Wireless sensor networks distributed signal processing has to operate under stringent energy and bandwidth limitations. Usually, the observations need to be quantized before they are sent to fusion center (FC). This p...
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Wireless sensor networks distributed signal processing has to operate under stringent energy and bandwidth limitations. Usually, the observations need to be quantized before they are sent to fusion center (FC). This paper we introduce a multiple bits distributed moving Horizon state estimation approach based on a multiple state single output Gaussian-Markov model. Each sensor node has a thresholds book, then the sensors quantize their measurements to several bits by using the thresholds book which are sent to fusion center. After receiving these information, fusion center make final estimation for system states. Compared with single bit distributed moving horizon state estimation (DMHE), this method ensures that FC need not to send the estimate information back to sensor nodes and provides higher precision of state estimation.
A distributed state estimation scheme based on quantized observations in wireless sensor network (WSN) is proposed. Unlike the SOI-KF approach, we address the state estimation problem in two steps: firstly, local sens...
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A distributed state estimation scheme based on quantized observations in wireless sensor network (WSN) is proposed. Unlike the SOI-KF approach, we address the state estimation problem in two steps: firstly, local sensors and the fusion center apply the decentralized estimation scheme (DES) to design the quantized message function and the fusion function; secondly, the fusion center constructs a linear filter to obtain the state estimation by minimizing an upper bound of the error power norm. The optimal filter is computed by the linear matrix inequality (LMI) solver. An example is presented to demonstrate the efficiency of our method.
Recently, in the smart-card based authentication system, there is an increasing trend of using fingerprint for the card holder verification, instead of passwords. However, the security of the fingerprint data is parti...
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Recently, in the smart-card based authentication system, there is an increasing trend of using fingerprint for the card holder verification, instead of passwords. However, the security of the fingerprint data is particularly important as the possible compromise of the data will be permanent. In this paper, we propose an approach for secure fingerprint verification by distributing both the secret and the computation based on the fuzzy vault (a cryptographic construct which has been proposed for crypto-biometric systems). That is, a user fingerprint template which is applied to the fuzzy vault is divided into two parts, and each part is stored into a smart-card and a server, respectively. At distributing the fingerprint template, we consider both the security level and the verification accuracy. Then, the geometric hashing technique is applied to solve the fingerprint alignment problem, and this computation is also distributed over the combination of the smart-card and the server in the form of the challenge-response. Finally, the polynomial can be reconstructed from the accumulated real points from both the smart-card and the server. Based on the experimental results, we confirm that our proposed approach can perform the fuzzy vault-based fingerprint verification more securely on a combination of a smart-card and a server without significant degradation of the verification accuracy.
In this paper, the mechanical construction, thermal regulator design and temperature measurement system of a local area were set up for large-scale linear measurement. Numerical analysis based on temperature correlate...
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In this paper, the mechanical construction, thermal regulator design and temperature measurement system of a local area were set up for large-scale linear measurement. Numerical analysis based on temperature correlated characteristic is discussed to obtain optimal observation points for the measurements. The horizontal temperature distribution of the measured area is compared with the measurement of the variation of temperature at 15℃ and 20℃ over time, and characteristic of dynamic response is also discussed. In addition, the long-time stability of measured temperature is analyzed by means of using the standard deviation. It characterizes the temperature distribution performance of a large area and how it may impact the measurement of a large-scale object.
annular beam tri-heterodyne confocal microscope has been proposed to improve the anti-environmental interference capability and the resolution of a eonfoeal microscope. It simultaneously detects far-, on-, and near-fo...
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annular beam tri-heterodyne confocal microscope has been proposed to improve the anti-environmental interference capability and the resolution of a eonfoeal microscope. It simultaneously detects far-, on-, and near-focus signals with given phase differences by dividing the measured light path of the eonfoeal microscope into three sub-paths （signals）. Pair-wise real-time heterodyne subtraction of the three signals is used to improve the anti-environmental interference capability, axial resolution, and linearity; and a shaped annular beam super-resolution technique is used to improve lateral resolution. Theoretical analyses and preliminary experiments indicate that an axial resolution of about 1 nm can be achieved with a shaped annular beam tri-heterodyne confoeal microscope and its lateral resolution can be better than 0.2 um for A = 632.8 nm, the numerical aperture of the lens of the microscope is NA = 0.85, and the normalized radius e = 0.5.
