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A visual inertial fusion method is proposed in this paper for the state estimation and control of a low-cost Unmanned Aerial Vehicle. A binary template matching algorithm is combined with a gradient based algorithm to compute optic flow (OF). The proposed OF method is capable of handling large displacement, illumination variation and gives subpixel accuracy. With a ground plane assumption, the Jacobian...
This paper presents the development of a new method for parameter estimation in linear state space model. The proposed method is based on a Rao-Blackwellised particle filter. The simulation results with a railway vehicle dynamic model are provided which demonstrate the effectiveness of the proposed method in comparison with the conventional EKF-based method.
A class of strict-feedback nonlinear systems with unknown system functions and time delays are considered in this paper. Nonlinearly parameterized fuzzy systems with adaptive mechanism are employed to approximate the unknown functions in a backstepping procedure. By using Taylor series expansion, the parameters are separated successfully, then adaptive laws can be designed to update them on-line....
Interleaving, an important technique in digital wireless communications systems, is commonly used to improve robustness against burst errors because it provides a form of time diversity. The unitive mathematical model of the convolutional interleaver was presented for the first time and the blind estimation of convolutional interleaving parameters has been investigated using the linearity of the linear...
In wireless sensor networks (WSNs), jamming attacks have become a great concern recently. Finding the location of a jamming device is important so as to take security actions against the jammer and restore the network communication. In this paper, we take a comprehensive study on the jammer localization problem, and propose a simple while effective algorithm called Double Circle Localization (DCL)...
Jamming attack is one of the most severe attacks in wireless sensor networks (WSNs). While existing countermeasures mainly focus on designing new communication mechanisms to survive under jamming, an alternative solution is to first localize the jammer(s) and then take necessary actions. In this work, we solve a multi-jammer localization problem, where multiple jammers launch collaborative jamming...
Precession is significant for midcourse discrimination. By modelling micro-Doppler of spatial precession cone and analysing its modulation characteristic, an instantaneous frequency estimation method based on an effective quadratic time-frequency analysis technique named S-method combined with the inverse Radon transform is proposed to extract micro-Doppler feature. Simulation results with electromagnetic...
The ratio of NPLs (non-performance loan) is one of the important indexes of assessing the security of credit assets, as well as it is an essential financial indicator to overall strength in commercial banks. In this paper we establish a time series model for the ratio of NPLs of Chinese state-owned commercial banks, taking the statistical data of the NPLs from 2002 to 2010 as an example, basing on...
In the MIMO-OFDM system channel estimation based on the superimposed pilot is one of most potential and powerful techniques for broad-band wireless communications. In most traditional algorithms, the channel parameters are estimated by calculating the first-order statistical properties of receiving information. However, there are some limitations in such methods. These methods require the first-order...
Stepping stone attacks are often used by network intruders to hide their identities. The Round Trip Times (RTT) between the send packets and corresponding echo packets for the connection chains of stepping stones are critical for detecting such attacks. In this paper, we propose a novel real-time RTT getting algorithm for stepping stones which is based on the estimation of the current RTT value. Our...
For Micro Aerial vehicles (MAV) flying low in the city, an attitude estimation method based on machine vision is presented. First, the method detects the straight edge lines using Hough transform from the downward looking images captured. Then, a voting scheme that uses pixels as accumulators is applied to simultaneously evaluate the vertical edge lines of buildings and the vanishing point at which...
Numerous studies for non-circular signals are being conducted to improve the performance of systems. However, the studies of Non-Circular MUSIC (NC-MUSIC) method include mostly uniform linear arrays and not as much effort has been devoted to other configurations. This paper extends the Non-circular MUSIC for the rectangular array. The simulation shows the NC-MUSIC method has a higher resolution and...
An intelligent water pipe leak detection and location instrument is developed based on adaptive filtering methods. To achieve its better performance in lower SNR and nonstationary environments, the paper studies two information processing schemes: bias-free LMS time delay estimation(LMSTDE) and real-time evaluation of the adaptive estimation result by dynamically discriminating the adaptation's convergence...
Multiple SAR images of the same area from slightly different slant angles show relative spectral shifts, which is used to improve the slant range resolution by combining their spectra. In the paper, an optimization modal, which maximizes the combined image's amplitude, is proposed to estimate the spectral shift. Simulated data show that the proposed estimation method is more precise than the interferometric...
The posterior union decision-based neural network (PUD-BNN) has been proposed in our previous work for dealing with face recognition task subject to partial occlusion and distortion. However, one difficult of this method is inaccurate to model classes with only a single, or a small number of training samples. In this paper, we proposed an extern approach to tackle above problem by two strategies....
In this paper, we propose a low-complexity iterative joint channel estimation, detection and decoding technique for doubly selective channels. The key is a segment-by-segment frequency domain equalization (FDE) strategy under the assumption that channel is approximately static within a short segment. Guard gaps (for cyclic prefixing or zero padding) are not required between adjacent segments, which...
Losses due to leaking is severe in underground pipes, which necessitates studies on techniques for detecting and locating the leaks. The classical adaptive time delay estimation method, LMSTDE, will give a biased estimate when input data are contaminated with noise. This paper develops and analyses a new adaptive filter structure for time delay estimation (TDE), which can eliminate this bias. Simulation...
In this paper, we propose a novel distributed weighting fault-tolerant algorithm for event region detection in wireless sensor networks. Considering the fault-tolerant range of ldquoneighborhoodpsilas neighborhoodrdquo, we first employ neighborhood nodes to exchange information with its surrounding nodes and estimate the status value of neighborhood nodes, and then weight and synthesize the estimating...
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