Electrical and Computer Engineering Commons^™

Design, Characterization And Application Of A Multiple Input Stethoscope Apparatus, Spencer Geng Wong

Master's Theses

For this project, the design, implementation, characterization, calibration and possible applications of a multiple transducer stethoscope apparatus were investigated. The multi-transducer sensor array design consists of five standard stethoscope diaphragms mounted to a rigid frame for a-priori knowledge of their relative spatial locations in the x-y plane, with compliant z-direction positioning to ensure good contact and pressure against the subject’s skin for reliable acoustic coupling. When this apparatus is properly placed on the body, it can digitally capture the same important body sounds investigated with standard acoustic stethoscopes; especially heart sounds. Acoustic signal inputs from each diaphragm are converted to …

A Comparison Of Image Processing Techniques For Bird Detection, Elsa Reyes

Master's Theses

Orchard fruits and vegetable crops are vulnerable to wild birds and animals. These wild birds and animals can cause critical damage to the produce. Traditional methods of scaring away birds such as scarecrows are not long-term solutions but short-term solutions. This is a huge problem especially near areas like San Luis Obispo where there are vineyards. Bird damage can be as high as 50% for grapes being grown in vineyards. The total estimated revenue lost annually in the 10 counties in California due to bird and rodent damage to 22 selected crops ranged from $168 million to $504 million (in …

Data Chunking In Quasi-Synchronous Ds-Cdma, Trevor Dalke

Master's Theses

DS-CDMA is a popular multiple access technique used in many mobile networks to efficiently share channel resources between users in a cell. Synchronization between users maximizes the user capacity of these systems. However, it is difficult to perfectly synchronize users in the reverse link due to the geographic diversity of mobile users in the cell. As a result, most commercial DS-CDMA networks utilize an asynchronous reverse link resulting in a reduced user capacity. A possible compromise to increase the user capacity in the reverse link is to implement a quasi-synchronous timing scheme, a timing scheme in which users are allowed …

Virtual Reality Engine Development, Varun Varahamurthy

Master's Theses

With the advent of modern graphics and computing hardware and cheaper sensor and display technologies, virtual reality is becoming increasingly popular in the fields of gaming, therapy, training and visualization. Earlier attempts at popularizing VR technology were plagued by issues of cost, portability and marketability to the general public. Modern screen technologies make it possible to produce cheap, light head-mounted displays (HMDs) like the Oculus Rift, and modern GPUs make it possible to create and deliver a seamless real-time 3D experience to the user. 3D sensing has found an application in virtual and augmented reality as well, allowing for a …

Atrengine: An Orientation-Based Algorithm For Automatic Target Recognition, Justin Ting-Jeuan Kuo

Master's Theses

Automatic Target Recognition (ATR) is a subject involving the use of sensor data to develop an algorithm for identifying targets of significance. It is of particular interest in military applications such as unmanned aerial vehicles and missile tracking systems. This thesis develops an orientation-based classification approach from previous ATR algorithms for 2-D Synthetic Aperture Radar (SAR) images. Prior work in ATR includes Chessa Guilas’ Hausdorff Probabilistic Feature Analysis Approach in 2005 and Daniel Cary’s Optimal Rectangular Fit in 2007.

A system incorporating multiple modules performing different tasks is developed to streamline the data processing of previous algorithms. Using images from …

A Frequency-Domain Method For Active Acoustic Cancellation Of Known Audio Sources, Ryan D. Rocha

Master's Theses

Active noise control (ANC) is a real-time process in which a system measures an external, unwanted sound source and produces a canceling waveform. The cancellation is due to destructive interference by a perfect copy of the received signal phase-shifted by 180 degrees. Existing active noise control systems process the incoming and outgoing audio on a sample-by-sample basis, requiring a high-speed digital signal processor (DSP) and analog-to-digital converters (ADCs) with strict timing requirements on the order of tens of microseconds. These timing requirements determine the maximum sample rate and bit size as well as the maximum attenuation that the system can …

Variable Precision Tandem Analog-To-Digital Converter (Adc), Colton A. Parsons

Master's Theses

This paper describes an analog-to-digital signal converter which varies its precision as a function of input slew rate (maximum signal rate of change), in order to best follow the input in real time. It uses Flash and Successive Approximation (SAR) conversion techniques in sequence.

As part of the design, the concept of "total real-time optimization" is explored, where any delay at all is treated as an error (Error = Delay * Signal Slew Rate). This error metric is proposed for use in digital control systems. The ADC uses a 4-bit Flash converter in tandem with SAR logic that has variable …