Dissertations / Theses on the topic 'Parameters of glottal pulse'

Tato disertační práce je zaměřena na analýzu řečového signálu za učelem detekce nemocí ovlivňujících strukturu hlasových orgánů, obzvláště těch, které mění strukturální character hlasivek. Poskytnut je přehled současných technik. Dále jsou popsány zdroje použitých nahrávek pro zdravé a nemocné mlučí. Hlavním učelem této disertační práce je popsat vypočetní postup k odhadu parametrů modelu hlasového zdroje, které umožní následnou detekci a klasifikaci nemocí hlasivek. Poskytujeme detailní popis analýzy řečových signálů, které mohou být odvozeny z parametrických modelů hlasivek.

Cette étude s'intéresse au problème de l'inversion d'un modèle de production de la voix étant donné un enregistrement audio de parole pour obtenir une représentation de le source sonore qui est générée au niveau de la glotte, la source glottique, ainsi qu'un représentation des résonances et anti-résonances créées par les cavités du conduit vocal. Cette séparation des éléments composants la voix donne la possibilité de manipuler indépendamment les caractéristiques de la source et le timbre des résonances. Nous supposons que la source glottique est un signal à phase mixte et que la réponse impulsionnelle du filtre du conduit vocal est un signal à minimum de phase. Puis, considérant ces propriétés, différentes méthodes sont proposées pour estimer les paramètres d'un modèle glottique qui minimisent la phase carrée moyenne du résiduel convolutif d'un spectre de parole observé et de son modèle. Une dernière méthode est décrite où un unique paramètre de forme est solution d'une forme quasi fermée du spectre observé. Ces méthodes sont évaluées et comparées avec des méthodes de l'état de l'art en utilisant des signaux synthétiques et electro-glotto-graphiques. Nous proposons également une procédure d'analyse/synthèse qui estime le filtre du conduit vocal en utilisant un spectre observé et sa source estimée. Des tests de préférences ont été menés et leurs résultats sont présentés dans cette étude pour comparer la procédure décrite et d'autres méthodes existantes.

Photoacoustic imaging for biomedical application has attracted much research in recent years. To date, most of the work has focused on pulsed photoacoustics. Recent developments have seen the implementation of a radar pulse compression methodology into continuous wave photoacoustic modality, however very little theory has been developed in support of this approach. In this thesis, the one-dimensional theory of radar photoacousticsfor pulse compressedlinear frequency modulated continuous sinusoidal laserphotoacoustics is developed.The effect of the chirp parameters on the corresponding photoacoustic signal is investigated, and guidelines for choosing the chirp parametersfor absorber profilometric detectionare given based on the developed theory and simulations. Simulated results are also compared to available experimental results and show a good agreement.

With the rise in prevalence of cardiovascular (CV) disease, risk stratification is becoming increasingly important. Accurate characterization of the CV system is required, for which central aortic blood pressure (BP) parameters form an integral part. However, invasive measurement of central aortic BP parameters (aP) is difficult. Therefore, non-invasive methods to estimate aP from the radial pressure pulse (rPulse) have been proposed. To analyze accuracy of estimated aP (aPhat) and applicability in risk stratification and diagnosis, this study presents: (1) a novel representation of the rPulse with minimal loss of information, (2) a framework for strict definition and statistical analysis of aPhat, and (3) a dynamic analysis of effects of mean BP (MP) and heart rate (HR) in the rPulse shape. Methods: (1) 2671 rPulse s measured by applanation tonometry were represented using the first eight principal components (PC) scores after standard PC transformation. rPulse shapes were compared in three subpopulations. (2) The concept of "estimation option" (EO) for aP estimation was presented. A framework for strict definition of aPhat and the comparison of EOs was proposed, and 7 different EOs compared. (3) A sequence of rPulse s was analyzed during soft exhalation maneuver (SEM) %, a mild Valsalva type maneuver, in eight healthy subjects. Radial BP and respiration pressure were continuously measured. The effects of MP and HR in the rPulse parameters were analyzed by standard linear regression for each subject. Results: (1) PC representation of the rPulse improves accuracy of the estimation of aPhat compared with the simple use of rPulse parameters. Subpopulations have distinctive rPulse shapes. (2) No single EO was better for the estimation of all aPhat. Inclusion of MP improves estimation accuracy. Despite further improvement when rPulse is included, the general transfer function EO is a biased estimator. (3) The dynamic analysis of the rPulse provides information of the effects of MP and HR in the rPulse not available in static analysis. The effects were specific for each individual and different from the results obtained from a general population. Conclusions: For accurate CV risk stratification, future studies should include a dynamic measurement of calibrated radial pressure pulse during SEM maneuver. Risk analysis and diagnosis should be based on representations of the rPulse with minimum loss of information. aPhat should be used for better understanding of the underlying physiological principles.

High Duty Cycle echolocating bats use high frequency echolocation pulses that have limited range but are clutter resistant i.e. can detect targets in dense clutter (the number of echoes produced other than those from the target of interest). A specialised echolocation pulse design (consisting of a constant frequency and frequency modulated components) facilitates foraging for prey in habitats characterised by dense vegetation or clutter. The constant frequency component, along with an acoustic fovea and Doppler Shift Compensation, allows them to distinguish small moving targets from stationary background objects. The frequency modulated components are thought to be used for depth resolution (i.e. ranging acuity). In contrast to their clutter specialist status, these species are found in a variety of biomes including open desert. A negative correlation between level of environmental clutter and frequency has been established for some species. The Foraging Habitat Hypothesis (FHH) proposes that the evolution of echolocation frequency is linked with changes in habitat clutter. In High Duty Cycle bats, the FHH predicts areas of low clutter should select lower frequency pulses because they are less susceptible to atmospheric attenuation making them more suited to long distance prey detection. Previous research has therefore focused on the methods by which bats vary the frequency of their pulses to achieve optimal propagation distances. However, the source levels of these signal emissions are also under control of the bat and must play a major role in signal propagation and therefore in detection of prey. My study tested the FHH by combining both an observational and experimental approach to determine how habitat clutter influences echolocation pulse divergence in High Duty Cycle bats. My focal species was Rhinolophus capensis, which has previously been shown to use different pulse frequencies apparently associated with differences in habitat structure. I focused on two populations, R. capensis in the fynbos (pulse frequency: 84 kHz) and R. capensis in the desert (pulse frequency: 74 kHz). Bats were recorded using a multiple microphone array in their natural habitat and in a flight room experiment where they were exposed to both a cluttered (simulating the fynbos biome) and open (simulating the desert biome) flight room. The experiment determined whether observed differences were a result of possible selection (as proposed by the FHH) or behavioural flexibility. A congeneric species, iii R. damarensis, was used as a control and additional test of the FHH because it inhabits the same desert biome as R. capensis but echolocates at a higher frequency (equivalent to the frequency used by R. capensis in the fynbos). In accordance with this hypothesis, I also tested if there were differences in the frequency modulated components of R. capensis pulses between biomes and whether these differences were due to possible selection for optimal ranging acuity in response to the degree of clutter in each biome. My results suggest the use of lower frequency echolocation pulses in R. capensis in the desert could have evolved for increased detection distance (as proposed by the FHH) but that lower frequencies may not be a prerequisite for successful foraging in open biomes. In R. capensis the greatest differences in prey detection between biomes was a product of both frequency and source level. However, higher source levels used by R. capensis in the desert had a greater contribution to observed differences in detection distances both within (emergence versus foraging area, cluttered versus open flight room) and between biomes (desert versus fynbos) than frequency. In addition, on average R. damarensis did not compensate for higher frequencies with higher source levels resulting in lower average detection distances than R. capensis in the desert. However, a few measurements of source levels for R. damarensis were the highest recorded and resulted in the largest prey detection distances recorded in my study. These findings support recent findings that suggest that SLs are energetically costly. In both biomes, bats used lower source levels when exposed to a cluttered versus open flight room. In the desert biome, bats actively lowered their source levels (compared to the source levels they use in the field) when exposed to a level of clutter that they do not experience naturally (cluttered flight room treatment). Unlike source levels, frequency (of the constant frequency component) was conserved during the flight room treatments. Frequency differences between R. capensis in the different biomes can therefore be attributed to possible selection rather than behavioural flexibility. The conservation of frequency prompted bats to vary their source levels to achieve appropriate detection distances when exposed to different environmental stimuli. Source level flexibility may therefore be the key to the capability of specialist clutter foragers to successfully hunt and survive in harsh open environments. To the same extent that source levels facilitate foraging in open environments, the frequency modulated components of High Duty Cycle bat pulses may facilitate the orientation and foraging of these bats in cluttered biomes. In accordance with the FHH, a strong correlation was found between the frequency (i.e. number of occurrences)/bandwidth of these components and the level of environmental clutter both within iv (between the two treatments of the experiment) and between biomes. The findings in my study highlight the importance of environmental pressures, such as clutter, in shaping the echolocation pulse parameters of bats.

With the deep exploration of particle physics, particle accelerators, detection methods, data recording and processing, and application of computing technology are continuously developing. It has not only brought progress in particle physics, but also promoted the development of the Science and Technology. The main focus of this thesis is data recording and processing. It provides a calibration method for pulses processed by ADCs. It uses some existing filters to achieve the accurate parameters of pulses and existing concept to do the comparison among filters. The  FPGA implementation scheme is also discussed in the paper.

