D. P. P. Meddage

Dr. D. P. P. Meddage


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 May 2022 in Buildings
Verified
Journal Article
Open access
PDF file
DMD. P. P. Meddage
D. P. P. Meddage
Imesh Udara EkanayakeImesh Udara Ekanayake
Imesh Udara Ekanayake
UPUdara Sachinthana Perera
Udara Sachinthana Perera
Hazi Mohammad AzamathullaHazi Mohammad Azamathulla
Hazi Mohammad Azamathulla
MSMd Azlin Md Said
Md Azlin Md Said
Upaka RathnayakeUpaka Rathnayake
Upaka Rathnayake
Conventional methods of estimating pressure coefficients of buildings retain time and cost constraints. Recently, machine learning (ML) has been successfully established to predict wind pressure coefficients. However, regardless of the accuracy, ML models are incompetent in providing end-users’ confidence as a result of the black-box nature of predictions. In this study, we employed tree-based regression models (Decision Tree, XGBoost, Extra-tree, LightGBM) to predict surface-averaged mean pressure coefficient (Cp,mean), fluctuation pressure coefficient (Cp,rms), and peak pressure coefficient (Cp,peak) of low-rise gable-roofed buildings. The accuracy of models was verified using Tokyo Polytechnic University (TPU) wind tunnel data. Subsequently, we used Shapley Additive Explanations (SHAP) to explain the black-box nature of the ML predictions. The comparison revealed that tree-based models are efficient and accurate in wind-predicting pressure coefficients. Interestingly, SHAP provided human-comprehensible explanations for the interaction of variables, the importance of features towards the outcome, and the underlying reasoning behind the predictions. Moreover, SHAP confirmed that tree-based predictions adhere to the flow physics of wind engineering, advancing the fidelity of ML-based predictions.

23 April 2022 in Fluids
Verified
Journal Article
Open access
PDF file
Randika Kalpa MakumburaRandika Kalpa Makumbura
Randika Kalpa Makumbura
DMD. P. P. Meddage
D. P. P. Meddage
Hazi Mohammad AzamathullaHazi Mohammad Azamathulla
Hazi Mohammad Azamathulla
Manish PandeyManish Pandey
Manish Pandey
Upaka RathnayakeUpaka Rathnayake
Upaka Rathnayake
Surface water quality is degraded due to industrialization; however, it is one of the widely used sources for water supply systems worldwide. Thus, the polluted water creates significant issues for the health of the end users. However, poor attention and concern can be identified on this important issue in most developing countries, including Sri Lanka. The Kelani River in Sri Lanka is the heart of the water supply of the whole Colombo area and has the water intake for drinking purposes near an industrialized zone (Biyagama). Therefore, this study intends to analyze the effect of industrialization on surface water quality variation of the Kelani River basin in Sri Lanka in terms of the water quality index (WQI). We proposed a regression model to predict the WQI using the water quality parameters. Nine water quality parameters, including pH, total phosphate, electric conductivity, biochemical oxygen demand, temperature, nitrates, dissolved oxygen, chemical oxygen demand, and chlorine evaluated the Kelani River water quality. The proposed regression model was used to examine the water quality of samples obtained at twelve locations from January 2005 to December 2012. The highest WQI values were found in Raggahawatte Ela throughout the 8 years, located near the Biyagama industrial zone. The relationship of industries to water quality in the Kelani River is stated. The surface water quality gradually decreased as a result of development and industrialized activities. Therefore, this work showcases and recommends the importance of introducing necessary actions and considerations for future water management systems.