The content of this work is focused on the neural network per speaker recognition. The work deals with problems of processing speech signal and there are introduction some types of neural network. The part of work was made database of records from speakers with have various sex and ages. The train and test group was made from the database. For classifier were suggested afterwards. One of them was nominated on base Gaussian mixture model and three of them were nominated on neural. This system was tested and analyzed on the basis of age, gender and both criterions each other at the end. Attention is focused on choice suitable feature in each mission of classification at the same time. At the end of work are introduced results of analysis for individual groups and features. The most suitable features are diagnosed from given mission of classification and the most prosperous classifier.

This diploma thesis deals with segmentation of blood vessel from images acquired by fundus camera. The characteristic of fundus images and current methods of segmentation are described in theoretical part. The reach of the practical part is method using statistical model. The model using Student´s distribution for automatic segmentation is gradually drafted. Firstly EM- algorithm has been incorporated and model drafted on Markov random fields for improving robustness to noise after that. Contrast of thin blood vessel is improved in image preprocessing part by discrete wave transformation. The output image is used as mask for grayscale intensity decrease of thinnest blood-vessel and intensity increase of background. Whole model was programed in Matlab. The model was tested on whole HRF database. The quantitative evaluation of binary images were compared with golden standard images.

South Africa is currently struggling to deal with a significant poaching and livestock theft problem. This work is concerned with the detection and classification of ground based targets using radar micro- Doppler signatures to aid in the monitoring of borders, nature reserves and farmlands. The research starts of by investigating the state of the art of ground target classification. Different radar systems are investigated with respect to their ability to classify targets at different operating frequencies. Finally, a Gaussian Mixture Model Hidden Markov Model based (GMM-HMM) classification approach is presented and tested in an operational environment. The GMM-HMM method is compared to methods in the literature and is shown to achieve reasonable (up to 95%) classification accuracy, marginally outperforming existing ground target classification methods. / Dissertation (MEng)--University of Pretoria, 2017. / Electrical, Electronic and Computer Engineering / MEng / Unrestricted

Tesis para optar al Título de Magíster en Finanzas / Este trabajo estudia el impacto que tiene la estabilidad política en el crecimiento económico para 132 países en los periodos de 1984 a 2016, se promedian los datos cada tres años para un total de 11 periodos que no se superponen. Se aplicó el Método Generalizado por Momentos Sistémico (S-GMM) para determinar el crecimiento económico y se realizo el análisis factorial para construir el índice de riesgo político. Específicamente se realizaron estimaciones para los países del mundo en general, para los países miembros de la OCDE y una tercera para los que no son miembros. La importancia de este trabajo radica en que el impacto económico global del gasto y el efecto económico relacionado con contener, prevenir y tratar las consecuencias del conflicto, tensiones étnicas, tensión racial, entre otras crea un gasto adicional en los gobiernos y limita el crecimiento económico de una nación. Los resultados revelan que la inestabilidad política (riesgo político) afecta negativamente el crecimiento económico, además una mayor calidad institucional y mejores condiciones socio-económicas afectan positivamente el crecimiento. Cuando se observa para los países OCDE, esta variable es significativa y el impacto es mayor que para los pases no miembros, evidenciando que para los países que tienen condiciones económicas y sociales similares, el crecimiento del PIB per cápita se ve afectado a largo plazo por la estabilidad política. Por otro lado, hay una fuerte relación entre la estabilidad financiera y el riesgo político; ya que al evaluar el efecto económico mediante variables interactivas se obtiene que estas afectan negativamente el crecimiento económico. Ademas al analizar el efecto marginal del crecimiento económico producto del riesgo político se obtiene que esta variación es dependiente de la estabilidad financiera, indicando que una mayor estabilidad financiera reduce el impacto del riesgo político en el crecimiento económico a largo plazo. Cabe destacar que este impacto es más pronunciado ante países miembros de la OCDE. Además, se encuentra evidencia sustancial del uso de la variable mujeres en el parlamento como una variable instrumental, dada su relación en la literatura con el crecimiento económico. Las variables dinero y cuasi dinero (M2), pasivos líquidos (M3) e inversionistas institucionales tienen una relación positiva con el crecimiento del PIB per cápita, aunque los inversionistas institucionales solo resulta ser significativo cuando se observa para los países OCDE. Como conclusión, se determina la importancia del desarrollo de políticas que ayuden al desarrollo humano a través de medidas de riesgo político y estructuras que creen y mantengan sociedades pacíficas ya que son un determinante profundo del crecimiento económico.

In this dissertation, we investigate the spread option pricing problem with stochastic interest rate. First, we will review the basic concept and theories of stochastic calculus, give an introduction of spread options and provide some examples of spread options in different markets. We will also review the market efficiency theory, arbitrage and assumptions that are commonly used in mathematical finance. In Chapter 3, we will review existing spread pricing models and term-structure models such as Vasicek Mode, and the Heath-Jarrow-Morton framework. In Chapter 4, we will use the martingale approach to derive a partial differential equation for the price of the spread option with stochastic interest rate. In Chapter 5, we will study the spread option numerically. We will conclude this dissertation with ideas for future research.