Muitas pesquisas tem sido feitas em processamento digital de sinais (PDS) na tentativa de se avaliar o sinal de fala para diagnosticar doenças da laringe. Medidas acústicas têm sido propostas de forma a avaliar indiretamente o trato glotal por meio do sinal de voz coletado através de microfone convencional. Para isso, o modelo paramétrico Liljencrants-Fant (LF) foi desenvolvido para representar o sinal glotal em condições normais e patológicas. Tais parâmetros apresentam vantagens sobre medidas acústicas por possuírem características fisiológicas reais das pregas vocais. Assim, podendo ser empregados para identificação de doenças da laringe. Além da estimação dos parâmetros LF, no domínio do tempo (parâmetros T), a forma de onda da derivativa glotal também pôde ser quantificada através dos parâmetros identificados na literatura por parâmetros R (Rd, Ra, Rk e Rg), parâmetros quocientes Q (SQ, OQ, CQ, AQ e NAQ), parâmetros B1 e B2 que são as extensões de bandas do pulso derivativo LF, e o parâmetro ece, que relaciona os parâmetros β e Ta. Os parâmetros B1 e B2 e ece apesar de serem propostos na literatura, não são encontrados resultados diferentes a essas duas medidas. Os resultados mostraram que os parâmetros B não foram confiáveis na discriminação entre as vozes, por outro lado, o parâmetro ece mostrou-se ser opção na discriminação entre as vozes normais, nódulo e Reinke. O objetivo deste trabalho é direcionar a atenção sobre o sinal glotal, estimando-o automaticamente mediante técnicas de PDS aplicadas ao sinal de fala, visando extrair parâmetros que identifiquem as condições normais e patológicas da laringe. Por fim foram propostos os parâmetros TRp e TRs, visando dissociar os efeitos de primeira ordem dos de ordem superior na fase de retorno do pulso glotal com a finalidade de estimar a real não-linearidade do sub-sistema glotal, retratando as condições normais e patológicas da laringe. Por fim foram propostos os parâmetros TRp e TRs, visando dissociar os efeitos de primeira ordem dos de ordem superior na fase de retorno do pulso glotal com a finalidade de estimar a real não-linearidade do sub-sistema glotal, retratando as condições fisiológicas do movimento das pregas vocais. Com um nível de confiança de 95%, o parâmetro de primeira ordem (TRp) é efetivo na discriminação do Edema de Reinke, porém mostrou-se ineficaz na detecção do nódulo. Em relação ao parâmetro de ordem superior, conclui-se que o TRs é um excelente detetor de vozes patológicas (nódulo e Edema de Reinke), porém não é capaz de discriminar as patologias.
Many researches has been conducted in digital signal processing (DSP) atempting to evaluate the physiological conditions of larynx. Acoustical parameters have been proposed to evaluate the glotal tract from voice signal. One technique proposed is the Liljencrants-Fant model (LF) developed to represent normal and pathologic conditions of the larynx. Those parameters compare favourably as far as real physiologic characteristic of vocal folds is concerned. So, a primary use of the model is the larynx pathologic identification. Beyond LF parameters estimation, (T parameters in the time domain), the waveform of glotal pulse derivative also can be quantified through, R parameters (Rd, Ra, Rk and Rg), quocient parameters (SQ, OQ, CQ, AQ and NAQ), B parameters (B1 and B2) that are band extension of the LF glotal pulse derivative and the ece parameter that in fact, is a relationship between β and Ta. Although proposed in the literature, no results are found, related to B and ece parameters. Our founds show that B parameters do not present good results in voice discrimination, however, ece parameter seems to be good option to discriminate normal voice, nodulo and Reinke edema. The main purpose of this work is to estimate the glotal signal from the voice signal using DSP techniques in order to obtain parameters that identifies the physiological larynx condition. In order to estimate the shape of return phase of glotal pulse, twoparameters have been proposed in this work. The first one evaluates the pulse (TRp, in other words, the first order component of the return phase. The second is responsible to evaluate superior orders components of the return phase (TRs), i.e, the non-linear component of the glotal pulse. With 95% of confidence level, TRp is effective in Reinke edema discrimination however it is inefficient for nodule e dection. By the other hand, the TRs parameter works well to detect pathologic voice however is unable to discriminated them.

Parametric uncertainty in blood flow simulations of cardiovascular systems has received little attention, although methods for blood flow simulation has been subject of many studies. This work presents the implementation and assessment of a method for one dimensional flow and pressure wave simulations in arterial networks with statistically distributed model parameters. The pressure and flow waves in the arterial system are characterized by means of cross-sectionally averaged 1D governing equations for mass and momentum, discretized with a MacCormack scheme (explicit and second order in time and space). The stochastic model considered is a combination of a generalized polynomial chaos with a stochastic collocation method and joined with the one dimensional model. The implementation is validated with the simulation of a single arterial bifurcation, which has been published by others previously, with a somewhat different approach. The assessment is completed with a sensitivity analysis of the wave dynamics, in particular reflected waves, in the systemic arterial tree in the context of ageing. The numerical simulations showed that the impact of model uncertainty in different compartments of the arterial tree on systolic and diastolic pressure peaks can be determined with the elaborated method. In particular, the uncertainty in material parameters of the aortic arch showed a strong influence on the pressure wave forms.

Filtration plants for solid-gas stream filtration are widely used in the industry in order to reduce the amount of particulate for process requirements or to obtain adequate atmosphere emissions. One of the technological problems in these systems is the formation of powder cakes on the filter which affects the filtration performance; therefore, the filter has to be cleaned and the cake removed in order to keep the pressure drop to a suitable level for the filtration process. In the present work, attention is paid on the identification and on the analysis of the critical parameters for the cake detachment from bag filters using pulse-jet cleaning. The influence of the powder cake properties on the detachment parameters is studied. To detach the powder cake from the filter, the applied stress must be equal or above a critical value defined as the detachment stress. It is the force necessary to remove the cake from the filter and to break the cake itself. The detachment stress is retrieved through pressure measurements on an air stream across a filter on which the cake is built. Also the pressure rate is registered and investigated as a critical parameter. The cohesion of the cake and the adhesion between the cake and the filter are measured at different consolidation states of the cake. Then, the detachment parameters behavior with respect to this variation is analysed. Three cake consolidation levels and three different types of powders are considered: limestone, aluminium oxide and hematite. A needlefelt filter fabricated of polyimide is used. The process of detachment was observed and presented. From the analysis of the results, the pressure rate cannot be defined as a critical parameter for the process. The detachment pressure seems to be independent on the cohesion and the adhesion stress and therefore on the consolidation stress. . Instead, a further analysis on the influence of the particle shape and size could be performed.

The ability of a propulsion system is very crucial for the capability of a missile or a rocket system. Unlike liquid propellant rocket motors, the only control mechanism of the thrust value is the propellant geometry in solid propellant rocket motors. When the operation of solid propellant rocket motor has started, it cannot be stopped anymore. For this main reason the advance of dual pulse motor technology has started. The aim of this study is to investigate the geometrical effects of design parameters on the flow behavior of a dual pulse solid propellant rocket motor by using commercial Computational Fluid Dynamics (CFD) methods. For the CFD analysis, a generic dual pulse rocket motor model is constituted. Within this model, initially four different geometry alternatives of Pulse Separation Device (PSD) are analyzed. To begin PSD analyses, mesh sensitivity analyses are performed on one PSD geometry alternative. By defined grid size, the analyses of PSD geometry alternatives are performed. Computed results were compared in terms of flow behavior (flow streamlines, velocity distribution, turbulent kinetic energy&hellip
etc.) with each other. With the selected PSD geometry alternative the effects of L/D ratio (Length/Diameter ratio) of first pulse chamber, Achamb/APSD ratio (Chamber area/PSD opening area) and APSD/Ath ratio (PSD opening area/Throat area) on the flow behavior is investigated. Flow analyses are performed by simulating the unsteady flow of second pulse operation. With the performed analyses, it is aimed to identify generic geometric definitions for a dual pulse rocket motor.

Establishment of relationships for predicting the lateral drift demands of near-fault ground motions is one of the major challenges in earthquake engineering. Excessive lateral drifts caused by earthquake ground motions are the major causes of structural damage observed in structures. In this study, some of the fundamental characteristics of near-fault ground motions are examined. Response characteristics of elastic frame structures to near-fault ground motions are investigated. An approximate method for estimating the elastic ground story and interstory drifts for regular frame type structures is presented. Inelastic displacement demands imposed on elasto-plastic single degree of freedom (SDOF) systems subjected to near-fault ground are examined. Three equations for estimating the maximum lateral inelastic displacement demand from the maximum elastic displacement demand are established. Two of these equations relate the inelastic and elastic displacement demands through natural period and strength reduction factor. The third equation relates the inelastic and elastic displacement demands through the ratio of natural period to pulse period and the strength reduction factor. Efficiency of the natural period to pulse period ratio for estimating the inelastic displacement ratio is shown. Error statistics of the proposed equations are presented and compared with similar studies in the literature. According to the results, these equations can be used for quick and rough estimates of displacement demands imposed on regular elastic moment resisting frames and elasto-plastic single degree of systems.

This paper deals with the effect of the MR pulse sequences on the temperature of the measured object. The theoretical part is dedicated to basic principle of magnetic resonance, the selected pulse sequences and risks that are connected with MRI. There is also described the draft of the testing phantom and information about the measurement and record of temperature during MR measurement. In the experimental part the effect of RF coils, pulse sequences and parameters of pulse sequences are tested on drafted phantom with experimental MR device located at the Institut of Scientific Instruments of the AS CR in Brno. These findings are then tested on live laboratory mouse. All results are analyzed and used as default data for developed simulation program.

