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This paper presents a new wavelet domain adaptive despeckling technique for contrast enhancement of medical ultrasound (US) images for improving the clinical diagnosis. This method uses the Rayleigh distribution for modeling the speckle wavelet coefficients and the signal wavelet coefficients are approximated using the Gaussian distribution. Combining these as statistical priors, we have developed...
The original electrical signals in Crassula portulacea were tested by a touching test used platinum sensors in a system of self-made double shields. Tested data of the electrical signals were denoised by the wavelet soft threshold and using Gaussian radial base function (RBF) as the time series at a delayed input window chosen at 50. An intelligent RBF forecasting system was set up to forecast the...
Based on the researches of LSB (least significant bit, i.e. the last bit of a binary pixel value) matching steganographic method and the steganalytic method which aims at histograms of cover images, this paper proposes a new LSB matching steganographic method. A steganographic information table is defined to record the changes which are introduced by the embedded secrete bits. According to the table,...
A modified Sobel edge detection is proposed in this paper. Dempster-Shafer theory, also known as the theory of belief function, is applied to improve the drawbacks of the conventional Sobel operator, for instance, the thick edge and sensitive to noise. The reason is that by selecting the mass function, Dempster-Shafer theory can distinguish the edge pixels from the uncertain edge pixels correctly,...
As a method of image feature extraction, centroid detection algorithm has been applied in many fields. Uncertainty evaluation of centroid detection is an important approach to evaluating the reliability of centroid detection. This paper presents a new method for uncertainty evaluation of centroid detection. The uncertainty associated with the intensity of a pixel, which involves in centroid detection,...
The Middleton class A interference model is a statistical-physical and parametric model for man-made and natural electromagnetic (EM) interference. In this paper, the efficient estimation of the Class A model parameters based on least square gradient method is derived. The considered estimator converges fast and low-complexity with performance approaching theoretical optima for large data samples...
Many packet-based clock recovery algorithms use only a subset of timing packet arrivals to discipline the local oscillator. One commonly used selection process is to partition the time into non-overlapping windows and, for each window, select only the one that had the smallest network transit time. This process is a non-linear filter, developed mostly based on intuition and widely accepted by many...
In this paper, we apply a method to view two-dimensional magnetic recording (TDMR) system as a binary error and erasure channel to experimentally determine some bounds on capacity for the TDMR channel. We analyze two different TDMR read-channel models, Voronoi-grain model and random-grain model, to determine the effects of write-errors on the capacity bounds.
This paper describes a practical several moving objects area extraction using a half-cosine function wavelet network. The network decomposes an image into weighted basis functions corresponding to spatial frequency. In this method, objects are distinguished by using a difference of object's size. First, moving objects area can be extracted from the weight image of the basis functions which constructs...
In this paper, a novel radial basis function (RBF) neural network is proposed and applied successively for online stable identification and control of nonlinear discrete-time systems. The proposed RBF network is a one hidden layer neural network (NN) with its all parameters being adaptable. The RBF network parameters are optimized by gradient descent method with stable learning rate whose stable convergence...
In order to deal with the inverse problem in aperture synthesis radiometers (ASRs) imaging, some deterministic inversion algorithms are proposed. However, these inversion algorithms are deficient in utilizing the statistical properties of visibility samples and reconstructed image. In this paper, the probability density functions of visibility samples and pixels of reconstructed image are investigated...
The problem of tracking small objects poses a number of challenges, which dues to the ambiguity of the observations and the presence of partial or complete occlusions. In this paper an efficient method of tracking before detecting for small object is proposed in the low signal to noise ratio image sequences under complex background. In the tracking phase, we introduce auxiliary particle filter to...
In Global Navigation Satellite Systems (GNSS) positioning, the receiver measures the pseudoranges with respect to each observable navigation satellite and determines the user position. The use of many constellations should lead to highly available, highly accurate navigation anywhere. However, it is important to notice that even if modern receivers achieve high position accuracy in line-of-sight (LOS)...
Low amplitude impulsive noise measurements have been carried out in the time domain on a vehicle power line network. These measurements were made on a stationary vehicle and the motor idling. The characteristics of the measured low amplitude pulses were studied in terms of amplitude, frequency, duration and time interval between successive pulses. Stochastic models based on mathematical distribution...
In this study, the effects of adding independent noise to observations of a suboptimal detector are studied for M-ary hypothesis-testing problems according to the minimax criterion. It is shown that the optimal additional noise can be represented by a randomization of at most M signal values under certain conditions. In addition, a convex relaxation approach is proposed to obtain an accurate approximation...
The sound radiation from transport facilities moved about city road is investigated theoretically with respect of the velocity and direction of wind. Solution for one moving sound source is presented by a sum of two waves, radiated from source and reflected from an elastic half-space. The solution for general problem is obtained as superposition of the many partial solutions. Calculated results for...
The noise propagation from moving sources on city controlled intersection with taking into account the wind velocity and direction of is investigated. The acoustic field is described as the waves superposition from many point sources, moving in two one-to-one perpendicular directions. Numerical results are obtained for acoustic pressure and sound intensity generated, in particular, on crossroad near...
Usually, source separation in Post-Nonlinear (PNL) models is achieved via one-stage methods, i.e. the two parts (linear and nonlinear) of a PNL model are dealt with at the same time. However, recent works have shown that the development of two-stage techniques may simplify the problem. Indeed, if the nonlinear stage can be compensated separately, then, in a second moment, one can make use of the well-established...
Non-negative matrix factorization (NMF) is an algorithm for decomposing multivariate data into a signal dictionary and its corresponding activations. When applied to experimental data, NMF has to cope with noise, which is often highly correlated. We show that correlated noise can break the Donoho and Stodden separability conditions of a dataset and a regular NMF algorithm will fail to decompose it,...
The paper deals with the statistical characterization of the so-called r.m.s. value of a harmonic subgroup defined in the Standard IEC 61000-4-7 regarding harmonics and interharmonics measurements and instrumentation for power supply systems and equipment connected thereto. A complete statistical characterization is provided in terms of probability density function, cumulative distribution function,...
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