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Dissertations / Theses on the topic 'Signal'
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1
Saruwatari, Hiroshi. "BLIND SIGNAL SEPARATION OF AUDIO SIGNALS." INTELLIGENT MEDIA INTEGRATION NAGOYA UNIVERSITY / COE, 2006. http://hdl.handle.net/2237/10406.
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Östlund, Nils. "Adaptive signal processing of surface electromyogram signals." Doctoral thesis, Umeå universitet, Strålningsvetenskaper, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-743.
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Electromyography is the study of muscle function through the electrical signals from the muscles. In surface electromyography the electrical signal is detected on the skin. The signal arises from ion exchanges across the muscle fibres’ membranes. The ion exchange in a motor unit, which is the smallest unit of excitation, produces a waveform that is called an action potential (AP). When a sustained contraction is performed the motor units involved in the contraction will repeatedly produce APs, which result in AP trains. A surface electromyogram (EMG) signal consists of the superposition of many AP trains generated by a large number of active motor units. The aim of this dissertation was to introduce and evaluate new methods for analysis of surface EMG signals. An important aspect is to consider where to place the electrodes during the recording so that the electrodes are not located over the zone where the neuromuscular junctions are located. A method that could estimate the location of this zone was presented in one study. The mean frequency of the EMG signal is often used to estimate muscle fatigue. For signals with low signal-to-noise ratio it is important to limit the integration intervals in the mean frequency calculations. Therefore, a method that improved the maximum frequency estimation was introduced and evaluated in comparison with existing methods. The main methodological work in this dissertation was concentrated on finding single motor unit AP trains from EMG signals recorded with several channels. In two studies single motor unit AP trains were enhanced by using filters that maximised the kurtosis of the output. The first of these studies used a spatial filter, and in the second study the technique was expanded to include filtration in time. The introduction of time filtration resulted in improved performance, and when the method was evaluated in comparison with other methods that use spatial and/or temporal filtration, it gave the best performance among them. In the last study of this dissertation this technique was used to compare AP firing rates and conduction velocities in fibromyalgia patients as compared with a control group of healthy subjects. In conclusion, this dissertation has resulted in new methods that improve the analysis of EMG signals, and as a consequence the methods can simplify physiological research projects.
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Östlund, Nils. "Adaptive signal processing of surface electromyogram signals /." Umeå : Department of Radiation Sciences, Umeå University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-743.
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Palekar, Trishul Ajit. "Signal optimization at isolated intersections using pre-signals." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4279.
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This research proposes a new signal operation strategy aimed at efficient utilization of
green time by cutting down on the start up and response loss times. The idea is to have a
"pre-signal" on each main approach a few hundred feet upstream of the intersection in
addition to the main intersection signal, which is coordinated with the pre-signal. The
offset between the main and pre-signal ensures that the majority of start up losses does
not occur at the main signal. The benefits of the system under various traffic conditions
were evaluated based on analysis of the queue discharge process and Corridor
Simulation (CORSIM) study. The proposed measure should reduce the travel time and
total control delay for the signalized network.
To attain the objective the following two studies were undertaken:
1. Development of a queue discharge model to investigate the expected benefits of
the system.
2. Simulation of the system: In the second part of the research, the proposed
strategy was tested using CORSIM to evaluate its performance vis-ÃÂ -vis the
baseline case.
The queue discharge model (QDM) was found to be linear in nature in contrast to prior
expectations. The model was used to quantify the benefits obtained from the pre-signal
system. The result of this analysis indicated that the proposed strategy would yield
significant travel time savings and reductions in total control delay. In addition to the QDM analysis, CORSIM simulations were used to code various
hypothetical scenarios to test the concept under various constraints and limitations. As
per expectations, it was found that the system was beneficial for high demand levels and
longer offsets. The upper limit on offsets was determined by visual observation of
platoon dispersion and therefore the maximum offset distance was restricted to 450 feet.
For scenarios where split phasing was used, the break even point in terms of demand
level was found to be 2500 vph on a three lane approach, whereas that for a lag-lag type
of phasing strategy was found to be 1800 vph, also on a three lane approach.
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Chan, M. K. "Adaptive signal processing algorithms for non-Gaussian signals." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269023.
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Bland, Denise. "Alias-free signal processing of nonuniformly sampled signals." Thesis, University of Westminster, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322992.
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Park, Subok. "Signal detection with random backgrounds and random signals." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280729.
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In this dissertation we explore theoretical and computational methods to investigate Bayesian ideal observers for performing signal-detection tasks. Object models are used to take into account object variability in image backgrounds and signals for the detection tasks. In particular, lumpy backgrounds (LBs) and Gaussian signals are used for various paradigms of signal-detection tasks. Simplified pinhole imaging systems in nuclear medicine are simulated for this work. Markov-chain Monte Carlo (MCMC) methods that estimate the ideal observer test statistic, the likelihood ratio, for signal-known-exactly (SKE) tasks, where signals are nonrandom, are employed. MCMC methods are extended to signal-known-statistically (SKS) tasks, where signals are random. Psychophysical studies for the SKE and SKS tasks using non-Gaussian and Gaussian distributed LBs are conducted. The performance of the Bayesian ideal observer, the human observer, and the channelized-Hotelling observer for the SKE and SKS tasks is compared. Human efficiencies for both the SKE tasks and SKS tasks are estimated. Also human efficiencies for non-Gaussian and Gaussian-distributed LBs are compared for the SKE tasks. Finally, the theory of the channelized-ideal observer (CIO) is introduced to approximate the performance of the ideal observer by the performance of the CIO in cases where the channel outputs of backgrounds and signals are non-Gaussian distributed. Computational approaches to estimate the CIO are investigated.
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Li, Jian. "Array signal processing for polarized signals and signals with known waveforms /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487687485808063.
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Hannaske, Roland. "Fast Digitizing and Digital Signal Processing of Detector Signals." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-27888.