Le but de ce travail a été d'étudier les différents effets microscopiques et macroscopiques susceptibles de nous aider à améliorer les procédures de chirurgie oculaire assistée par les lasers à impulsions ultra-courtes ; plus particulièrement en kératoplastie (greffe de cornée), qui nécessite des systèmes lasers opérationnels dans les tissus pathologiques et donc de diffusant fortement la lumière. Antérieurement, le groupe Optique Photonique Santé (OPS) du Laboratoire d'Optique Appliquée (LOA) a identifié 1650 nm comme étant une longueur d'onde optimale à laquelle les processus de diffusion de la lumière à l'intérieur de la cornée pathologique sont minimisés. Au cours de cette thèse, trois tâches principales ont été abordées. Un système laser à impulsions ultra-courtes à base de cristaux optiques non linéaires a été mis au point, optimisée par rapport aux exigences de chirurgie oculaire au laser, et entièrement caractérisé. Le montage achevé est compact, robuste, simple et potentiel-lement apte à un usage en clinique. En collaboration avec un groupe de l’IESL- FORTH (Iraklion, Grèce) et avec la parti-cipation d'un ancien doctorant du groupe, nous avons étudié l'interaction des impulsions ultra-brèves avec de l'eau, une solution de collagène (type I) et des cornées de porcs. Les données sur les interactions laser-tissu sont précieuses car la dynamique d'interaction est habituellement uniquement documentée pour l'eau; nos résultats aide-ront à élaborer un modèle spécifique de tissu pour le processus d'interaction. Nous avons étudié l'interaction entre les impulsions laser et les effets causés sur des cellules vivantes de l'endothélium cornéen. La préservation de la viabilité des cellules endothéliales est cruciale, notamment pour les routines de kératoplastie spécifiques exigeant des incisions à proximité de l'endothélium ; la viabilité des cellules endothéliales compromise – probablement causée par les effets des ondes de choc générées par claquage optique et la formation de bulles – peut conduire à un échec de l'interven-tion chirurgicale. Des jeux de paramètres « saufs » concernant l'énergie d'impulsion et de la géométrie de l'incision doivent être définis. Nous avons ainsi exploré les valeurs maximales autorisées de l'énergie de l'impulsion à une quelconque distance donnée des cellules endothéliales et les distances minimales pour les énergies d'impulsions données, et estimé les amplitudes des ondes de choc associées
He goal of this work was to study different microscopic and macroscopic effects that will ultimately help us to improve procedures in eye surgery assisted by ultrashort pulse lasers and most notably keratoplasty (corneal grafting), which requires laser systems which are operational in pathological and therefore strongly light scattering tissue. Previously, the Optique Photonique Santé (OPS) group at the Laboratoire d'Optique Appliquée (LOA) had identified 1650 nm as an optimum wavelength at which light scattering processes inside the pathological cornea are minimised. During the present thesis, three main tasks have been addressed. An ultrashort pulse laser system based on non-linear optical crystals has been developed, optimised with respect to the requirements of laser eye surgery, and fully char-acterised. The finished set-up is compact, robust, simple and potentially qualified for clinical use. In collaboration with a group at IESL-FORTH (Iraklion, Greece) and with the participation of a previous PhD student of the group we have studied the interaction of ultrashort pulses with water, collagen (type I) solution and porcine cornea. Data on laser-tissue-interaction is precious because the interaction dynamics is usually only documented for water; our results will help to develop a tissue-specific model for the interaction process. We have investigated the interaction of the laser pulses and the effects it causes with live cells in the corneal endothelium. The preservation of endothelial cell viability is crucial notably for specific keratoplasty routines which require incisions close to the endothelium; compromised endothelial cell viability – which is likely caused by the effects of shock waves generated by optical breakdown and bubble formation – may lead to a failure of the surgical intervention. “Safe” sets of parameters concerning pulse energy and incision geometry need to be defined. We explored the maximum permitted pulse energy values at any given distance to the endothelial cells and mini-mal distances for given pulse energies and estimated the associated shock wave amplitudes

Thesis (Ph. D.)--Mechanical Engineering, Georgia Institute of Technology, 2008.
Jeremy P. Harvey, Committee Member ; Carl S. Kirkconnell, Committee Member ; Kurt D. Pennell, Committee Member ; S. Mostafa Ghiaasiaan, Committee Chair ; Prateen V. Desai, Committee Member ; Sheldon M. Jeter, Committee Member.

This thesis deals with lasers, their general theory and application. Then a theoretical part describes laser micromachining and engraving. Experimental part of thesis deals with several experiments performed by powered fibre laser which is not primarily intended for the field of micromachining. Experiments were mainly evaluated by several types of microscopes where the amount of removed material was appraised. By particular experiments removed material was in accordance with used working parameters of laser and a significant role plays machining material. It emerges from the experiments that for the field of laser micromachining and engraving shorter pulses are more suitable (minimal pulse duration was 1 ms in experiment) and it is connected even with a way of removing material. Applied powered laser can be used for micromachining in specific fields of production.

This thesis explores, through a number of production andperception studies, the nature of the voice source signal andhow it varies in spoken communication. Research is alsopresented that deals with the techniques and methodologies foranalysing and synthesising the voice source. The main analytictechnique involves interactive inverse filtering for obtainingthe source signal, which is then parameterised to permit thequantification of source characteristics. The parameterisationis carried by means of model matching, using the four-parameterLF model of differentiated glottal flow.

The first three analytic studies focus on segmental andsuprasegmental determinants of source variation. As part of theprosodic variation of utterances, focal stress shows for theglottal excitation an enhancement between the stressed voweland the surrounding consonants. At a segmental level, the voicesource characteristics of a vowel show potentially majordifferences as a function of the voiced/voiceless nature of anadjacent stop. Cross-language differences in the extent anddirectionality of the observed effects suggest differentunderlying control strategies in terms of the timing of thelaryngeal and supralaryngeal gestures, as well as in thelaryngeal tensions settings. Different classes of voicedconsonants also show differences in source characteristics:here the differences are likely to be passive consequences ofthe aerodynamic conditions that are inherent to the consonants.Two further analytic studies present voice source correlatesfor six different voice qualities as defined by Laver'sclassification system. Data from stressed and unstressedcontexts clearly show that the transformation from one voicequality to another does not simply involve global changes ofthe source parameters. As well as providing insights into theseaspects of speech production, the analytic studies providequantitative measures useful in technology applications,particularly in speech synthesis.

The perceptual experiments use the LF source implementationin the KLSYN88 synthesiser to test some of the analytic resultsand to harness them to explore the paralinguistic dimension ofspeech communication. A study of the perceptual salience ofdifferent parameters associated with breathy voice indicatesthat the source spectral slope is critically important andthat, surprisingly, aspiration noise contributes relativelylittle. Further perceptual tests using stimuli with differentvoice qualities explore the mapping between voice quality andits paralinguistic function of expressing emotion, mood andattitude. The results of these studies highlight the crucialrole of voice quality in expressing affect as well as providingpointers to how it combines withf₀for this purpose.

The last section of the thesis focuses on the techniquesused for the analysis and synthesis of the source. Asemi-automatic method for inverse filtering is presented, whichis novel in that it optimises the inverse filter by exploitingthe knowledge that is typically used by the experimenter whencarrying out manual interactive inverse filtering. A furtherstudy looks at the properties of the modified LF model in theKLSYN88 synthesiser: it highlights how it differs from thestandard LF model and discusses the implications forsynthesising the glottal source signal from LF model data.Effective and robust source parameterisation for the analysisof voice quality is the topic of the final paper: theeffectiveness of global, amplitude-based, source parameters isexamined across speech tokens with large differences inf₀. Additional amplitude-based parameters areproposed to enable a more detailed characterisation of theglottal pulse.

Keywords:Voice source dynamics, glottal sourceparameters, source-filter interaction, voice quality,phonation, perception, affect, emotion, mood, attitude,paralinguistic, inverse filtering, knowledge-based, formantsynthesis, LF model, fundamental frequency,f₀.

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To obtain a process stability and a quality weld bead it is necessary an adequate parameters set: base current and time, pulse current and pulse time, because these influence the mode of metal transfer and the weld quality in the MIG-P, sometimes requiring special sources with synergistic modes with external control for this stability. This work aims to analyze and compare the effects of pulse parameters and droplet size in arc stability in MIG-P, four packets of pulse parameters were analysed: Ip = 160 A, tp = 5.7 ms; Ip = 300 A and tp = 2 ms, Ip = 350 A, tp = 1.2 ms and Ip = 350 A, tp = 0.8 ms. Each was analyzed with three different drop diameters: drop with the same diameter of the wire electrode; droplet diameter larger drop smaller than the diameter of the wire electrode. For purposes of comparison the same was determined relation between the average current and welding speed was determined generating a constant (Im / Vs = K) for all parameters. Welding in flat plate by simple deposition for the MIG-P with a distance beak contact number (DBCP) constant was perfomed subsequently making up welding in flat plate by simple deposition with an inclination of 10 degrees to vary the DBCP, where by assessment on how the MIG-P behaved in such a situation was possible, in addition to evaluating the MIG-P with adaptive control, in order to maintain a constant arc stability. Also high speed recording synchronized with acquiring current x voltage (oscillogram) was executed for better interpretation of the transfer mechanism and better evaluation in regard to the study of the stability of the process. It is concluded that parameters 3 and 4 exhibited greater versatility; diameters drop equal to or slightly less than the diameter of the wire exhibited better stability due to their higher frequency of detachment, and the detachment of the drop base does not harm the maintenance the height of the arc
Para obter a estabilidade no processo e uma boa qualidade no cord?o de solda ? necess?rio um bom ajuste nos par?metros: corrente e tempo de base e corrente e tempo de pulso e Va, pois estes influenciam no modo de transfer?ncia met?lica e sobre a qualidade da solda no processo MIG-P, ?s vezes, sendo necess?rio um aux?lio ?s fontes com os modos sin?rgicos com controle externo para obter esta estabilidade. Este trabalho tem como objetivo analisar e comparar os efeitos dos par?metros de pulso e o di?metro de gota na estabilidade do arco voltaico no processo MIG-P, sendo analisados quatro pacotes de par?metros de pulso: Ip=160 A, tp=5,7 ms; Ip=300 A e tp=2 ms; Ip=350 A, tp=1,2 ms; e Ip=350 A, tp=0,8 ms. Cada um foi analisado com tr?s diferentes di?metros, calculados, de gota: gota com o mesmo di?metro do arame-eletrodo; gota com di?metro de gota maior e menor que o di?metro do arame eletrodo. Para fins de compara??o foi determinada a mesma rela??o entre a corrente m?dia e a velocidade de soldagem gerando uma constante (Im/Vs=K) para todos os par?metros. Realizou-se a soldagem em chapa plana por simples deposi??o para o processo MIG-P com uma dist?ncia bico contato pe?a (DBCP) constante; e posteriormente, efetuando-se a soldagem em chapa plana por simples deposi??o com uma inclina??o de 10? para variar o DBCP, p?de-se avaliar como o MIG-P se comportou em tal situa??o, al?m de avaliar o MIG-P com controle adaptativo, com o objetivo de manter constante a estabilidade do arco voltaico. Tamb?m executou-se a filmagem de alta velocidade sincronizadamente a aquisi??o da corrente x tens?o (oscilograma) para melhor interpreta??o do mecanismo de transfer?ncia e melhor avalia??o no que se refere ao estudo da estabilidade do processo. Conclu?mos que os par?metros 3 e 4 apresentaram uma maior versatilidade; os di?metros de gota igual ou ligeiramente menos que o di?metro do arame apresentaram uma melhor estabilidade, devido a sua maior frequ?ncia de destacamento; e o destacamento da gota na base n?o prejudicou a manuten??o da altura do arco voltaico

Předložená disertační práce se zabývá vývojem algoritmů pro detekci stresu z řečového signálu. Inovativnost této práce se vyznačuje dvěma typy analýzy řečového signálu, a to za použití samohláskových polygonů a analýzy hlasivkových pulsů. Obě tyto základní analýzy mohou sloužit k detekci stresu v řečovém signálu, což bylo dokázáno sérií provedených experimentů. Nejlepších výsledků bylo dosaženo pomocí tzv. Closing-To-Opening phase ratio příznaku v Top-To-Bottom kritériu v kombinaci s vhodným klasifikátorem. Detekce stresu založená na této analýze může být definována jako jazykově i fonémově nezávislá, což bylo rovněž dokázáno získanými výsledky, které dosahují v některých případech až 95% úspěšnosti. Všechny experimenty byly provedeny na vytvořené české databázi obsahující reálný stres, a některé experimenty byly také provedeny pro anglickou stresovou databázi SUSAS.

