Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, December 2009. / Second Reader: Pace, Phillip E. "December 2009." Description based on title screen as viewed on January 27, 2010. Author(s) subject terms: Spectrum estimation, Frequency estimation, Frequency down-conversion, MUSIC, ESPRIT, MRSS. Includes bibliographical references (p. 89). Also available in print.

Thesis (M.S. in System Engineering)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Knorr, Jeffrey B. Second Reader: Janaswamy, R. "September 1990." Description based on title screen as viewed on March 18, 2010. DTIC Identifier(s): Finlines, Inductive Strips, Ohmic Losses. Author(s) subject terms: Finline, Inductive Strip, Finline Discontinuity, Ohmic Losses. Includes bibliographical references (p. 61). Also available in print.

Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Moose, P. H. Second Reader: Christi, R. "September 1990." Description based on title screen as viewed on March 22, 2010. DTIC Identifier(s): Amplitude Modulation. Author(s) subject terms: Facsimile, MFM, Communications. Includes bibliographical references (p. 43-44). Also available in print.

Thesis (Ph. D.)--Rutgers University, 2010. / "Graduate Program in Electrical and Computer Engineering." Includes bibliographical references (p. 218-230).

Thesis (M.S.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 80-81)

This thesis explores various coding aspects of multiple access communications, mainly for spread spectrum multiaccess(SSMA) communications and collaborative coding multiaccess(CCMA) communications. Both the SSMA and CCMA techniques permit efficient simultaneous transmission by several users sharing a common channel, without subdivision in time or frequency. The general principle behind these two multiaccess schemes is that one can find sets of signals (codes) which can be combined together to form a composite signal; on reception, the individual signals in the set can each be recovered from the composite signal. For the CCMA scheme, the isolation between users is based on the code structure; for the SSMA scheme, on the other hand, the isolation between users is based on the autocorrelation functions(ACFs) and crosscorrelation functions (CCFs) of the code sequences. It is clear that, in either case, the code design is the key to the system design. For the CCMA system with a multiaccess binary adder channel, a class of superimposed codes is analyzed. It is proved that every constant weight code of weight w and maximal correlation λ corresponds to a subclass of disjunctive codes of order T < w/λ. Results related to the decomposition of the disjunctive codes in the noiseless and noisy cases are derived. Decoding algorithms for both the noiseless and the noisy cases are proposed. For the CCMA system operating over a multiaccess Q-ary adder channel, a class of cyclic uniquely decodable codes is proposed and analyzed by employing cyclic codes with symbols from an arbitrary finite integer rings. A very low complexity decoding procedure is presented. For a synchronous SSMA system, a new approach employing orthogonal complementary sets is presented; the properties of such orthogonal complementary sets are studied in detail. Recursive formulas for constructing orthogonal complementary sets are given. Methods for synthesizing new orthogonal complementary sets from known ones with the same dimensions are also discussed. For an asynchronous SSMA system, several new spreading codes are presented and studied: 1. A new class of polyphase codes with two-valued periodic ACF and CCF properties is derived. It is proved that, for a given prime length L > 3, the out-of-phase ACFs and CCFs of the codes are constant and equal to √L. In addition, all codes of the same length are mutually orthogonal. 2. Maximal length sequences (m-sequences) over Gaussian integers, suitable for use with QAM modulation, are considered. Two sub-classes of m-sequences with quasi-perfect periodic autocorrelations are obtained. The CCFs between the decimated m-sequences are studied. By applying a simple operation, it is shown that some m-sequences over rational and Gaussian integers can be transformed into perfect sequences with impulsive ACFs. 3. Frank codes and Chu codes have perfect periodic ACFs and optimum periodic CCFs. In addition, it is shown that they also have very favourable nonperiodic ACFs; some new results concerning the behaviour of the nonperiodic ACFs are derived. Further, it is proved that the sets of combined Frank/Chu codes, which contain a larger number of codes than either of the two constituent sets, also have very good periodic CCFs. Based on Frank codes and Chu codes, two interesting classes of real-valued codes with good correlation properties are defined. It is shown that these codes have periodic complementary properties and good periodic and nonperiodic ACF/CCFs. Finally, a hybrid CCMA/SSMA coding scheme is proposed. This new hybrid coding scheme provides a very flexible and powerful multiple accessing capability and allows simple and efficient decoding. Given an SSMA system with K users and a CCMA system with N users, where at most T users are active at any time, then the hybrid system will have K . N users with at most T.K users active at any time. The hybrid CCMA/SSMA coding scheme is superior to the individual CCMA system or SSMA system in terms of information rate, number of users, decoding complexity and external interference rejection capability.