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A fast-digitizer data acquisition system recently installed at the neutron time-of-flight experiment nELBE, which is located at the superconducting electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf, is tested with two different detector types. Preamplifier signals from a high-purity germanium detector are digitized, stored and finally processed. For a precise determination of the energy of the detected radiation, the moving-window deconvolution algorithm is used to compensate the ballistic deficit and different shaping algorithms are applied. The energy resolution is determined in an experiment with γ-rays from a 22Na source and is compared to the energy resolution achieved with analogously processed signals. On the other hand, signals from the photomultipliers of barium fluoride and plastic scintillation detectors are digitized. These signals have risetimes of a few nanoseconds only. The moment of interaction of the radiation with the detector is determined by methods of digital signal processing. Therefore, different timing algorithms are implemented and tested with data from an experiment at nELBE. The time resolutions achieved with these algorithms are compared to each other as well as to reference values coming from analog signal processing. In addition to these experiments, some properties of the digitizing hardware are measured and a program for the analysis of stored, digitized data is developed. The analysis of the signals shows that the energy resolution achieved with the 10-bit digitizer system used here is not competitive to a 14-bit peak-sensing ADC, although the ballistic deficit can be fully corrected. However, digital methods give better result in sub-ns timing than analog signal processing.
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Case, David Robert. "Real-time signal processing of multi-path video signals." Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334170.
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Haghighi-Mood, Ali. "Analysis of phonocardiographic signals using advanced signal processing techniques." Thesis, University of Sussex, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321465.
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Lin, Junne Lung. "Use of combined signals for reactor shutdown signal validation." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/33515.
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Hannaske, Roland. "Fast Digitizing and Digital Signal Processing of Detector Signals." Forschungszentrum Dresden-Rossendorf, 2009. https://hzdr.qucosa.de/id/qucosa%3A21615.
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A fast-digitizer data acquisition system recently installed at the neutron time-of-flight experiment nELBE, which is located at the superconducting electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf, is tested with two different detector types. Preamplifier signals from a high-purity germanium detector are digitized, stored and finally processed. For a precise determination of the energy of the detected radiation, the moving-window deconvolution algorithm is used to compensate the ballistic deficit and different shaping algorithms are applied. The energy resolution is determined in an experiment with γ-rays from a 22Na source and is compared to the energy resolution achieved with analogously processed signals. On the other hand, signals from the photomultipliers of barium fluoride and plastic scintillation detectors are digitized. These signals have risetimes of a few nanoseconds only. The moment of interaction of the radiation with the detector is determined by methods of digital signal processing. Therefore, different timing algorithms are implemented and tested with data from an experiment at nELBE. The time resolutions achieved with these algorithms are compared to each other as well as to reference values coming from analog signal processing. In addition to these experiments, some properties of the digitizing hardware are measured and a program for the analysis of stored, digitized data is developed. The analysis of the signals shows that the energy resolution achieved with the 10-bit digitizer system used here is not competitive to a 14-bit peak-sensing ADC, although the ballistic deficit can be fully corrected. However, digital methods give better result in sub-ns timing than analog signal processing.
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Ghaderi, Foad. "Signal processing techniques for extracting signals with periodic structure : applications to biomedical signals." Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/55183/.
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In this dissertation some advanced methods for extracting sources from single and multichannel data are developed and utilized in biomedical applications. It is assumed that the sources of interest have periodic structure and therefore, the periodicity is exploited in various forms. The proposed methods can even be used for the cases where the signals have hidden periodicities, i.e., the periodic behaviour is not detectable from their time representation or even Fourier transform of the signal. For the case of single channel recordings a method based on singular spectrum anal ysis (SSA) of the signal is proposed. The proposed method is utilized in localizing heart sounds in respiratory signals, which is an essential pre-processing step in most of the heart sound cancellation methods. Artificially mixed and real respiratory signals are used for evaluating the method. It is shown that the performance of the proposed method is superior to those of the other methods in terms of false detection. More over, the execution time is significantly lower than that of the method ranked second in performance. For multichannel data, the problem is tackled using two approaches. First, it is assumed that the sources are periodic and the statistical characteristics of periodic sources are exploited in developing a method to effectively choose the appropriate delays in which the diagonalization takes place. In the second approach it is assumed that the sources of interest are cyclostationary. Necessary and sufficient conditions for extractability of the sources are mathematically proved and the extraction algorithms are proposed. Ballistocardiogram (BCG) artifact is considered as the sum of a number of independent cyclostationary components having the same cycle frequency. The proposed method, called cyclostationary source extraction (CSE), is able to extract these components without much destructive effect on the background electroencephalogram (EEG)
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Ahmed, A. "Signal separation." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595390.
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The problem of signal separation is a very broad and fundamental one. A powerful paradigm within which signal separation can be achieved is the assumption that the signals/sources are statistically independent of one another. This is known as Independent Component Analysis , (ICA). In this thesis, the theoretical aspects and derivation of ICA are examined, from which disparate approaches to signal separation are drawn together in a unifying framework. This is followed by a review of signal separation techniques based on ICA. Second order statistics based output decorrelation methods are employed to try to solve the challenging problem of separating convolutively mixed signals, in the context of mainly audio source separation and the Cocktail Party Problem. Various optimisation techniques are devised to implement second order signal separation of both artificially mixed signals and real mixtures. A study of the advantages and limitations of decorrelation methods is made and some theoretical insights are drawn into a major identifiability problem associated with convolutive source separation using second order statistics only. Motivated by the fact that many signals in real life, especially audio signals, exhibit large degrees of non-stationarity, decorrelation algorithms that take into consideration aspects of non-stationarity are devised. Next, a model based approach to source separation is considered. The problem of non-stationary ICA (nsICA) is addressed, where the mixing system is scalar but time-varying. The density of the sources are modelled as finite mixtures of Gaussians. Simulation based Bayesian methods, notably Markov Chain Monte Carlo (MCMC) techniques, are employed to separate both synthetic and real data that have been mixed by non-stationary mixing matrices. Satisfactory results have been obtained with very few data points, using batch methods, such as Gibbs sampling. The techniques of Sequential Monte Carlo (SMC) methods, or particle filtering, are employed to this problem as well, in the context of both blind and semi-blind signal separation, which involve tracking the time varying mixing system.
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Mabrouk, Mohamed Hussein Emam Mabrouk. "Signal Processing of UWB Radar Signals for Human Detection Behind Walls." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/31945.
