Digital Commons Network^™

Multi-Channel Real-Time Communication In Wireless Sensor Network, Nitish Kumar Jha

Masters Theses

Many radio chips used in today's sensor mote hardware can work at different frequencies. Recently, several multi-channel communication protocols have been proposed to improve network throughput and reduce packet loss for wireless sensor networks. However, existing work does not provide explicit guarantees for application-specified end-to-end communication delays, which are critical to many real-time applications such as surveillance and disaster response. On the other hand, those radio chips also have adaptable transmission power which allows a trade-off between communication delays and energy efficiency.

This work proposes two multi-channel real-time communication protocols. One of the protocols features a node-based channel assignment policy …

Design And Development Of An Apd Algorithm Development Board For Positron Emission Tomography, Rakesh Mallem

Masters Theses

Using the PET scanner, three dimensional images of the human body with sufficient detail can be viewed which help physicians to visualize both normal metabolic functions and discover the chemical processes underlying physical abnormalities. Commercial PET scanners employ Photo Multiplier Tubes to detect the anti-matter annihilation photons and amplify the signals to a suitable level for digital sampling. Photomultiplier tubes provide extremely high sensitivity and exceptionally low noise compared to other photosensitive devices currently used to detect radiant energy in the ultraviolet, visible and near infrared regions. A combined magnetic resonance positron emission tomography (MR-PET) modality would require a solid-state …

Wide-Area Surveillance System Using A Uav Helicopter Interceptor And Sensor Placement Planning Techniques, Marcus James Jackson

Masters Theses

This project proposes and describes the implementation of a wide-area surveillance system comprised of a sensor/interceptor placement planning and an interceptor unmanned aerial vehicle (UAV) helicopter. Given the 2-D layout of an area, the planning system optimally places perimeter cameras based on maximum coverage and minimal cost. Part of this planning system includes the MATLAB implementation of Erdem and Sclaroff’s Radial Sweep algorithm for visibility polygon generation. Additionally, 2-D camera modeling is proposed for both fixed and PTZ cases. Finally, the interceptor is also placed to minimize shortest-path flight time to any point on the perimeter during a detection event. …

Design And Analysis Of A Delta Sigma Modulator For A Fractional N Phase Locked Loop Frequency Synthesizer Operating At 2.4 Ghz, Timothy R. Grundman

Masters Theses

With the advances in communications, frequency synthesizers are becoming essential for many different circuits and broadcast bands. This need led to the creation of the fractional N frequency synthesizer. This synthesizer has proven itself to be a great invention allowing for many improvements over similar concepts. However, it only reaches the full extents of its capabilities when it is combined with a Delta Sigma modulator. This combined circuit shows great advances in noise performance and frequency resolution.

The fractional N frequency synthesizer is merely an integer N PLL with the ability to change the division ratio. The first attempts to …

Development Of Gate-Controlled Dc Electrokinetic Micropumps, Prachya Mruetusatorn

Masters Theses

Lab-on-chip (LOC) devices have received considerable attention in research and development for automated, high-throughput biological and chemical analysis. While much progress has been accomplished; however, fluid flow control still needs improvement and reminds one of the significant challenges for the future practical LOC devices. This thesis explores the application of electroosmosis (EO) technique and field effect flow control (FEFC) technology for micropumps, an important microfluidic component of LOC systems.

In this work, electroosmosis method was employed to electro-kinetically move the working fluid under a longitudinal electric field, and the FEFC technique was also utilized to manipulate the Electroosmotic Flow (EOF) …

Temperature Characterization Of The Ultracapacitor Serial Resistance Using A Constant Voltage Source, Curtis W. Miller

Masters Theses

This thesis examines the temperature effects on an ultracapacitor’s equivalent series resistance using a constant voltage source. Previous research has focused on developing models using constant current source. However, as the ultracapacitor technology develops, allowing for the expansion of these devices into new power applications, it is important to understand how ultracapacitors will perform in various temperatures and charging and discharging methods. By predicting the ultracapacitor behavior, systems can be optimized for efficiency and minimize internal circuit losses.

For this thesis, Matlab was used to plot the experimental data and to provide best fit curves with their respective coefficients to …

A Low Power Integrated Circuit For Implantable Biosensor Incorporating An On-Chip Fsk Modulator, Taeho Oh

Masters Theses

Medical care has been significantly improved in recent years due to tremendous technological advancement in the field of CMOS technology. Among those improvements, integrated circuit design and sensing techniques have brought to the doctors more flexibility and accuracy of examinations of their patients. For example, a diabetic patient needs to visit a hospital on a regular basis for the examination and proper treatment. However, with the tremendous advancement in electronic technology, a patient can soon monitor his or her own blood glucose level at home or at office with an implantable sensor which can also trigger insulin pump attached to …

Remote Monitoring Of Barowell Pumps Using A Radio Link, Paul R. Schwer

Masters Theses

Barowell pumps are notorious for having problems and failures, which sometimes occur at the most inopportune times during aeropropulson testing. These failures could be better predicted with proper health monitoring. Continuous monitoring of changes in the health of the pump would allow timely preventive and corrective maintenance to be performed as necessary to reduce failures and reduce plant downtime.

This thesis addresses a wireless method to monitor these pumps remotely by a user located in the control room. The operator can note the ultrasonic amplitude of the bearings on the pumps and make a decision to schedule preventive maintenance.

An …

Ac Electrokinetic Manipulation Of Microfluids And Particles Using Orthogonal Electrodes, Kai Yang

Masters Theses

AC electrokinetics (ACEK) is a promising technique to manipulate micro/bio-fluids and particles. It has many advantages over DC electrokinetics for its low applied voltage, portability and compatibility for integration into lab-on-a-chip devices. This thesis focuses on the design of a multi-functional orthogonal microelectrode system that induces ACEK effect for manipulation of microfluids and particles. Orthogonal electrode configuration used in this research can achieve maximum non-uniform electric field distribution, resulting in strong fluid and particle motion. In the experiments, three types of microflow fields were observed by changing the applied electric signals. Three ACEK processes, capacitive electrode polarization, Faradaic polarization, and …

Multichannel Time-Stamping-Based Correlator And Hardware Simulator For Photon Correlation Spectroscopy, Isaac P. Lescano Mendoza

Masters Theses

In fluorescence correlation spectroscopy and dynamic light scattering, digital correlators acquire the autocorrelation function of detected photons to measure diffusional dynamics of biomolecules and small particles. Multi-channel data from different wavelengths or scattering angles provide increased information for resolving multiple species. Similarly, in single-molecule spectroscopy and in experiments on photon entanglement, there is a need to acquire time stamps of photons from multiple detectors. To enable such advances, a cost-effective Multichannel Time-Correlator (MTC) and a Multichannel Hardware Simulator (MHS) were developed, each based on a reconfigurable digital input/output card, recently available from National Instruments. The field-programmable-gate-array (FPGA) cores of the …