Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421973
Ayesha Sandaruwani, C. Kumarasinghe, D. Samarakoon, T. Ariyadasa, S. Gunawardena
Dairy industry is considered as the largest producer of wastewater in the food industry in many countries. Dairy wastewater contains high concentrations of nutrients, organic and inorganic constituent. Therefore, discharging untreated/partially treated dairy wastewater causes serious environmental problems. Biological treatment methods show the highest efficiency for treating dairy wastewater. Aim of the present study was to identify indigenous bacteria capable of degrading dairy wastewater efficiently. Bacterial isolates were tested individually and in combinations using synthetic wastewater medium, incubated at 30°C, for 2 days and Chemical Oxygen Demand (COD), pH, free fatty acid content, cell growth rate and the lipase activity were obtained at 6 hr time intervals for 36 hours. All the tested bacteria along with the consortium exhibited lipid degradation as well as removal of organic matter. Pseudomonas aeruginosa showed the highest activity in lipid degradation and COD reduction to 250mgO2/ltr at 12 hours.
{"title":"Investigation of the Efficiency of Dairy Wastewater Treatment Using Lipid-Degrading Bacterial Strains","authors":"Ayesha Sandaruwani, C. Kumarasinghe, D. Samarakoon, T. Ariyadasa, S. Gunawardena","doi":"10.1109/MERCON.2018.8421973","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421973","url":null,"abstract":"Dairy industry is considered as the largest producer of wastewater in the food industry in many countries. Dairy wastewater contains high concentrations of nutrients, organic and inorganic constituent. Therefore, discharging untreated/partially treated dairy wastewater causes serious environmental problems. Biological treatment methods show the highest efficiency for treating dairy wastewater. Aim of the present study was to identify indigenous bacteria capable of degrading dairy wastewater efficiently. Bacterial isolates were tested individually and in combinations using synthetic wastewater medium, incubated at 30°C, for 2 days and Chemical Oxygen Demand (COD), pH, free fatty acid content, cell growth rate and the lipase activity were obtained at 6 hr time intervals for 36 hours. All the tested bacteria along with the consortium exhibited lipid degradation as well as removal of organic matter. Pseudomonas aeruginosa showed the highest activity in lipid degradation and COD reduction to 250mgO2/ltr at 12 hours.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"104 9","pages":"362-366"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91424583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421929
T.A.U. Roshan, B. Basnayake, Y. Amarasinghe, Dimuthu Wijethunge, N. Nanayakkara
Shape Memory Alloy (SMA) spring actuator was designed and fabricated using commercially available NiTiNOL material by shape setting with the use of a special fixture. So, before applying the actuator to an application, a force characterization was conducted and force variation respect to uncontrolled temperature was analyzed. Due to the difference between force and temperature sensor's response time, a lag can occur between force and temperature measurements. Therefore, a more controlled technique was further implemented by developing a Proportional-Integral-Derivative (PID) based closed loop controller, together with a Graphical User Interface (GUI) which supports parameter control and sensor calibration. Finally, a force feedback controlling method also developed using the same PID technique for a force sensitive applications, where controlled forces need to be maintained by varying temperature of SMA accordingly.
{"title":"Development of a PID Based Closed Loop Controller for Shape Memory Alloy Actuators","authors":"T.A.U. Roshan, B. Basnayake, Y. Amarasinghe, Dimuthu Wijethunge, N. Nanayakkara","doi":"10.1109/MERCON.2018.8421929","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421929","url":null,"abstract":"Shape Memory Alloy (SMA) spring actuator was designed and fabricated using commercially available NiTiNOL material by shape setting with the use of a special fixture. So, before applying the actuator to an application, a force characterization was conducted and force variation respect to uncontrolled temperature was analyzed. Due to the difference between force and temperature sensor's response time, a lag can occur between force and temperature measurements. Therefore, a more controlled technique was further implemented by developing a Proportional-Integral-Derivative (PID) based closed loop controller, together with a Graphical User Interface (GUI) which supports parameter control and sensor calibration. Finally, a force feedback controlling method also developed using the same PID technique for a force sensitive applications, where controlled forces need to be maintained by varying temperature of SMA accordingly.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"62 1","pages":"460-464"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91546256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421957
S. Hendawitharana, S. Nanayakkara
Cellular Lightweight Concrete (also referred to as foam concrete) has increased its popularity due to its favorable features such as thermal comfort, lightweight, high strength/weight ratio and fire resistance. The production of foam concrete often uses river sand which is a depleting natural resource. Bottom Ash, a by-product of coal fired thermal power plants, is currently considered as a waste material. Use of bottom ash, in production of foam concrete, results in a sustainable product, as the use of sand is reduced, while making use of a by-product. This research was focused on the suitability of use of bottom ash in foam concrete with respect to compressive strength and drying shrinkage. The results indicate that the use of bottom ash in foam concrete has increased the compressive strength and reduced drying shrinkage, in comparison to foam concrete prepared without bottom ash. Based on the findings of the study, it can be stated that bottom ash can be effectively utilized in production of foam concrete.
