Function generator has been widely used in each electronics fields recent years. In this thesis, the authors will introduce some basic structure and working principles of a function generator, moreover a function generator which can create three kinds of wave: sine wave, square wave and triangle wave has been implemented. There are many ways to build the function generator; a method of combine the operational amplifier and discrete components is introduced in this thesis. First use the RC Wien bridge oscillator to achieve sinusoidal wave; and convert it into square wave by using the shaping circuit. Lastly, use the integrating circuit to obtain triangle wave. The basic simulation software Multisim has been used to simulate the circuit.

Šiame darbe yra nagrinėjami negęstančių sinusoidžių modeliai. Pagrindinis dėmesys yra skiriamas šių modelių netiesinių parametrų (dažnių) įvertinimui. Darbe pateikti nagrinėjamų parametrų įvertinimo Pisarenko, MUSIC ir Prony metodų rezultatai. Pateiktos išvados apie šių metodų taikymo galimybes ir jų ribotumą. Pateikti sukurtos programinės įrangos, realizuojančios negęstančių sinusoidžių modelių generavimą ir jų parametrų įvertinimą Pisarenko, MUSIC ir Prony metodais, aprašymas ir kodai. / Updamped sinusoidal models are considered in this work. The main attention is given to estimation of nonlinear parameters (correlation and frequencies) of these models. The results of estimation of the considered parameters by Pisarenko, MUSIC and Prony methods are analyzed. The conclusions on possibilities and restrictions of these methods are presented. The description and program codes of the software developed are given. The software is intended for generating of updamped sinusoidal models and estimating by Pisarenko, MUSIC and Prony methods.

Perceptual deficits related to phonology in children with speech delay (SD) and children with dyslexia have been identified in separate lines of research. However, there has only been a small number of studies that have investigated the perceptual deficits of children with SD and/or dyslexia in the same study to better understand the overlap of their speech perception abilities. Children with SD have previously shown deficits perceiving speech stimuli that is acoustically sparse, particularly when stimuli contain speech sounds they do not produce correctly. Yet in contrast to children with dyslexia, children with SD are better able to recover linguistic structure from speech stimuli that preserves global acoustic structure in the absence of spectral detail. Therefore, the purpose of this study is to further investigate how children with SD, dyslexia, SD + dyslexia, and typically developing (TD) peers perceive different types of speech. To do this, we used both vocoded speech and sine-wave speech recognition tasks. In this study, 40 children (ages 7-10 years) with SD, dyslexia, SD + dyslexia, and/or typically developing were presented with both sine-wave and vocoded speech recognition tasks to investigate their speech perception. Findings revealed no differences between groups for both the sine-wave and vocoded speech perception tasks, regardless of SD and/or dyslexia status. Increasing the number of participants or utilizing more sensitive speech perception tasks may provide clinically applicable resources for assessment or intervention. We discuss these findings in the context of previous research literature and also discuss limitations of the current study and future directions for follow-up investigations.

No description available.

The phase and amplitude gradient estimator (PAGE) method has proven successful in improving the accuracy of measured energy quantities over the p-p method, which has traditionally been used, in several applications. One advantage of the PAGE method is the use of phase unwrapping, which allows for increased measurement bandwidth above the spatial Nyquist frequency. However, phase unwrapping works best for broadband sources in free-field environments with high coherence. Narrowband sources often do not have coherent phase information over a sufficient bandwidth for a phase unwrapping algorithm to unwrap properly. In fact, phase unwrapping processing can cause significant error when there is no coherent signal near and above the spatial Nyquist frequency. However, for signals at any frequencies up to the spatial Nyquist frequency, the PAGE method provides correct intensity measurements regardless of the bandwidth of the signal. This is an improved bandwidth over the traditional method. For narrowband sources above the spatial Nyquist frequency, additional information is necessary for the PAGE method to provide accurate acoustic intensity. With sufficient bandwidth and a coherence of at least 0.1 at the spatial Nyquist frequency, a relatively narrowband source above the spatial Nyquist frequency can be unwrapped accurately. One way of using extra information, called the extrapolated PAGE method, uses the phase of a tone below the spatial Nyquist frequency and an assumption of a propagating field, and therefore linear phase, to extrapolate the phase above the spatial Nyquist frequency. Also, within certain angular and amplitude constraints, low-level broadband noise can be added to the field near a source emitting a narrowband signal above the spatial Nyquist frequency. The low-level additive broadband noise can then provide enough phase information for the phase to be correct at the frequencies of the narrowband signal. All of these methods have been shown to work in a free-field environment.

