The present work investigates the applicability of Genetic Algorithms (GA) to the problem of signal propagation in Native Neuronal Networks (NNNs). These networks are comprised of neurons, some of which receive input signals. The signals propagate though the network by transmission between neurons. The research focuses on the regeneration of the output signal of the network without knowing the original input signal. The computational complexity of the problem is prohibitive for the exact computation. We propose to use a heuristic approach called Genetic Algorithm. Three algorithms are developed, based on the GA technique. The developed algorithms are tested on two different networks with varying input signals. The results obtained from the testing indicate significantly better performance of the developed algorithms compared to the Uniform Random Search (URS) technique, which is used as a control group. The importance of the research is in the demonstration of the ability of GA-based algorithms to successfully solve the problem at hand.

The objective of this research is to investigate different propagation models to determine if specified models accurately predict received signal levels for short path 900 MHz spread spectrum radio systems. The City of Denton, Texas provided data and physical facilities used in the course of this study. The literature review indicates that propagation models have not been studied specifically for short path spread spectrum radio systems. This work should provide guidelines and be a useful example for planning and implementing such radio systems. The propagation model involves the following considerations: analysis of intervening terrain, path length, and fixed system gains and losses.

Genome annotation is an important topic since it provides information for the foundation of downstream genomic and biological research. It is considered as a way of summarizing part of existing knowledge about the genomic characteristics of an organism. Annotating different regions of a genome sequence is known as structural annotation, while identifying functions of these regions is considered as a functional annotation. In silico approaches can facilitate both tasks that otherwise would be difficult and timeconsuming. This study contributes to genome annotation by introducing several novel bioinformatics methods, some based on machine learning (ML) approaches. First, we present Dragon PolyA Spotter (DPS), a method for accurate identification of the polyadenylation signals (PAS) within human genomic DNA sequences. For this, we derived a novel feature-set able to characterize properties of the genomic region surrounding the PAS, enabling development of high accuracy optimized ML predictive models. DPS considerably outperformed the state-of-the-art results. The second contribution concerns developing generic models for structural annotation, i.e., the recognition of different genomic signals and regions (GSR) within eukaryotic DNA. We developed DeepGSR, a systematic framework that facilitates generating ML models to predict GSR with high accuracy. To the best of our knowledge, no available generic and automated method exists for such task that could facilitate the studies of newly sequenced organisms. The prediction module of DeepGSR uses deep learning algorithms to derive highly abstract features that depend mainly on proper data representation and hyperparameters calibration. DeepGSR, which was evaluated on recognition of PAS and translation initiation sites (TIS) in different organisms, yields a simpler and more precise representation of the problem under study, compared to some other hand-tailored models, while producing high accuracy prediction results. Finally, we focus on deriving a model capable of facilitating the functional annotation of prokaryotes. As far as we know, there is no fully automated system for detailed comparison of functional annotations generated by different methods. Hence, we developed BEACON, a method and supporting system that compares gene annotation from various methods to produce a more reliable and comprehensive annotation. Overall, our research contributed to different aspects of the genome annotation.

