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Pulmonary crackles are used as indicators for the diagnosis of different pulmonary disorders. Crackles are very common adventitious sounds which have transient characteristics. From the characteristics of crackles such as timing and number of occurrences, the type and the severity of the pulmonary diseases can be obtained. In this study, a method is proposed for crackle detection. In this method,...
In this work, we present a sequence generator module on FPGA that provides the generation of K-distributed samples used in sea clutter modelling. Sequence generator is obtained by modification of widely used Box-Muller based Gaussian sequence generators into Rayleigh and Gamma sequence generators. The sqrt and ln functions in Box-Muller algorithm are approximated using piecewise polynomial function...
Near codewords of low-density parity-check (LDPC) codes are known to be one of the main reasons of errors that occur in decoding. For high signal-to-noise ratios, these codewords cause error floors in decoding and they are called trapping sets. Especially, trapping sets with small size devastate the performance of communication systems that use LDPC codes. Unfortunately, trapping sets are difficult...
In this study, the performance of constant false alarm rate (CFAR) processors in nonhomogeneous clutter background is analyzed. The nonhomogeneous clutter power is modeled as varying linearly in logarithmic scale from one low fixed level to a high fixed level, rather than modeled as an abrupt change. For different values of the linearly varying clutter power region width with respect to the reference...
In this work, a concatenated forward error correction (FEC) scheme together with Orthogonal Frequency Division Multiplexing (OFDM) have been used for effective transmission of data/images over additive and fading channels. With a Bose Chaudhuri Hocquenghem (BCH) code as the outer code and a Low Density Parity Check (LDPC) code as the inner code, the transmission has been simulated over both the Gilbert-Elliot...
In this paper, data acquired from five sensory units mounted on the human body, each containing a tri-axial accelerometer, gyroscope, and magnetometer, during 19 different human activities is used to calculate inter-subject and inter-activity variations using different methods and the results are summarized in various forms. Absolute, Euclidean, and dynamic time-warping distances are used to assess...
In this paper, a minimum bit-error rate (MBER) linear multi-user detection (MUD) algorithm for time-varying frequency-selective fading direct-sequence code-division multiple-access (DS-CDMA) channels is proposed. The BER cost function of the MUD is highly non-linear and may have several local minimum. It is shown that with some appropriate constraints the MBER MUD problem is equivalent to a constrained...
This paper presents a modified sectoral sweeper based localization estimation (SSLE) method which is improved version of our previously proposed SSLE technique and it's modeling in OPNET. Simplified message formats are required by this technique. Only a central node estimates locations of sensor nodes, which needs to have smart antenna processing capability. The modified SSLE is modeled using OPNET...
In this study, an approach is developed for automatic gender classification from human face images. For representing the face images, different kinds of feature extraction methods (Local Binary Pattern operator, Gabor filtering, Local Gabor Binary Pattern operator) are used. The feature vectors are tested with AdaBoost and Support Vector Machine (SVM) algorithms. The experiments conducted on the face...
In this paper, an ECG beat clustering method based on fuzzy c-means algorithm and particle swarm optimization is proposed. For this purpose, ECG records which are selected from MIT-BIH arrhythmia database are firstly preprocessed and then four morphological features are extracted for six different types of beats. These features are then clustered with the proposed method. During the classification...
In this paper, using “context tree weighting method”, a novel classification algorithm is proposed for real time machine learning applications, which is mathematically shown to be “competitive” with respect to a certain class of algorithms. The computational complexity of our algorithm is independent with the amount of data to be processed and linearly controllable. The proposed algorithm, hence,...
In this study, a new adaptive post-filtering algorithm is proposed to remove observed blocking artifacts as a result of discrete cosine transform (DCT) based image and video compression standarts at low bit rates. With identification of blocking artifact strength, fuzzy filter is applied by adjusting filtering range and its parameters. Experimental results showed that, the proposed algorithm exhibits...
The oscillating and swinging parts of a target observed by radar cause additional frequency modulation and induce sidebands in the target's Doppler frequency shift (micro-Doppler). This effect provides unique features for classification in radar systems. In this paper, the micro-Doppler spectra and range-Doppler matrices of single bird and bird flocks are obtained by simulations for linear FMCW radar...
An efficient graph based image segmentation algorithm exploiting a novel and fast turbo pixel extraction method is introduced. The images are modeled as weighted graphs whose nodes correspond to super pixels; and normalized cuts are utilized to obtain final segmentation. Utilizing super pixels provides an efficient and compact representation; the graph complexity decreases by hundreds in terms of...
In this study, a series of methods with some contributions have been proposed in order to segment brain tissues affected by the multiple sclerosis (MS). Since MS disease usually occurs in white matter of the brain and noting that corpus callosum is the largest white matter structure in the brain, filtering out the parts of corpus callosum that are not affected by disease helps improve segmentation...
How much people's thought processes are similar to each other? Modeling the thought processes is one of the questions that still preserves the mystery of the world. Thought process cannot be directly observed. But it is possible to measure indirectly with its products such as speaking, writing. In this study, word paths of several texts were constructed. For this purpose, firstly, the semantic coordinates...
In this paper, convexity properties of outage probability are investigated under Rayleigh fading for an average power-constrained communications system that employs maximal-ratio combining (MRC) at the receiver. By studying the first and second order derivatives of the outage probability with respect to the transmitted signal power, it is found out that the outage probability is a monotonically decreasing...
Snow attenuation depends on many factors which are hard to observe and identify or classify. Modeling of snow attenuation is relatively complex. There are two main classes of methods used in snow attenuation prediction: the empirical method and the physical method. Physical method which we used in this work focuses on reproducing the physical behavior of factors involved in the process. The attenuation...
In this paper, we discuss a communication network with a cooperative transmitter and relay. The receiver calculates the hard decisions of received symbols from the observations obtained from the relay and the transmitter. The calculation of log-likelihood ratio at the receiver requires marginalization over a joint density, which is known to be bear high complexity in general. Marginalization over...
In this paper, a new equivalent relay channel model is developed for analyzing the error performance of detect-and-forward (DetF) relay networks and is compared to the minimum equivalent relay channel model typically used in DetF systems. The considered cooperative relay network comprises two users, single destination, 4-ary Galois field (GF(4)) network coded, QPSK modulated, DetF in a flat Rayleigh...
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