Thesis (M.S.)--Baylor University, 2006. / Includes bibliographical references (p. 48).

Patients in hospital can be prone to sudden, life-threatening changes in their cardiovascular state. Haemodynamic parameters such as blood pressure, pulse transit time (PTT) and perfusion can be monitored in clinical situations to identify these changes as early as possible. Continuous blood pressure is usually monitored using a catheter placed into a major artery, but this is invasive and involves risk to the patient. In the last decade, the field of non-contact vital sign monitoring has emerged, with growing evidence that the remote photoplethysmogram (rPPG) signal can be used to estimate vital signs using video cameras. If the analysis of the rPPG signal can be expanded to include the estimation of haemodynamic parameters, it could result in methods for the continuous, non-contact monitoring of a subject's haemodynamic state. In a physiology study, a series of video recordings were made of 43 healthy volunteers. The subjects sat in a purpose-built chamber, and the composition of the air was carefully adjusted to cause the subjects to experience large, controlled changes in blood oxygen levels. To validate the video camera algorithms, reference data were also collected. Along with the volunteer study, a clinical study was performed to acquire data in a challenging clinical environment. Data were collected from patients on haemodialysis in the Renal Unit, a population likely to experience sudden changes in haemodynamics. The reference data from the Renal Unit study were analysed to determine the extent to which PTT and mean arterial pressure (MAP) are related. The correlation coefficients and linear fits were found on a global and a per-subject basis. In addition, the video recordings from the Physiology study were processed to derive rPPG signals, and these signals were analysed to obtain estimates for PTT. Local rPPG signals were also derived for different regions of interest, and the waveforms were analysed using a novel application of the technique of signal averaging to produce spatial maps of perfusion and blood flow. The correlation between conventionally measured PTT and MAP was found to be weaker in the haemodialysis population than has been shown elsewhere in the literature, except for a sub-set of patients. The results of the video analysis showed that PTT could be estimated robustly and consistently, although direct validation of these estimates was not possible because of the different method used to calculate the reference PTT. For most subjects, the spatial mapping methods produced robust maps that were consistent over time. These results suggest that it is possible to detect changes in haemodynamics using a video camera, and that this could have applications in healthcare, providing that challenges such as subject movement and clinical validation can be overcome.

Thesis (Ph.D.)--University of Wollongong, 2006. / Typescript. Includes bibliographical references: leaf 236-258.

Back pain is responsible for British employees taking 5 million sick days per year. Low back pain (LBP) has a controversial aetiology, with 95% of cases caused by mechanical, non-pathological causes. Current medical treatment for mechanical LBP is an exercise regime designed to restore lumbar stability. Unfortunately this is often a painful process, and therefore difficult to complete. Electromyography (EMG) variables have been shown to be able to discriminate between subjects with and without mechanical LBP. If these variables could be shown to have discriminatory abilities before the actual onset of LBP they could be used to predict future episodes of LBP in currently otherwise asymptomatic individuals and allow the rehabilitation process to begin before the onset of symptoms. However a number of problems persist with EMG measurement. The test must be administered under closely controlled conditions in order to record clean signals, and interpretation of this data requires special tools and training. This thesis aims to make contributions in three main areas; Automated Analysis: Manual analysis of a large store of EMG raw data files is a time consuming process. If outcome variables that require manual interpretation are included this effect is magnified, with necessary questions being raised as to the accuracy and consistency levels that can be maintained. A successfully implemented automated system would reduce analysis time and improve confidence in the outcome variables recorded. Investigations will also be carried out into the addition of error detection and correction algorithms that could be performed during the analysis procedure. ECG Contamination Removal: Previous studies have identified ECG as a potential source of contamination of lumbar EMG signals. Compensation for this effect is non-trivial as the ECG frequencies overlap an area of interest in the EMG spectrum, and the ECG signal characteristics would change over a fatiguing EMG test. The Independent Component Analysis method will be used to attempt to extract and remove the ECG component of a recorded signal whilst preserving the underlying EMG data. If this is successful an analysis of the effect that removing ECG contamination has on EMG outcome variables will be presented. Colour Map Diagnostic Method: Colour maps are an excellent method of presenting a large amount of signal data to a researcher, and have been used to discriminate between LBP and non-LBP subjects. The usefulness of this diagnostic display too has been somewhat limited however by the difficulty in producing such maps. Investigations will be carried out into methods that will be able to quickly and accurately produce these colour maps to the same specification as earlier studies. Colour maps of subjects that did not report LBP at the time of testing, but who then did report LBP at their next presentation, will be examined to assess whether or not EMG colour maps can be used as a predictor for low back pain.