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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Equivalent Model Extracting by the Least-square Estimation Method in Time Domain Measurement

Ho, Wen-Bo 01 July 2000 (has links)
Equivalent model extracting by the least-square estimation method and optimation in time domain measurement.It discuss at the effect of step soure rising and how to use TDR measurements in high speed digital system.It can determine characteristic impedances of DUT,compute accurate models for inductance and capacitance,and predict interconnect component more accurately.
2

The Effect of Remittances on Socio-Economic Condition and Decision Making Process of Rural Families : A Case Study of Peshawar Khyber Pukhunkhuwa Pakistan

Ullah, Obaid January 2015 (has links)
The objective of the study is to analyze the effect of remittances on socio-economic conditions of rural families in Peshawar, and how remittances change the decision-making process of families. This study examines the effects of remittances on local population in three towns of Peshawar, i.e. Hayatabad, Faqir-Abad and Gulberg-area. The study is basically conducted to see how remittances bring changes in the life of the recipients. The research is quantitative, data was collected through questionnaires. For the research, a sample of 300 respondents was selected from three towns in Peshawar District. The results of the research were interpreted through statistical tools, regression model. The Ordinary least square method (OLS) was used to find out the effect of remittances on health sector and investment made by respondents in the form of purchased property and investment made in establishing their own businesses. Along with that, the simple Logit Model was also used. The result is generalized on linear model with link logit and binomial response. Findings stated that the literacy level of the emigrant’s household positively impacted on children’s probability to move to private education. The results reveals that the recipient invest 4% of their income on investment as a form of business and purchasing property while educated people appears not to be interested in investing money in businesses as they want to continue their jobs. Respondent are not using a large portion of their remittances for health perhaps mostly people are entitled to free services from the government. Remittances changed their standard of living and socio economic affairs of the remittances receiving respondents. According to my demographic information about respondents life, the remittances mostly brings changes in the physical part of people life such as Private Education, Personal transport, new houses, investment in buying properties, more electric appliances, bank balance etc., but culturally people are still conservative and believe in cultural values that have been practices by local population for centuries. Following are some main recommendations that this research has identified, Foreign remittances are improving the socio-economic conditions and decision making of rural families, however, their consumption behavior is not inclined towards investment, they rather prefer to enjoy luxurious household’s equipment. Therefore, it is recommended that these families should utilize their resources in more efficient way, and should go for short and long term investment avenues. Government must design policies in order to educate these families and create awareness among them that will enable them to look for sustainable domestic income, which would help the families in the long run. These families follow the norms and traditions, and they prefer sending their children abroad for earning purposes, which in turn is comparatively less profitable idea as compared to sending these children for higher education purpose.
3

Theoretical Analysis for Moving Least Square Method with Second Order Pseudo-Derivatives and Stabilization

Clack, Jhules January 2014 (has links)
No description available.
4

Data-based Harmonic Source Identification

Erfanian Mazin, Hooman Unknown Date
No description available.
5

Fairness Perceptions and Compliance Behaviour: Taxpayers' Judgments in Self-Assessment Environments

Saad, Natrah January 2011 (has links)
This cross cultural study compares the fairness perceptions of New Zealand and Malaysian individual taxpayers of their respective income tax systems, and investigates the consequences of those perceptions, together with other important variables, on their compliance behaviour. A theoretical framework was developed based on Equity Theory and the Theory of Planned Behaviour. The study’s hypotheses were tested using the responses to questionnaire surveys (which included two scenarios) and in-depth telephone interviews, which were conducted sequentially in both countries. Partial Least Squares and thematic analysis were used to analyse the surveys and interviews data, respectively. The results suggest that Malaysian taxpayers have significantly better perceptions of fairness of their income tax systems than their New Zealand counterparts, yet New Zealand taxpayers are more compliant. The most consistently important factor in explaining taxpayers’ compliance behaviour across the two countries is their attitude towards compliance, followed by subjective norms. Fairness perceptions, which are highly influenced by their tax knowledge and perceived complexity of the tax system, are also influential, particularly in the understating other incomes scenario. This cross-cultural study demonstrates that regardless of the differences between the two countries under study (in relation to economies, cultures and ethnicities), taxpayers generally respond in quite similar ways when it comes to meeting their tax obligations.
6

Aplicación y comparación de algoritmos de valoración de opciones reales para la evaluación de proyectos de generación eléctrica bajo incertidumbre

