In this paper, we present an improvement on the discrete wavelet transform (DWT)-based feature extraction algorithm used in vehicle classification in Wireless Sensor Networks (WSN) [1] by providing a rule of selecting...
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An efficient framework utilizing both local features and geometrical distribution for detecting facial components is presented. First, candidate facial components are efficiently collected by cascaded boosting of Haar...
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An X-ray tube spectra measuring method is presented in this paper. The measurement is accomplished by reconstruction from attenuation data based on a nine-parameter tungsten anode X-ray spectral model. The proposed mo...
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ISBN:
(纸本)0819461857
An X-ray tube spectra measuring method is presented in this paper. The measurement is accomplished by reconstruction from attenuation data based on a nine-parameter tungsten anode X-ray spectral model. The proposed model is derived from a physical basis and composed of three parts: bremsstrahlung spectra, photoemission attenuation by X-ray tube inherent and added filter, characteristic radiations denoted by four Dirac delta functions. Firstly, for simplicity, the four characteristic radiations of the spectra model are merged into two according to a reasonable hypothesis. Secondly, the spectra reconstruction based on the modified model is carried out by calculating the model parameters from measured attenuation data. To further improve stability, two kinds of materials are used as the attenuators. Experiments show that this method can reach high precision and is insensitive to the noise in measured attenuation data. From the 10 measured attenuation data (7 from Al, and 3 from Copper) with 5% Poisson noise added, the precision of the reconstructed spectra can reach 98.56% for the 70kVp X-ray tube with tiny characteristic radiation, and 98.24% for the 120kVp X-ray tube with characteristic radiation. Spectrum is the characteristic of X-ray tube and widely used for many purposes. In engineering, the spectrum is mostly reconstructed from attenuation data, which is an ill-posed problem in mathematics. The method we presented with the features of including characteristic radiation, insensitive to noise and demanding fewer attenuation data will help to solve this problem perfectly.
image segmentation is an important research topic in imageprocessing and computer vision community. In this paper, a new unsupervised method for MR brain image segmentation is proposed based on fuzzy c-means (FCM) an...
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The PnP problem is a widely used technique for pose determination in computer vision community,and finding out geometric conditions of multiple solutions is the ultimate and most desirable goal of the multi-solution a...
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The PnP problem is a widely used technique for pose determination in computer vision community,and finding out geometric conditions of multiple solutions is the ultimate and most desirable goal of the multi-solution analysis,which is also a key research issue of the *** this paper,we prove that given 3 control points,if the camera's optical center lies on the so-called“danger cylinder”and is enough far from the supporting plane of control points,the corresponding P3P problem must have 3 positive *** result can bring some new insights into a better understanding of the multi-solution *** example,it is shown in the literature that the solution of the P3P problem is instable if the optical center lies on this danger cylinder,we think such occurrence of triple-solution is the primary source of this instability.
In this paper, we employ the concept of characteristic line to show some useful properties of planar homography matrix. These properties relate the characteristic line of a planar homography matrix with Euler angles o...
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A new Fuzzy ART neural network model based on dual competition and resonance technique is proposed. This new model takes the competition and resonance method of the input nodes into the output nodes, putting the input...
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The work presented in this paper mainly focuses on designing a monolithic current-mode boost DC-DC converter with integrated 22V DMOS FET power switch and control circuits. The boost converter operating at fixed frequ...
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The work presented in this paper mainly focuses on designing a monolithic current-mode boost DC-DC converter with integrated 22V DMOS FET power switch and control circuits. The boost converter operating at fixed frequency of 1.6MHz has been fabricated with a 1.5μm Bipolar-CMOS-DMOS (BCD) process. The chip with features of wide input voltage range (2.7V to 14V), high efficiency over large load range (1mA to 500mA), low shutdown current, fast transient response and low power, was designed for mobile power management applications. Besides issues such as technology choice, power switch optimization and ramp compensation, the paper also copes with the monolithic switching noise in switching power IC circuits.
In real-world applications, selecting the appropriate hyper-parameters for support vector machines (SVM) is a difficult and vital step which impacts the generalization capability and classification performance of clas...
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In recent years, iris recognition has become a pro-active topic in both research and practical applications. In general, a typical iris recognition system includes iris preprocessing, feature extraction, and recogniti...
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In recent years, iris recognition has become a pro-active topic in both research and practical applications. In general, a typical iris recognition system includes iris preprocessing, feature extraction, and recognition. In this paper, an efficient iris recognition system is illustrated. The major procedure includes three steps: 1) the geometrical method is used to localize the pupil;2) in order to reduce computational cost, the outer (or limbus) boundary is localized using the shrunk image with the Hough transform and modified Canny edge detector;3) Log-Gabor filter is adopted to capture local and global characteristics of the iris. The phase of the filtered iris is recorded as features. The proposed method is implemented and tested on two iris database sets, i. e CASIA and SJTU-IDB, with different contrast quality. The experimental results show that the performance of the proposed method is encouraging.
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