{"title":"Use of Bottom Ash from Coal Fired Thermal Power Plants in Production of Cellular Lightweight Concrete","authors":"S. Hendawitharana, S. Nanayakkara","doi":"10.1109/MERCON.2018.8421957","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421957","url":null,"abstract":"Cellular Lightweight Concrete (also referred to as foam concrete) has increased its popularity due to its favorable features such as thermal comfort, lightweight, high strength/weight ratio and fire resistance. The production of foam concrete often uses river sand which is a depleting natural resource. Bottom Ash, a by-product of coal fired thermal power plants, is currently considered as a waste material. Use of bottom ash, in production of foam concrete, results in a sustainable product, as the use of sand is reduced, while making use of a by-product. This research was focused on the suitability of use of bottom ash in foam concrete with respect to compressive strength and drying shrinkage. The results indicate that the use of bottom ash in foam concrete has increased the compressive strength and reduced drying shrinkage, in comparison to foam concrete prepared without bottom ash. Based on the findings of the study, it can be stated that bottom ash can be effectively utilized in production of foam concrete.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"8 1","pages":"209-214"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90415683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421959
Rafhan Rifan, V. Adikariwattage
This paper is a preliminary attempt to evaluate the regulatory gap for Unmanned aerial system (UAS) operations in Sri Lanka and to propose improvements to the regulatory framework. Data were collected on the existing distribution of UAS usage in the country. A sample of users of UASs was surveyed to determine current and intended future use of UASs. Using UAS regulations applied elsewhere in the world and other scientific studies, a list of criteria was established. The relative importance of the established evaluation criteria was determined based on the perception of both UAS operators and a sample of the general public. Using the identified criteria and newly imposed UAS regulations in Sri Lanka, the regulatory gap analysis was performed to evaluate the regulatory performance.
{"title":"Evaluation of Regulatory Gap in UAS Operations in Sri Lanka","authors":"Rafhan Rifan, V. Adikariwattage","doi":"10.1109/MERCON.2018.8421959","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421959","url":null,"abstract":"This paper is a preliminary attempt to evaluate the regulatory gap for Unmanned aerial system (UAS) operations in Sri Lanka and to propose improvements to the regulatory framework. Data were collected on the existing distribution of UAS usage in the country. A sample of users of UASs was surveyed to determine current and intended future use of UASs. Using UAS regulations applied elsewhere in the world and other scientific studies, a list of criteria was established. The relative importance of the established evaluation criteria was determined based on the perception of both UAS operators and a sample of the general public. Using the identified criteria and newly imposed UAS regulations in Sri Lanka, the regulatory gap analysis was performed to evaluate the regulatory performance.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"52 1","pages":"408-413"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80035116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421961
S. Sethunga, I. Perera
Almost all IT organizations carryout performance reward schemes to evaluate and compensate employees based on their performance. However not all reward schemes are effective in retaining employees, thus this study attempt to reveal the most effective reward types that can help IT organizations to minimize Employee Turnover. This study uses quantitative method through an online survey. The population for this study is software professionals working in Sri Lankan software organizations, estimated to be around 34,000 [1]. Data analysis was carried out using Pearson correlation and Linear Regression. In the present study Monetary Rewards, Non-Monetary Rewards and Reward Frequency were negatively correlated with Employee Turnover. This means that as the Monetary Rewards and Non-Monetary Rewards are less, and the rewards are offered at lesser frequency, employees tend to turnover more in IT organizations. Detailed analysis revealed that long term monetary rewards are more successful in retaining employees which are offered at semi-annual intervals. This research brings out valuable results that can be incorporated in organizational performance reward policy by the top managements making a special emphasis on the turnover of their employees. The research findings hint on other avenues in performance rewards at workplace and its impact on the individuals that could be explored as future research.