Objective: Despite the advanced therapy with statins, antithrombotics, and antihypertensive agents, the medical treatment of atherosclerotic disease is less than optimal. Therefore, additional therapeutic antiatherosclerotic options are desirable. This pilot study was performed to assess the potential antiatherogenic effect of the peroxisome proliferator-activated receptor-γ agonist pioglitazone in nondiabetic patients. Methods: A total of 54 nondiabetic patients were observed in a prospective, double-blind, placebo-controlled study. Patients were randomized to pioglitazone or placebo. The following efficacy parameters were determined by serial analyses: artery pulse wave analysis and carotid-femoral pulse wave velocity (PWV), static and dynamic retinal vessel function, and the common carotid intima-media thickness (IMT). The main secondary endpoint was the change in different biochemical markers. Results: After 9 months, no relevant differences could be determined in the two treatment groups in PWV (pioglitazone 14.3 ± 4.4 m/s vs. placebo 14.2 ± 4.2 m/s), retinal arterial diameter (pioglitazone 112.1 ± 23.3 μm vs. placebo 117.9 ± 21.5 μm) or IMT (pioglitazone 0.85 ± 0.30 mm vs. placebo 0.79 ± 0.15 mm). Additionally, there were no differences in the change in biochemical markers like cholesteryl ester transfer protein, lowdensity lipoprotein cholesterol, high-sensitivity C-reactive protein or white blood cell count. Conclusions : Treatment with a peroxisome proliferator-activated receptor-γ agonist in nondiabetic patients did not improve the function of large and small peripheral vessels (PPP Trial, clinicaltrialsregister. eu: 2006-000186-11).

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CNPq
A busca por novos modelos que representem a biofísica da fonação da voz é importante em aplicações que incluem o processamento do sinal de voz por representar uma ferramenta no conhecimento de característica dos locutores. Esta tese de doutorado apresenta uma nova abordagem para a teoria fonte-filtro de geração de voz, mais precisamente sons sonoros, que realiza a modelagem da voz por meio de três subsistemas independentes: fonte de excitação, trato vocal e radiação dos lábios e narinas. Trata-se de um modelo em que a geração da voz é feita por meio de filtros lineares e invariantes ao deslocamento no tempo e que leva em consideração a física da fonação, a partir da característica cicloestacionária do sinal de voz, proveniente do comportamento de vibração das cordas vocais. É sugerido que a frequência de oscilação das cordas vocais é dada em função da massa e comprimento delas, e que seu valor é alterado principalmente pela tensão longitudinal aplicada a elas. No modelo proposto para geração da voz, o movimento vibratório das cordas vocais é modelado por meio de um de gerador de trem de impulsos cicloestacionário, controlado por um sinal de tensão obtido a partir da forma de onda do sinal de voz. É realizada toda a análise matemática que abrange o novo modelo para a excitação glotal, apresentando-se uma expressão matemática da densidade espectral de potência do sinal que excita a glote, bem como para o sinal de voz, cujos parâmetros podem ser ajustados para emular patologias na glote. Além disso, apresenta-se a análise no domínio da frequência do pulso glotal usado. Para analisar o desempenho do modelo proposto, testes com locução foram realizados e os resultados indicam que o modelo proposto se ajusta bem a geração da voz.
The search for new models that represent the biophysics of voice phonation is important for applications that include voice signal processing because it represents a tool for getting to know the characteristics of the speakers. This doctoral thesis presents a new proposal for the source-filter theory of voice production, more precisely related to voiced sounds, that performs the voice modelling using three independent subsystems: the excitation source, the vocal tract, the lip and nostrils radiation system. It is a proposal for a model to generate voice using linear and time-invariant systems, and takes into account the phonation physics and the cyclestationarity characteristics of the voice signal, related to the vibrational behavior of the vocal cords. The model suggests that the frequency oscillation of the vocal folds is a function of the mass and length, but controlled by the longitudinal tension applied to them. In the proposed voice generation model, the vibratory movement of the vocal cords is modeled by a cyclestationary train of impulses, controlled by a tension signal obtained from the voice signal waveform. A mathematical analysis encompassing the new model for glottal excitation is accomplished by presenting a mathematical expression of the signal power spectral density which excites the glottis, as well as the voice signal, whose parameters can be adjusted to emulate pathologies in the glottis. Moreover, the analysis of the utilized glottal pulse in the frequency domain is presented. To analyze the performance of the proposed model, tests with locutions were done and the results indicate that the proposed model adjusts well to voice generation.

Project Magnetotherapeutic device for Child Neurology in his forepart paies medical use of Pulsatile Magnetic Field. Summaries a therapeutic effects of field which is interacting with biotic issue and determines which of those effects are acceptable for treatment of Infantile Paralysis. Below it describes single Bio-Parametres of Pulsatile Magnetic Field and analyses reasons and effects of Infantile Paralysis. In second part is described a block diagram of magnetotherapeutic device for treatment of Infantile Paralysis. Described is principle of function of blocks. In third part is defined circuit solving of controlling, supervisory and generating part of magnetotherapeutic device. Function and wiring of components is described in detail. There is also created a Printed Circuit Board. Device is controlled by three microcontrollers, therefore there are described flowcharts and controlling programs for microcontrollers.

碩士
國立清華大學
電機工程學系
103
The most common way for people to communicate is by means of talking. Some people suffer from voice disorder because of overusing the vocal folds or due to other vocalfold pathology. In an ear-nose-throat clinic, ways of diagnosing the vocal-fold pathology include listening to patients’ voice and watching the movement of patients’ vocal folds. The former method is performed through recording and then analyzing the acoustic parameters to examine whether phonation is normal or not. This method is objective. Alternatively, a subjective way is for the doctor to grade the condition of patients’ voice directly through hearing, and these evaluation indexes include Grade, Roughness, Breathiness, Aesthenia and Strain (GRBAS). The latter method is using stroboscopy to observe the dynamic variation of vocal folds, then the doctor evaluates whether the appearance and movement of vocal folds are normal. Stroboscopy is usually used by doctors to judge the severity of vocal-fold damage subjectively. There is currently no standard way to automate this process. Therefore, we attempt to quantify common glottal physiological parameters (GPPs) including Aperiodicity, Opening Quotient (OQ), Symmetry and Roughness by image processing. The ultimate purpose of this research is to use acoustic parameters to predict the vocal-fold damage severity observed from stroboscopic images. Our motivation was based on the fact that stroboscopy is an invasive instrument which could hurt the patient. In this research, we collected the recording voice files and acoustic parameters including Jitter, Shimmer and Noise-to-Harmonic Ratio (NHR) and also collected the data of GRBAS from 15 patients before they went through vocal-fold surgery. Then we used the linear prediction method to analyze the voice files and calculated their prediction error signals. Finally we calculated the correlation function of the prediction error signals and defined a parameter called Pitch Amplitude (PA). Then combinations of these parameters were used to construct a linear model that gives the best prediction of GPPs in terms of least-square approximation. The R-square, which is used to evaluate the performance of each GPP, can reach Aperiodicity=0.907, OQ=0.774, Symmetry=0.783 and Roughness=0.833. The GPPs can be predicted well by the linear combination of the acoustic parameters which is a non-invasive method.

Dissertação de mestrado em Bioinformática (área de especialização em Engenharia)
O processo de produção humana de voz é, resumidamente, o resultado da convolução entre o sinal de excitação, o impulso glótico, e a resposta impulsiva resultante da função de transferência do trato vocal. Este modelo de produção de voz é frequentemente referido na literatura como um modelo fontefiltro, em que a fonte representa o fluxo de ar que sai dos pulmões e passa pela glote (espaço entre as pregas vocais), e o filtro retrata as ressonâncias do trato vocal e a radiação labial/nasal. Estimar a forma do impulso glótico a partir do sinal de voz é de importância significativa em diversas áreas e aplicações, uma vez que as características de voz relacionadas, por exemplo, com a qualidade da voz, esforço vocal e distúrbios da voz, devem-se, principalmente, ao fluxo glotal. No entanto, este fluxo é um sinal difícil de determinar de forma direta e não invasiva. Ao longo das últimas décadas foram desenvolvidos vários métodos para estimar o impulso glótico mas sem o desenvolvimento de um algoritmo eficiente e automático. A maioria dos métodos desenvolvidos baseia-se num processo designado por filtragem inversa. A filtragem inversa representa a desconvolução, ou seja, procura obter o sinal de entrada aplicando o inverso da função de transferência do trato vocal ao sinal de saída. Apesar da simplicidade do conceito, o processo de filtragem inversa não é simples uma vez que o sinal de saída pode incluir ruído e não é alcançável modelar com precisão as características do filtro do trato vocal. Nesta dissertação apresentamos um novo método de filtragem de um sinal de modo a melhorar um método robusto de estimação da fonte glótica, no domínio das frequências, que usa uma característica de fase baseada nos Atrasos Relativos Normalizados (NRD) dos harmónicos. Este modelo é aplicado a diversos sinais de voz (sintéticos e reais), e os resultados obtidos da estimação do impulso glótico são comparados com os obtidos usando outros métodos analisados no estado da arte com e sem o referido método de filtragem.
The human speech production system is, briefly, the result of the convolution between the excitation signal, the glottal pulse, and the impulse response resulting from the transfer function of the vocal tract. This model of voice production is often mentioned in the literature as a source-filter model, where the source represents the flow of the air leaving the lungs and passing through the glottis (space between the vocal folds), and the filter stands for the resonances of the vocal tract and the lip/nostrils radiation. The estimation of the shape of the glottal pulse from the speech signal is of significant importance in many fields and applications, since the most important features of speech related to voice quality, vocal effort and speech disorders, for example, are mainly due to the voice source. Unfortunately, the glottal flow waveform which is at the origin of the glottal pulse, is a very difficult signal to measure directly and non-invasively. Several methods to achieve the estimation of the glottal flow have been proposed over the last decades, but an efficient and automatic algorithm which performs reliably is not yet available. Most of the developed methods are based on the inverse filtering method. The inverse filtering approach represents a deconvolution process, i.e., it seeks to obtain the source signal by applying the inverse of the vocal tract transfer function to the output speech signal. Despite the simplicity of the concept, the inverse filtering procedure is complex because the output signal may include noise and it is not straightforward to accurately model the characteristics of the vocal tract filter. In this dissertation we discuss a new filtering method for voiced signals with the goal to improve the assessment of a robust frequency-domain algorithm for glottal source estimation that uses a phaserelated feature based on the Normalized Relative Delays (NRDs) of the harmonics. This model is applied to several speech signals (synthetic and real), and the results of the estimation of the glottal pulse are compared with the ones obtained using other state-of-the-art methods with and without the presence of that filtering method.