A new method is presented to solve the mode mixing problem, which caused by intermittency signal of sifting process of Empirical mode decomposition (EMD). For achieving exact location of intermittency signal, the time...
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ISBN:
(纸本)0980326702
A new method is presented to solve the mode mixing problem, which caused by intermittency signal of sifting process of Empirical mode decomposition (EMD). For achieving exact location of intermittency signal, the time scale difference between intermittency signal and normal background signal, as well as instantaneous frequency characteristic of intrinsic mode function (IMF) are both used in this method. Depending on the located intermittency signal segment, by boundary extending, redo EMD to separate intermittency signal, accordingly removing the influence of intermittency signal in the following EMD. Compare the results of removing intermittency signal using this method with using wavelet method, results indicate that, using this method, the signal distortion is less than wavelet method. And intermittency signal can be decomposed into one FMF.
To resolve the problem of the missile detection in the space early-warning process, an efficient method based on nonlinear adaptive filtering is proposed to detect the small IR target of low SNR under the complex back...
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Spectral irradiance is an important parameter in the fields of aerospace, aviation, national defense and military. Its advance in emissivity measurement has been reviewed during recent years. The apparatus for measuri...
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Spectral irradiance is an important parameter in the fields of aerospace, aviation, national defense and military. Its advance in emissivity measurement has been reviewed during recent years. The apparatus for measuring infrared target simulator was constructed in author's lab by using standard IR Spectro radiometer. Moreover, some applications of measurement technique were reviewed. In the end, the conclusion was made. There is extensive application in the infrared technology of infrared goal simulator. For ensuring the accuracy and availability of transmitting value on measuring infrared radiation, it is necessary to measure and verify the output of the radiation illumination of infrared goal simulator. The principle of method and each part of the measuring device are described, and the method of signal processing is analyzed in this paper.
A molecular dynamics model of nanoelectromechanical (NEM) switch is established and the dynamic characteristic of this model is investigated. The air damping effect on nanostructure is studied and auto-oscillation of ...
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A molecular dynamics model of nanoelectromechanical (NEM) switch is established and the dynamic characteristic of this model is investigated. The air damping effect on nanostructure is studied and auto-oscillation of an atom is simulated when carbon nanotube (CNT) is in balanced state. For obtaining the natural frequency of CNT by means of exerting external force on the end of CNT, the curve of amplitude-frequency response is given too. Finally, the amplitude is analyzed when CNT has resonance vibration in low vacuum. The simulation results show the natural vibration frequency of atom is 2 THz and the natural frequency of CNT is 4.79 GHz. The results also show that the frequency of CNT decreases with the applied force increase at first, but then increases with the force increase, until the switch is closed. Finally, the experiment indicates that if the variation range of pressure is in the same, the amplitude variation under low pressure is higher than that under high pressure.
A novel and precise measurement scheme for the planar object's surface area is proposed. This scheme consists of two steps which are the measurement of the image target's pixel area and the calibration of the ...
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A novel and precise measurement scheme for the planar object's surface area is proposed. This scheme consists of two steps which are the measurement of the image target's pixel area and the calibration of the pixel's size equivalence. A 2D image measuring machine is used to obtain the detected object's image. A cubic B-spline active contour is applied to converge to the target's contour edge. The image target's pixel area is computed with the area formula of a closed cubic B-spline curve. Similarly, the centroid coordinate of the convergent active contour is computed. A novel centroid-self-calibration method is devised, which measures the pixel's size equivalence with the displacement of the centroid coordinate and that measured by a dual-frequency laser. This scheme is applied to measure the small circular aperture's true area in a work surface, which indicates that when the control point number is 20, the measuring repetition error of the true area is less than 0.30%.
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