<div>The aim of this study was to compare a newly developed ultrathin wearable surface electromyography (sEMG) sensors patch (patent pending, inventors: Lee & Malandraki) (i.e., experimental sensors) to commercially available and widely-used sEMG sensors (i.e., conventional sensors) in monitoring submental muscle activity during swallowing in healthy older adults. A randomized crossover design was employed to compare the performance of the experimental sensors with the performance of conventional snap-on sensors. Forty healthy older adults participated (24F; age range 53-85). Participants completed the same experimental protocol with both sensor types in a counterbalanced order. Swallow trials completed with both types of sensors included 5 trials of 5ml and 10ml water swallows. Comparisons were made on: a) signal related factors (i.e., signal-to-noise ratio, baseline amplitude, normalized amplitude of the swallow trials, and duration of sEMG burst during swallow trials); and b) safety and preclinical factors (safety/adverse effects, efficiency, and satisfaction/comfort).</div><div><br></div><div><div>In terms of signal related factors (Aim 1), we hypothesized that the signal-to-noise ratio and baseline amplitude values acquired using the experimental sensors will not be inferior to the ones acquired using the conventional sensors. These hypotheses were tested using non-inferiority tests. Moreover, we hypothesized that the normalized amplitude values and the sEMG burst duration during swallow trials will be comparable/equivalent between the two sensor types. These hypotheses were tested using equivalency tests. In terms of safety and pre-clinical factors</div><div>(Aim 2), we predicted that no adverse effects will be reported after using either type of sensors. We also hypothesized that sensor placement will be more efficient, and satisfaction/comfort level will be higher with the experimental sensors. These hypotheses were tested using paired t-tests.</div></div><div><br></div><div><div>Overall, the findings supported our hypotheses for Aim 1. Results showed that the experimental sensors did not perform inferiorly to the conventional sensors based on signal-tonoise ratio (left sensors: t(39) = 3.95, p <0.0002; right sensors: t(39) = 2.66, <i>p <0.0056</i>) and baseline amplitude values (left sensors: t(39) = -7.72, p <<i>0.0001</i>; right sensors: t(39) = -7.43, <i>p</i><<i>0.0001</i>). The normalized amplitude values were deemed equivalent for all swallow trials (5ml left: t_u = 4.25, t_l = -6.22; overall <i>p-value <0.0001</i>; 5ml right: t_u = 2.07, t_l = -4.06; overall <i>p-value <0.0224</i>; 10ml left: t_u = 5.49, t_l = -7.20; overall <i>p-value <0.0001</i>; 10ml right: t_u = 3.36 t_l = -5.28; overall <i>p-value <0.0012</i>).The duration of sEMG burst was also deemed equivalent for all variables (5ml left: t_u = 9.48, t_l = -7.25; overall <i>p-value <0.0001</i>; 5ml right: t_u = 9.03, t_l = -6.35; overall <i>p-value <0.0001</i>; 10ml left: t_u = 6.75, t_l = -6.11; <i>p-value <0.0001</i>; 10ml right: t_u = 6.58, t_l = -6.23; overall <i>p-value < 0.0001</i>).</div></div><div><br></div><div><div>In terms of safety and adverse effects (Aim 2, hypothesis #1), mild redness and itchiness occurred with the conventional sensors in six participants, whereas only one participant reported itchiness with the experimental sensors. No redness or skin irritation was observed or reported by any of the participants after the removal of the experimental sensors. In terms of time efficiency of electrode placement (Aim 2, hypothesis #2), our hypothesis was not proven, as there were no statistically significant differences in the time it took to place both sensor types; (t(39) = 1.87, <i>p= 0.9657</i>). However, as hypothesized (Aim 2, hypothesis #3) satisfaction/comfort level was significantly higher with the experimental sensors than the conventional ones, albeit with a relatively small effect size, t(39) = 1.71, <i>p = 0.0476</i>, <i>d = 0.226</i>.</div></div><div><br></div><div><div>Taken together, these findings indicate that the newly developed ultrathin wearable sEMG sensors obtain comparable signal quality and signal parameters to conventional and widely used sEMG snap-on electrodes; have fewer adverse effects associated with them compared to the conventional sensors, and healthy older adults are highly satisfied and comfortable using them. Future research is warranted to optimize the wearable sEMG sensors, before clinical trials examining the effectiveness of these sensors in the treatment of dysphagia can be initiated.</div></div>

This thesis deals with the creating, visualization and processing data in a military environment. The task is to design and implement a system that enables the creation, visualization and processing ESM data. The result of this work is a ESMBD application that allows using a classical approach, which is a relational database, and BigData technologies for data storage and manipulation. The comparison of data processing speed while using the classic approach (Postgres database) and BigData technologies (Cassandra databases and Hadoop) has been carried out as well.