碩士
國立成功大學
機械工程學系碩博士班
101
This study investigated the effect of different processing conditions on the laser machining material removal process. First, laser added to improve the Machinability in Laser-assisted milling experiments to explore the influence of laser-assisted milling on the processing stability and compared with the relationship of material removal rate without laser-assisted machining. According to cutting coefficients experiments, the tangential cutting coefficients decreased significantly with laser assisted milling, and the results of milling stability experiments found that using laser assisted most effective way to increased critical depth of cut, thus the case had a better material removal rate in same radial depth of cut and feed processing. Then laser machining experiments with different laser parameters processed material surface, to observe the surface morphology and to explore the relationship of laser processing parameters on material removal rate. Taguchi experiment shows that pulses feed rate effect depth and width of groove most, pulse frequency effect least, and peak power between them. The maximum of material removal rate occurs at peak power, pulse feed rate and pulse frequency is high.

abstract: Speech is generated by articulators acting on a phonatory source. Identification of this phonatory source and articulatory geometry are individually challenging and ill-posed problems, called speech separation and articulatory inversion, respectively. There exists a trade-off between decomposition and recovered articulatory geometry due to multiple possible mappings between an articulatory configuration and the speech produced. However, if measurements are obtained only from a microphone sensor, they lack any invasive insight and add additional challenge to an already difficult problem. A joint non-invasive estimation strategy that couples articulatory and phonatory knowledge would lead to better articulatory speech synthesis. In this thesis, a joint estimation strategy for speech separation and articulatory geometry recovery is studied. Unlike previous periodic/aperiodic decomposition methods that use stationary speech models within a frame, the proposed model presents a non-stationary speech decomposition method. A parametric glottal source model and an articulatory vocal tract response are represented in a dynamic state space formulation. The unknown parameters of the speech generation components are estimated using sequential Monte Carlo methods under some specific assumptions. The proposed approach is compared with other glottal inverse filtering methods, including iterative adaptive inverse filtering, state-space inverse filtering, and the quasi-closed phase method.
Dissertation/Thesis
Masters Thesis Electrical Engineering 2018

碩士
東海大學
應用物理學系
103
In this study we investigated the fluorescence lifetime of fluorescent nanodiamonds under different excitation laser repetition rates and different peak powers. We found that the fluorescence lifetime decreases as the period of excitation pulse laser is increased. According to the numerical simulation of the rate equations of the nitrogen-vacancy center, the phenomenon is attributable to thermal transitions among the three ground-state sublevels. Thermal transitions change the population in each sublevels and as a consequence the fluorescence lifetime changes. On the other hand, we found that the fluorescence lifetime increases as the peak power of the excitation pulse laser is increased. According to experimental results, this is caused by the transformation of negative charged nitrogen vacancy centers to neutral charged nitrogen vacancy centers under strong excitation.

碩士
朝陽科技大學
資訊工程系
107
According to the advancement of wearable technology, many physiological monitoring instruments are gradually converted into wearable devices.However, the blood pressure monitor still is a cuff-type device in the consumer market, which also can not perform the beat-by-beat continuous blood pressure measurement. Recently, the cuffless blood pressure measurement has been developed based on the pulse transit time (PTT) but its accuracy is not better. According to the cardiac hemodynamic theorem, the blood pressure relate to the arterial characteristics. Therefore, the purpose of this study was to use the characteristics of the pulse wave measured by the photoplethysmography (PPG) and impedance-plethysmography (IPG) to estimate the blood pressure with a multi-dimension regression model and deep neural network. The contour of pulse wave has some characteristics of the artery. There were 20 subjects participating the experiment, and the blood pressure of the subject was changed by the exercise. PPGresults showed that the root mean square errors using multi-dimension regression model of the estimated systolic and diastolic pressures with the multi-parameters were 5.877mmHg and 4.334 mmHg and were better than those only using the PTTparameter, 7.796 mmHg and 6.039 mmHg. IPG results show that the multi-dimension regression model root mean square error of the estimated systolic and diastolic pressures with the multi-parameters were 5.387mmHg and 5.528 mmHg and were better than those only using the PTTparameter, PTT, 6.324 mmHg and 6.480 mmHg. PPG results showed that the best estimated error of the systolic and diastolic blood pressures with the deep neural network were 8.08 mmHg and 4.62 mmHg. Such results were better than those by using single-parameter PTT 8.21 mmHg and 4.64 mmHg.

碩士
國立高雄大學
電機工程學系--先進電子構裝技術產業研發碩士專班
104
While semiconductor packages become thinner, lighter, and smaller, the wafer used for dies sawing become thinner and more complex of structure. Recently, laser processing become an effective solution in advance semiconductor package technology, such as laser marking, laser drilling, and laser grooving. Laser grooving is an effective pretreatment way to solve die peeling and cracking after diamond sawing. However, optimization of the laser grooving is difficult to achieve due to the complexity of substrate materials, versatile functions of laser machining, and the specification of the diamond sawing. Previous study showed that the shapes of laser grooving were more effective to the yield in die sawing. This thesis is focused on the control of laser grooving shape for optimization in die sawing. Parameters of laser grooving such as laser power, pulse frequency, cutting speed, masked pattern of beam light are studied to achieve the optimized grooved shape for die sawing. By using laser grooving parameters of dual laser grooving beam of 35um ~ 50um, laser power of 2.6W, and pulse frequency of 40kHz can create the best U-shape grooving structure with dual narrow sides + dual wide sides can achieve the best yield rate after die sawing. By utilizing the same optimization process for the laser grooving parameters, we can extend this approach to set the best die sawing process of other wafer structures.

碩士
國立交通大學
環境工程研究所
82
The pulse jet fabric filtration system is the main stream among various fabric filtration systems. In the design of a pulse jet fabric filtration system, both fabric filtration and pulse jet cleaning must be considered. This study has investigated pressure drop, filtration efficiency, and pulse jet cleaning efficiency of a pulse jet fabric filtration system in the laboratory. According to the experimental results, the dust cake has been found to be compressed substantially when filtration velocity is high. In order to avoid "blinding" of the fabric, the restriction of the filtration velocity below a certain value is important. The K2 (specific dust resistance coefficient) is the main parameter to predict pressure drop. Experimental data of K2 has been found to fit well with the equation by Williams et al. Total filtration efficiency has been found to reach nearly 100% within the first minute of filtration. Particle close to 0.1μｍ have been found to have the highest penetration regardless of the type of fabrics and filtration velocity. This is because that the characteristic of fabric dominates the initial period of filtration, and the dust cake dominates the filtration process afterwards. In the aspect of pulse jet cleaning efficiency, it has been found that dust particles are removed ea er when the dust areal density is greater. At the same pressur impulse, the pulse jet cleaning effienciency has been found to be higher when the peak static pressure is higher. A model has been developed to predict the pulse jet cleaning efficiency by considering the balance between the adhesion force and drag force on particles. The theoretical results of pulse jet cleaning efficiency have been found to fit well with the experimental data.

Multiple industry applications, including combustion, flow control, and medicine, have leveraged nanosecond pulsed plasma (NPP) discharges to create plasma generated reactive species (PGRS). The PGRS are essential to induce plasma-assisted mechanisms, but the rate of generation and permanence of these species remains complex. Many of the mechanisms surrounding plasma discharge have been discovered through experiments, but a consistent challenge of time scales limits the plasma measurements. Thus, a well-constructed model with experimental research will help elucidate complex plasma physics. The motivation of this work is to construct a feasible physical model within the additional numerical times scale limitations and computational resources. This thesis summarizes the development of a one-moment fluid model for NPP discharges, which are applied due to their efficacy in generating ionized and excited species from vacuum to atmospheric pressure.

From a pulsed power perspective, the influence of pulse parameters, such as electric field intensity, pulse shape and repetition rate, are critical; however, the effects of these parameters on PGRS remain incompletely characterized. Here, we assess the influence of pulse conditions on the electric field and PGRS computationally by coupling a quasi-one-dimensional model for a parallel plate geometry, with a Boltzmann solver (BOLSIG+) used to improve plasma species characterization. We first consider a low-pressure gas discharge (3 Torr) using a five-species model for argon. We then extend to a 23 species model with a reduced set of reactions for air chemistry remaining at low pressure. The foundations of a single NPP is first discussed to build upon the analysis of repeating pulses. Because many applications use multiple electric pulses (EPs) the need to examine EP parameters is necessary to optimize ionization and PGRS formation.

The major goal of this study is to understand how the delivered EP parameters scale with the generated species in the plasma. Beginning with a similar scaling study done by Paschen we examine the effects of scaling pressure and gap length when the product remains constant for the two models. This then leads to our study on the relationship of pulsed power for different voltages and pulse widths of EPs. By fixing the energy delivered to the gap for a single pulse we determine that the electron and ion number densities both increased with decreasing pulse duration; however, the rate of this increase of number densities appeared to reach a limit for 3 ns. These results suggest the feasibly of achieving comparable outputs using less expensive pulse generators with higher pulse duration and lower peak voltage. Lastly, we study these outcomes when increasing the number of pulses and discuss the effects of pulse repetition and the electron temperature.

Future work will extend this parametric study to different geometries (i.e. pin-to-plate, and pin-to pin) and ultimately incorporate this model into a high-fidelity computational fluid dynamics (CFD) model that may be compared to spectroscopic results under quiescent and flowing conditions will be discussed.

