Mrs N.A.M.R.Senaviratna | Open University of Sri Lanka (original) (raw)
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Papers by Mrs N.A.M.R.Senaviratna
European Journal of Medical and Health Research, Oct 31, 2023
Air pollution has been identified as one of the major environmental problems faced by most countr... more Air pollution has been identified as one of the major environmental problems faced by most countries across the world in the last few decades. The objective of this study is to develop models to forecast air pollutants SO2 and NO2 at Fort Railway station, which is one of the most congested area in Sri Lanka. In this study, monthly concentration of SO2 and NO2 (µg/m 3) were used from October 2012 to December 2016. Augmented Dickey-Fuller test is used to check the stationary condition of series. Diagnostic tests are carried out using Jarque-Bera test, Breusch-Godfrey LM test and White's test. Akaike information criterion (AIC), Schwartz's Bayesian Criterion (SBC), Mean Square Error (MSE) and coefficient of determination (R 2) are used as the model selection criteria. Mean Absolute Percentage Error (MAPE) value was used to validate the model. ARIMA(0,1,2) and ARIMA(0,0,2) model were found to be the optimal model to forecast the NO2 and SO2 concentration respectively as this model comply with all assumptions of ARIMA model.
The Apparel industry in Sri Lanka represent as one of the largest contributors for the export rev... more The Apparel industry in Sri Lanka represent as one of the largest contributors for the export revenue of the country. The quality of garments is vital to its survival in an increasingly competitive apparel industry in order to maintain the production of high quality garments and improved productivity in the apparel industry. The objective of this study is to improve efficiency of the sewing process in apparel industry through the reduction of defectives. This study is focused in three major defect types; run off stitches, unbalanced shape and wavy seams. I have developed generalized linear models for each defect type to find the significant factors affecting on the proportion of occurrence of defects. Under these models, I have recommended few remedial actions to be implemented. On implementation of recommended remedial actions, the percentage of defectives was up to an acceptable level. The outcome of this study reflected that an industry may gain higher productivity and profitabil...
Increasing road accidents is a heavy burden to a developing country like Sri Lanka. The objective... more Increasing road accidents is a heavy burden to a developing country like Sri Lanka. The objective of this study is to identify the significant factors affecting the motor vehicle accidents in Sri Lanka. Secondary data used in this study between the period 2014 to 2016 were acquired from the traffic police headquarters in Sri Lanka. A total number of 78531 motor vehicle accidents were included in the analysis. Factors considered in the study were vehicle type, gender of driver, validity of license, accident cause, alcohol test, time of accident, weekday/weekend, road surface, weather condition, light condition, location and age of driver. Two third of data (52354) was used to develop the model, and the remaining 1/3 of data (26177) was used to validate the model. Severity of accidents was categorized as grievous and non-grievous accidents. Chi-square test of independence has detected that road surface and weather are not significantly associated with the severity of accidents. The li...
Asian Journal of Probability and Statistics, 2019
One of the key problems arises in binary logistic regression model is that explanatory variables ... more One of the key problems arises in binary logistic regression model is that explanatory variables being considered for the logistic regression model are highly correlated among themselves. Multicollinearity will cause unstable estimates and inaccurate variances that affects confidence intervals and hypothesis tests. Aim of this was to discuss some diagnostic measurements to detect multicollinearity namely tolerance, Variance Inflation Factor (VIF), condition index and variance proportions. The adapted diagnostics are illustrated with data based on a study of road accidents. Secondary data used from 2014 to 2016 in this study were acquired from the Traffic Police headquarters, Colombo in Sri Lanka. The response variable is accident severity that consists of two levels particularly grievous and non-grievous. Multicolinearity is identified by correlation matrix, tolerance and VIF values and confirmed by condition index and variance proportions. The range of solutions available for logis...
Increasing road accidents and traffic flow is a heavy burden to a developing country like Sri Lan... more Increasing road accidents and traffic flow is a heavy burden to a developing country like Sri Lanka. The objective of this study is to identify the significant factors affecting motor vehicle accidents in Sri Lanka. Secondary data used in this study between the period 2014 to 2016 were acquired from the traffic police headquarters in Sri Lanka. A total number of 78531 motor vehicle accidents were included in the analysis. Factors considered in the study were vehicle type, gender of driver, validity of license, accident cause, alcohol test, time of accident, weekday/weekend, road surface, weather condition, light condition, location and age of driver. Two third of data (52354) was used to develop the model, and the remaining 1/3 of data (26177) was used to validate the model. Severity of accidents was categorized as grievous and non-grievous accidents. Chi-square test of independence has detected that road surface and weather are not significantly associated with the severity of acci...
The Apparel industry in Sri Lanka represent as one of the largest contributors for the export rev... more The Apparel industry in Sri Lanka represent as one of the largest contributors for the export revenue of the country. The quality of garments is vital to its survival in an increasingly competitive apparel industry in order to maintain the production of high quality garments and improved productivity in the apparel industry. The objective of this study is to improve efficiency of the sewing process in apparel industry through the reduction of defectives. This study is focused in three major defect types; run off stitches, unbalanced shape and wavy seams. I have developed generalized linear models for each defect type to find the significant factors affecting on the proportion of occurrence of defects. Under these models, I have recommended few remedial actions to be implemented. On implementation of recommended remedial actions, the percentage of defectives was up to an acceptable level. The outcome of this study reflected that an industry may gain higher productivity and profitability with improved quality product by minimising reworks activities.