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Non-contact life detection is a significant component of both civilian and military rescue applications. As a consequence, this interest has resulted in a very active area of research. The primary goal of this research is reliable detection of a human breathing signal. Additional goals of this research are to carry out detection under realistic conditions, to distinguish between two targets, to determine human breathing rate and estimate the posture. Range gating and Singular Value Decomposition (SVD) have been used to remove clutter in order to detect human breathing under realistic conditions. However, the information of the target range or what principal component contains target information may be unknown. DFT and Short Time Fourier Transform (STFT) algorithms have been used to detect the human breathing and discriminate between two targets. However, the algorithms result in many false alarms because they detect breathing when no target exists. The unsatisfactory performance of the DFT-based estimators in human breathing rate estimation is due to the fact that the second harmonic of the breathing signal has higher magnitude than the first harmonic. Human posture estimation has been performed by measuring the distance of the chest displacements from the ground. This requires multiple UWB receivers and a more complex system. In this thesis, monostatic UWB radar is used. Initially, the SVD method was combined with the skewness test to detect targets, discriminate between two targets, and reduce false alarms. Then, a novel human breathing rate estimation algorithm was proposed using zero-crossing method. Subsequently, a novel method was proposed to distinguish between human postures based on the ratios between different human breathing frequency harmonics magnitudes. It was noted that the ratios depend on the abdomen displacements and higher harmonic ratios were observed when the human target was sitting or standing. The theoretical analysis shows that the distribution of the skewness values of the correlator output of the target and the clutter signals in a single range-bin do not overlap. The experimental results on human breathing detection, breathing rate, and human posture estimation show that the proposed methods improve performance in human breathing detection and rate estimation.
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Krishnan, Sridhar. "Adaptive signal processing techniques for analysis of knee joint vibroarthrographic signals." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0016/NQ47897.pdf.
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Andrikogiannopoulos, Nikolas I. "RF phase modulation of optical signals and optical/electrical signal processing." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/42930.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 125-127).
Analog RF phase modulation of optical signals has been a topic of interest for many years, mainly focusing on Intensity Modulation Direct Detection (IMDD). The virtues of coherent detection combined with the advantages of Frequency Modulation, however, have not been explored thoroughly. By employing Frequency Modulation Coherent Detection (FMCD), the wide optical transmission bandwidth of optical fiber can be traded for higher signal-to-noise performance. In this thesis, we derive the FM gain over AM modulation -- the maximum achievable signal-to-noise ratio (by spreading the signal's spectrum) for specific carrier-to-noise ratio. We then employ FMCD for a scheme of remote antennas for which we use optical components and subsystem to perform signal processing such as nulling of interfering signals. The performance of optical processing on different modulation schemes are compared, and some important conclusions are reported relating to the use of conventional FMCD, FMCD with optical discriminator (FMCD O-D), and IMDD. Specifically, the superiority of conventional FMCD is shown; and, on the other hand, the inferiority of FMCD O-D is shown (same performance as IMDD) because of the use of an O-D. Finally, the remote antenna scheme is generalized for N antennas and N users.
by Nikolas I. Andrikogiannopoulos.
S.M.
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Atherton, Philip James. "Signal transduction in skeletal muscle mediating responses to phenotype altering signals." Thesis, University of Central Lancashire, 2005. http://clok.uclan.ac.uk/8584/.
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Skeletal muscle phenotype, size and function respond to exercise, disease and ageing. The aim of this thesis was to investigate the signal transduction pathways responsible for selected skeletal muscle phenotype and size changes. Myostatin, recently identified as a negative regulator of muscle mass was exposed at 10 ng ml 4 to C2C12 cells, and using cDNA genome-wide profiling, was shown to act as a transcriptional suppressor. Furthermore, in these cells myostatin significantly (n8, p<0.05) reduced phosphorylation of components in the P1-3K pathway: PKB Ser473 -30 %, mTOR Ser2448 -50 %, p70 S6K Thr389 -60 %, whereas 4E-BP1 Thr37/46 remained unaffected. These data provide insights in to the mechanisms by which myostatin controls muscle mass, through negatively affecting transcription and translation. Differences in the concentrations of signalling proteins often alter cellular function and phenotype, as is evident from numerous heterozygous knock-out models. Whilst the levels of metabolic enzymes differ between fibre types, and are regulable by exercise, it is not known if this is also true of signal transduction proteins. Therefore, it was hypothesised that the relative levels of signalling proteins implicated in the adaptation to exercise in both fast rat extensor digitorum longus (EDL; 3% type I fibres) and slow Soleus (84% type I fibres) would be systematically different. Secondly, it was hypothesised that following 6 weeks of chronic electrical stimulation (CMNS) where the EDL undergoes a fast-to-slow transformation, the relative signalling protein concentrations between control EDL/stimulated EDL would mirror the differences shown in control EDL/Soleus. Finally, that CMNS would induce chronic signalling to produce, and maintain a slower phenotype. Western blots revealed that the concentrations of some proteins such as Calcineurin (2.6-fold) and p38 MAPK (1.36-fold) were higher in EDL, whilst others such as PGC-la (1.4-fold); and NFkB (3-fold) (all n=4, pc0.05) were higher in Soleus. CMNS of EDL also led to changes in protein levels between control EDL/stimulated EDL: AMPK which is higher in Soleus was actually 1.4-fold lower following stimulation of EDL, whereas other proteins such as PGC-la moved in the direction of that of Soleus. CMNS was also able to induce chronic phosphorylation of proteins involved in fibre type and mitochondrial biogenesis, such as AMPK 4 fold, and p38 -4.5-fold. These data show that signal transduction protein concentrations vary between fast and slow muscles, presumably reflecting differences at a fibre level. Furthermore, signalling proteins are regulated by CMNS of EDL, but do not always change in the direction of slow Soleus. Chronic phosphorylation of many signalling proteins can explain the characteristic phenotypic change in response to CMNS. Resistance training stimulates adaptive protein synthesis and hypertrophy whereas endurance training induces a partial fast-to-slow fibre phenotype transformation. To simulate these conditions, isolated rat muscles were stimulated at 25 °C with either high frequency (HFS; 6 x 10 repetitions, 3 s-bursts at 100 Hz to mimic resistance training) or low frequency (LFS; 3 h at 10 Hz to mimic endurance training). HFS significantly increased myofibrillar and sarcoplasmic protein synthesis 3 h after stimulation 5.3 and 2.7-fold, respectively (n=6, p<0.05). LFS had no significant effect on protein synthesis 3 h after stimulation, but increased UCP3 mRNA 11.7-fold, whereas HFS had no significant effect on UCP3 mRNA (n6, p<0.05). Only LFS increased AMPK phosphorylation significantly at Thr172 by 2-fold and increased POC- 1 a protein to 1.3-fold of control. LFS had no effect on PICB phosphorylation but reduced TSC2 phosphorylation at Thr1462 and deactivated translational regulators. In contrast, HFS acutely increased phosphorylation of PKB at Ser473 5.3-fold and the phosphorylation of TSC2, mTOR, GSK-3j3 at PKB-sensitive sites. HFS also caused a prolonged activation of the translational regulators p70 56k, 4E-BPI, eIF2B, and eEF2 (all n=8, p<0.05). This behaviour has been termed the AMPK-PICB switch, and is hypothesised to mediate specific adaptations to endurance and resistance training, respectively. Ageing is associated with a loss of muscle mass tenned sarcopenia. Essential amino acids (EAA) are potent stimulators of muscle protein synthesis (MPS), and therefore defects in EAA-induced anabolism might affect ability to maintain muscle mass in ageing and disease. MPS and signalling responses to EAA-stimulation of 20 fasted young versus 24 elderly subjects (age 28 ± 6 and 70 ± 6; BMI 24 ± 3, 25 ± 4 kg.m 2 respectively; means ± SD) and 8 fasted elderly versus 8 elderly with type II DM (age 66 ± 3 and 70 ± 6; BMI: 25 ± 4 vs. 32 ± 2 kg.m 2, respectively means ± SD) were measured using gas combustion mass spectrometry and Western blotting methods. Basal MPS rates were indistinguishable, but the elderly displayed a reduced anabolic responsiveness of MPS to EAA, possibly due to decreased intramuscular phosphorylation after EAA, of amino acid sensing/signalling proteins mTOR, p70 S6 kinase, 4E-BPI and eIF2Bs by —50 %. This was further exacerbated in elderly with type II DM whom exhibited reduced Ser2448 phosphorylation of mTOR by —50 %, reflecting decreased downstream signalling. Associated with the anabolic deficits were — 4-fold increases in NFiB protein, the inflammation-associated transcription factor, as well as —50 % and —20 % decreases in protein expression of p70 S6K of healthy elderly and elderly with type II DM, respectively. These results suggest that the elderly are unable to mount a full anabolic response to EAA and that this blunting is further pronounced in type II DM.
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Aprea, Matthew. "A model for predicting indoor signal levels of satellite transmitted signals." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-07292009-090621/.
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Kbayer, Nabil. "Advanced Signal Processing Methods for GNSS Positioning with NLOS/Multipath Signals." Thesis, Toulouse, ISAE, 2018. http://www.theses.fr/2018ESAE0017/document.
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Les avancées récentes dans le domaine de navigation par satellites (GNSS) ontconduit à une prolifération des applications de géolocalisation dans les milieux urbains. Pourde tels environnements, les applications GNSS souffrent d’une grande dégradation liée à laréception des signaux satellitaires en lignes indirectes (NLOS) et en multitrajets (MP). Cetravail de thèse propose une méthodologie originale pour l’utilisation constructive des signauxdégradés MP/NLOS, en appliquant des techniques avancées de traitement du signal ou àl’aide d’une assistance d’un simulateur 3D de propagation des signaux GNSS. D’abord, nousavons établi le niveau maximal réalisable sur la précision de positionnement par un systèmeGNSS "Stand-Alone" en présence de conditions MP/NLOS, en étudiant les bornes inférieuressur l’estimation en présence des signaux MP/NLOS. Pour mieux améliorer ce niveau deprécision, nous avons proposé de compenser les erreurs NLOS en utilisant un simulateur 3D dessignaux GNSS afin de prédire les biais MP/NLOS et de les intégrer comme des observationsdans l’estimation de la position, soit par correction des mesures dégradées ou par sélectiond’une position parmi une grille de positions candidates. L’application des approches proposéesdans un environnement urbain profond montre une bonne amélioration des performances depositionnement dans ces conditionsRecent trends in Global Navigation Satellite System (GNSS) applications inurban environments have led to a proliferation of studies in this field that seek to mitigatethe adverse effect of non-line-of-sight (NLOS). For such harsh urban settings, this dissertationproposes an original methodology for constructive use of degraded MP/NLOS signals, insteadof their elimination, by applying advanced signal processing techniques or by using additionalinformation from a 3D GNSS simulator. First, we studied different signal processing frameworks,namely robust estimation and regularized estimation, to tackle this GNSS problemwithout using an external information. Then, we have established the maximum achievablelevel (lower bounds) of GNSS Stand-Alone positioning accuracy in presence of MP/NLOSconditions. To better enhance this accuracy level, we have proposed to compensate for theMP/NLOS errors using a 3D GNSS signal propagation simulator to predict the biases andintegrate them as observations in the estimation method. This could be either by correctingdegraded measurements or by scoring an array of candidate positions. Besides, new metricson the maximum acceptable errors on MP/NLOS errors predictions, using GNSS simulations,have been established. Experiment results using real GNSS data in a deep urban environmentshow that using these additional information provides good positioning performance enhancement,despite the intensive computational load of 3D GNSS simulation
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Perelli, Alessandro <1985>. "Sparse Signal Representation of Ultrasonic Signals for Structural Health Monitoring Applications." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6321/1/Perelli_Alessandro_tesi.pdf.
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Assessment of the integrity of structural components is of great importance for aerospace systems, land and marine transportation, civil infrastructures and other biological and mechanical applications. Guided waves (GWs) based inspections are an attractive mean for structural health monitoring. In this thesis, the study and development of techniques for GW ultrasound signal analysis and compression in the context of non-destructive testing of structures will be presented. In guided wave inspections, it is necessary to address the problem of the dispersion compensation. A signal processing approach based on frequency warping was adopted. Such operator maps the frequencies axis through a function derived by the group velocity of the test material and it is used to remove the dependence on the travelled distance from the acquired signals. Such processing strategy was fruitfully applied for impact location and damage localization tasks in composite and aluminum panels. It has been shown that, basing on this processing tool, low power embedded system for GW structural monitoring can be implemented. Finally, a new procedure based on Compressive Sensing has been developed and applied for data reduction. Such procedure has also a beneficial effect in enhancing the accuracy of structural defects localization. This algorithm uses the convolutive model of the propagation of ultrasonic guided waves which takes advantage of a sparse signal representation in the warped frequency domain. The recovery from the compressed samples is based on an alternating minimization procedure which achieves both an accurate reconstruction of the ultrasonic signal and a precise estimation of waves time of flight. Such information is used to feed hyperbolic or elliptic localization procedures, for accurate impact or damage localization.
