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Full-Text Articles in Engineering

Performance Of Xor Rule For Decentralized Detection Of Deterministic Signals In Bivariate Gaussian Noise, Xingjian Sun, Shailee Yagnik, Ramanarayanan Viswanathan, Lei Cao Jan 2022

Performance Of Xor Rule For Decentralized Detection Of Deterministic Signals In Bivariate Gaussian Noise, Xingjian Sun, Shailee Yagnik, Ramanarayanan Viswanathan, Lei Cao

Faculty and Student Publications

In this paper, we consider the performance of exclusive-OR (XOR) rule in detecting the presence or absence of a deterministic signal in bivariate Gaussian noise. Signals, when present at the two sensors, are assumed unequal, whereas the noise components have identical marginal distribution but are correlated. The sensors send their one-bit quantized data to a fusion center, which then employs the XOR rule to arrive at the final decision. Here we prove that, in the limit as the correlation coefficient r approaches 1, the optimum fusion rule for both parallel and tandem topologies is XOR with identical, alternating partitions (XORAP) …


Accurate And Compact Stochastic Computations By Exploiting Correlation, Hamdan Abdellatef, Mohamed Khalil Hani, Nasir Shaikh-Husin Jan 2019

Accurate And Compact Stochastic Computations By Exploiting Correlation, Hamdan Abdellatef, Mohamed Khalil Hani, Nasir Shaikh-Husin

Turkish Journal of Electrical Engineering and Computer Sciences

Recent studies have shown, contrary to what was previously believed, that by exploiting correlation in stochastic computing (SC) designs, more accurate SC circuits with low area cost can be realized. However, if these basic SC circuits or blocks are cascaded in series to form a large complex system, correlation between stochastic numbers (SNs) from one block to the next would be lost; thus, inaccuracies are introduced. In this study, we propose correlating circuits to be used in building complex correlated SC systems. One of the circuits is the correlator that restores lost correlations between two SNs due to previous processing. …


Leveraging 3d Models For Sar-Based Navigation In Gps-Denied Environments, Zachary A. Reid Jan 2018

Leveraging 3d Models For Sar-Based Navigation In Gps-Denied Environments, Zachary A. Reid

Browse all Theses and Dissertations

This thesis considers the use of synthetic aperture radar (SAR) to provide absolute platform position information in scenarios where GPS signals may be degraded, jammed, or spoofed. Two algorithms are presented, and both leverage known 3D ground structure in an area of interest, e.g. provided by LIDAR data, to provide georeferenced position information to airborne SAR platforms. The first approach is based on the wide-aperture layover properties of elevated reflectors, while the second approach is based on correlating backprojected imagery with digital elevation imagery. Both of these approaches constitute the system we have designated: SARNAV. Building on 3D backprojection, localization …


Real-Time Beamforming Algorithms For The Focal L-Band Array On The Green Bank Telescope, Mark William Ruzindana Dec 2017

Real-Time Beamforming Algorithms For The Focal L-Band Array On The Green Bank Telescope, Mark William Ruzindana

Theses and Dissertations

A phased array feed (PAF) provides a contiguous, electronically synthesized wide field of view for large-dish astronomical observatories. Significant progress has been made in recent years in improving the sensitivity of PAF receivers though optimizing the design of the antenna array, cryogenic cooling of the front end, and implementation of real-time correlation and beamforming in digital signal processing. FLAG is a 19 dual-polarized element phased array with cryogenic LNAs, direct digitization of RF signals at the front end, digital signal transport over fiber, and a real time signal processing back end with up to 150 MHz bandwidth. The digital back …


On The Use Of Wheeler Cap For Mimo Antennas, Florian Reher, Adam Narbudowicz, Max Ammann, Dirk Heberling Jan 2017

On The Use Of Wheeler Cap For Mimo Antennas, Florian Reher, Adam Narbudowicz, Max Ammann, Dirk Heberling

Conference Papers

A new equivalent circuit based Wheeler Cap method to calculate MIMO efficiency is introduced. The method works without the necessity for interpolation by avoiding concur of resonating and cavity modes. The method is tested with a set of three differently correlated MIMO antennas. Results are compared with the recently proposed quality factor method for MIMO antennas and efficiency data from spherical near field measurements.