碩士
國立清華大學
電子工程研究所
107
GaN presents the property of high electronic mobility, high critical electric and low turn on voltage, which make it a better power device material than silicon. However, the performance of the device is restricted by heating effects and the device parameters. Therefore, some researches worked on improving the device performance by changing the device structure. This thesis mainly focuses on GaN HEMT, taking some of the previous researches as reference, and combines with practical methods to design and improve the device performance. In addition, it presents three measurement methods to characterization the devices: pulse I-V, load-pull, and X-parameter measurement. In chapter 2, the GaN material properties are introduced, followed by the basic GaN HEMT properties. In chapter 3, the three measurement methods for characterizing the devices are presented, including pulse I-V, load-pull, and X-parameter measurement. In chapter 4, a new method to improve the device performance would be introduced. With the new method applied to process technology, the chips can be measured by the three measurements introduced in chapter 3. Finally, the conclusion of the thesis would be made in chapter 5, along with some possible directions of further research.

碩士
中原大學
醫學工程研究所
96
The purpose of this research was to develop a cardiovascular and pulse parameters measurement and analysis system. In this study, we not only developed the system, but also compared the parameters and investigated the difference between hypertension patients and normal people. In the development of the system, we measured the real-time pulse signal and ECG signal simultaneously by the infrared rays photoplethysmography and electrocardiogram. With the data recording interface and graphical user interface, we could also acquire the cardiovascular and pulse parameters. By using the fixed gamma density function model, the pulse signal components could be separated and let us obtain additional gamma density function parameters for analysis. In the clinical experiment, fifteen hypertension patients and fifteen healthy adults without cardiovascular disease were recruited. We measured subjects’ pulse signal and ECG signal by the cardiovascular and pulse parameters measuring instrument, and used the signal analysis interface by Matlab to get the characteristic parameters. The study used t-test analysis to find the difference between hypertension patients and healthy adults. The results showed that the physiological parameters could be obtained effectively from human bodies by the instrument and signal analysis, and the fixed gamma density function could provide help for boundary setting and objectivity on the pulse curve fitting. In clinical observation about pulse parameters, we found that the hypertension patients had higher values in main pulse angle(∠P, ∠P1, ∠P2), main pulse time(TP), main pulse time to pulse period ratio(TP/T), main pulse wide(W), main pulse wide to pulse period ratio(W/T), and had lower values in upstroke angle(∠U), dicrotic pulse time to pulse period ratio(TD/T). In clinical observation about cardiovascular parameters, we found that the hypertension patients had higher values in reflection index(RI), stiffness index(SI), pulse wave velocity(PWV), low frequency to high frequency bands ratio in HRV(LF/HF), and had lower values in pulse transit time(PTT). Also, in clinical observation about gamma density function parameters, we found that the hypertension patients had lower values in fitting parameter(β1), dicrotic pulse shift(t), dicrotic pulse shift to pulse period ratio(t/T). With the above parameters, we could speculate the cardiovascular status of the subjects. Therefore, it was feasible to apply the combination of infrared rays pulse and electrocardiogram measurement for self-monitoring of cardiovascular functions.

Tese de doutoramento em cotutela, na área de Engenharia Biomédica, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra e à Université Angers - França
Laser speckle is an interference effect that has been considered as a main drawback in the use of coherent light sources. However, for a specific set of applications, this effect is used as source of information. Among these applications we can find the biomedical ones. Laser speckle has been used for decades for microvascular blood flow monitoring but only now starts to be considered as a method that can also be used for macrocirculation parameters extraction. This work aims at demonstrating that the laser speckle can be used for macrocirculation assessment with good reliability, using the same technique as the ones used in microcirculation assessment. The use of the same methods could lead to a rapid inclusion of this new evaluation in the existing devices. One of the most important laser speckle issues, that prevents a fully quantitative analysis, is the effect of static scatterers. This type of scatterers strongly influences the measurement of speckle contrast, leading to a wrong interpretation of the data. The other objective of this work is to study the effect of static scatterers on the laser speckle correlation and contrast which are used to quantify the blood flow. This thesis presents the studies conducted to explore the possibility of using the speckle effect for hemodynamic parameters measurement in macrocirculation and the experimental work performed on the effect of static scatterers in microcirculation. Before the experimental work, the thesis begins by an introduction to the basic laser speckle theory. A critical analysis of the available literature is performed in addition to the identification of the future laser speckle challenges. Several ideas are also proposed to deal with the most common issues. The work developed in the macrocirculation field shows that the laser speckle effect can be used to reliably extract the pulse pressure waveform. A multi-wavelength study was also conducted to determine which light wavelength is better for laser speckle macrocirculation analysis. Shorter wavelengths achieved the best results in identifying the heart rate. In a second test, using the same processing methods as the ones that are used in the current devices, speckle effect was able to reconstruct the pulse pressure waveform and identify feature points like the systolic peak and dicrotic notch. Moreover, the same system has been used to perform a two-dimensional segmentation of targets with longitudinal movements. An entropy-based algorithm was applied to the laser speckle data in order to discern between two identical targets where only one is moving. This method was able to perform a two-dimensional segmentation without any a priori knowledge on the scene or the target movement. Regarding the microcirculation field, an experimental test was performed to study the effect of static scatterers on the laser speckle signal. The experimental test consisted of a micro-channel device, used to simulate the blood flow inside small blood vessels, coupled with a set of different static scatterers layers. The recorded laser speckle data were analyzed in terms of correlation and contrast. The results show that the correlation between two consecutive images can identify the proportion of statics/dynamic scatterers and should be used in order to achieve a quantitative laser speckle technique. The speckle correlation also proved to be independent from the dynamic scatterers velocity. Regarding the laser speckle contrast, the temporal algorithm presents a good independence on the variation of static scatterers concentration. The spatio-temporal algorithm should be used because it presents a better concordance with laser speckle theory. To conclude, laser speckle is a highly versatile tool and proved to be able to extract hemodynamic parameters in macrocirculation. This work also demonstrates that the laser speckle correlation is able to estimate the ratio between static/dynamic scatterers with good reliability. Moreover, the temporal speckle contrast achieved a very good performance in discerning dynamic scatterers with different velocities. RESUMO: O laser speckle corresponde a um efeito de interferometria que foi muitas vezes considerado como uma grande limita c~ao do uso de fontes de luz coerente. No entanto, para um conjunto espec co de aplica c~oes, este efeito pode ser usado como fonte de informa c~ao. Entre estas aplica c~oes podemos encontrar v arias no ^ambito da biomedicina. Esta t ecnica tem vindo a ser utilizada durante d ecadas para avaliar a perfus~ao sangu nea mas, apenas agora, come ca a despertar interesse como meio de avaliar tamb em a macrocircula c~ao. Este trabalho pretende demonstrar que o efeito de laser speckle pode ser usado, tamb em, para extrair informa c~ao importante relativa a condi c~ao cardiovascular, nomeadamente da macrocircula c~ao, com boa abilidade e usando m etodos semelhantes aos j a aplicados na avalia c~ao da microcircula c~ao. O facto de serem usados os mesmo m etodos poder a levar a uma r apida inclus~ao deste tipo de an alise nos dispositivos j a existentes. No campo do uso de laser speckle para avalia c~ao da microcircula c~ao, uma das quest~oes mais importantes est a relacionada com o efeito dos dispersores est aticos. A quantidade de dispersores est aticos in uencia fortemente o sinal de laser speckle, levando a interpreta c~oes incorretas dos dados. Este e um dos fatores que impede a exist^encia de dispositivos laser speckle com capacidade de quanti car o uxo sangu neo. Devido a isto, o estudo do efeito de diferentes concentra c~oes de dispersores est aticos nos sinais de contraste e correla c~ao speckle e tamb em um dos objetivos deste trabalho. Esta tese apresenta os estudos realizados com o objetivo de testar a possibilidade de usar o efeito de laser speckle para avalia c~ao de par^ametros hemodin^amicos da microcircula c~ao e o trabalho experimental realizado no ^ambito do efeito dos dispersores est aticos. Antes do trabalho experimental, esta tese come ca por descrever os princ pios b asicos da teoria de laser speckle. Nesta sec c~ao e realizada uma an alise cr tica da literatura dispon vel e s~ao identi cados os desa os futuros desta t ecnica. Algumas ideias inovadoras s~ao tamb em propostas como m etodos para lidar com alguns dos problemas atuais da t ecnica de laser speckle. Os trabalhos desenvolvidos na area da macrocircula c~ao demonstraram que o efeito de laser speckle pode ser usado para extrair a forma de onda de pulso. Um estudo com fontes de luz de diferentes comprimentos de onda foi efetuado para determinar qual destes comprimentos de onda apresenta melhores resultados. Os comprimentos de onda mais curtos (luz verde) conseguiram atingir os melhores resultados na identi ca c~ao do ritmo card aco. Num segundo teste, usando os mesmo m etodos j a usados para a avalia c~ao da microcircula c~ao, o efeito de laser speckle foi capaz de reconstruir a onda de pulso e identi car pontos caracter sticos como o pico sist olico e o n o dicr otico. Para alem disto, este mesmo sistema foi usado num teste piloto para segmentar alvos bidimensionais com movimentos longitudinais. Um algoritmo baseado no c alculo da entropia foi usado com sucesso para distinguir dois alvos id^enticos, onde apenas um apresentava movimento. Para al em disto, este m etodo permitiu segmentar o alvo em movimento sem nenhuma informa c~ao antecipada sobre a movimenta c~ao dos alvos ou a disposi c~ao da cena. Relativamente ao campo da microcircula c~ao, um teste experimental foi desenvolvido para estudar o efeito dos dispersores est aticos no sinal de laser speckle. Este teste consistiu na avalia c~ao de um fantoma constitu do por um micro-canal e diferentes camadas de dispersores. Este fantoma foi usado para simular a perfus~ao sangu nea em vasos de pequeno calibre. Os dados recolhidos foram processados em termos de contraste e correla c~ao. Os resultados indicaram que a correla c~ao entre duas imagens consecutivas e capaz de identi- car a quantidade relativa de dispersores est aticos/din^amicos e deve ser usada como meio para atingir uma t ecnica completamente quantitativa. A correla c~ao de speckle demonstrou tamb em ser independente da velocidade dos dispersores din^amicos. Em rela c~ao ao contraste de speckle, o algoritmo temporal apresentou uma boa independ^encia em termos de concentra c~ao de dispersores est aticos. O algoritmo espa co-temporal demonstrou ser aquele que apresenta uma melhor coer^encia com a teoria do efeito laser speckle. Concluindo, o efeito de laser speckle e uma ferramenta altamente vers atil e provou ser capaz de extrair par^ametros hemodin^amicos relacionados com a macrocircula c~ao. Este trabalho tamb em demonstrou que a correla c~ao de laser speckle permite estimar o r acio entre a quantidade de dispersores est aticos/din^amicos com boa abilidade.
O laser speckle corresponde a um efeito de interferometria que foi muitas vezes considerado como uma grande limita¸c˜ao do uso de fontes de luz coerente. No entanto, para um conjunto espec´ıfico de aplica¸c˜oes, este efeito pode ser usado como fonte de informa¸c˜ao. Entre estas aplica¸c˜oes podemos encontrar v´arias no ˆambito da biomedicina. Esta t´ecnica tem vindo a ser utilizada durante d´ecadas para avaliar a perfus˜ao sangu´ınea mas, apenas agora, come¸ca a despertar interesse como meio de avaliar tamb´em a macrocircula¸c˜ao. Este trabalho pretende demonstrar que o efeito de laser speckle pode ser usado, tamb´em, para extrair informa¸c˜ao importante relativa `a condi¸c˜ao cardiovascular, nomeadamente da macrocircula¸c˜ao, com boa fiabilidade e usando m´etodos semelhantes aos j´a aplicados na avalia¸c˜ao da microcircula¸c˜ao. O facto de serem usados os mesmo m´etodos poder´a levar a uma r´apida inclus˜ao deste tipo de an´alise nos dispositivos j´a existentes. No campo do uso de laser speckle para avalia¸c˜ao da microcircula¸c˜ao, uma das quest˜oes mais importantes est´a relacionada com o efeito dos dispersores est´aticos. A quantidade de dispersores est´aticos influencia fortemente o sinal de laser speckle, levando a interpreta¸c˜oes incorretas dos dados. Este ´e um dos fatores que impede a existˆencia de dispositivos laser speckle com capacidade de quantificar o fluxo sangu´ıneo. Devido a isto, o estudo do efeito de diferentes concentra¸c˜oes de dispersores est´aticos nos sinais de contraste e correla¸c˜ao speckle ´e tamb´em um dos objetivos deste trabalho. Esta tese apresenta os estudos realizados com o objetivo de testar a possibilidade de usar o efeito de laser speckle para avalia¸c˜ao de parˆametros hemodinˆamicos da microcircula¸c˜ao e o trabalho experimental realizado no ˆambito do efeito dos dispersores est´aticos. Antes do trabalho experimental, esta tese come¸ca por descrever os princ´ıpios b´asicos da teoria de laser speckle. Nesta sec¸c˜ao ´e realizada uma an´alise cr´ıtica da literatura dispon´ıvel e s˜ao identificados os desafios futuros desta t´ecnica. Algumas ideias inovadoras s˜ao tamb´em propostas como m´etodos para lidar com alguns dos problemas atuais da t´ecnica de laser speckle. Os trabalhos desenvolvidos na ´area da macrocircula¸c˜ao demonstraram que o efeito de laser speckle pode ser usado para extrair a forma de onda de pulso. Um estudo com fontes de luz de diferentes comprimentos de onda foi efetuado para determinar qual destes comprimentos de onda apresenta melhores resultados. Os comprimentos de onda mais curtos (luz verde) conseguiram atingir os melhores resultados na identifica¸c˜ao do ritmo card´ıaco. Num segundo teste, usando os mesmo m´etodos j´a usados para a avalia¸c˜ao da microcircula¸c˜ao, o efeito de laser speckle foi capaz de reconstruir a onda de pulso e identificar pontos caracter´ısticos como o pico sist´olico e o n´o dicr´otico. Para alem disto, este mesmo sistema foi usado num teste piloto para segmentar alvos bidimensionais com movimentos longitudinais. Um algoritmo baseado no c´alculo da entropia foi usado com sucesso para distinguir dois alvos idˆenticos, onde apenas um apresentava movimento. Para al´em disto, este m´etodo permitiu segmentar o alvo em movimento sem nenhuma informa¸c˜ao antecipada sobre a movimenta¸c˜ao dos alvos ou a disposi¸c˜ao da cena. Relativamente ao campo da microcircula¸c˜ao, um teste experimental foi desenvolvido para estudar o efeito dos dispersores est´aticos no sinal de laser speckle. Este teste consistiu na avalia¸c˜ao de um fantoma constitu´ıdo por um micro-canal e diferentes camadas de dispersores. Este fantoma foi usado para simular a perfus˜ao sangu´ınea em vasos de pequeno calibre. Os dados recolhidos foram processados em termos de contraste e correla¸c˜ao. Os resultados indicaram que a correla¸c˜ao entre duas imagens consecutivas ´e capaz de identi- ficar a quantidade relativa de dispersores est´aticos/dinˆamicos e deve ser usada como meio para atingir uma t´ecnica completamente quantitativa. A correla¸c˜ao de speckle demonstrou tamb´em ser independente da velocidade dos dispersores dinˆamicos. Em rela¸c˜ao ao contraste de speckle, o algoritmo temporal apresentou uma boa independˆencia em termos de concentra¸c˜ao de dispersores est´aticos. O algoritmo espa¸co-temporal demonstrou ser aquele que apresenta uma melhor coerˆencia com a teoria do efeito laser speckle. Concluindo, o efeito de laser speckle ´e uma ferramenta altamente vers´atil e provou ser capaz de extrair parˆametros hemodinˆamicos relacionados com a macrocircula¸c˜ao. Este trabalho tamb´em demonstrou que a correla¸c˜ao de laser speckle permite estimar o r´acio entre a quantidade de dispersores est´aticos/dinˆamicos com boa fiabilidade.
FCT - PESSOA/Hubert Curien travelling program
Ações integradas Luso Francesas/PAUILF - CRUP e CPU

