In this study, the problem of vehicle detection, tracking and speed estimation in the nighttime traffic surveillance videos captured in highly reflective environments is considered. In this case, a robust algorithm is...
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In this study, the problem of vehicle detection, tracking and speed estimation in the nighttime traffic surveillance videos captured in highly reflective environments is considered. In this case, a robust algorithm is proposed which uses vehicle headlights as their prominent features. The proposed algorithm consists of three main stages. In the first stage, bright objects are segmented by thresholding the grey-scale image. An effective algorithm is then applied to distinguish between vehicles lights and lights reflected on the road and on the vehicles bodies. In the second stage, the segmented bright objects are tracked using their spatial characteristics and their shapes and then, their speeds are estimated. To correct the camera perspective effect and reduce computationalcomplexity, a projective transformation is used. In the third stage, the lights of each vehicle are grouped and paired using their positions and speeds. Motorbikes are also identified among the unpaired lights in this stage. Finally, the proposed real-time system is implemented in C and applied to videos captured by traffic surveillance cameras in some highways in Iran. Experimental results reveal that accuracy of the algorithm proposed for vehicle detection is more than 98%.
The structure matrix with semi-tensor product provides a basic tool for analysing the characteristics of Boolean networks (BNs). Directly calculating the structure matrix of BNs is very complex and requires considerab...
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The structure matrix with semi-tensor product provides a basic tool for analysing the characteristics of Boolean networks (BNs). Directly calculating the structure matrix of BNs is very complex and requires considerable computational work. To overcome the drawbacks of the conventional method, this study gives an alternative way to obtain the network structure matrix through a series of matrix transformations. The key of the proposed new method is applying the superposition and expansion techniques to the initial matrix and the target matrix, which dramatically reduces computationalcomplexity. An example is given to analyse the structure of the BN, and demonstrate the effectiveness of the proposed approach.
This paper focuses on the classification of faults in an electromechanical switch machine, which is an equipment used for handling railroad switches. In this paper, we introduce the use of Set-Membership concept, deri...
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This paper focuses on the classification of faults in an electromechanical switch machine, which is an equipment used for handling railroad switches. In this paper, we introduce the use of Set-Membership concept, derived from the adaptive filter theory, into the training procedure of type-1 and singleton/non-singleton fuzzy logic systems, in order to reduce computationalcomplexity and to increase convergence speed. We also present different criteria for using along with Set-Membership. Furthermore, we discuss the usefulness of delta rule delta, local Lipschitz estimation, variable step size, and variable step size adaptive techniques to yield additional improvement in terms of computational complexity reduction and convergence speed. Based on data set provided by a Brazilian railway company, which covers the four possible faults in a switch machine, we present performance analysis in terms of classification ratio, convergence speed, and computational complexity reduction. The reported results show that the proposed models result in improved convergence speed, slightly higher classification ratio, and remarkable computation complexityreduction when we limit the number of epochs for training, which may be required due to real-time constraint or low computational resource availability.
Recently the wavelet-based contourlet transform (WBCT) is adopted for image coding because it matches better image textures of different orientations. However, its computationalcomplexity is very high. In this paper,...
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Recently the wavelet-based contourlet transform (WBCT) is adopted for image coding because it matches better image textures of different orientations. However, its computationalcomplexity is very high. In this paper, we propose three tools to enhance the WBCT coding scheme, in particular, on reducing its computationalcomplexity. First, we propose short-length 2-D filters for directional transform. Second, the directional transform is applied to only a few selected subbands and the selection is done by a mean-shift-based decision procedure. Third, we fine-tune the context tables used by the arithmetic coder in WBCT coding to improve coding efficiency and to reduce computation. Simulations show that, at comparable coded image quality, the proposed scheme saves over 92% computing time of the original WBCT scheme. Comparing to the conventional 2-D wavelet coding schemes, it produces clearly better subjective image quality. (c) 2012 Elsevier Inc. All rights reserved.
This article studies the problem of stability analysis for neural networks (NNs) with two additive time-varying delay components. By taking both the independence and the variation of the two delay components into cons...
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This article studies the problem of stability analysis for neural networks (NNs) with two additive time-varying delay components. By taking both the independence and the variation of the two delay components into consideration, a more general Lyapunov functional is defined. By estimating the upper bound of the derivative of the Lyapunov functional more tightly, a less conservative delay-dependent stability criterion is established in terms of linear matrix inequalities. To reduce the computationalcomplexity, a method for eliminating slack variables is provided, and then a simplified stability criterion is obtained. Some numerical examples are given to illustrate the effectiveness of the proposed method and the significant improvement over the existing results.
