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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.
71

Determinants of employment in the Platinum mining industry in South Africa

Khoza, Nyiko January 2017 (has links)
Thesis (M. Com. (Economics)) -- University of Limpopo, 2017 / The study intends to investigate the determinants of employment in the platinum mining industry in South Africa. Employment levels decreased dramatically in the platinum mining industry in South Africa. This is due to decrease in export demand for platinum, high operating cost, labour unrest, low levels of production and other determinants of employment. The specific objective of the study is to determine the nexus between employment, output, domestic demand and export demand. Annual time series data covering the period between 1992-2013 was used. The study employed the Vector Error Correction Model approach. Johansen Cointegration test results confirmed the existence of a long run relationship amongst variables under investigation. Export demand and output are found to be positively related with employment. The speed of adjustment to equilibrium is -0.283202. Impulse response functions and variance decomposition are also generated to explain the response to shock amongst variables. The results of the study vindicate that the platinum mining industry should implement policies and strategies to increase output which will lead to higher levels of employment as well as economic growth. In addition, government should also create a conducive environment to enable the industry to expand and the industry should also intensify its export drive, these findings are envisaged to contribute significantly to the existing but limited literature on the subject under investigation. / National Research Foundation
72

An econometric approach to measuring productivity: Australia as a case study

Agbenyegah, Benjamin Komla January 2007 (has links)
Seminal papers of Solow (1957) and Swan (1956) stimulated debate among economists on the role of technical change in productivity improvements and for that matter economic growth. The consensus is that technological change accounts for a significant proportion of gross national product (GNP) growth in industrialised economies. In the case of Australia, the aggregate productivity performance was poor in the 1970s and 1980s, but picked up very strongly by the 1990s, and was above the OECD average growth level for the first time in its productivity growth history. However, this high productivity growth rate could not be sustained and Australia started to experience a slowdown in productivity growth since 2000. This study empirically measures the performance of productivity in Australia’s economy for the period 1950-2005, using an econometric approach. Time-series data are used to develop econometric models that capture the dynamic interactions between GDP, fixed capital, labour units, human capital, foreign direct investment (FDI) and information and communication technology (ICT). The Johansen (1988) cointegration techniques are used to establish a long-run steady-state relation between or among economic time series. The econometric analysis pays careful attention to the time-series properties of the data by conducting unit root and conintegration tests for the variables in the system. / This study finds that Australia experienced productivity growth in the 1950s, a slow down in the mid 1960s, a very strong productivity growth in the mid 1990s and another slowdown from 2000 onwards. The study finds evidence that human capital, FDI and ICT are very strong determinants of long-run GDP and productivity growth in Australia. The study finds that the three, four and the five factor models are likely to give better measures of productivity performance in Australia as these models recognise human capital, FDI and ICT and include them as separate factors in the production function, This study finds evidence that the previous studies on the Australia’s productivity puzzle have made a very significant omission by not considering human capital, FDI and ICT as additional exogenous variables and by excluding them from the production function for productivity analysis.
73

Transparent Satellite Switching using Flexible Frequency-band Reallocation

Yagüe, Edgar Cámara, Carretero, José Manuel Menéndez January 2006 (has links)
<p>The society expects a global interconected digital communication system offering multimedia services, information on demand and interchange of information with a high data rates and low cost. </p><p>All this can not be realized with the terrestrial nets used nowadays cause it is necessary a high economic inversion to get a competitive capacity to interchange information between server and user. The next generation of satellite must have characteristics which improve the current generation, one important requirement is that the same satellite could make a treatment of the different input signals. With this we can avoid a spent of lots of money and time because we do not need terrestrial stations which modify the signals before the information is sent to the satellite.</p><p>For all this, we need an on board treatment of the information in the satellite. We design a frequency bank reallocation (FBR) network by using a filter bank system. This is the first step of the thesis. After we get FBR we introduce some different input signals and analyze the output, using parameters like symbol error rate and variance.</p><p>One important part in the thesis is the QAM signals used to test our system. For this, we design a modulator and a demodulator of QAM4, 16 and 64, paying more attention in the QAM64, cause is the modulation where more errors can appear due to we have got more possible chances which means more precision in the recovery of the signal.</p>
74

Svenska aktiemarknaden : Hur påverkas den svenska aktiemarknaden av makroekonomiska variabler / The Swedish Stock Market : How is the Swedish Stock Market affected by macroeconomic variables

