Signal Processing Commons^™

Microphone Array Optimization In Immersive Environments, Jingjing Yu

Theses and Dissertations--Electrical and Computer Engineering

The complex relationship between array gain patterns and microphone distributions limits the application of traditional optimization algorithms on irregular arrays, which show enhanced beamforming performance for human speech capture in immersive environments. This work analyzes the relationship between irregular microphone geometries and spatial filtering performance with statistical methods. Novel geometry descriptors are developed to capture the properties of irregular microphone distributions showing their impact on array performance. General guidelines and optimization methods for regular and irregular array design are proposed in immersive (near-field) environments to obtain superior beamforming ability for speech applications. Optimization times are greatly reduced through the objective ...

Radio Frequency Direction Of Arrival Determination, Daniel A. Lazar

Undergraduate Research Symposium

This project is focused on implementing source location algorithms to find the direction of arrival of transmitted radio frequency signals on an array of receivers. The MuSIC (multiple signal classification) algorithm is used, as well as a variant, smooth-MuSIC, which mitigates the effects of multipath interference. Beamforming techniques, which combine temporal and spatial filtering, are also used to find the direction of arrival. These strategies minimize the transmission power needed to send a signal. Further work building on this research can implement directional transmission and receiving with beamforming, which yields many advantages including minimized signal interception. The results from this ...

A Low-Power, Highly Stabilized Three-Electrode Potentiostat Using Subthreshold Techniques, Melika Roknsharifi

Doctoral Dissertations

Implantable micro- and nano- sensors and implantable microdevices (IMDs) have demonstrated potential for monitoring various physiological parameters such as glucose, lactate, CO₂ [carbon dioxide], pH, etc. Potentiostats are essential components of electrochemical sensors such as glucose monitoring devices for diabetic patients. Diabetes is a metabolic disorder associated with insufficient production or inefficient utilization of insulin. The most important role of this enzyme is to regulate the metabolic breakdown of glucose generating the necessary energy for human activities. Diabetic patients typically monitor their blood glucose levels by pricking a fingertip with a lancing device and applying the blood to a ...

Techniques For Wireless Channel Modeling In Harsh Environments, Phani Teja Kuruganti

Doctoral Dissertations

With the rapid growth in the networked environments for different industrial, scientific and defense applications, there is a vital need to assure the user or application a certain level of Quality of Service (QoS). Environments like the industrial environment are particularly harsh with interference from metal structures (as found in the manufacturing sector), interference generated during wireless propagation, and multipath fading of the radio frequency (RF) signal all invite novel mitigation techniques. The challenge of achieving the benefits like improved energy efficiency using wireless is closely coupled with maintaining network QoS requirements. Assessment and management of QoS needs to occur ...

Target Tracking With Binary Sensor Networks, Mengmei Liu

Theses and Dissertations--Electrical and Computer Engineering

Binary Sensor Networks are widely used in target tracking and target parameter estimation. It is more computationally and financially efficient than surveillance camera systems. According to the sensing area, binary sensors are divided into disk shaped sensors and line segmented sensors. Different mathematical methods of target trajectory estimation and characterization are applied. In this thesis, we present a mathematical model of target tracking including parameter estimation (size, intrusion velocity, trajectory, etc.) with line segmented sensor networks. Software simulation and hardware experiments are built based on the model. And we further analyze how the quantization noise affects the results.

Multi-Mode Self-Referencing Surface Plasmon Resonance Sensors, Jing Guo

Theses and Dissertations--Electrical and Computer Engineering

Surface-plasmon-resonance (SPR) sensors are widely used in biological, chemical, medical, and environmental sensing. This dissertation describes the design and development of dual-mode, self-referencing SPR sensors supporting two surface-plasmon modes (long- and short-range) which can differentiate surface binding interactions from bulk index changes at a single sensing location. Dual-mode SPR sensors have been optimized for surface limit of detection (LOD). In a wavelength interrogated optical setup, both surface plasmons are simultaneously excited at the same location and incident angle but at different wavelengths. To improve the sensor performance, a new approach to dual-mode SPR sensing is presented that offers improved differentiation ...