{"title":"Impact of Performance Rewards on Employee Turnover in Sri Lankan IT Industry","authors":"S. Sethunga, I. Perera","doi":"10.1109/MERCON.2018.8421961","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421961","url":null,"abstract":"Almost all IT organizations carryout performance reward schemes to evaluate and compensate employees based on their performance. However not all reward schemes are effective in retaining employees, thus this study attempt to reveal the most effective reward types that can help IT organizations to minimize Employee Turnover. This study uses quantitative method through an online survey. The population for this study is software professionals working in Sri Lankan software organizations, estimated to be around 34,000 [1]. Data analysis was carried out using Pearson correlation and Linear Regression. In the present study Monetary Rewards, Non-Monetary Rewards and Reward Frequency were negatively correlated with Employee Turnover. This means that as the Monetary Rewards and Non-Monetary Rewards are less, and the rewards are offered at lesser frequency, employees tend to turnover more in IT organizations. Detailed analysis revealed that long term monetary rewards are more successful in retaining employees which are offered at semi-annual intervals. This research brings out valuable results that can be incorporated in organizational performance reward policy by the top managements making a special emphasis on the turnover of their employees. The research findings hint on other avenues in performance rewards at workplace and its impact on the individuals that could be explored as future research.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"85 1","pages":"114-119"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83956456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421908
F. R. Munas, Y. Amarasinghe, P. Kumarage, D. Dao, V. Dau
This paper presents the design and simulation of MEMS based piezoresistive pressure sensor for microfluidic applications. Geometrical parameters are very much considerable when designing microstructure of the pressure sensor. Hence, an analysis is carried out by changing the dimensional parameters of three different diaphragm geometries namely square shaped diaphragm, circular shaped diaphragm and cross sectional beam shaped diaphragm respectively. This is performed in three dimensional mesh plots using Matlab. The Finite Element Method (FEM) analyses are performed in COMSOL and by comparing the results, the square type diaphragm is chosen as best diaphragm geometry for the microfluidic applications. In addition, modal analysis is carried out by using Ansys to identify the natural frequency of the best diaphragm geometry. Also Piezoresistive sensing elements are designed and simulated by performing coupled field analysis using COMSOL Multiphysics. Simulation results reveal that piezo resistive square type pressure sensors have high sensitivity in a wide range of pressures.
{"title":"Design and Simulation of MEMS Based Piezoresitive Pressure Sensor for Microfluidic Applications","authors":"F. R. Munas, Y. Amarasinghe, P. Kumarage, D. Dao, V. Dau","doi":"10.1109/MERCON.2018.8421908","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421908","url":null,"abstract":"This paper presents the design and simulation of MEMS based piezoresistive pressure sensor for microfluidic applications. Geometrical parameters are very much considerable when designing microstructure of the pressure sensor. Hence, an analysis is carried out by changing the dimensional parameters of three different diaphragm geometries namely square shaped diaphragm, circular shaped diaphragm and cross sectional beam shaped diaphragm respectively. This is performed in three dimensional mesh plots using Matlab. The Finite Element Method (FEM) analyses are performed in COMSOL and by comparing the results, the square type diaphragm is chosen as best diaphragm geometry for the microfluidic applications. In addition, modal analysis is carried out by using Ansys to identify the natural frequency of the best diaphragm geometry. Also Piezoresistive sensing elements are designed and simulated by performing coupled field analysis using COMSOL Multiphysics. Simulation results reveal that piezo resistive square type pressure sensors have high sensitivity in a wide range of pressures.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"10 1","pages":"215-220"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83634464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421918
N. Jayasooriya, S. Bandara
At present, majority of traffic management initiatives are mostly based on trial and error procedures, where no proper traffic theory or simulations are involved. When considering the context of Sri Lanka, the use of traffic simulation software has been the newest addition for the traffic engineering field. However, the outputs obtained from VISSIM traffic simulation software can become unrealistic, if no proper calibration is conducted for the local context. Therefore, the aim of the research is to develop a calibration procedure and identify representative values for parameters required for VISSIM micro simulation software to suit the local Condition. Based on the findings of the literature review, 9 key parameters were identified for calibration purposes of VISSIM, which are further reduced to 5 key parameters based on the sensitivity using statistical tools. These 5 parameters were further simulated in order to identify optimum input values, resulting in minimum percentage error for the difference between observed and simulated queue lengths. The calibrated parameters were successfully validated using 23 signalized intersections in Colombo and Gampaha Districts and these parameter values can be used in future traffic and transportation micro simulation studies.