Bodin, Oscar, Nielsen, Jenny January 2013 (has links)
Bakgrund och Problem: Aktiemarknaden påverkas både av inhemska och utländska faktorer. Därför är det av intresse att se vilka makroekonomiska variabler som påverkar den svenska aktiemarknaden. Anledningen till att Sverige har valts som den geografiska punkten är att det är av intresse att se hur ett litet land som Sverige, som har en öppen ekonomi påverkas av de utvalda makroekonomiska variablerna. Syfte: Syftet med uppsatsen är att med hjälp av information samt analys, studera hur de olika makroekonomiska variablerna påverkar den inhemska aktiemarknaden. Olika faktorer som påverkar aktiemarknaden kommer att lyftas fram för att i sin tur även se till de olika branscherna. Metod: Då data enbart består av hämtning av tidigare information fokuseras det enbart på sekundärdata i form av historiska siffror samt historiska undersökningar. De statistiska tester som tillämpas är Granger Causality test, Johansens Cointegration test, Impulse Response Function test, ADF test, KPSS test, Mulitpel regression. Slutsats: Med de resultat som presenterades i denna studie, skulle vi nog inte kunna säga att vi har ett svar över vilka aktier en investerare ska införskaffa. Dock skulle vi kunna poängtera att den potentiella investeraren bör ha dessa variabler i beaktning vid beslut. Genom att studera dessa variabler kan man få en känsla om vilket håll variablerna kommer att röra sig och på så sätt säga att de kan påverka aktieindexen. Att bara kolla på de makroekonomiska variabler som denna studie belyser räcker inte för att förstå hur aktieindex kommer att se ut i framtiden, men det är en bit på vägen till att förstå aktiemarknadens rörelse.
75

Transparent Satellite Switching using Flexible Frequency-band Reallocation

Yagüe, Edgar Cámara, Carretero, José Manuel Menéndez January 2006 (has links)
The society expects a global interconected digital communication system offering multimedia services, information on demand and interchange of information with a high data rates and low cost. All this can not be realized with the terrestrial nets used nowadays cause it is necessary a high economic inversion to get a competitive capacity to interchange information between server and user. The next generation of satellite must have characteristics which improve the current generation, one important requirement is that the same satellite could make a treatment of the different input signals. With this we can avoid a spent of lots of money and time because we do not need terrestrial stations which modify the signals before the information is sent to the satellite. For all this, we need an on board treatment of the information in the satellite. We design a frequency bank reallocation (FBR) network by using a filter bank system. This is the first step of the thesis. After we get FBR we introduce some different input signals and analyze the output, using parameters like symbol error rate and variance. One important part in the thesis is the QAM signals used to test our system. For this, we design a modulator and a demodulator of QAM4, 16 and 64, paying more attention in the QAM64, cause is the modulation where more errors can appear due to we have got more possible chances which means more precision in the recovery of the signal.
76

Implementation of the LMS and NLMS algorithms for Acoustic Echo Cancellationin teleconference systemusing MATLAB

Nguyen Ngoc, Hung, Dowlatnia, Majid, Sarfraz, Azhar January 2009 (has links)
In hands-free telephony and in teleconference systems, the main aim is to provide agood free voice quality when two or more people communicate from different places.The problem often arises during the conversation is the creation of acoustic echo. Thisproblem will cause the bad quality of voice signal and thus talkers could not hearclearly the content of the conversation, even thought lost the important information.This acoustic echo is actually the noise which is created by the reflection of soundwaves by the wall of the room and the other things exist in the room. The mainobjective for engineers is the cancellation of this acoustic echo and provides an echofree environment for speakers during conversation. For this purpose, scientists designdifferent adaptive filter algorithms. Our thesis is also to study and simulate theacoustics echo cancellation by using different adaptive algorithms.
77

A Precoding Scheme for Semi-Blind Channel Estimation in Cooperative Networks

Chen, Yen-cheng 01 August 2012 (has links)
In this thesis, we proposed a precoding scheme for semi-blind channel estimation in amplify-and-forward (AF) multipath two-way relay networks (TWRN), where two terminals exchange their information through multi-relays. The precoding scheme, which diminishes computational complexity of semi-blind channel estimator, is used to distinguish received signal at both terminals from multi-relays. By applying a non-redundant linear precoding scheme at multi-relays, we proposed a semi-blind channel estimation to estimate the channel impulse response (CIR) of direct link and the cascaded source-relay-terminal links. Firstly, semi-blind channel estimation adopts least-square (LS) estimation to find the CIR of direct link between both terminals using a smaller number of training symbols. Secondly, the CIR of the cascaded source-relay-terminal links are obtained through second-order statistics (SOS) of received signals at both terminals. Consequently, the proposed scheme can effectively reduce the computational complexity and enhance the spectral efficiency in overall system. Simulation results corroborate the effectiveness of the proposed scheme.
78