Quantitative Estimation Of Causality And Predictive Modeling For Precipitation Observation Sites And River Gage Sensors, Tri Vu Nguyen Jan 2017

Quantitative Estimation Of Causality And Predictive Modeling For Precipitation Observation Sites And River Gage Sensors, Tri Vu Nguyen

LSU Master's Theses

This project seeks to investigate two questions: correlations from precipitation measurement sensors to river gage sensors, and predictive modeling of peak river gage heights during precipitation events. First, if correlations can be quantified, then a predictive model can be explored to predict peak water levels at river gage sensors, in response to precipitation inputs. Answering both research questions can provide early flood detection benefits and provide quantitative time assessments for flood risks. An extensive data-driven study was conducted across a geographical area of the U.S, spanning the time period 2008-2016 to identify river gage sensors that are closely correlated to …


Calculating The Envelope Correlation Coefficient Directly From Spherical Modes Spectrum, Adam Narbudowicz, Max Ammann, R. Cornelius, D. Heberling Jan 2017

Calculating The Envelope Correlation Coefficient Directly From Spherical Modes Spectrum, Adam Narbudowicz, Max Ammann, R. Cornelius, D. Heberling

Conference Papers

This paper proposes an improved technique to calculate the Envelope Correlation Coefficient (ECC) by directly using the spherical mode spectrum of the antenna under test. The technique avoids errors due to numerical pattern integration and simplifies post-processing for near-field measurements. The technique is successfully tested on two different antenna types, in the total number of four MIMO configurations.


Mutual Correlation Of Nist Statistical Randomness Tests And Comparison Of Their Sensitivities On Transformed Sequences, Ali̇ Doğanaksoy, Fati̇h Sulak, Muhi̇ddi̇n Uğuz, Okan Şeker, Zi̇ya Akcengi̇z Jan 2017

Mutual Correlation Of Nist Statistical Randomness Tests And Comparison Of Their Sensitivities On Transformed Sequences, Ali̇ Doğanaksoy, Fati̇h Sulak, Muhi̇ddi̇n Uğuz, Okan Şeker, Zi̇ya Akcengi̇z

Turkish Journal of Electrical Engineering and Computer Sciences

Random sequences are widely used in many cryptographic applications and hence their generation is one of the main research areas in cryptography. Statistical randomness tests are introduced to detect the weaknesses or nonrandom characteristics that a sequence under consideration may have. In the literature, there exist various statistical randomness tests and test suites, defined as a collection of tests. An efficient test suite should consist of a number of uncorrelated statistical tests each of which measures randomness from another point of view. `Being uncorrelated' is not a well-defined or well-understood concept in the literature. In this work, we apply Pearson's …


On The Independence Of Statistical Randomness Tests Included In The Nist Test Suite, Fati̇h Sulak, Muhi̇ddi̇n Uğuz, Onur Koçak, Ali̇ Doğanaksoy Jan 2017

On The Independence Of Statistical Randomness Tests Included In The Nist Test Suite, Fati̇h Sulak, Muhi̇ddi̇n Uğuz, Onur Koçak, Ali̇ Doğanaksoy

Turkish Journal of Electrical Engineering and Computer Sciences

Random numbers and random sequences are used to produce vital parts of cryptographic algorithms such as encryption keys and therefore the generation and evaluation of random sequences in terms of randomness are vital. Test suites consisting of a number of statistical randomness tests are used to detect the nonrandom characteristics of the sequences. Construction of a test suite is not an easy task. On one hand, the coverage of a suite should be wide; that is, it should compare the sequence under consideration from many different points of view with true random sequences. On the other hand, an overpopulated suite …


Recursive Non-Local Means Filter For Video Denoising With Poisson-Gaussian Noise, Redha A. Almahdi, Russell C. Hardie Jul 2016

Recursive Non-Local Means Filter For Video Denoising With Poisson-Gaussian Noise, Redha A. Almahdi, Russell C. Hardie

Electrical and Computer Engineering Faculty Publications

In this paper, we describe a new recursive Non-Local means (RNLM) algorithm for video denoising that has been developed by the current authors. Furthermore, we extend this work by incorporating a Poisson-Gaussian noise model. Our new RNLM method provides a computationally efficient means for video denoising, and yields improved performance compared with the single frame NLM and BM3D benchmarks methods. Non-Local means (NLM) based methods of denoising have been applied successfully in various image and video sequence denoising applications. However, direct extension of this method from 2D to 3D for video processing can be computationally demanding. The RNLM approach takes …