{"title":"Calibrating and Validating VISSIM Microscopic Simulation Software for the Context of Sri Lanka","authors":"N. Jayasooriya, S. Bandara","doi":"10.1109/MERCON.2018.8421918","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421918","url":null,"abstract":"At present, majority of traffic management initiatives are mostly based on trial and error procedures, where no proper traffic theory or simulations are involved. When considering the context of Sri Lanka, the use of traffic simulation software has been the newest addition for the traffic engineering field. However, the outputs obtained from VISSIM traffic simulation software can become unrealistic, if no proper calibration is conducted for the local context. Therefore, the aim of the research is to develop a calibration procedure and identify representative values for parameters required for VISSIM micro simulation software to suit the local Condition. Based on the findings of the literature review, 9 key parameters were identified for calibration purposes of VISSIM, which are further reduced to 5 key parameters based on the sensitivity using statistical tools. These 5 parameters were further simulated in order to identify optimum input values, resulting in minimum percentage error for the difference between observed and simulated queue lengths. The calibrated parameters were successfully validated using 23 signalized intersections in Colombo and Gampaha Districts and these parameter values can be used in future traffic and transportation micro simulation studies.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"42 1","pages":"494-499"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81669934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421931
H.V.R.L. Gunasekara, Yapa Mahinda Bandara
Concession has been acknowledged as an important tool for port authorities to retain control of ports by contracts out the management and operation to the private sector for a specific time period [1]. This study focuses on developing a model to measure the concessionaire impact on port performance and efficiency using the pre and post privatization data. Parameters such as Crane rate, Elapsed rate, Total TEU and Ships handled were used as variable for the assessment and the secondary data were collected from a website of Australian government. The statistical report called ‘Waterline’ provides the latest data available on stevedoring productivity and landside performance of five Australian major port terminals for the period of 1990 to 2007. The samples were drawn as panel data by indicating 90 observations to test the model. The collected data was analyzed using Multiple Regression analysis and “Minitab 16” as the analytical software. Analysis revealed a continuous improvement in the developed model and the findings of the research indicated that crane rate of ports with the concessionaire are higher than that of ports without concessionaire while that value of Elapsed rate was lower than that. From observation in this study, a decision can be made that the increased trend in transferring government port operations and asset to the private sector suggests that public ports can benefit from greater private sector participation than fully privatization.
{"title":"Assessing Impact of Concessionaires on Sea Ports","authors":"H.V.R.L. Gunasekara, Yapa Mahinda Bandara","doi":"10.1109/MERCON.2018.8421931","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421931","url":null,"abstract":"Concession has been acknowledged as an important tool for port authorities to retain control of ports by contracts out the management and operation to the private sector for a specific time period [1]. This study focuses on developing a model to measure the concessionaire impact on port performance and efficiency using the pre and post privatization data. Parameters such as Crane rate, Elapsed rate, Total TEU and Ships handled were used as variable for the assessment and the secondary data were collected from a website of Australian government. The statistical report called ‘Waterline’ provides the latest data available on stevedoring productivity and landside performance of five Australian major port terminals for the period of 1990 to 2007. The samples were drawn as panel data by indicating 90 observations to test the model. The collected data was analyzed using Multiple Regression analysis and “Minitab 16” as the analytical software. Analysis revealed a continuous improvement in the developed model and the findings of the research indicated that crane rate of ports with the concessionaire are higher than that of ports without concessionaire while that value of Elapsed rate was lower than that. From observation in this study, a decision can be made that the increased trend in transferring government port operations and asset to the private sector suggests that public ports can benefit from greater private sector participation than fully privatization.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"155 1","pages":"276-281"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79776565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421991
D. Amarasinghe, D. Attygalle, S. Weragoda, Roshan Dodampola, S. Dehipawala
Integrated photonics will play an important role in future technologies and the advancement of optical integrated circuits (OICs) is unquestionably dependent on the ability to develop compact and reliable optical components at low cost. Here the authors investigate, the technological viability of a novel technology that has the potential to fabricate functional optical components and integrated them into miniaturized circuits. Three-dimensional refractive index patterns printed on porous vycor glass can be stabilized through consolidation of the glass matrix. The refractive index difference between low and high index regions or the refractive index contrast, is a key decider of the efficiency of those functional optical components. This paper discusses the 3D index contrast variations of photo-lithographically constructed volume Bragg gratings and their index contrast variation at the low and high index interface region. The study also examines the effect of matrix consolidation on the index pattern resolution.
