video sequence more reasonably, this paper proposes an image mosaicing approach based on space-time manifolds for the video sequence taking the properties of high-overlapped ratio between neighbor frames and multiple frames into account. Firstly, we iterate Lucas-Kanade optical flow under Gaussian pyramid strategy to compute the motion parameters between neighbor frames with higher accuracy and align the sequence, in the meantime, eliminate the brightness difference among the neighbors combining with the result of motion computation, and then stitch together the whole sequence whose brightness is already uniform into a high resolution image using the space-time manifolds mosaicing technique. It was verified by the experiment that the proposed approach was very effective to video sequences and the mosaicing result was nice.
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...
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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.
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