Hidalgo Arancibia, Juan Francisco January 2014 (has links)
Ingeniero Civil Industrial / La presente memoria se centra en desarrollar una metodología de evaluación de proyectos, para uso en generación eléctrica, que captura las dinámicas del valor de un proyecto de inversión. Esto en base a la evolución de la principal variable de mercado que afecta la rentabilidad usando las técnicas de valoración, llamados Least Square Monte Carlo y Árboles Trinomiales. Esto porque, los proyectos en este rubro son priorizados respecto a la tecnología de desarrollo más eficiente disponible usando un análisis de Valor Actual Neto (VAN) que no considera las dinámicas a las cuales están sujetos los valores de los proyectos. Como se prevé que las instalaciones de generación eléctrica se mantendrán en operación por un 50% más de su vida útil pronosticada, se vuelve más significativa la evaluación dinámica para el largo plazo incorporando incertidumbre. Para ello, se hace un análisis empírico del comportamiento de los precios de electricidad, en un nodo representativo del Sistema Interconectado Central, el principal mercado eléctrico en Chile. Con esto, se estiman los parámetros de un modelo que incorpora estas características, conocido como Mean Reverting Jump Diffusion en conjunto con un modelo de simulación de operación para la determinación de expectativas de largo plazo en precios de electricidad. Para la aplicación del análisis de opciones reales, se utilizan los procedimientos Least Square Monte Carlo y árboles trinomiales basados en los parámetros encontrados del proceso de precios para diseñar la estrategia óptima de inversión en el largo plazo en generación de tecnologías disponibles en Chile. Los resultados incluyen un análisis de las estrategias de inversión de diversas centrales disponibles para la expansión de la matriz energética de Chile dadas las condiciones actuales del mercado. En particular, el análisis de árboles sugiere invertir inmediatamente en centrales Hidroeléctricas, térmicas de Carbón y Diésel y no invertir en tecnología de ciclos combinados. Por otra parte, el algoritmo de Least Square Monte Carlo sugiere esperar en todos los casos, ya que estima que el valor de estos proyectos incrementará en el futuro respecto a sus valores estimados actuales. Por ello, el análisis comparativo entre los modelos sugiere de un sesgo relativo hacia arriba por parte del algoritmo de Least Square Monte Carlo. Este sesgo es analizado en mayor profundidad, arribando a la conclusión que a medida que se aumentan las simulaciones consideradas, este sesgo relativo va disminuyendo, pero de manera desacelerada. Para complementar, se incluye un análisis de sensibilidad de los resultados usando parámetros de cobertura de riesgo, conocidos coloquialmente como las griegas , calculados a partir de los Árboles trinomiales. Los resultados de estos análisis indican que el valor del precio de la electricidad, la volatilidad y la duración de la oportunidad de inversión impactan positivamente en el proyecto, lo que es consistente con la teoría de opciones reales que postula que a mayor volatilidad, más valor se puede generar en un proyecto al aprovechar las flexibilidades inherentes.
7

Capital structure and determinants of capital structure, before, during and after the 2008 financial crisis: A South African study

Ntshobane, Gcobisa 15 September 2021 (has links)
This study examines the effects of 2007/8 financial crisis on capital structure determinants of Johannesburg Stock Exchange (JSE) listed companies in South Africa. Data extracted from INET BFA Expert database was analyzed using regression models on the correlation between the leverage and company size, growth, profitability, tangibility, liquidity, non-debt tax shield along with Ordinary Least Squares based on the sample of JSE listed companies for the period of 2004 to 2013. The study examined two industries namely, Real estate and Retail industry. The results show that size, tangibility, profitability and liquidity have significant impact on the capital structure before, during and after financial crisis. Growth results were inconsistent over the period under review, and non-debt tax shield was found to be statistically insignificant. The study also shows that the 2007/8 had statistical significance on the capital structure of the listed companies in South Africa.
8

