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Low Frequency Ultrasonic Array Imaging Using Signal Post-Processing For Concrete Material, Akio Ozawa, Hideki Izumi, Kazuyuki Nakahata, Katsumi Ohira, Kenzo Ogawa 2016 Ehime University

Low Frequency Ultrasonic Array Imaging Using Signal Post-Processing For Concrete Material, Akio Ozawa, Hideki Izumi, Kazuyuki Nakahata, Katsumi Ohira, Kenzo Ogawa

Review of Progress in Quantitative Nondestructive Evaluation

The use of ultrasonic arrays for conducting non-destructive evaluation has been drastically increased in recent years. As one of the array imaging, a post-processing beam-forming technique has been proposed that utilizes a complete set of signals of all combinations of transmission and reception elements. This approach is referred to as full matrix capture (FMC) [1]. In FMC, each array element is sequentially used as an emitter and all other array elements are used as receivers. By changing the emitting element, we obtained a set of flaw signals that was used to form the focal beam. The delay-and-sum beam reconstruction based ...


Results Of Using Frequency Banded Saft For Examining Three Types Of Defects, Dwight Clayton, Alan Barker, Hector Santos-Villalobos 2016 Oak Ridge National Laboratory

Results Of Using Frequency Banded Saft For Examining Three Types Of Defects, Dwight Clayton, Alan Barker, Hector Santos-Villalobos

Review of Progress in Quantitative Nondestructive Evaluation

A multitude of concrete-based structures are typically part of a light water reactor (LWR) plant to provide the foundation, support, shielding, and containment functions. Concrete has been used in the construction of nuclear power plants (NPPs) because of three primary properties; its inexpensiveness, structural strength, and ability to shield radiation. Examples of concrete structures important to the safety of LWR plants include the containment building, spent fuel pool, and cooling towers. This use has made concrete’s long-term performance crucial for the safe operation of commercial NPPs. Extending reactor life to 60 years and beyond will likely increase susceptibility and ...


Coded Sequences For Low Power Pulse Echo Systems, Julio Isla-Garcia, Frederic Cegla 2016 Imperial College London

Coded Sequences For Low Power Pulse Echo Systems, Julio Isla-Garcia, Frederic Cegla

Review of Progress in Quantitative Nondestructive Evaluation

There are many ultrasound applications where power is limited and as a result signals with low signal to noise ratio (SNR) are produced, electromagnetic-acoustic transducers (EMATs) and air coupled transducers being some examples. In those cases the SNR can be increased by averaging or pulse compression techniques. However, averaging is often lengthy because of the long wait periods required for the signals to die out in-between subsequent transmissions. Pulse compression, such as coded sequences, permits a more rapid injection of energy into the medium. Longer sequences mean a higher SNR can be realised; however, the length of the sequence is ...


Disrupting Long-Range Polar Order With An Electric Field, Hanzheng Guo, Xiaoming Liu, Fei Xue, Long-Qing Chen, Wei Hong, Xiaoli Tan 2016 Iowa State University

Disrupting Long-Range Polar Order With An Electric Field, Hanzheng Guo, Xiaoming Liu, Fei Xue, Long-Qing Chen, Wei Hong, Xiaoli Tan

Materials Science and Engineering Publications

lectric fields are known to favor long-range polar order through the aligning of electric dipoles in relation to Coulomb's force. Therefore, it would be surprising to observe a disordered polar state induced from an ordered state by electric fields. Here we show such an unusual phenomenon in a polycrystalline oxide where electric fields induce a ferroelectric-to-relaxor phase transition. The nonergodic relaxor phase with disordered dipoles appears as an intermediate state under electric fields during polarization reversal of the ferroelectric phase. Using the phenomenological theory, the underlying mechanism for this unexpected behavior can be attributed to the slow kinetics of ...