<p>Fluid simulating is one of the most difficult problems in computer graphics. On the other hand, water appears in our life very frequently. This thesis focuses on water simulating. We have two main methods to do this in the thesis: the first is wave based water simulating; Sine wave summing based and Fast Fourier Transform based methods are all belong to this part. The other one is physics based water simulating. We make it based on Navier-Stokes Equation and it is the most realistic animation of water. It can deal with the boundary and spray which other method cannot express. Then we put our emphasis on implement by the physics method using Navier-Stokes Equation.</p>

Structural Health Monitoring (SHM) techniques are widely used in a number of Non – destructive Evaluation (NDE) applications. There is a need to develop effective techniques for SHM, so that the safety and integrity of the structures can be improved. Two most widely used SHM methods for plates and rods use either the spectrum of the impedances or monitor the propagation of lamb waves. Piezoelectric wafer – active sensors (PWAS) were used for excitation and sensing. In this study, surface response to excitation (SuRE) and Lamb wave propagation was monitored to estimate the integrity of the round objects including the pipes, tubes and cutting tools. SuRE obtained the frequency response by applying sweep sine wave to surface. The envelope of the received signal was used to detect the arrival of lamb waves to the sensor. Both approaches detect the structural defects of the pipes and tubes and the wear of the cutting tool.

[pt] A medição da qualidade de energia é um aspecto cada vez mais importante com o avanço tecnológico. Um destes aspectos é a estimação dos harmônicos em sinais de potência. Este trabalho, apresenta um algoritmo para obter, simultaneamente, os valores reais de freqüência, amplitude e fase de cada componente do sinal, baseados em valores distorcidos originários do uso da FFT. Contrário a outros métodos, o algoritmo requer um número reduzido de dados, permitindo sua implementação em tempo real. Para estender este método a um sinal com componentes de harmônicos de ordem elevada utilizam-se bancos de filtros para decomposição em sub-bandas e eventual reconstrução numa estrutura de operação orientada ao tempo real. O trabalho apresenta resultados comprovando a correta operação e robustez do processo. O método é otimizado para implementação com reduzido número de operações em ponto flutuante. / [en] Power quality measurement is a key issue with the technology advance in power systems. One fo these issues is harmonics estimation of power systems signals. This work shows an algorithm to obtain, simultaneously, the real values of frequency, amplitude and phase of each signal component, based in distorted values originated by the use of FFT. In contrast to other methods, the algorithm requires a small number of data, allowing its implementation in real time. To extended this method to a high harmonic order signal, filter banks are used to decompose it in sub bands and eventually reconstruct it, in a real time operation structure. This work shows results testing the correct operation and robustness of the process. Th eAlgorithm is optimized to its imlementation with a reduced number of float point operations.

