https://ir.kdu.ac.lk/handle/345/3837 2026-04-22T01:44:10Z https://ir.kdu.ac.lk/handle/345/1349 Volatility Models for World Stock Indices and Behaviour of All Share Price Index Samayawardena, DN; Dharmarathne, HASG; Tilakaratne, CD The purpose of the study is to model the volatility of the world stock indices. The word volatility is derived as the results of unequal variances of the error terms of the return series. The technical term used here is Heteroscedasticity. The investors in financial market consider the movement of the volatility of several locations for the risk management, derivatives pricing and hedging, market making, portfolio and for the different financial aims .The volatility modelling and forecasting is not very common in the Sri Lankan aspect. Volatility modelling with great emphasize on Sri Lanka is a very noteworthy attempt. The identification of the volatility models for the stock indices of Colombo stock exchange and stock markets of United States, India and United Kingdom are highly useful to the investors. The purpose of modelling the volatility of these selected stock indices is that Investors try to invest in several stock markets to diversify the risk. To capture the characteristics of volatility in the stock price series, Generalized Autoregressive Conditional Heteroscedasticity (GARCH) models have been used. Many GARCH family models were considered in this study. All Share Price Index of Colombo stock exchanges (ASPI), S & P 500 index of New York stock exchange, FTSE 100 of the London stock exchange and BSE SENSEX index of Bombe stock exchange have been considered in this study and the study period is from 1st January 2004 to 1st January 2014. GARCH (1, 1) model was identified as the best model for the ASPI return series, EGARCH (1,1) model was identified as the best model for both the FTSE 100 and BSESENSEX indices return series and while S & P 500 return series is best expressed by EGARCH (2,1) model. The model adequacy of the selected models have been tested using the ARCH LM test, Correlogram of squared returns and Correlogram of standardized residuals, while Q-Q plot was applied to check the error distribution. After the investigation of the numerical accuracy of the model estimated, the models have been used to forecast future volatility. Article Full Text 2015-01-01T00:00:00Z https://ir.kdu.ac.lk/handle/345/1348 Novel solid state solar cell made from n-cu2o using granular active carbon as upper - electrode Perera, NWPS; Fernando, CAN; Ariadurai, SA Coir is a natural vegetable fibre obtained from the coconut tree. In this research, alkaline-bio scoured bristle coir fibres powders were subjected to alkaline activation method. Potassium Hydroxide (0.1M) was used to treat the carbon powder subjecting it to activation. The coir carbon powder was fed into a tube furnace with a constant heating rate of 20Co min-1 until the temperature reached different temperatures between 380 oC to 450 oC. At a selected temperature between 380Co to 450Co the samples were kept inside the tube furnace for 15 min in a nitrogen flow. Subsequently they were cooled up to room temperature. Then determine iodine number. Copper plate was fabricated by thin film of Cu2O .which is formed by well boil (5*10-3M) solution of copper sulphate and make in n-Cu2O solar cell. n- Cu2O band gap was about 2.2eV.Coir active carbon powder (GAC) act as an upper electrode of this specific photo electrode. The diffused reflectance spectra and the X-ray diffraction peak (XRD) and SEM the cell were measured to determine the effectiveness of the solid state thin film solar cell. A significant variation in photo current occurred by stability of GAC is clearly observed in the upper electrode with the thin film and conductive glass plate solar cell Article Full Text 2015-01-01T00:00:00Z https://ir.kdu.ac.lk/handle/345/1347 Characterization of Montmorillonite Clay from Naturally Occurring Clay Deposits in Murunkan Area Adikary, SU; Ashokcline, M; Nirojan, K Engineering fields widely use montmorillonite(MMT) nano clay for wide range of applications. Identify the presence of MMT and other minerals in naturally occurred clay deposits in Murunkan region and discussing the possibilities to extract MMT for commercial purpose was the objective of this research. In this research, naturally occurring clay deposits in Murunkan region was considered. Non-clay particles were removed in order to enhance the clay content and to prepare the samples. Selected samples were undergone characterizations method such as Fourier transform infrared spectroscopy (FTIR), Differential thermal analysis (DTA), linear shrinkage test, X-ray diffraction (XRD). Then MMT was isolated through the process of ultrasonic treatment and sedimentation. Presence of MMT in higher percentage is ensured through X-ray diffraction analysis on Murunkan clay. The ultrasonic method and sedimentation method has improved the amount of finer particles and removed coarse particles. Article Full Text 2015-01-01T00:00:00Z https://ir.kdu.ac.lk/handle/345/1346 A Stochastic Model for Variation of Exchange Rates in Sri Lanka Alupotha, KN In Sri Lankan economy, exchange rates have been a one of the critical factors as domestic inflation mostly occurs on depreciation of currency value. Exchange rate is the rate at which currency of a country is bought and sold against the currency of another country in the foreign exchange market. In this work, buying price of the US dollar has been used as a better yardstick to analyze the exchange rates in Sri Lanka as US dollar is being concerned as a world most accepted trade denominator and its buying price was used as purchasing power of the Sri Lankan rupee is deteriorating. The main objectives of this analysis are to derive a stochastic model to represent the variation of exchange rates and hence make conclusions about the variation. Vasicek model was used to model the variation of exchange rates as variation of exchange rates is a stochastic process and there is a mean reversion. Vasicek model is the first stochastic model to capture the value of mean reversion. The model describes the dynamics of the short rate in a linear equation and short rates can be solved explicitly. In this analysis, using daily authentic data from 2005 to 2012 and maximum likelihood estimation, parameters of the Vasicek model were derived. According to the final model, exchange rate is fluctuating around the value Rs.108.3488 and there is an ascent of the variation. Therefore, it is clear that currency value is deteriorating and hence, investors have to pay more money to import their products. Then this additional cost has to be covered by enhancing price levels inside the country. In order to control the depreciation of currency value government intervention is needed. Improvement of the gross domestic product can be concerned as a best economic strategy to regulate the depreciation of currency value. Article Full Text 2015-01-01T00:00:00Z