Shih, Kai = 在中和漂移壓縮實驗中的脈衝長度縮減與在實驗層面上的粒子束縱向參數的討論 / 師愷.
Thesis M.Phil. Chinese University of Hong Kong 2014.
Includes bibliographical references (leaves 94-96).
Abstracts also in Chinese.
Title from PDF title page (viewed on 27, September, 2016).
Shih, Kai = Zai zhong he piao yi ya suo shi yan zhong de mai chong chang du suo jian yu zai shi yan ceng mian shang de li zi shu zong xiang can shu de tao lun / Shi Kai.

Tese de doutoramento em Engenharia Biomédica, apresentada à Faculdade de Medicina da Universidade de Coimbra
A grande incidência das doenças cardiovasculares no mundo estimulou a procura de novas soluções que permitam a deteção precoce de processos patológicos associados a este tipo de doenças. Especial ênfase foi dada a métodos que permitem a monitorização da pressão arterial e da forma de onda de pressão arterial, que fornecem uma ferramenta precisa que complementa o diagnóstico baseado em múltiplos parâmetros. Da análise das características da forma de onda da pressão arterial, e da sua velocidade de propagação, podem ser extraídas importantes parâmetros clínicos de modo a avaliar o risco cardiovascular, a adaptação vascular e a eficácia terapêutica. O uso de múltiplos parâmetros permite minimizar erros na estimação de um dos parâmetros. As soluções emergentes para a monitorização cardiovascular têm-se afastado de tecnologias invasivas e caras para soluções não invasivas e sem contacto. Neste sentido, os sistemas ópticos apresentam uma grande vantagem devido ao grande progresso tecnológico sofrido nas últimas décadas. A natureza de não contacto desta tecnologia permite a medição sem distorção da forma da onda arterial ultrapassando as limitações dos aparelhos comerciais usados para este tipo de avaliação. O principal objetivo deste trabalho consistia em demonstrar que é possível adquirir através do uso de uma metodologia óptica, a forma da onda de pressão arterial sem contacto, com uma configuração que permite medir a velocidade onda de pulso (VOP) local e determinar os principais parâmetros usando algoritmos dedicados. Foram desenvolvidos quatro protótipos: três baseados em luz não-coerente e um em luz coerente. As sondas foram desenvolvidas usando uma configuração comum, composta por dois fotodetectores distanciados de 2 cm, o que garante a deteção da onda de pulso em dois pontos distintos e permite uma determinação rigorosa do tempo de trânsito. Nas sondas de luz não-coerente foram testados três fotodetectores: fotodíodos de avalanche, fotodíodos planares, e fotodíodos de efeito lateral (LEP). Os componentes do sistema óptico (protótipos das sondas e caixa de aquisição) foram desenhados com as características físicas que permitem o uso clínico, como a portabilidade, o tamanho compacto, leves, de baixo consumo e com materiais de baixo custo, ergonómicas para o operador e confortáveis para o paciente, de modo a serem consideradas uma solução interessante para a comercialização. Os testes in vivo permitiram a seleção da melhor combinação sonda/algoritmo para a determinação da PWV, usando o método da correlação e a sonda baseada em fotodíodos planares que demonstrou ser mais eficiente para a aquisição de sinais em humanos. O sistema óptico desenvolvido mostrou boa reprodutibilidade na avaliação inter e intra-operador. Um estudo alargado foi desenvolvido em 131 sujeitos jovens, com um valor médio PWV de 33.33±0.72 ms-1, confirmando o seu aumento com a idade. O teste comparativo entre a onda de distensão medida com o sistema óptico na carótida e o perfil da onda de pressão adquirida invasivamente por um cateter intra-arterial mostrou uma grande correlação entre as duas ondas (valor médio de 0.958), validando a capacidade das sondas ópticas para estimar a forma da onda de pulso de modo não-invasivo e sem contacto. A sonda óptica baseada em luz coerente foi testada em combinação com algoritmos de processamento de sinal baseados nos métodos short time Fourier transform e empirical mode decomposition, demonstrando ser capaz de determinar os pontos característicos da forma de onda com baixo erro (menor que 5ms). Uma configuração alternativa foi testada usando um fotodetector com uma maior área que permitiu obter o efeito de self-mixing fora da cavidade laser. Esta característica abriu a possibilidade de construir uma nova sonda adaptada a esta nova técnica de modo a melhorar a qualidade do sinal e permitir uma aplicação biomédica. Globalmente, os resultados obtidos para a metodologias desenvolvidas (protótipos e ferramentas de processamento de sinal associados) mostraram ser possível de medir a onda de pulso arterial na carótida, para determinar vários parâmetros clínicos e avaliar a condição cardiovascular.
The world wide incidence of cardiovascular diseases (CVDs), has spurred the research efforts targeting new solutions that may be able to perform an early detection of the pathological processes associated with these diseases. Special emphasis has been given to the methods that allow the monitoring of the blood pressure and the arterial pulse waveform, thus providing a more precise tool to complement the diagnosis process based on a multi-parameter assessment approach. From the analysis of arterial pulse pressure waveform features, and its propagation velocity, important clinical parameters can be extracted in order to evaluate the CVD risk, the vascular adaptation and the therapeutic efficacy. The use of multiple parameters allows to minimize the error when compared to the approach where a subject is classified solely based on a single parameter. Emerging trends in cardiovascular monitoring are moving away from invasive and costly technologies towards non-invasive and low-cost solutions. In this sense, optical solutions represent a great advantage due to the immense technological progresses observed in the recent decades. The truly non-contact nature of optical techniques allows measurements without distortion in the shape of the pulse curve, which is one of the main limitations of the current commercial devices used in hemodynamic parameters assessment. The main objective of this work consists in demonstrating that with an optical system it is possible to acquire the arterial pulse waveform with a configuration that allows the local pulse wave velocity (PWV) measurement and the determination of the most important clinical parameters using dedicated algorithms, without physical contact with the skin of the patient. Four prototypes were developed: three based in non-coherent light and one with coherent light. All the developed optical probes have a common design structure. They include two identical photodetectors placed 2 cm apart from each other to guarantee accurate determination of local pulse transit time. Relatively to the non-coherent light probes three different probes base on photodetectors were tested: an avalanche photodiode, a planar photodiode and a lateral effect photodiode (LEP). The optical system components (probe prototypes and acquisition box) were designed to meet specific requirements that allow the clinical use, such as portability, compact size and low weight, low cost, limited power consumption, ergonomics and easy user-interface in order to be considered as an interesting solution for commercial purposes. The in vivo tests allowed the selection of the best algorithm and probe combination to determine PWV: cross-correlation algorithm and the probe with planar photodiodes demonstrated to be the most efficient. This system showed good reproducibility, as evaluated by both inter-operator and intra-operator analysis. A large study was performed in 131 young subjects, obtaining a mean value for PWV of 3.33±0.72 ms-1, thus confirming its significant increase with age. A comparative test between the distension waveform measured with the optical probe at the carotid artery and the invasive profile of the pulse pressure acquired by an intra arterial catheter showed a strong correlation (mean value of 0.958), and validates the ability of this non-invasive device to estimate the arterial pulse waveform. Also a coherent light probe was developed and tested using several processing techniques based on the short time Fourier transform and empirical mode decomposition algorithm. This approach demonstrated the ability to determine the main feature points in the waveform with low error in the pulse transit time determination (less than 5ms). An alternative configuration for the Doppler effect-based probe was tested, using a photodetector with a larger area in order to obtain the self-mixing effect outside the laser cavity. This feature opened the possibility to improve the quality of the signal which may foresee potential future biomedical applications. Globally, the results obtained with the developed methodologies (prototypes and associated algorithmic tools) proved that it is possible to measure the arterial pulse waveform in the carotid artery, to determine several clinical parameters and assess the cardiovascular condition with optical technology.
Fundação para a Ciência e Tecnologia - SFRH / BD / 79334 / 2011