Experimental Characterization And Correlation Analysis Of Indoor Channels At 15 Ghz, Xin Zhou, Zhangdui Zhong, Bei Zhang, Ruisi He, Ke Guan, Qi Wang, David W. Matolak Feb 2015

Experimental Characterization And Correlation Analysis Of Indoor Channels At 15 Ghz, Xin Zhou, Zhangdui Zhong, Bei Zhang, Ruisi He, Ke Guan, Qi Wang, David W. Matolak

Faculty Publications

The indoor radio channels at 15 GHz are investigated based on measurements. The large- and small-scale fading behaviors as well as the delay dispersion characteristics are discussed. It is found that the large-scale fading, Ricean -factor, and delay spread can be described by log-normal distributions. Furthermore, both autocorrelation and cross correlation properties of the above parameters are analyzed and modeled. These parameters characterize fading and delay behaviors as well as their mutual dependency and can be used as empirical values for future wireless system design and simulation in 15 GHz short-range indoor channels.


Large-Scale Site And Frequency Diversity In Urban Peer-To-Peer Channels For Six Public Safety Frequency Bands, David W. Matolak, Kate A. Remley, Christopher L. Holloway, Qian Zhang, Qiong Wu Apr 2014

Large-Scale Site And Frequency Diversity In Urban Peer-To-Peer Channels For Six Public Safety Frequency Bands, David W. Matolak, Kate A. Remley, Christopher L. Holloway, Qian Zhang, Qiong Wu

Faculty Publications

We report on peer-to-peer large-scale wireless channel characteristics for an urban environment in six public-safety bands, for five simultaneous receiving sites. Results are based upon measurements taken in Denver in July 2009 with stationary receivers and a pedestrian transmitter. The six frequencies at which we measured are (in MHz) 430, 750, 905, 1834, 2400, and 4860. We quantify both site and frequency diversity, and show that 5-site selection yields minimum average gains of 15 dB in mean received power levels; 5-site selection diversity also reduces received power variation by 17-29 dB, depending on frequency. Frequency diversity yields similar gains. By …


Covariance Modeling And Space-Time Coding For Mimo Systems, Farnaz Karimdady Sharifabad Feb 2013

Covariance Modeling And Space-Time Coding For Mimo Systems, Farnaz Karimdady Sharifabad

Theses and Dissertations

The full spatial covariance matrix of the multiple input multiple-output (MIMO) channel is an important quantity in channel modeling, communication system signal processing, and performance analysis, and therefore this matrix forms the heart of the research outlined in this dissertation. The work begins with an investigation of a generalized framework for computing the full MIMO spatial covariance based on the power angular spectrum (PAS) of the multipath field and the transmit and receive antenna element radiation patterns. For the case of uniform linear arrays and when the PAS clusters satisfy uniform, truncated Gaussian, or truncated Laplacian distributions, a series expansion …


Reliable Power Delivery System Design For Three-Dimensional Integrated Circuits (3d Ics), Pei Wen Luo, Tao Wang, Chin Long Wey, Liang Chia Cheng, Bih Lan Sheu, Yiyu Shi Oct 2012

Reliable Power Delivery System Design For Three-Dimensional Integrated Circuits (3d Ics), Pei Wen Luo, Tao Wang, Chin Long Wey, Liang Chia Cheng, Bih Lan Sheu, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Three-dimensional integrated circuits (3D ICs) have drawn groundswell of interest in both academia and industry in recent years. However, the power integrity of 3D ICs is threatened by the increased current density brought by vertical integration. to enhance reliability, the locations of power/ground through-silicon-vias (P/G TSVs), which are used to deliver power/ground signals to different layers, must be carefully placed to minimize IR-drop. However, the currents in 3D ICs are not deterministic and exhibit both spatial and temporal correlations. in view of this, we propose a correlation based heuristic algorithm for P/G TSV placement. Unlike most existing works, the proposed …