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Perelli, Alessandro <1985>. "Sparse Signal Representation of Ultrasonic Signals for Structural Health Monitoring Applications." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6321/.
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Assessment of the integrity of structural components is of great importance for aerospace systems, land and marine transportation, civil infrastructures and other biological and mechanical applications. Guided waves (GWs) based inspections are an attractive mean for structural health monitoring. In this thesis, the study and development of techniques for GW ultrasound signal analysis and compression in the context of non-destructive testing of structures will be presented. In guided wave inspections, it is necessary to address the problem of the dispersion compensation. A signal processing approach based on frequency warping was adopted. Such operator maps the frequencies axis through a function derived by the group velocity of the test material and it is used to remove the dependence on the travelled distance from the acquired signals. Such processing strategy was fruitfully applied for impact location and damage localization tasks in composite and aluminum panels. It has been shown that, basing on this processing tool, low power embedded system for GW structural monitoring can be implemented. Finally, a new procedure based on Compressive Sensing has been developed and applied for data reduction. Such procedure has also a beneficial effect in enhancing the accuracy of structural defects localization. This algorithm uses the convolutive model of the propagation of ultrasonic guided waves which takes advantage of a sparse signal representation in the warped frequency domain. The recovery from the compressed samples is based on an alternating minimization procedure which achieves both an accurate reconstruction of the ultrasonic signal and a precise estimation of waves time of flight. Such information is used to feed hyperbolic or elliptic localization procedures, for accurate impact or damage localization.
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Englehart, Kevin. "Signal representation for classification of the transient myoelectric signal." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0016/NQ46463.pdf.
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Englehart, K. "Signal representation for classification of the transient myoelectric signal." Thesis, University of New Brunswick, 1998. http://hdl.handle.net/1882/808.
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Neuman, Bartosz P. "Signal processing in diffusion MRI : high quality signal reconstruction." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/27691/.
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Magnetic Resonance Imaging (MRI) is a medical imaging technique which is especially sensitive to different soft tissues, producing a good contrast between them. It allows for in vivo visualisation of internal structures in detail and became an indispensable tool in diagnosing and monitoring the brain related diseases and pathologies. Amongst others, MRI can be used to measure random incoherent motion of water molecules, which in turn allows to infer structural information. One of the main challenges in processing and analysing four dimensional diffusion MRI images is low signal quality. To improve the signal quality, either denoising algorithm or angular and spatial regularisations are utilised. Regularisation method based on Laplace--Beltrami smoothing operator was successfully applied to diffusion signal. In this thesis, a new regularisation strength selection scheme for diffusion signal regularisation is introduced. A mathematical model of diffusion signal is used in Monte--Carlo simulations, and a regularisation strength that optimally reconstructs the diffusion signal is sought. The regularisation values found in this research show a different trend than the currently used L-curve analysis, and further improve reconstruction accuracy. Additionally, as an alternative to regularisation methods a backward elimination regression for spherical harmonics is proposed. Instead of using the regularisation term as a low-pass filter, the statistical t-test is classifying regression terms into reliable and corrupted. Four algorithms that use this information are further introduced. As the result, a selective filtering is constructed that retains the angular sharpness of the signal, while at the same time reducing corruptive effect of measurement noise. Finally, a statistical approach for estimating diffusion signal is investigated. Based on the physical properties of water diffusion a prior knowledge for the diffusion signal is constructed. The spherical harmonic transform is then formulated as a Bayesian regression problem. Diffusion signal reconstructed with the addition of such prior knowledge is accurate, noise resilient, and of high quality.
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Liljekvist, Erika, and Oscar Hedlund. "Uncovering Signal : Simplifying Forensic Investigations of the Signal Application." Thesis, Högskolan i Halmstad, Akademin för informationsteknologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-44835.
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The increasing availability of easy-to-use end-to-end encrypted messaging applications has made it possible for more people to conduct their conversations privately. This is something that criminals have taken advantage of and it has proven to make digital forensic investigations more difficult as methods of decrypting the data are needed. In this thesis, data from iOS and Windows devices is extracted and analysed, with focus on the application Signal. Even though other operating systems are compatible with the Signal application, such as Android, it is outside the scope of this thesis. The results of this thesis provide access to data stored in the encrypted application Signalwithout the need for expensive analysis tools. This is done by developing and publishing the first open-source script for decryption and parsing of the Signal database. The script is available for anyone at https://github.com/decryptSignal/decryptSignal.
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Ashraf, Pouya, Linnar Billman, and Adam Wendelin. "Teaching Signals to Students: a Tool for Visualizing Signal, Filter and DSP Concepts." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-297168.
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Students at Uppsala University have for some years been given the opportunity to take courses in subjects directly, or indirectly, related to the fields of signal processing and signal analysis. According to the directors of these courses, a considerable number of students are recurringly having difficulties grasping different concepts related to this field of study. This report covers a tool that easily allows teachers to visualize and listen to different manipulations of signals, which should help students get an intuitive understanding of the subject. Features of the system include multiple kinds of analog filters, sampling with variable settings and zero-order hold reconstruction. The finished system is flexible, tunable and modifiable to the teachers every need, making it usable for a wide variety of courses involving signal processing. The system meets its requirements even though individual components’ results de- viate slightly from ideal values.Studenter vid Uppsala Universitet har, under ett antal år, givits möjligheten att läsa kurser inom ämnen direkt, eller indirekt, relaterade till signalbehandling/signalanalys. Enligt kursansvariga för dessa kurser har en ansenlig andel av studenterna svårigheter med att förstå en del av de begrepp och fenomen som förekommer under kurserna. Denna rapport behandlar ett verktyg som ger lärare i dessa kurser möjlighet att på ett enkelt sätt visualisera och lyssna på olika manipulationer av signaler, vilket bör hjälpa studenterna bygga en intuition för ämnet. Systemets olika funktioner inkluderar flera olika typer av analoga filter, sampling med olika inställningar, och så kallad ’Zero-Order-Hold’ rekonstruktion. Det resulterande systemet är flexibelt, inställbart och modifierbart till användarens behov, vilket gör det applicerbart i flera kurser som innefattar signalbehandling/analys. Systemet möter kraven som ställs, även fast resultaten hos individuella komponenter avviker aningen från ideala värden.
