Current Issue : July - September Volume : 2013 Issue Number : 3 Articles : 5 Articles
The subspace segmentation problem is fundamental in many applications. The goal is to cluster data drawn from an unknown\r\nunion of subspaces. In this paper we state the problem and describe its connection to other areas of mathematics and engineering.\r\nWe then review the mathematical and algorithmic methods created to solve this problem and some of its particular cases.We also\r\ndescribe the problem of motion tracking in videos and its connection to the subspace segmentation problem and compare the\r\nvarious techniques for solving it....
The aim of this survey is to provide a comprehensive overview of the state of the art in the area of image forensics. These techniques have been designed to identify the source of a digital image or to determine whether the content is authentic or modified, without the knowledge of any prior information about the image under analysis (and thus are defined as passive). All these tools work by detecting the presence, the absence, or the incongruence of some traces intrinsically tied to the digital image by the acquisition device and by any other operation after its creation. The paper has been organized by classifying the tools according to the position in the history of the digital image in which the relative footprint is left: acquisition-based methods, coding-based methods, and editing-based schemes....
High speed data acquisition technology is receiving increasing attention attributable to exponentially increasing management and measure usage. This technique performs the acquisition of physical signal, conversion of analog signal to digital signal and storing of the information. FPGA, as the core of the data acquisition system, collects and stores the information. The analog to digital converter (ADC) adopted in the system is a high-speed chip, ADC0809 data acquisition component which is a monolithic CMOS device with an 8-bit analog-to-digital converter, 8-channel multiplexer and microprocessor compatible control logic. The 8-bit A/D converter uses successive approximation as the conversion technique. This paper presents an idea behind the hardware designing of ADC and simulation of ADC controller code used for FPGA implementation of high speed data acquisition system. Xilinx Spartan3 does not have a facility of in build ADC so designing of ADC and interfacing it with FPGA is extremely necessary....
A blind source separation method is described to extract sources from data mixtures where the underlying sources are sparse and\r\ncorrelated. The approach used is to detect and analyze segments of time where one source exists on its own. The method does not\r\nassume independence of sources and probability density functions are not assumed for any of the sources. A comparison is made\r\nbetween the proposed method and the Fast-ICA and Clusterwise PCA methods. It is shown that the proposed method works best\r\nfor cases where the underlying sources are strongly correlated because Fast-ICA assumes zero correlation between sources and\r\nClusterwise PCA can be sensitive to overlap between sources. However, for cases of sources that are sparse and weakly correlated\r\nwith each other, there is a tendency for Fast-ICA and Clusterwise PCA to have better performances than the proposedmethod, the\r\nreason being that these methods appear to be more robust to changes in input parameters to the algorithms. In addition, because\r\nof the deflationary nature of the proposed method, there is a tendency for estimates to be more affected by noise than Fast-ICA\r\nwhen the number of sources increases. The paper concludes with a discussion concerning potential applications for the proposed\r\nmethod....
We study a new MART-AP algorithm of few-views discrete tomography. Its efficiency for high-frequency structure reproduction is investigated in a numerical experiment where we reconstruct a 2D model for the estimation of the spatial resolution limit. We estimate the modulation transfer function of the reconstruction algorithm and compare it with the modulation transfer function of projection distortions. Our results show that MART-AP weakly influences the contrast of spatial structures being reproduced and can be used for high-resolution reconstruction when only a few projections are registered....
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