The Interrelationships among Stock Returns and Institutional Investors' Buy-sell Difference in Taiwan's Stock Market: An Empirical Analysis

Hsueh, Lung-chin 28 August 2009 (has links)
This study investigates the long-term and short-term dynamic relationships among the variables of stock returns and institutional investors' buy-sell difference in Taiwan's stock market for the sample periods from Jan., 2000 through May, 2009. Some econometrical methodologies are used in this study, such as unit test, vector autoregressive model, cointegration test, vector error correction model, impulse response function. The major empirical results are shown as follows: 1. Cointegration test For the sample periods, one long-term equilibrium relationship is found from the Johansen's cointegration test, significantly with 5% confidence level between stock year returns and the buy-sell difference for the foreign investment institutions, the domestic investment institutions, and the dealers. The long-term equilibrium relationship is Ry=1.65*QFII+4.28*FUND+35.22*DLR-1142.6. 2. VECM estimation (1)With the vector error correction model (VECM) being applied to the sample periods, the findings indicate that the changes of stock returns are not influenced among the short-term dynamic relationships by the changes of institutional investors' buy-sell difference, but only affected by one-period-lag of itself. (2) Among the short-term dynamic relationships, the changes of foreign investment institutions' buy-sell difference are affected by one-period-lag of institutional investors that positively affected by one-period-lag of the dealers, and inversely affected by one-period-lag of itself and one-period-lag of the domestic investment institutions. However, it is positively affected by one-period-lag of long-term equilibrium, which indicates foreign investment institutions follow positive feedback trading strategies. (3)The changes of the domestic investment institutions' buy-sell difference are only affected by one-period-lag of itself among the short-term dynamic relationships. (4)The changes of the dealers' buy-sell difference are positively affected among the short-term dynamic relationships by one-period-lag of the foreign investment institutions. As for the long-term relationships, it is affected by one-period-lag of long-term equilibrium, which also indicates the dealers follow positive feedback trading strategies. (5)The foreign investment institutions and the dealers have the mutual feedback relationship.
79

Implementation of the LMS and NLMS algorithms for Acoustic Echo Cancellationin teleconference systemusing MATLAB

Nguyen Ngoc, Hung, Dowlatnia, Majid, Sarfraz, Azhar January 2009 (has links)
<p>In hands-free telephony and in teleconference systems, the main aim is to provide agood free voice quality when two or more people communicate from different places.The problem often arises during the conversation is the creation of acoustic echo. Thisproblem will cause the bad quality of voice signal and thus talkers could not hearclearly the content of the conversation, even thought lost the important information.This acoustic echo is actually the noise which is created by the reflection of soundwaves by the wall of the room and the other things exist in the room. The mainobjective for engineers is the cancellation of this acoustic echo and provides an echofree environment for speakers during conversation. For this purpose, scientists designdifferent adaptive filter algorithms. Our thesis is also to study and simulate theacoustics echo cancellation by using different adaptive algorithms.</p>
80

Evaluation of Unknown Foundations

Florkowski, Ronald W. 27 March 2007 (has links)
In recent years, bridge foundations have been in the spotlight throughout the nation. Bridges built over running water are susceptible to erosion or scour around their foundations. The reduction in load capacity to piers and abutments pose a safety risk to highway motorists. It has become necessary for engineers to examine and monitor these "scour critical" bridges. The difficulty arises with subsurface foundations of which very little is known about their construction. Hence, the methods applied to analyzing "Unknown Foundations" have become a necessary topic of research. This thesis explores a method to determine foundation lengths. Similar to Sonic Echo / Impulse Response, this procedure measures reflected shock waves sent through concrete pilings. The technique is non-destructive in nature and is performed near the surface of the foundation. The test is performed on the side of the exposed piling. Current methods are limited by the fact that the tops of most pilings are inaccessible due to pilecaps or beams. Often times, pilings are embedded in stiff soils, which have a dampening effect on the stress waves. This thesis employs a method of analysis that will overcome such limitations and provide engineers with another tool to determine subsurface foundation lengths.

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