Electromagnetic Scattering Models For Insar Correlation Measurements Of Vegetation And Snow, Yang Lei 2016 University of Massachusetts Amherst

Electromagnetic Scattering Models For Insar Correlation Measurements Of Vegetation And Snow, Yang Lei

Doctoral Dissertations

Interferometric Synthetic Aperture Radar (InSAR) has proved successful and efficient in measuring the vertical structure of the distributed targets such as vegetation and snow, which are dominated by volume scattering. In particular, the InSAR correlation measurement has been utilized to retrieve the target vertical structural information. One existing and well-known electromagnetic scattering model of the InSAR correlation was first brought forward focusing on the single-pass InSAR observation of a sparse random medium like vegetation. However, the lack of the adaption of this InSAR scattering model for repeat-pass InSAR observation of vegetation as well as for single-pass InSAR observation of snow ...


Applications In Low-Power Phased Array Weather Radars, Robert A. Palumbo Jr 2016 University of Massachusetts Amherst

Applications In Low-Power Phased Array Weather Radars, Robert A. Palumbo Jr

Doctoral Dissertations

Low-cost X-band radars are an emerging technology that offer significant advantages over traditional systems for weather remote sensing applications. X-band radars provide enhanced angular resolution at a fraction of the aperture size compared to larger, lower frequency systems. Because of their low cost and small form factor, these radars can now be integrated into more research and commercial applications. This work presents research and development activities using a low-cost, X-band (9410 MHz) Phase-Tilt Radar. The phase-tilt design is a novel phased array architecture that allows for rapid electronic scanning in azimuth and mechanical tilting in elevation, as a compromise between ...


Rapid Optical Ptychographic Prototyping With Broad Bandwidth Illumination, Jonathan T. Reichanadter 2016 University of Colorado, Boulder

Rapid Optical Ptychographic Prototyping With Broad Bandwidth Illumination, Jonathan T. Reichanadter

Undergraduate Honors Theses

The focus of the experiment is to construct an optical CDI microscope for rapid prototype development of techniques and algorithms for multicolor experiments. CDI is often accomplished using a monochromatic beam, but in this experiment the probe will be polychromatic. This multicolor illumination ptychography offers probe and object characterization for each color, meaning that ptychography identifies the spectral response of the object. In my research I explore multicolor ptychography using a broad bandwidth illumination.


Wearable Privacy Protection With Visual Bubble, Shaoqian Wang 2016 University of Kentucky

Wearable Privacy Protection With Visual Bubble, Shaoqian Wang

Theses and Dissertations--Electrical and Computer Engineering

Wearable cameras are increasingly used in many different applications such as entertainment, security, law enforcement and healthcare. In this thesis, we focus on the application of the police worn body camera and behavioral recording using a wearable camera for one-on-one therapy with a child in a classroom or clinic. To protect the privacy of other individuals in the same environment, we introduce a new visual privacy protection technique called visual bubble. Visual bubble is a virtual zone centered around the camera for observation whereas the rest of the environment and people are obfuscated. In contrast to most existing visual privacy ...


Analysis Of Vocal Fold Kinematics Using High Speed Video, Harikrishnan Unnikrishnan 2016 University of Kentucky

Analysis Of Vocal Fold Kinematics Using High Speed Video, Harikrishnan Unnikrishnan

Theses and Dissertations--Electrical and Computer Engineering

Vocal folds are the twin in-folding of the mucous membrane stretched horizontally across the larynx. They vibrate modulating the constant air flow initiated from the lungs. The pulsating pressure wave blowing through the glottis is thus the source for voiced speech production. Study of vocal fold dynamics during voicing are critical for the treatment of voice pathologies. Since the vocal folds move at 100 - 350 cycles per second, their visual inspection is currently done by strobosocopy which merges information from multiple cycles to present an apparent motion. High Speed Digital Laryngeal Imaging(HSDLI) with a temporal resolution of up to ...