Stochastic Model For Solar Sensor Array Data, Faris Alfaris Jan 2012

Stochastic Model For Solar Sensor Array Data, Faris Alfaris

Masters Theses

Statistical approaches are often used in time series analysis, for example, to predict the future trend of a time series. Trend forecasting can be applied in many time related parameters such as: solar radiation, generation of electricity and other variables related to time series to improve the efficiency and to set the design requirements. Since the design of any solar energy system requires knowledge of the availability of solar radiation data at the location of interest. Therefore, this research seeks the application of a statistical model to fit the solar radiation time series and predict the future values. There are …


Denoising Using Adaptive Thresholding And Higher Order Statistics, Samuel Peter Kozaitis, Tim Young Mar 2009

Denoising Using Adaptive Thresholding And Higher Order Statistics, Samuel Peter Kozaitis, Tim Young

Electrical Engineering and Computer Science Faculty Publications

We showed that a hard threshold for wavelet denoising based on higher order statistics is comparable to a second order soft threshold. The hard threshold can be made adaptive by using a third order statistic as an estimate of the noise. In addition, the relationship between an adaptive hard threshold and retaining a fraction of wavelet coefficients is shown. Qualitative and quantitative metrics based on the mean-squared error are used to compare the hard thresholding and a soft-thresholding technique, BayesShrink.


Correlating Orphaned Windows Registry Data Structures, Damir Kahvedžić, Tahar Kechadi Jan 2009

Correlating Orphaned Windows Registry Data Structures, Damir Kahvedžić, Tahar Kechadi

Journal of Digital Forensics, Security and Law

Recently, it has been shown that deleted entries of the Microsoft Windows registry (keys) may still reside in the system files once the entries have been deleted from the active database. Investigating the complete keys in context may be extremely important from both a Forensic Investigation point of view and a legal point of view where a lack of context can bring doubt to an argument. In this paper we formalise the registry behaviour and show how a retrieved value may not maintain a relation to the part of the registry it belonged to and hence lose that context. We …


Thresholding For Higher-Order Statistical Denoising, Samuel Peter Kozaitis, Tim Young Apr 2008

Thresholding For Higher-Order Statistical Denoising, Samuel Peter Kozaitis, Tim Young

Electrical Engineering and Computer Science Faculty Publications

Hard thresholding seems to work well for denoising signals using higher-order statistics. We statistically examined the best values for hard thresholding and related this to the fraction of wavelet coefficients set to zero to obtain the minimum MSE. In addition, we found that the minimum MSE obtained was less sensitive to the threshold when implemented based on a third-order parameter rather than the noise power. Alternatively, we found that this approach to thresholding could be implemented by setting a fixed fraction of wavelet coefficients to zero.


Improved Denoising Approach Using Higher-Order Statistics, Samuel Peter Kozaitis Apr 2007

Improved Denoising Approach Using Higher-Order Statistics, Samuel Peter Kozaitis

Electrical Engineering and Computer Science Faculty Publications

We presented a method to reduce noise in signals using a higher-order, correlation-based approach. This paper examines the differences between hard and soft thresholds using the higher-order method, and the use of different wavelets in the denoising algorithm. Using a detection algorithm derived from third-order statistics, we determined if a wavelet coefficient was either mostly noise or mostly signal based on third-order statistics. We found that hard thresholding worked best when compared to soft thresholding but there is the possibility of improvement using soft thresholding.


Semi Autonomous Vehicle Intelligence: Real Time Target Tracking For Vision Guided Autonomous Vehicles, Jonathan D. Anderson Mar 2007

Semi Autonomous Vehicle Intelligence: Real Time Target Tracking For Vision Guided Autonomous Vehicles, Jonathan D. Anderson

Theses and Dissertations

Unmanned vehicles (UVs) are seeing more widespread use in military, scientific, and civil sectors in recent years. These UVs range from unmanned air and ground vehicles to surface and underwater vehicles. Each of these different UVs has its own inherent strengths and weaknesses, from payload to freedom of movement. Research in this field is growing primarily because of the National Defense Act of 2001 mandating that one-third of all military vehicles be unmanned by 2015. Research using small UVs, in particular, is a growing because small UVs can go places that may be too dangerous for humans. Because of the …


Denoising Of Imagery For Inspection Tasks Using Higher-Order Statistics, Samuel Peter Kozaitis Oct 2006