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Millette, Veronique. "Signal processing of heart signals for the quantification of non-deterministic events." Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28579.
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The issue of cavitation in mechanical heart valve (MHV) patients was first recognized when damaged mechanical heart valves were observed. Cavitation bubble implosion can cause mechanical damage to the valve structure and blood elements, when it occurs near the surface of the MHV. Some methods have been suggested to quantify the level of cavitation present in MHV patients. Two algorithms from the literature were selected for implementation and comparison. These algorithms were selected as they have been previously proposed and implemented for in vivo heart signals. In this thesis, a rigorous closed-form mathematical analysis of the algorithms is presented with the aim of improving robustness, reliability and accuracy. Improvements are made to the selected algorithms, including a new improved segmentation algorithm, alignment of the S1 and S2 peaks in the signal, and the implementation of the Short-Time Fourier Transform to study the time evolution of the energy in the signal. In vitro measurements were made using a left-heart simulator to test the new improved algorithm. The improvements result in better heart beat alignment and better detection and measurement of the random events in the heart signals, so that they may provide a method to analyze cavitation in MHV patients. The use of the Short-Time Fourier Transform allows the examination of the random events in both time and frequency allowing for further investigation and interpretation of the signal. Cavitation results from the physiologically realistic left-heart simulator indicate that cavitation may not occur under normal physiological heart conditions.
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Rasch, Jennifer [Verfasser]. "Signal Adaptive Methods To Optimize Prediction Signals in Video Coding / Jennifer Rasch." Berlin : epubli, 2019. http://d-nb.info/1199686522/34.
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Gartheeban, Ganeshapillai. "Methods to improve the signal quality of corrupted multi-parameter physiological signals." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65969.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 121-125).
A modern Intensive Care Unit (ICU) has automated analysis systems that depend on continuous uninterrupted real-time monitoring of physiological signals such as Electrocardiogram (ECG), Arterial Blood Pressure (ABP), and the Photo Plethysmogram (PPG). Unfortunately, these signals are often corrupted by noise, artifacts, and missing data, which can result in a high incidence of false alarms. We present a novel approach to improve the Signal Quality of a multi-parameter physiological signal by identifying the corrupted regions in the signal, and reconstructing them using the information available in correlated signals. The method is specifically designed to preserve the clinically most signicant aspects of the signals. We use template matching to jointly segment the multi-parameter signal, morphological dissimilarity to estimate the quality of the signal segment, similarity search to nd the closest match from a database of templates, and time-warping to reconstruct the corrupted segment using the matching template. Experiments carried out on the MIT-BIH Arrhythmia Database, a multi-parameter ECG database with many clinically signicant arrhythmias, demonstrate the effectiveness of the method. Our method improved the classification accuracy of the beat type by more than 700% on the signal corrupted with white Gaussian noise, and increased the similarity to the original signal, as measured by the normalized residual distance, by more than 250%. When the method was applied to the multi-parameter physiological signal data from Cinc Challenge 2010 database at Physionet.org, our method improved the classification accuracy of beat type by more than 33 times on a signal corrupted with white Gaussian noise, and increased the similarity to the original signal by more than 280%.
by Gartheeban Ganeshapillai.
S.M.
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Yan, Yan. "Statistical signal processing for echo signals from ultrasound linear and nonlinear scatterers." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/11634.
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Shariat-Yazdi, Ramin. "Mixed signal design flow a mixed signal PLL case study /." Waterloo, Ont. : University of Waterloo, [Dept. of Electrical and Computer Engineering], 2001. http://etd.uwaterloo.ca/etd/rshariatyazdi2001.pdf.
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Thesis (M.A.Sc.) - University of Waterloo, 2001."A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master of Applied Science in Electrical and Computer Engineering". Includes bibliographical references.
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Figueroa, Toro Miguel E. "Adaptive signal processing and correlational learning in mixed-signal VLSI /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/6856.
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Shariat, Yazdi Ramin. "Mixed signal design flow, a mixed signal PLL case study." Thesis, University of Waterloo, 2001. http://hdl.handle.net/10012/916.
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Mixed-signal designs are becoming more and more complex every day. In order to adapt to the new market requirements, a formal process for design and verification of mixed signal systems i. e. top-down design and bottom-up verification methodology is required. This methodology has already been established for digital design. The goal of this research is to propose a new design methodology for mixed signal systems. In the first two chapters of this thesis, the need for a mixed signal design flow based on top-down design methodology will be discussed. The proposed design flow is based on behavioral modeling of the mixed signal system using one of the mixed signal behavioral modeling languages. These models can be used for design and verification through different steps of the design from system level modeling to final physical design. The other advantage of the proposed flow is analog and digital co-design. In the remaining chapters of this thesis, the proposed design flow was verified by designing an 800 MHz mixed signal PLL. The PLL uses a charge pump phase frequency detector, a single capacitor loop filter, and a feed forward error correction architecture using an active damping control circuit instead of passive resistor in loop filter. The design was done in 0. 18- µ m CMOS process technology.
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李潔安 and Kit-on Niko Li. "Comprehensive restoration plan for Signal Tower at Signal Hill, Tsimshatsui." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B42181549.
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Chen, Cheng. "Simultaneous transmission of baseband signal and in band RF signal." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708805.
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Hoppe, Elizabeth A. "Improving Signal Clarity through Interference Suppression and Emergent Signal Detection." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/39325.
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Microphone arrays have seen wide usage in a variety of fields; especially in sonar, acoustic source monitoring and localization, telecommunications, and diagnostic medicine.
The goal of most of these applications is to detect or extract a signal of interest. This task is complicated by the presence of interferers and noise, which corrupts the recorded array signals. This dissertation explores two new techniques that increase signal clarity: interferer suppression and emergent signal detection.