Characterization Of The Libyan Desert In Support Of Vicarious Calibration, Bridget Brooke

Electrical and Computer Engineering Master's Theses

Thorough calibration of electro-optical sensors being designed for today's space-based applications is essential to utilize remotely sensed imagery products. A complete sensor calibration provides in-depth understanding of operation and performance, while verifying that the system meets mission standards. Accurate calibration is crucial in order to give the data physical meaning and allow the imagery to be used and compared for a variety of applications. The use of invariant sites for vicarious calibration has become a valuable tool for the changing design and demands of new instruments. Pseudo-invariant calibration sites provide the opportunity to utilize a much larger site to ...

Self-Calibrated Wireless Sleep Sensing System For Brain Injury Diagnostics, Ali Abedi, Frederick Schwaner, E Mougharbel, M J. Hayes

WiSe-Net Laboratory

A wide range of conditions fall under the category of Mild Traumatic Brain Injury (mTBI) diagnosis. In this article, we focus on a new method during sleep to detect mTBI associated with neuro-cognitive impairment that is not apparent using standard neuro-imaging methods. A wireless pressure sensor system comprising a piezo-resistive flexible substrate paired with a microcontroller and a radio is designed and built to provide information relevant to mTBI detection. The collected information is then processed with a software program to remove noise and interference, and detect both sleep states and cardio-respiratory movements.

Wireless Sensors Without Batteries, Ali Abedi

WiSe-Net Laboratory

No abstract provided.

Development And Evaluation Of A Real-Time Framework For A Portable Assistive Hearing Device, Aleksandar Dimitrov Mihaylov

Electronic Thesis and Dissertation Repository

Testing and verification of digital hearing aid devices, and the embedded software and algorithms can prove to be a challenging task especially taking into account time-to-market considerations. This thesis describes a PC based, real-time, highly configurable framework for the evaluation of audio algorithms. Implementation of audio processing algorithms on such a platform can provide hearing aid designers and manufacturers the ability to test new and existing processing techniques and collect data about their performance in real-life situations, and without the need to develop a prototype device. The platform is based on the Eurotech Catalyst development kit and the Fedora Linux ...

Noise Reduction With Microphone Arrays For Speaker Identification, Zachary Gideon Cohen

Master's Theses and Project Reports

The presence of acoustic noise in audio recordings is an ongoing issue that plagues many applications. This ambient background noise is difficult to reduce due to its unpredictable nature. Many single channel noise reduction techniques exist but are limited in that they may distort the desired speech signal due to overlapping spectral content of the speech and noise. It is therefore of interest to investigate the use of multichannel noise reduction algorithms to further attenuate noise while attempting to preserve the speech signal of interest.

Specifically, this thesis looks to investigate the use of microphone arrays in conjunction with multichannel ...

Online Nonintrusive Condition Monitoring And Fault Detection For Wind Turbines, Xiang Gong

Electrical Engineering Theses and Dissertations

The goal of this dissertation research is to develop online nonintrusive condition monitoring and fault detection methods for wind turbine generators (WTGs). The proposed methods use only the current measurements that have already been used by the control and protection systems of WTGs; no additional sensors or data acquisition devices are needed. Current-based condition monitoring and fault detection techniques have great economic benefits and the potential to be adopted by the wind energy industry. However, there are challenges in using current measurements for wind turbine condition monitoring and fault detection. First, it is a challenge to extract WTG fault signatures ...

Characterization And Implementation Of An Injection Locked Frequency Divider Based On Relaxation Oscillator, Kai Zhu

Doctoral Dissertations

There has been a dramatic increase in wireless awareness among the user community in the past few years. As the wireless communication devices require more integration in terms of both hardware and software, the low-power integrated circuit (IC) solution has gained higher dedication and will dominate in the future radio-frequency IC (RFIC) design. Complementary Metal-Oxide Semiconductor (CMOS) process is extremely attractive for such applications because of its low cost and the possibility to integrate baseband and high frequency circuits on the same chip. The transceiver is often the most power-hungry block in a wireless communication system. The frequency divider (prescaler ...

Prognostic Approaches Using Transient Monitoring Methods, Michael Eric Sharp

Doctoral Dissertations

The utilization of steady state monitoring techniques has become an established means of providing diagnostic and prognostic information regarding both systems and equipment. However, steady state data is not the only, or in some cases, even the best source of information regarding the health and state of a system. Transient data has largely been overlooked as a source of system information due to the additional complexity in analyzing these types of signals. The development for algorithms and techniques to quickly, and intuitively develop generic quantification of deviations a transient signal towards the goal of prognostic predictions has until now, largely ...