Denoising Of Imagery For Inspection Tasks Using Higher-Order Statistics, Samuel Peter Kozaitis

Electrical Engineering and Computer Science Faculty Publications

We reduced noise in images using a higher-order, correlation-based method. In this approach, wavelet coefficients were classified as either mostly noise or mostly signal based on third-order statistics. Because the higher than second-order moments of the Gaussian probability function are zero, the third-order correlation coefficient may not have a statistical contribution from Gaussian noise. Using a detection algorithm derived from third-order statistics, we determined if a wavelet coefficient was noisy by looking at its third-order correlation coefficient. Using imagery of space shuttle tiles, our results showed that the minimum mean-squared error obtained using third-order statistics was often less than that …


Information Analysis Of Dna Sequences, Riyazuddin Mohammed Jan 2006

Information Analysis Of Dna Sequences, Riyazuddin Mohammed

LSU Master's Theses

The problem of differentiating the informational content of coding (exons) and non-coding (introns) regions of a DNA sequence is one of the central problems of genomics. The introns are estimated to be nearly 95% of the DNA and since they do not seem to participate in the process of transcription of amino-acids, they have been termed “junk DNA.” Although it is believed that the non-coding regions in genomes have no role in cell growth and evolution, demonstration that these regions carry useful information would tend to falsify this belief. In this thesis, we consider entropy as a measure of information …


Object Tracking Using Log-Polar Transformation, Saikiran Sri Thunuguntla Jan 2005

Object Tracking Using Log-Polar Transformation, Saikiran Sri Thunuguntla

LSU Master's Theses

In this thesis, we use log-polar transform to solve object tracking. Object tracking in video sequences is a fundamental problem in computer vision. Even though object tracking is being studied extensively, still some challenges need to be addressed, such as appearance variations, large scale and rotation variations, and occlusion. We implemented a novel tracking algorithm which works robustly in the presence of large scale changes, rotation, occlusion, illumination changes, perspective transformations and some appearance changes. Log-polar transformation is used to achieve robustness to scale and rotation. Our object tracking approach is based on template matching technique. Template matching is based …


Correlation And Covariance Of Satellite Scatterometer Measurements, David G. Long, Peter K. Yoho Jun 2004

Correlation And Covariance Of Satellite Scatterometer Measurements, David G. Long, Peter K. Yoho

Faculty Publications

Capable scatterometer designs have been developed that seek improved resolution through the use of higher pulse sampling rates. The high sampling rates bring the traditional scatterometry assumption of measurement independence into question. This paper uses fundamental scattering theory to derive general expressions for correlation and covariance between scatterometer measurements and provides practical analysis using current and future instruments as examples. The paper derives expressions for the measurement variance parameter Kp when measurement correlation due to Rayleigh fading effects is present and relates Kp to the statistics of multiple pulse measurements. A function of the transmit signal modulation and receive processing, …


Channel Probing For An Indoor Wireless Communications Channel, Brandon Hunter Mar 2003

Channel Probing For An Indoor Wireless Communications Channel, Brandon Hunter

Theses and Dissertations

The statistics of the amplitude, time and angle of arrival of multipaths in an indoor environment are all necessary components of multipath models used to simulate the performance of spatial diversity in receive antenna configurations. The model presented by Saleh and Valenzuela, was added to by Spencer et. al., and included all three of these parameters for a 7 GHz channel. A system was built to measure these multipath parameters at 2.4 GHz for multiple locations in an indoor environment. Another system was built to measure the angle of transmission for a 6 GHz channel. The addition of this parameter …


The Effect Of An Adaptive Optical System's Spatio-Temporal Response On Imaging Performance, Patrick M. Harrington Dec 1992

The Effect Of An Adaptive Optical System's Spatio-Temporal Response On Imaging Performance, Patrick M. Harrington

Theses and Dissertations

Ideally, an adaptive optical control system would have instantaneous temporal response and infinite spatial bandwidth. In real systems, the response time of the adaptive optical control system is limited by the integration time of the wave front sensor, the computational time of the control algorithm, and the actuator response time. Additionally, finite inter actuator spacing limits the deformable mirror's ability to reproduce spatial frequencies having a period less than twice this spacing. Although analyses general enough to account for both the temporal and spatial characteristics of the adaptive optical system exist, they are complex and require detailed information regarding the …