Spatial processing is often used to suppress interferers that are spatially distinct from the signal of interest. If the signal of interest and the interferer are statistically independent, blind source separation can be used to statistically extract the signal of interest. The first new method to improve signal clarity presented in this work combines spatial processing with blind source separation to suppress interferers. This technique allows for the separation of independent sources that are not necessarily simultaneously mixed or spatially distinct. Simulations and experiments are used to show the capability of the new algorithm for a variety of conditions. The major contributions in this dissertation under this topic are to use independent component analysis to extract the signal of interest from a set of array signals, and to improve existing independent component analysis algorithms to allow for time delayed mixing.
This dissertation presents a novel method of improving signal clarity through emergent signal detection. By determining which time frames contain the signal of interest, frames that contain only interferers and noise can be eliminated. When a new signal of interest emerges in a measurement of a mixed set of sources, the principal component subspace is altered. By examining the change in the subspace, the emergent signal can be robustly detected. This technique is highly effective for signals that have a near constant sample variance, but is successful at detecting a wide variety of signals, including voice signals. To improve performance, the algorithm uses a feed-forward processing technique. This is helpful for the VAD application because voice does not have a constant sample variance. Experiments and simulations are used to demonstrate the performance of the new technique.Ph. D.
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Wang, Limin. "The ECG signal processing by ADSP-21062 digital signal processor." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=840.
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Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains vi, 110 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 66-68).
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Li, Kit-on Niko. "Comprehensive restoration plan for Signal Tower at Signal Hill, Tsimshatsui." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B42181549.
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Howell, Brian. "Signal transducing molecules." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39347.
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The involvement of protein phosphorylation and gene regulation in signal transduction pathways are examined. In particular the role of the novel STY kinase in signal transduction networks is suggested, followed by a study of the liver-specific and inducible expression of the carbamyl phosphate synthetase I (CPSI) gene. In a screen of an embryonal carcinoma (EC) cell cDNA expression library with an antibody to phosphotyrosine, the STY kinase was identified. STY is represented by a single 1.8 kb transcript in undifferentiated P19 cells. During differentiation of these cells, mRNAs of 3.2 and 5.6 are induced and persist to adulthood. Sequence analysis of the STY kinase revealed a catalytic domain homologous to kinases with serine/threonine phosphorylating specificity especially those involved in cell-cycle control, such as the FUS3 gene. Biochemical analysis of recombinant STY synthesized in bacteria or in vitro indicated a serine-, threonine-, and tyrosine-phosphorylating capability, suggesting that it belongs to a previously unappreciated family of kinases.The promoter region of the liver specific, glucocorticoid and cAMP inducible gene, CPSI was analyzed for transcriptional activity. Sequences extending from the in vivo start site of CPSI gene to $-$1200 bp, were shown to support in vitro transcription with liver nuclear extracts. A region proximal to transcription initiation, from $-$104 to $-$124 was shown to specifically interact with the abundant liver nuclear factor C/EBP. Double stranded oligonucleotides corresponding this cis element abolishes in vitro transcription reactions in a competitive manner. The C/EBP and related factors, LAP and LIP, interaction with CPSI promoter elements has implications in the developmental, liver-specific, as well as the inducible aspects of CPSI gene expression.
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Mishin, A. "Biomagnetic signal analysis." Thesis, Swansea University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638202.
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Most of this thesis is an account of the effort to develop new methods for biomagnetic data analysis. Variations of the heart rate reflect the neural heart control mechanisms which are performed via the electrical modulation of the sinoatrial node by the autonomic nervous system. This modulation involves the interaction of several physiological mechanisms that operate on differing time scales. Using SQUID (superconducting quantum interference device) instrumentation, the fetal cardiogram can be measured with great accuracy and a high temporal resolution, thereby providing the opportunity to assess the neural function in the fetus non-invasively by analysing heart rate variability (HRV). However, a quantitative analysis of HRV requires several other physiological parameters such as blood pressure, respiration etc. to be analysed simultaneously with HRV. These parameters are obviously inaccessible in the fetus although they are routinely recorded in premature neonates treated in the intensive care units. Using a time domain correlation method, the behaviour of different HRV components was quantitatively studied for both fetuses and premature neonates and a number of consistent features were found. The correlation between neonatal HRV, respiration and arterial blood pressure was studied with the ultimate goal of constructing a numerical model of HRV. It was also observed that different types of ventilation equipment used in neonatal intensive care cause different patterns of respiration/HRV correlation, which may be indicative of the efficacy of the ventilator. Investigation of the spontaneous activity of the human brain and in particular alpha rhythm is another area where SQUID-based biomagnetic techniques can make an important contribution. In the final chapter of this work the multichannel alpha magnetoencephalogram (MEG) is considered as a sequences of MEG maps. A neural-net based algorithm for segmentation of MEG records into words is presented. Using this method three recurring words were found in an eight-second magnetoecephalogram. This could be of value for active testing of the functional role of the cortex in neurological experiments.
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Chan, D. C. B. "Blind signal separation." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597415.
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The separation of independent sources from mixed observed data is a fundamental and challenging signal processing problem. In many practical situations, one or more desired signals need to be recovered from the mixtures only. A typical example is speech recordings made in an acoustic environment in the presence of background noise and/or competing speakers. Other examples include EEG signals, passive sonar applications and cross-talk in data communications. The audio signal separation problem is sometimes referred to as The Cocktail Party Problem. When several people in the same room are conversing at the same time, it is remarkable that a person is able to choose to concentrate on one of the speakers and listen to his or her speech flow unimpeded. This ability, usually referred to as the binaural cocktail party effect, results in part from binaural (two-eared) hearing. In contrast, a person with a severe hearing loss in one ear finds it is difficult to focus on a particular speaker under the same circumstances. A signal separation pre-process would be desirable in such circumstances. Signal separation techniques can also be applied in many other areas such as noise reduction, speech recognition and multi-media applications. The term 'Blind Signal Separation' refers to the lack of any propagation model: only statistical independence of the sources is assumed. The lack of other prior information underlines the difficulty of the problem. Observations may be modelled as linear mixtures of a number of source signals, i.e. a linear multi-input multi-output system. In this dissertation, the general n-source n-sensor (n x n) linear time invariant wide-band system is studied, in which, n random signals are received at n sensors and these signals originated from n sources. The problem is to recover the sources from observed signals only. Various block-based iterative algorithms are proposed which use output decorrelation as a signal separation criterion. These algorithms search for a linear transformation that minimises the statistical correlation between the components. Some existing solutions are reviewed and compared.
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Lee, Li 1975. "Distributed signal processing." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86436.