Early Forest Fire Detection Using Texture, Blob Threshold, And Motion Analysis Of Principal Components, Georges Fouad Moussa Mr.

Master's Theses and Project Reports

Forest fires constantly threaten ecological systems, infrastructure and human lives. The purpose behind this study is minimizing the devastating damage caused by forest fires. Since it is impossible to completely avoid their occurrences, it is essential to accomplish a fast and appropriate intervention to minimize their destructive consequences. The most traditional method for detecting forest fires is human based surveillance through lookout towers. However, this study presents a more modern technique. It utilizes land-based real-time multispectral video processing to identify and determine the possibility of fire occurring within the camera’s field of view. The temporal, spectral, and spatial signatures ...

L2 Optimized Predictive Image Coding With L∞ Bound, Sceuchin Chuah

Open Access Dissertations and Theses

In many scientific, medical and defense applications of image/video compression, an l_∞ error bound is required. However, pure l_∞-optimized image coding, colloquially known as near-lossless image coding, is prone to structured errors such as contours and speckles if the bit rate is not sufficiently high; moreover, previous l_∞-based image coding methods suffer from poor rate control. In contrast, the l₂ error metric aims for average fidelity and hence preserves the subtlety of smooth waveforms better than the l_∞ error metric and it offers fine granularity in rate control; but pure l₂-based image coding methods ...

Development Of A Novel Handheld Device For Active Compensation Of Physiological Tremor, Abhijit Saxena

Electronic Thesis and Dissertation Repository

In microsurgery, the human hand imposes certain limitations in accurately positioning the tip of a device such as scalpel. Any errors in the motion of the hand make microsurgical procedures difficult and involuntary motions such as hand tremors can make some procedures significantly difficult to perform. This is particularly true in the case of vitreoretinal microsurgery. The most familiar source of involuntary motion is physiological tremor. Real-time compensation of tremor is, therefore, necessary to assist surgeons to precisely position and manipulate the tool-tip to accurately perform a microsurgery. In this thesis, a novel handheld device (AID) is described for compensation ...

A Study For Detection Of Drift In Sensor Measurements, Sungwhan Cho

Electronic Thesis and Dissertation Repository

This study aims to develop methods for detection of drift in sensor measurements. The study consists of three major components; 1) residual generation, 2) statistical change detection, and 3) model building.

To identify the statistical properties of the residuals and to utilize them for detection of the drift, a new method for estimation of the drift rate is proposed. The method formulates an augmented system matrix model and processes the model using a Kalman filter. An analytical method for estimation of the drift rate is also derived. A Hamiltonian approach is used for evaluation of the steady state covariance of ...

Multitarget Tracking Using Multistatic Sensors, Maheswaran Subramaniam

Open Access Dissertations and Theses

In this thesis the problem of multitarget tracking in multistatic sensor networks is studied. This thesis focuses on tracking airborne targets by utilizing transmitters of opportunity in the surveillance region. Passive Coherent Location (PCL) system, which uses existing commercial signals (e.g., FM broadcast, digital TV) as the illuminators of opportunity for target tracking, is an emerging technology in air defence systems. PCL systems have many advantages over conventional radar systems such as low cost, covert operation and low vulnerability to electronic counter measures.

One of another opportunistic signals available in the surveillance region is multipath signal. In this thesis ...

Regularized Latent Variable Methods In The Presence Of Structured Noise And Their Application In The Analysis Of Electroencephalogram Data, Siamak Salari Sharif

Open Access Dissertations and Theses

This thesis provides new regression methods for the removal of structured noise in datasets. With multivariable data, the variables and the noise can be both temporally correlated (i.e. auto correlated in time) and contemporaneously correlated (i.e. cross-correlated at the same time). In many occasions it is possible to acquire measurements of the noise, or some function of it, during the data collection. Several new constrained latent variable methods (LVM) that are built upon previous LVM regression frameworks are introduced. These methods make use of the additional information available about the noise to decompose a dataset into basis for ...