5G ultra-dense network (UDN) systems consist of massive deployment of small cells. This technology allows increasing spectral efficiency and solving the spectrum scarcity problem. However, as small cell count increase...
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5G ultra-dense network (UDN) systems consist of massive deployment of small cells. This technology allows increasing spectral efficiency and solving the spectrum scarcity problem. However, as small cell count increases, the probability of severe interference increases, causing a network capacity degradation. The resource allocation (RA) algorithms distribute the available spectrum resources with the least interference. It is modeled as an optimization problem, and allocating the different resources results exceedingly complex. In this work, a new design approach for RA is proposed. The strategy is based on allocating a single block of channels to either users or cells instead of disjoint channels across the available spectrum. We call them user block allocation and cell block allocation, respectively. They consider a filtered search space of channel allocations providing two-dimensionality reduction levels to the channel allocation problem. The scenario evaluation consists of an unplanned UDN and a uniform small cell deployment, where at least one active user is present for each cell. The results obtained through the genetic algorithm solution on the network's spectral efficiency, cell's average capacity, and subchannel allocation rate show that the proposed arrangements alleviate the high complexity of the channel allocation problem and find feasible solutions for UDN scenarios.
List-sphere detection (LSD) is a sub-optimal multiple-input multiple-output (MIMO) detection scheme which searches candidate symbol vectors that lie within a sphere of a given radius. This study presents an efficient ...
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List-sphere detection (LSD) is a sub-optimal multiple-input multiple-output (MIMO) detection scheme which searches candidate symbol vectors that lie within a sphere of a given radius. This study presents an efficient LSD based method for a joint iterative MIMO detection scheme. The proposed method utilises a channel condition in order to define the list size. During the search process, the radius is adaptively updated to reduce the computationalcomplexity. Owing to the list size and corresponding radius are adaptively determined by the channel condition, the authors can operate the detector at the most appropriate complexity to produce the required performance. Simulation results show that the proposed methods provide substantial complexityreduction without bit error rate performance degradation.
The authors propose a new application-specific, post-acquisition quality evaluation method for brain magnetic resonance imaging (MRI) images. The domain of a MRI slice is regarded as universal set. Four feature images...
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The authors propose a new application-specific, post-acquisition quality evaluation method for brain magnetic resonance imaging (MRI) images. The domain of a MRI slice is regarded as universal set. Four feature images;greyscale, local entropy, local contrast and local standard deviation are extracted from the slice and transformed into the binary domain. Each feature image is regarded as a set enclosed by the universal set. Four qualities attribute;lightness, contrast, sharpness and texture details are described by four different combinations of feature sets. In an ideal MRI slice, the four feature sets are identically equal. Degree of distortion in real MRI slice is quantified by fidelity between the sets that describe a quality attribute. Noise is the fifth quality attribute and is described by the slice Euler number region property. Total quality score is the weighted sum of the five quality scores. The authors' proposed method addresses current challenges in image quality evaluation. It is simple, easy-to-use and easy-to-understand. Incorporation of binary transformation in the proposed method reduces computational and operational complexity of the algorithm. They provide experimental results that demonstrate efficacy of their proposed method on good quality images and on common distortions in MRI images of the brain.
Considering all possible candidate motion vectors in a given search area and calculating a distortion measure at every search position, as with the full-search block-matching motion estimation algorithm (FSBME), place...
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Considering all possible candidate motion vectors in a given search area and calculating a distortion measure at every search position, as with the full-search block-matching motion estimation algorithm (FSBME), places a prohibitively high computational burden on the video encoder, making it unsuitable for real-time/portable video applications. To reduce computationalcomplexity while maintaining accuracy, a new version of the reduced-bit, sum of absolute difference (RBSAD) algorithm is presented, which allows for optional correction to full resolution (FSBME) when appropriate. Analysis of a number of video sequence shows that this correction is required for blocks for which there is little motion between frames.
Synthetic transmit aperture focusing (STAF) has the problem of high computationalcomplexity. An STAF scheme with greatly reduced computationalcomplexity by using an optimal periodic sparse receive array (SRA) is pro...
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Synthetic transmit aperture focusing (STAF) has the problem of high computationalcomplexity. An STAF scheme with greatly reduced computationalcomplexity by using an optimal periodic sparse receive array (SRA) is proposed. An analytic method to design optimal SRAs that provide minimum main lobe width and grating lobe levels for a given number of active receive elements is also suggested. The experiment results show that the proposed STAF method can reduce computationalcomplexity by up to 66.67% compared with conventional STAF.
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