Robust Background Subtraction For Moving Cameras And Their Applications In Ego-Vision Systems, Hasan Sajid 2016 University of Kentucky

Robust Background Subtraction For Moving Cameras And Their Applications In Ego-Vision Systems, Hasan Sajid

Theses and Dissertations--Electrical and Computer Engineering

Background subtraction is the algorithmic process that segments out the region of interest often known as foreground from the background. Extensive literature and numerous algorithms exist in this domain, but most research have focused on videos captured by static cameras. The proliferation of portable platforms equipped with cameras has resulted in a large amount of video data being generated from moving cameras. This motivates the need for foundational algorithms for foreground/background segmentation in videos from moving cameras. In this dissertation, I propose three new types of background subtraction algorithms for moving cameras based on appearance, motion, and a combination ...


Machine Learning Through Mimicry And Association, Nickolas S. Holcomb 2016 Georgia Southern University

Machine Learning Through Mimicry And Association, Nickolas S. Holcomb

University Honors Program Theses

Adaptability is a key missing features that has impeded the growth of assistive robotics. In the traditional model, all actions must be explicitly coded by a skilled programmer familiar with the hardware. This project explores a method of teaching a webcam equipped arm type robot new primitive movement using visual demonstrations.


Blind Front-End Processing Of Dynamic Multi-Channel Wideband Signals, Kevin Jackson 2016 Utah State University

Blind Front-End Processing Of Dynamic Multi-Channel Wideband Signals, Kevin Jackson

All Graduate Theses and Dissertations

In wireless digital communications, the sender and receiver typically know the modulation scheme with which they will be communicating. Automatic modulation identification is the ability to identify the modulation in a communication system with little to no prior knowledge of the modulation scheme. Many techniques for modulation identification operate on many assumptions including that the input signal is base-banded, the carrier frequency is known and that the signal is narrow-band (i.e. neighboring signals in the wide-band are excluded). This work provides the blind processing of an arbitrary wide-band signal to allow such assumptions. The challenges of such a front-end ...


Design, Analysis And Evaluation Of Unmanned Aerial Vehicle Ad Hoc Network For Emergency Response Communications, Robin D. Grodi 2016 Georgia Southern University

Design, Analysis And Evaluation Of Unmanned Aerial Vehicle Ad Hoc Network For Emergency Response Communications, Robin D. Grodi

Electronic Theses & Dissertations

In any emergency situation, it is paramount that communication be established between those affected by an emergency and the emergency responders. This communication is typically initiated by contacting an emergency service number such as 9-1-1 which will then notify the appropriate responders. The communication link relies heavily on the use of the public telephone network. If an emergency situation causes damage to, or otherwise interrupts, the public telephone network then those affected by the emergency are unable to call for help or warn others. A backup emergency response communication system is required to restore communication in areas where the public ...


Design, Analysis, Implementation And Evaluation Of Real-Time Opportunistic Spectrum Access In Cloud-Based Cognitive Radio Networks, Nimish Sharma 2016 Georgia Southern University

Design, Analysis, Implementation And Evaluation Of Real-Time Opportunistic Spectrum Access In Cloud-Based Cognitive Radio Networks, Nimish Sharma

Electronic Theses & Dissertations

Opportunistic spectrum access in cognitive radio network is proposed for remediation of spectrum under-utilization caused by exclusive licensing for service providers that are intermittently utilizing spectrum at any given geolocation and time. The unlicensed secondary users (SUs) rely on opportunistic spectrum access to maximize spectrum utilization by sensing/identifying the idle bands without causing harmful interference to licensed primary users (PUs). In this thesis, Real-time Opportunistic Spectrum Access in Cloud-based Cognitive Radio Networks (ROAR) architecture is presented where cloud computing is used for processing and storage of idle channels. Software-defined radios (SDRs) are used as SUs and PUs that identify ...


Performance Analysis Of Secondary Users In Heterogeneous Cognitive Radio Network, Tanjil Amin 2016 Georgia Southern University

Performance Analysis Of Secondary Users In Heterogeneous Cognitive Radio Network, Tanjil Amin

Electronic Theses & Dissertations

Continuous increase in wireless subscriptions and static allocation of wireless frequency bands to the primary users (PUs) are fueling the radio frequency (RF) shortage problem. Cognitive radio network (CRN) is regarded as a solution to this problem as it utilizes the scarce RF in an opportunisticmanner to increase the spectrumefficiency. InCRN, secondary users (SUs) are allowed to access idle frequency bands opportunistically without causing harmful interference to the PUs. In CRN, the SUs determine the presence of PUs through spectrum sensing and access idle bands by means of dynamic spectrum access. Spectrum sensing techniques available in the literature do not ...