{"title":"Investigation of 3D Refractive Index Contrast Variations in PVG Based Photo Printed Passive Optical Integrated Circuit Components.","authors":"D. Amarasinghe, D. Attygalle, S. Weragoda, Roshan Dodampola, S. Dehipawala","doi":"10.1109/MERCON.2018.8421991","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421991","url":null,"abstract":"Integrated photonics will play an important role in future technologies and the advancement of optical integrated circuits (OICs) is unquestionably dependent on the ability to develop compact and reliable optical components at low cost. Here the authors investigate, the technological viability of a novel technology that has the potential to fabricate functional optical components and integrated them into miniaturized circuits. Three-dimensional refractive index patterns printed on porous vycor glass can be stabilized through consolidation of the glass matrix. The refractive index difference between low and high index regions or the refractive index contrast, is a key decider of the efficiency of those functional optical components. This paper discusses the 3D index contrast variations of photo-lithographically constructed volume Bragg gratings and their index contrast variation at the low and high index interface region. The study also examines the effect of matrix consolidation on the index pattern resolution.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"119 1","pages":"517-521"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78544613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-01DOI: 10.1109/MERCON.2018.8421989
G. Perera, R. Rajapakse
Water resource management has become vital with the increase of demand for fresh water and modelling of ungauged basins under the conditions of data scarcity has always been a challenge. The two-parameter (2-P) and four-parameter (4-P) models have been used in this study to simulate the response of two river basins Maha Oya and Kelani River in Sri Lanka in an attempt to investigate the potential of these lumped parameter models. Both daily and monthly rainfall and streamflow data sets have been used to evaluate the model performance. Two key performance indices, Pearson Correlation Coefficient (PC) and Mean Relative Error (MRE) have been used as objective functions to compare goodness of fit of the observed and simulated streamflow. The two models were calibrated and validated for 2011~2014 and 2008~2010 periods, respectively. Based on the comparison of the results, it was found that the 4-P model provides a greater accuracy for the evaluation of the streamflow of the two selected river basins with a PC > 0.75 in both basins with both daily and monthly data. Even the 2-P model provided results with PC > 0.70 when used with monthly and daily data and within the acceptable range.
{"title":"Daily and Monthly Lumped Parameter Hydrologic Models for Analysis of Small Watersheds in Sri Lanka","authors":"G. Perera, R. Rajapakse","doi":"10.1109/MERCON.2018.8421989","DOIUrl":"https://doi.org/10.1109/MERCON.2018.8421989","url":null,"abstract":"Water resource management has become vital with the increase of demand for fresh water and modelling of ungauged basins under the conditions of data scarcity has always been a challenge. The two-parameter (2-P) and four-parameter (4-P) models have been used in this study to simulate the response of two river basins Maha Oya and Kelani River in Sri Lanka in an attempt to investigate the potential of these lumped parameter models. Both daily and monthly rainfall and streamflow data sets have been used to evaluate the model performance. Two key performance indices, Pearson Correlation Coefficient (PC) and Mean Relative Error (MRE) have been used as objective functions to compare goodness of fit of the observed and simulated streamflow. The two models were calibrated and validated for 2011~2014 and 2008~2010 periods, respectively. Based on the comparison of the results, it was found that the 4-P model provides a greater accuracy for the evaluation of the streamflow of the two selected river basins with a PC > 0.75 in both basins with both daily and monthly data. Even the 2-P model provided results with PC > 0.70 when used with monthly and daily data and within the acceptable range.","PeriodicalId":6603,"journal":{"name":"2018 Moratuwa Engineering Research Conference (MERCon)","volume":"51 1","pages":"372-377"},"PeriodicalIF":0.0,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78288649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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