European Journal of Medical and Health Research, Oct 31, 2023
Air pollution has been identified as one of the major environmental problems faced by most countr... more Air pollution has been identified as one of the major environmental problems faced by most countries across the world in the last few decades. The objective of this study is to develop models to forecast air pollutants SO2 and NO2 at Fort Railway station, which is one of the most congested area in Sri Lanka. In this study, monthly concentration of SO2 and NO2 (µg/m 3) were used from October 2012 to December 2016. Augmented Dickey-Fuller test is used to check the stationary condition of series. Diagnostic tests are carried out using Jarque-Bera test, Breusch-Godfrey LM test and White's test. Akaike information criterion (AIC), Schwartz's Bayesian Criterion (SBC), Mean Square Error (MSE) and coefficient of determination (R 2) are used as the model selection criteria. Mean Absolute Percentage Error (MAPE) value was used to validate the model. ARIMA(0,1,2) and ARIMA(0,0,2) model were found to be the optimal model to forecast the NO2 and SO2 concentration respectively as this model comply with all assumptions of ARIMA model.
The Apparel industry in Sri Lanka represent as one of the largest contributors for the export rev... more The Apparel industry in Sri Lanka represent as one of the largest contributors for the export revenue of the country. The quality of garments is vital to its survival in an increasingly competitive apparel industry in order to maintain the production of high quality garments and improved productivity in the apparel industry. The objective of this study is to improve efficiency of the sewing process in apparel industry through the reduction of defectives. This study is focused in three major defect types; run off stitches, unbalanced shape and wavy seams. I have developed generalized linear models for each defect type to find the significant factors affecting on the proportion of occurrence of defects. Under these models, I have recommended few remedial actions to be implemented. On implementation of recommended remedial actions, the percentage of defectives was up to an acceptable level. The outcome of this study reflected that an industry may gain higher productivity and profitabil...
Increasing road accidents is a heavy burden to a developing country like Sri Lanka. The objective... more Increasing road accidents is a heavy burden to a developing country like Sri Lanka. The objective of this study is to identify the significant factors affecting the motor vehicle accidents in Sri Lanka. Secondary data used in this study between the period 2014 to 2016 were acquired from the traffic police headquarters in Sri Lanka. A total number of 78531 motor vehicle accidents were included in the analysis. Factors considered in the study were vehicle type, gender of driver, validity of license, accident cause, alcohol test, time of accident, weekday/weekend, road surface, weather condition, light condition, location and age of driver. Two third of data (52354) was used to develop the model, and the remaining 1/3 of data (26177) was used to validate the model. Severity of accidents was categorized as grievous and non-grievous accidents. Chi-square test of independence has detected that road surface and weather are not significantly associated with the severity of accidents. The li...
Asian Journal of Probability and Statistics, 2019
One of the key problems arises in binary logistic regression model is that explanatory variables ... more One of the key problems arises in binary logistic regression model is that explanatory variables being considered for the logistic regression model are highly correlated among themselves. Multicollinearity will cause unstable estimates and inaccurate variances that affects confidence intervals and hypothesis tests. Aim of this was to discuss some diagnostic measurements to detect multicollinearity namely tolerance, Variance Inflation Factor (VIF), condition index and variance proportions. The adapted diagnostics are illustrated with data based on a study of road accidents. Secondary data used from 2014 to 2016 in this study were acquired from the Traffic Police headquarters, Colombo in Sri Lanka. The response variable is accident severity that consists of two levels particularly grievous and non-grievous. Multicolinearity is identified by correlation matrix, tolerance and VIF values and confirmed by condition index and variance proportions. The range of solutions available for logis...
Increasing road accidents and traffic flow is a heavy burden to a developing country like Sri Lan... more Increasing road accidents and traffic flow is a heavy burden to a developing country like Sri Lanka. The objective of this study is to identify the significant factors affecting motor vehicle accidents in Sri Lanka. Secondary data used in this study between the period 2014 to 2016 were acquired from the traffic police headquarters in Sri Lanka. A total number of 78531 motor vehicle accidents were included in the analysis. Factors considered in the study were vehicle type, gender of driver, validity of license, accident cause, alcohol test, time of accident, weekday/weekend, road surface, weather condition, light condition, location and age of driver. Two third of data (52354) was used to develop the model, and the remaining 1/3 of data (26177) was used to validate the model. Severity of accidents was categorized as grievous and non-grievous accidents. Chi-square test of independence has detected that road surface and weather are not significantly associated with the severity of acci...
The Apparel industry in Sri Lanka represent as one of the largest contributors for the export rev... more The Apparel industry in Sri Lanka represent as one of the largest contributors for the export revenue of the country. The quality of garments is vital to its survival in an increasingly competitive apparel industry in order to maintain the production of high quality garments and improved productivity in the apparel industry. The objective of this study is to improve efficiency of the sewing process in apparel industry through the reduction of defectives. This study is focused in three major defect types; run off stitches, unbalanced shape and wavy seams. I have developed generalized linear models for each defect type to find the significant factors affecting on the proportion of occurrence of defects. Under these models, I have recommended few remedial actions to be implemented. On implementation of recommended remedial actions, the percentage of defectives was up to an acceptable level. The outcome of this study reflected that an industry may gain higher productivity and profitability with improved quality product by minimising reworks activities.