Development Of Compressive Sensing Techniques For Wideband Spectrum Scanning In Cognitive Radio Networks, Fatima Salahdine, Naima Kaabouch, Hassan El Ghazi 2015 university of north dakota

Development Of Compressive Sensing Techniques For Wideband Spectrum Scanning In Cognitive Radio Networks, Fatima Salahdine, Naima Kaabouch, Hassan El Ghazi

fatima salahdine

Next generation of communication systems will be smart and frequency agile. They will be able to scan the wideband radio spectrum to find the available frequency channel. This process is called compressive sensing. Existing compressive sensing techniques are not accurate and have high processing time, hardware limitations, and computational cost. Thus, this project aims to develop efficient compressive sensing algorithms that deal with uncertainty and enhance the radio spectrum scanning.
 
 


Exploiting Cross Domain Relationships For Target Recognition, Wei Wang 2015 University of Tennessee - Knoxville

Exploiting Cross Domain Relationships For Target Recognition, Wei Wang

Doctoral Dissertations

Cross domain recognition extracts knowledge from one domain to recognize samples from another domain of interest. The key to solving problems under this umbrella is to find out the latent connections between different domains. In this dissertation, three different cross domain recognition problems are studied by exploiting the relationships between different domains explicitly according to the specific real problems.

First, the problem of cross view action recognition is studied. The same action might seem quite different when observed from different viewpoints. Thus, how to use the training samples from a given camera view and perform recognition in another new view ...


Real-Time Digital Effects Processing Using Ios, Jonah W. Clinard 2015 California Polytechnic State University - San Luis Obispo

Real-Time Digital Effects Processing Using Ios, Jonah W. Clinard

Computer Engineering

In today’s society, we are seeing incredible improvements in terms of creating smaller technological devices that behave more and more like the personal computers of yesterday. Mobile “Smart” devices, in particular, are becoming incredibly powerful not just in terms of processing power, but in the fact that they are able to provide assistance to users in their everyday lives. Application developers are now able utilize the power and size of these devices, to create and realize ideas that would have been previously viewed as impossible. This project applies the fields of digital signal processing, music, and mobile application development ...


Hvdc Systems Fault Analysis Using Various Signal Processing Techniques, Benish Paily 2015 Dublin Institute of Technology

Hvdc Systems Fault Analysis Using Various Signal Processing Techniques, Benish Paily

Doctoral

The detection and fast clearance of faults are important for the safe and optimal operation of HVDC systems. In HVDC systems, various types of AC faults (rectifier & inverter side) and DC faults can occur. It is therefore necessary to detect the faults and classify them for better protection and diagnostics purposes. Various techniques for fault detection and classification in HVDC systems using signal processing techniques are presented and investigated in this research work. In this research work, it is shown that the wavelet transformation can effectively detect abrupt changes in system signals which are indicative of a fault. This research ...


Scaled Synthetic Aperture Radar System Development, Ryan K. Green 2015 Cal Poly SLO

Scaled Synthetic Aperture Radar System Development, Ryan K. Green

Master's Theses and Project Reports

Synthetic Aperture Radar (SAR) systems generate two dimensional images of a target area using RF energy as opposed to light waves used by cameras. When cloud cover or other optical obstructions prevent camera imaging over a target area, SAR can be substituted to generate high resolution images. Linear frequency modulated signals are transmitted and received while a moving imaging platform traverses a target area to develop high resolution images through modern digital signal processing (DSP) techniques. The motivation for this joint thesis project is to design and construct a scaled SAR system to support Cal Poly radar projects. Objectives include ...


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