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Eldar, Yonina Chana 1973. "Quantum signal processing." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/16805.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2002.Includes bibliographical references (p. 337-346).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Quantum signal processing (QSP) as formulated in this thesis, borrows from the formalism and principles of quantum mechanics and some of its interesting axioms and constraints, leading to a novel paradigm for signal processing with applications in areas ranging from frame theory, quantization and sampling methods to detection, parameter estimation, covariance shaping and multiuser wireless communication systems. The QSP framework is aimed at developing new or modifying existing signal processing algorithms by drawing a parallel between quantum mechanical measurements and signal processing algorithms, and by exploiting the rich mathematical structure of quantum mechanics, but not requiring a physical implementation based on quantum mechanics. This framework provides a unifying conceptual structure for a variety of traditional processing techniques, and a precise mathematical setting for developing generalizations and extensions of algorithms. Emulating the probabilistic nature of quantum mechanics in the QSP framework gives rise to probabilistic and randomized algorithms. As an example we introduce a probabilistic quantizer and derive its statistical properties. Exploiting the concept of generalized quantum measurements we develop frame-theoretical analogues of various quantum-mechanical concepts and results, as well as new classes of frames including oblique frame expansions, that are then applied to the development of a general framework for sampling in arbitrary spaces. Building upon the problem of optimal quantum measurement design, we develop and discuss applications of optimal methods that construct a set of vectors.
(cont.) We demonstrate that, even for problems without inherent inner product constraints, imposing such constraints in combination with least-squares inner product shaping leads to interesting processing techniques that often exhibit improved performance over traditional methods. In particular, we formulate a new viewpoint toward matched filter detection that leads to the notion of minimum mean-squared error covariance shaping. Using this concept we develop an effective linear estimator for the unknown parameters in a linear model, referred to as the covariance shaping least-squares estimator. Applying this estimator to a multiuser wireless setting, we derive an efficient covariance shaping multiuser receiver for suppressing interference in multiuser communication systems.
by Yonina Chana Eldar.
Ph.D.
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Valero, Daniel. "Wireless Signal Conditioning." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc862776/.
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This thesis presents a new approach to extend and reduce the transmission range in wireless systems. Conditioning is defined as purposeful electromagnetic interference that affects a wireless signal as it propagates through the air. This interference can be used constructively to enhance a signal and increase its energy, or destructively to reduce energy. The constraints and limitations of the technology are described as a system model, and a flow chart is used to describe the circuit process. Remaining theoretical in nature, practical circuit implementations are foregone in the interest of elementary simulations depicting the interactions of modulated signals as they experience phase mismatch. Amplitude modulation and frequency modulation are explored with using both positive and negative conditioning, and conclusions to whether one is more suitable than the other are made.
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Burke, Christine. "From the signal." Thesis, University of Iowa, 2017. https://ir.uiowa.edu/etd/5432.
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from the signal is a piece for two simultaneously existing trios, where Trio 1 is comprised of clarinet, trumpet and percussion, and Trio 2 of violin, viola and violoncello. I use open form, indeterminacy, and non standard methods of notation to neutralize narrative form, creating instead a static world where sounds interact without implying purpose or direction.
The ideas of identity and concealment are central to from the signal, as each trio embodies a set of timbral characteristics that are respectively unique but exposed in different ways. Trio 1’s direct, strident material is an orchestrated amplification/extension of the slow progression of an EBow down the string of an acoustic guitar (played by the percussionist), while Trio 2’s softer sounds explore notions of space and closeness as they relate to pitch. The title refers to the roles of the percussionist and violinist, as they are responsible for leading and pacing their respective trios throughout the piece.
This piece may raise questions about power dynamics, relationships and balance, but is in no way an attempt to make a conclusion about these things. My intent is rather to create a musical situation where listeners are invited to consider the ramifications of such juxtaposition for themselves (drawing their own conclusions, or not). from the signal was written for the Chicago Civic Orchestra Composers Project, and will be premiered on May 28th, 2017.
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Manmontri, Uttachai. "A gradient-based approach to unsupervised signal separation using signal properties." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442068.
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Lei, Chi-un, and 李志遠. "VLSI macromodeling and signal integrity analysis via digital signal processing techniques." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45700588.
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Clewell, Matthew John. "Reducing signal coupling and crosstalk in monolithic, mixed-signal integrated circuits." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/18138.
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Master of ScienceDepartment of Electrical Engineering
William B. Kuhn
Designers of mixed-signal systems must understand coupling mechanisms at the system, PC board, package and integrated circuit levels to control crosstalk, and thereby minimize degradation of system performance. This research examines coupling mechanisms in a RF-targeted high-resistivity partially-depleted Silicon-on-Insulator (SOI) IC process and applying similar coupling mitigation strategies from higher levels of design, proposes techniques to reduce coupling between sub-circuits on-chip. A series of test structures was fabricated with the goal of understanding and reducing the electric and magnetic field coupling at frequencies up to C-Band. Electric field coupling through the active-layer and substrate of the SOI wafer is compared for a variety of isolation methods including use of deep-trench surrounds, blocking channel-stopper implant, blocking metal-fill layers and using substrate contact guard-rings. Magnetic coupling is examined for on-chip inductors utilizing counter-winding techniques, using metal shields above noisy circuits, and through the relationship between separation and the coupling coefficient. Finally, coupling between bond pads employing the most effective electric field isolation strategies is examined. Lumped element circuit models are developed to show how different coupling mitigation strategies perform. Major conclusions relative to substrate coupling are 1) substrates with resistivity 1 kΩ·cm or greater act largely as a high-K insulators at sufficiently high frequency, 2) compared to capacitive coupling paths through the substrate, coupling through metal-fill has little effect and 3) the use of substrate contact guard-rings in multi-ground domain designs can result in significant coupling between domains if proper isolation strategies such as the use of deep-trench surrounds are not employed. The electric field coupling, in general, is strongly dependent on the impedance of the active-layer and frequency, with isolation exceeding 80 dB below 100 MHz and relatively high coupling values of 40 dB or more at upper S-band frequencies, depending on the geometries and mitigation strategy used. Magnetic coupling was found to be a strong function of circuit separation and the height of metal shields above the circuits. Finally, bond pads utilizing substrate contact guard-rings resulted in the highest degree of isolation and the lowest pad load capacitance of the methods tested.