Multisource Least-squares Reverse Time Migration

Dai, Wei 12 1900 (has links)
Least-squares migration has been shown to be able to produce high quality migration images, but its computational cost is considered to be too high for practical imaging. In this dissertation, a multisource least-squares reverse time migration algorithm (LSRTM) is proposed to increase by up to 10 times the computational efficiency by utilizing the blended sources processing technique. There are three main chapters in this dissertation. In Chapter 2, the multisource LSRTM algorithm is implemented with random time-shift and random source polarity encoding functions. Numerical tests on the 2D HESS VTI data show that the multisource LSRTM algorithm suppresses migration artifacts, balances the amplitudes, improves image resolution, and reduces crosstalk noise associated with the blended shot gathers. For this example, multisource LSRTM is about three times faster than the conventional RTM method. For the 3D example of the SEG/EAGE salt model, with comparable computational cost, multisource LSRTM produces images with more accurate amplitudes, better spatial resolution, and fewer migration artifacts compared to conventional RTM. The empirical results suggest that the multisource LSRTM can produce more accurate reflectivity images than conventional RTM does with similar or less computational cost. The caveat is that LSRTM image is sensitive to large errors in the migration velocity model. In Chapter 3, the multisource LSRTM algorithm is implemented with frequency selection encoding strategy and applied to marine streamer data, for which traditional random encoding functions are not applicable. The frequency-selection encoding functions are delta functions in the frequency domain, so that all the encoded shots have unique non-overlapping frequency content. Therefore, the receivers can distinguish the wavefield from each shot according to the frequencies. With the frequency-selection encoding method, the computational efficiency of LSRTM is increased so that its cost is comparable to conventional RTM in the examples of the Marmousi2 model and a field data set from the Gulf of Mexico. With more iterations, the LSRTM image quality is further improved. The numerical results suggest that LSRTM with frequency-selection is an efficient method to produce better reflectivity images than conventional RTM. In Chapter 4, I present an interferometric method for extracting the diffraction signals that emanate from diffractors, also denoted as seismic guide stars. The signal-to-noise ratio of these interferometric diffractions is enhanced by √N, where N is the number of source points coincident with the receiver points. Thus, diffractions from subsalt guide stars can then be rendered visible and so can be used for velocity analysis, migration, and focusing of subsalt reflections. Both synthetic and field data records are used to demonstrate the benefits and limitations of this method.
9

Non-Negative Least Square Optimization Model for Industrial Peak Load Estimation

Moda, Hari Priya 05 January 2010 (has links)
Load research is the study of load characteristics on a power distribution system which helps planning engineer make decisions about equipment ratings and future expansion decisions. As it is expensive to collect and maintain data across the entire system, data is collected only for a sample of customers, where the sample is divided into groups based upon the customer class. These sample measurements are used to calculate the load research factors like kWHr-to-peak kW conversion factors, diversity factors and 24 hour average consumption as a function of class, month and day type. These factors are applied to the commonly available monthly billing kW data to estimate load on the system. Among various customers on a power system, industrial customers form an important group for study as their annual kWHr consumption is among the highest. Also the errors with which the estimates are calculated are also highest for this class. Hence we choose the industrial class to demonstrate the Lawson-Hanson Non-Negative Least Square (NNLS) optimization technique to minimize the residual squared error between the estimated loads and the SCADA currents on the system. Five feeders with industrial dominant customers are chosen to demonstrate the improvement provided by the NNLS model. The results showed significant improvement over the Nonlinear Load Research Estimation (NLRE) method. / Master of Science
10

DATA FITTING AND LEAST-SQUARE ESTIMATION OF NONLINEAR PARAMETERS FOR MODELS OF DIELECTRIC RELAXATION DATA

Zou, Hai 06 1900 (has links)
<p> The work in this thesis is to develop a tool for calculating the parameters corresponding to certain theoretical model of dielectric relaxation phenomena and then doing the curve fitting using the result after fetching the data from the user. To our best knowledge, this the first such tool to calculate the parameters corresponding to certain theoretical model of dielectric relaxation phenomena while the user only need to provide the experimental data. The parameters are calculated by using a nonlinear least square algorithm implemented in Matlab and a nonlinear function minimizer available in Matlab. The way to do the curve fitting is not by the traditional way such as cubic spline but by calculating the simulated data using the chosen model and the calculated result for the parameters. </p> <p> The available mathematical models include all of popular theoretical models, the Cole-Davidson (DC), the Kohlrausch-Williams-Watts (KWW), the Havriliak-Negami (HN) and the model proposed by R. Hilfer (FD). </p> <p> There are two ways to calculate the parameters for each model as mentioned before. The result returned by this system may not be unique. Especially if the frequency range of data is not wide enough, the result would most likely be non-unique. Since the iterative method is used in the system, it is suggested that the user provides the initial values for the system with his best knowledge or background for the data and the tested sample related to dielectric relaxation process. </p> <p> It is normal if there is a part having worse fitting than the other parts. One of reasons could be the mathematical model's defect, which the model does not work for that part. For the further information, please contact me by email at zouhaijun at yahoo.com. </p> / Thesis / Master of Science (MSc)

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