Sexual selection is a frame of reference that attempts to explain exaggerated signaling traits, including acoustic signals between male and female animals. Contemporary studies in the field of sexual selection are focused on the evolution of female mating preferences, with particular emphasis being placed on the good genes models of sexual selection. Here I investigate whether sexual selection is in operation in the acoustic communication system of the field cricket, Gryllus bimaculatus. Through development of new methodology I show that female crickets have a distinct and repeatable preference and selectivity for certain male song traits. For sexual selection to operate in acoustic communication systems, males must advertise some aspect of their phenotype that will influence female choice. I demonstrate that the basis for arguments invoking sexual selection for spectral song traits in a sister species, G. campestris, which is that tegmen harp area predicts song frequency, is an invalid assumption for sound production in G. bimaculatus. As a result of this finding I investigated what aspects of male song were condition- and morphology-dependent. Temporal and spectral male song traits did not convey information regarding body condition, body size or the ability to withstand developmental instability (as indicated by fluctuating asymmetry). I was unable to detect handicap sexual selection for spectral characteristics of male song despite repeatable female preference for male song frequency. Furthermore, female preference for spectral bandwidth of male song, thought to be a sexually selected trait, was shown to be governed by preference for frequency and therefore not a distinct preference. The lack of detectable sexual selection, together with observed patterns of phenotypic variation in signals and the equivalent response system, suggest that some of the male song traits function for mate recognition. However, sexual selection for call traits not considered here (e.g. duration of calling) is probable. / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

M. S.

Sampling and interpolation are two important topics in signal processing. Signal processing is a vast field of study that deals with analysis and operations of signals such as sounds, images, sensor data, telecommunications and so on. It also utilizes many mathematical theories such as approximation theory, analysis and wavelets. This dissertation is divided into two chapters: Modified Pal´ Interpolation and Sampling Bilevel Signals with Finite Rate of Innovation. In the first chapter, we introduce a new interpolation process, the modified Pal interpolation, based on papers by P ´ al, J ´ oo´ and Szabo, and we establish the existence and uniqueness of interpolation polynomials of modified ´ Pal type. ´ The paradigm to recover signals with finite rate of innovation from their samples is a fairly recent field of study. In the second chapter, we show that causal bilevel signals with finite rate of innovation can be stably recovered from their samples provided that the sampling period is at or above the maximal local rate of innovation, and that the sampling kernel is causal and positive on the first sampling period. Numerical simulations are presented to discuss the recovery of bilevel causal signals in the presence of noise.

Converting an analog signal to digital involves more than just digitizing some measurements. Consequences result from sampling an analog signal and care has to be taken to capture all the desired frequencies and avoid creating new ones.

This thesis is in two parts. Part A is about the study of the LD-4 Regenerator and Part B is about Lasing Action. Both are essential for the completion of Stephen Brown's Master of Engineering Degree. / <p>The switching mechanism of the LD-4 regenerator is studied by applying triangular signals with variable slope and phasing with respect to the sampling pulse in order to investigate their effect on the output signal voltage. Experimental results are obtained in the form of finite sampling crosshairs. These represent the family of input signals that produce all output between the 0 and 1 state. In effect they characterize PST input signals at the N^(th) regenerator to the eventual PST signals at the N+1^(th) regenerator input. </p><p> An attempt is a 1 so made to correlate the experimenta 1 data with either a constant voltage or constant charge sensitivity model in order to understand the mechanism of sampling. </p><p>Results of a detailed investigation of the time-dependence of the stimulated emission from electron-beam pumped CdS platelets are reported. Unlike lower threshold platelets previously reported (1), the platelet examined here exhibits rapid tuning with time of the stimulated emission to longer wavelength. The rate of this frequency tuning canpares favourably with the value reported by Shewchun et al (2) for CdS crystals many times thicker and with a higher threshold than the one measured in this report. Furthermore, there is a temporal variation of the angular position of the spatial mode. This temporal variation or angular tuning rate was compared with angular tuning data reported for GaAs and CdSe as well as with the theory that predicts such tuning in these crystals (3). </p> / Thesis / Master of Engineering (ME)