碩士
國立彰化師範大學
機電工程學系
103
This study mainly focuses on developing an automatic pulse charging and discharging system. A Taguchi Method is used to estimate the effects of battery charging capacity corresponding to four parameters: temperature, pulse charging current, pulse charging frequency and pulse charging duty-cycle, and to find the optimal combinational parameters. The results show that each parameter presents different extent to affect the battery charging capacity in which the pulse charging current and temperature have obvious influence individually. In addition, the validation test of using the optimal parameters presents higher charging capacity than other parameters to demonstrate the better charging efficiency. An automatic experimental system was developed in this study. We analysis the charge-discharge cycle life using traditional Constant Current-Constant Voltage (CC-CV) method and Pulse Charging method. An Electrochemical Impedance Spectroscopy (EIS) is used to analysis the inner-resistance of battery. The result of EIS shows that the Li-ion battery of using Pulse Charging method presents lower rate on Solid Electrolyte Interface (SEI) layer increase and lower Charge-Transfer Kinetic Resistance (Rct) than using CC-CV method. It shows that Pulse Charging method can effective in slowing the speed of resistance increase, extending the life of Li-ion battery. The Capacity Fade results also show that the life of Li-ion battery of using Pulse Charging method have better lifespan, which have the same tendency with EIS analysis. Above all, Pulse Charging method is a batter charging method than the CC-CV in presenting measurement in this study.

碩士
長庚大學
化工與材料工程研究所
97
An advanced horizontal pulse-reverse plating system was employed to study the operation parameters i.e. concentration of ferric ion, electrolyte pumping frequency (pumping rate), and reverse plating time on the copper-plating performance of via in the PCB (plated circuit board).The plating efficiency, throwing power, via filling ability, mechanical properties, and surface morphology of the plating layer were tested and calculated by various instruments. In the Fe3+ concentration range of 3~10 g/l, plating efficiency and throwing power are decreased with the increase of Fe3+ concentration; however, surface roughness and copper lattice size are increased with the increase of Fe3+ concentration. The elongation reaches maximum of 23% as the Fe3+ concentration is 7%. For the pumping frequency in the range of 35~55Hz, corresponding the pumping rate of 99~165 l/min, plating efficiency and via filling ability are decreased with the increase of pumping frequency, but the surface roughness and the morphology of copper filling are little effected by the pumping rate of electrolyte. The period of pulse plating fixed in 80ms, via filling ability, surface roughness, and lattice size are increased with the increase of reverse plating step. Hole inclusion may occurs for the blind via filling as the reverse plating step is set at 8ms, it is found the elongation reach maximum of 24% for the reverse plating time 4ms. The optimum operation parameters of the horizontal pulse-reverse plating system studied in this work are summarized as the following: concentration of Fe3+ 7 g/l, pumping frequency 35 Hz, and time of the reverse pulse 4 ms.

Until recently, there had been a gap between the output frequencies of electronic and optical sources, which included waves of frequencies around 300 GHz to 3 THz and was known as the Terahertz gap. After the development of sources and detectors that operated at these frequencies, Terahertz radiation began to find its way through a variety of applications such as surveillance, spectroscopy and medical imaging. Terahertz radiation has been used in medical imaging experiments on different in-vitro and some in-vivo biological tissues and has shown promising results in differentiating certain features in those tissues. Moreover, it has demonstrated well in detecting certain polar molecules due to these molecules’ fingerprint in Terahertz range of frequencies. Considering these facts, Terahertz has been proved to have the potential for being a perspective medical imaging method, which can be used as a complement to other imaging techniques such as MRI or X-ray or even as a separate method. Due to the capacity of Terahertz radiation, much research is being done on using Terahertz generation-detection set-ups for medical imaging and improving the imaging parameters of these set-ups to capture more precise and meaningful images. In this thesis, the imaging parameters of two different THz imaging set-ups have been studied and compared. One of these imaging set-ups is a THz pulse set-up with photoconductive dipole antennas as source and detector and the other one is a continuous-wave set-up with a backward wave oscillator as the source and a Golay cell as the detector. To the best of our knowledge, a comparative analysis of the imaging parameters of these two types of THz imaging set-ups has not been performed previously. In this thesis, parameters such as modulation transfer function (MTF), resolution and beam profile have been measured through the experiments, for both the THz pulse and THz CW imaging set-ups. These results are compared to the results obtained by theoretical formulas and the reason for any differences occurred between these two results has been explained. Moreover, the imaging parameters found from the experiments for the two set-ups have been compared together and similarities and differences have been discussed. In this thesis, a set of experiments has also been done to verify the capability of the two imaging set-ups for in-vitro tooth imaging, towards developing THz imaging systems suitable for clinical imaging application. These experiments have been performed on a tooth crown sample with the pulse set-up and on a tooth cross-section sample with the continuous-wave set-up. The capability of our THz pulse imaging system to distinguish thickness variations in a tooth crown sample by time-of-flight imaging has been shown and discussed.

碩士
國立成功大學
機械工程學系
102
In the present study, SKD61 tool steel specimen were polished by a long pulsed Yb:fiber laser system. In order to define the workable range and achieve the mean areal surface roughness (SRa) as small as possible, the laser operating conditions were designed at three stages. The experiments of three stages includes Taguchi method, all factors experiments and change-levels of the important factors. And six adjusted parameters of laser polishing are the laser power, the scanning velocity, the pulse duration, the scanning frequency, the overlap percentage and the focal offset. By measuring the surface roughness, the spatial Fourier analysis, the material ratio and the transfer function, the optimization of process parameters of large area polishing can be found. And the microstructure of the heat affected zone also be study to realize the influence of laser polishing.

There has been increasing interest in evaluating the performance of existing reinforced concrete (RC) bridges just after natural disasters or man-made events especially when the defects are invisible, or in quantifying the improvement after rehabilitations. In order to obtain an accurate assessment of the reliability of a RC bridge, it is critical to incorporate information about its current structural properties, which reflects the possible aging and deterioration. This dissertation proposes to develop an adaptive reliability analysis of RC bridges incorporating the damage detection information obtained from nondestructive testing (NDT). In this study, seismic fragility is used to describe the reliability of a structure withstanding future seismic demand. It is defined as the conditional probability that a seismic demand quantity attains or exceeds a specified capacity level for given values of earthquake intensity. The dissertation first develops a probabilistic capacity model for RC columns and the capacity model can be used when the flexural stiffness decays nonuniformly over a column height. Then, a general methodology to construct probabilistic seismic demand models for RC highway bridges with one single-column bent is presented. Next, a combination of global and local NDT methods is proposed to identify in-place structural properties. The global NDT uses the dynamic responses of a structure to assess its global/equivalent structural properties and detect potential damage locations. The local NDT uses local measurements to identify the local characteristics of the structure. Measurement and modeling errors are considered in the application of the NDT methods and the analysis of the NDT data. Then, the information obtained from NDT is used in the probabilistic capacity and demand models to estimate the seismic fragility of the bridge. As an illustration, the proposed probabilistic framework is applied to a reinforced concrete bridge with a one-column bent. The result of the illustration shows that the proposed framework can successfully provide the up-to-date structural properties and accurate fragility estimates.