This study examines the impact of fiscal deficits on economic growth in developing countries. Based on deduction from the relevant theoretical and empirical literature, the study tests the following hypotheses regarding the impact of fiscal deficits on economic growth. First, fiscal deficits have significant positive or negative impact on economic growth in developing countries. Second, the impact of fiscal deficits on economic growth depends on the size of deficits as a percentage of GDP – that is, there is a non-linear relationship between fiscal deficits and economic growth. Third, the impact of fiscal deficits on economic growth depends on the ways in which deficits are financed. Fourth, the impact of fiscal deficits on economic growth depends on what deficit financing is used for. The study also examines whether there are any significant regional differences in terms of the relationship between fiscal deficits and economic growth in developing countries. The study uses panel data for thirty-one developing countries covering the period 1972- 2001, which is analysed based on the econometric estimation of a dynamic growth model using the Arellano and Bond (1991) generalised method of moments (GMM) technique. Overall, the results suggest the following. First, fiscal deficits per se have no any significant positive or negative impact on economic growth. Second, by contrast, when the deficit is substituted by domestic and foreign financing, we find that both domestic and foreign financing of fiscal deficits exerts a negative and statistically significant impact on economic growth with a lag. Third, we find that both categories of economic classification of government expenditure, namely, capital and current expenditure, have no significant impact on economic growth. When government expenditure is disaggregated on the basis of a functional classification, the results suggest that spending on education, defence and economic services have positive but insignificant impact on growth, while spending on health and general public services have positive and significant impact. Fourth, in terms of regional differences with regard to the estimated relationships, the study finds that, while there are some regional differences between the four different regions represented in our sample of thirty-one developing countries - namely, Asia and the Pacific, Latin America and the Caribbean, Middle East and North Africa, and Sub-Saharan Africa – these differences are not statistically significant. On the basis of these findings, the study concludes that fiscal deficits per se are not necessarily good or bad for economic growth in developing countries; how the deficits are financed and what they are used for matters. In addition, the study concludes that there are no statistically significant regional differences in terms of the relationship between fiscal deficits and economic growth in developing countries.

Digital marknadsföring är i dagsläget en snabbt växande bransch och aktörer söker ständigt efter nya sätt att bedriva marknadsföring. I denna rapport studeras en av dessa aktörer, Adoveo, vars värdeerbjudande är att inkludera ett tävlingsmoment i reklamkampanjerna som ger deltagare möjlighet att vinna priser. Problematiskt är dock att priserna riskeras att inte delas ut till mänskliga deltagare, utan istället delas ut till bottar som deltar i tävlingarna både omänskligt många gånger och med omänskligt bra resultat. Syftet med rapporten är att med hjälp av data från denna aktör försöka skilja mänskliga deltagare från bottar. För detta tillämpades två oövervakade maskininlärningsalgoritmer för att klustra datapunkterna, Gaussian Mixture Model och K-medelvärde. Resultatet var en otydlig klusterstruktur där det inte gick att pålitligt identifiera något kluster som mänskligt respektive botliknande. Orsakerna bakom denna osäkerhet var främst designen av reklamtävlingarna samt att attributen i den studerade datan var otillräckliga. Rekommendationer gavs till hur dessa problem skulle kunna åtgärdas. Slutligen genomfördes en analys avseende affärsnyttan med botsäkra tävlingar och vilket mervärde det skapar för företaget. Analysen visade att affärsnyttan från att botsäkra tävlingarna skulle vara stor, då det skulle ge fördelar gentemot konsumenter såväl som annonsörer och konkurrenter. / Digital marketing is a fast-growing market and its actors are constantlylooking for innovative and new ways of marketing. In this paper, an actoron this market called Adoveo will be studied. Their specialization and valueproposition is to include a competition part in their advertisement campaigns,giving its participators the possibility to win a prize. What could turn out to beproblematic is that the prizes are not rewarded to human contestants, insteadgoing to a bot that can participate in the competition with unreasonably goodresults. The purpose of this paper is to try to separate bots from human contestantswith the data provided from Adoveo. To that end, two unsupervised machinelearning algorithms were implemented to cluster the data points, GaussianMixture Model and K-Means. The result was an uninterpretable cluster structurefrom which there was no reliable identification of bot-like and human-likebehaviour to be made. The reason behind this was twofold, the design of thecompetition and a lack of decisive attributes in the data. Recommendationswere provided to how both of these issues could be rectified.Finally, an analysis was provided on the business value of bot-securingcompetitions and the value it gives to the company. The analysis showed thatthe business value of bot-securing competitions would be beneficial, becauseit would give a competitive advantage against competitors and also improvebusiness with advertisers and consumers.

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The aim of this research was to investigate the effect of taxes on household consumption using panel data from 94 countries from 1997―2020. These countries are grouped into 64 high―and 30 low―income countries. This study employed the generalised method of moment estimation. The results were based on estimation regressions and sensitivity analyses indicating that taxes negatively affect household consumption. Furthermore, taxes were found to be more effective at limiting household consumption in high―income countries. In conclusion, this study supports findings that were previously reported in literature. Policy makers should limit the distortive nature of taxes on household consumption by periodically assessing and controlling tax rates.