<p>The general aim of this thesis was to investigate phonological processing skills in dyslexic children and adults and their relation to speech perception. Dyslexia can be studied at various levels: at a biological, cognitive and an environmental level. This thesis mainly looks at environmental and cognitive factors. It is a commonly held view that dyslexia is related to problems with phonological processing, that is, dyslexics have problems dealing with the sound structure of language. The problem is for example seen in tasks where the individual has to manipulate sound segments in the spoken language, read non-words, rapidly name pictures and digits, keep verbal material in short-term memory, and categorize and discriminate sound contrasts in speech perception. To fully understand the dyslexic’s problems we have to investigate both children and adults since the problems might change during the lifespan as a result of changes in the language system and compensatory mechanisms in the poor reader. Research indicates that adult dyslexics can reach functional reading proficiency but still perform poorly on tasks of phonological processing. Even though they can manage many everyday reading situations problems often arise when adult dyslexics enter higher education. The phonological problems of dyslexics are believed to be related to the underlying phonological representations of the language. The phonological representations have been hypothesized to be weakly specified or indistinct and/or not enough segmented. Deviant phonological representations are believed to cause problems when the mapping of written language is to be made to the phonological representations of spoken language during reading acquisition. In Paper 1 adults’ phonological processing and reading habits were investigated in order to increase our understanding of how the reading problems develop into adulthood and what the social consequences are. The results showed that adult dyslexics remained impaired in their phonological processing and that they differed substantially from controls in their choices regarding higher education and also regarding reading habits. Paper 2 reviews research that has used the sine wave speech paradigm in studies of speech perception. The paper also gives a detailed description of how sine wave speech is made and how it can be characterized. Sine wave speech is a course grained description of natural speech lacking phonetic detail. In Paper 3 sine wave speech varying with regard to how much suprasegmental information it contains is employed. Results showed that dyslexics were poorer at identifying monosyllabic words but not disyllabic words and a sentence, plausibly because the dyslexics had problems identifying the phonetic information in monosyllabic words. Paper 4 tested dyslexics’ categorization performance of fricative-vowel syllables and the results showed that dyslexics were less consistent than controls in their categorization indicating poorer sensitivity to phonetic detail. In all the results of the thesis are in line with the phonological deficit hypothesis as revealed by adult data and the performance on task of speech perception. It is concluded that dyslexic children and adults seem to have less well specified phonological representations. </p>

The general aim of this thesis was to investigate phonological processing skills in dyslexic children and adults and their relation to speech perception. Dyslexia can be studied at various levels: at a biological, cognitive and an environmental level. This thesis mainly looks at environmental and cognitive factors. It is a commonly held view that dyslexia is related to problems with phonological processing, that is, dyslexics have problems dealing with the sound structure of language. The problem is for example seen in tasks where the individual has to manipulate sound segments in the spoken language, read non-words, rapidly name pictures and digits, keep verbal material in short-term memory, and categorize and discriminate sound contrasts in speech perception. To fully understand the dyslexic’s problems we have to investigate both children and adults since the problems might change during the lifespan as a result of changes in the language system and compensatory mechanisms in the poor reader. Research indicates that adult dyslexics can reach functional reading proficiency but still perform poorly on tasks of phonological processing. Even though they can manage many everyday reading situations problems often arise when adult dyslexics enter higher education. The phonological problems of dyslexics are believed to be related to the underlying phonological representations of the language. The phonological representations have been hypothesized to be weakly specified or indistinct and/or not enough segmented. Deviant phonological representations are believed to cause problems when the mapping of written language is to be made to the phonological representations of spoken language during reading acquisition. In Paper 1 adults’ phonological processing and reading habits were investigated in order to increase our understanding of how the reading problems develop into adulthood and what the social consequences are. The results showed that adult dyslexics remained impaired in their phonological processing and that they differed substantially from controls in their choices regarding higher education and also regarding reading habits. Paper 2 reviews research that has used the sine wave speech paradigm in studies of speech perception. The paper also gives a detailed description of how sine wave speech is made and how it can be characterized. Sine wave speech is a course grained description of natural speech lacking phonetic detail. In Paper 3 sine wave speech varying with regard to how much suprasegmental information it contains is employed. Results showed that dyslexics were poorer at identifying monosyllabic words but not disyllabic words and a sentence, plausibly because the dyslexics had problems identifying the phonetic information in monosyllabic words. Paper 4 tested dyslexics’ categorization performance of fricative-vowel syllables and the results showed that dyslexics were less consistent than controls in their categorization indicating poorer sensitivity to phonetic detail. In all the results of the thesis are in line with the phonological deficit hypothesis as revealed by adult data and the performance on task of speech perception. It is concluded that dyslexic children and adults seem to have less well specified phonological representations.