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Characteristics of Narrow Bipolar Pulses observed from lightning in Sri Lanka

Gunasekara, T.; Fernando, M.; Sonnadara, D.U.J.; Cooray, V. (2016)

Century Scale Climate Change in the Central Highlands of Sri Lanka

De Silva, J.; Sonnadara, D.U.J. (2016)

ABSTRACT An analysis of century scale climate trends in the central highlands of Sri Lanka is presented. Monthly rainfall and temperature records of the period 1869 – 2006 from five climatological stations were analyzed. ...

Simulation of optical flow and fuzzy based obstacle avoidance system for mobile robots

Illeperuma, D.G.; Sonnadara, D.U.J. (2015)

Honey bees use optical flow to avoid obstacles effectively. In this research work similar methodology was tested on a simulated mobile robot. Simulation framework was based on VRML and Simulink in a 3D world. Optical ...

Evaluation of Downscaled Climate Projections over Sri Lanka

Thevakaran, A.; McGregor, J.L.; Katzfey, J.; Thatcher, M.; Suppiah, R.; Sonnadara, D.U.J. (IPSL, 2015)

This study presents an assessment of the Conformal Cubic Atmospheric Model downscaled climate projections at 8 km spatial resolution which are forced by sea surface temperature and sea ice concentration of three global ...

Automated Rain Sampler for Real time pH and Conductivity Measurements

Weerasinghe, R.; Pannila, A.S.; Jayananda, M.K.; Sonnadara, D.U.J. (IPSL, 2015)

To monitor the acidity of rain water in real time, a rain water sampling system was developed. The rain sampler detects the initial rain after a dry spell and collects a water sample. Before performing the measurements, ...

The onset, retreat and the length of growing season in the north-eastern region of Sri Lanka

Sonnadara, D.U.J. (John Wiley & Sons, Ltd., 2015)

Traffic composition and variability of road traffic noise levels in the vicinity of Colombo, Sri Lanka

Kalansuriya, C.M.; Pannila, A.S.; Sonnadara, D.U.J. (NSF, 2015)

Abstract: A study was conducted to determine the contribution of different types of vehicles to road traffic noise levels. Measurements were carried out on three different categories of roads at six separate locations, ...

Interannual variability of precipitation in Sri Lanka

Jayawardene, H.; Jayewardene, D.R.; Sonnadara, D.U.J. (2015)

Abstract: Two different spectral analysis methods, the multitaper method (MTM) and the maximum entropy method (MEM) were applied to investigate the presence of low-frequency periodicities in precipitation records of ...

Fractal dimension of long electrical discharges

Amarasinghe, D.; Sonnadara, D.U.J.; Berg, M.; Cooray, V. (Elsevier, 2015)

A Markov chain probability model to describe wet and dry patterns of weather at Colombo

Sonnadara, D.U.J.; Jayewardene, D.R. (Springer, 2015)

High speed optical observations of cloud flashes

Vayanganie, S.P.A.; Fernando, M.; Sonnadara, D.U.J.; Perera, D.C.; Cooray, V. (2014)

Abstract—Luminosity variations of natural cloud lightning channels were studied using high speed video recordings in Sri Lanka in the tropic. Five cloud flashes were selected for the study, which were recorded with 5000 ...

Electric field signatures of narrow negative bipolar pulse activities from lightning observed in Sri Lanka

Gunasekara, T.A.L.N.; Mendis, U.; Fernando, M.; Sonnadara, D.U.J.; Cooray, V. (2014)

- Isolated Narrow Bipolar Pulses (NBP) have been observed in the past in sub tropical and tropical regions. This study presents detail electric field characteristics of NBP pulses observed in Sri Lanka in the tropic. ...

A Markov chain probability model to describe wet and dry patterns of weather at Colombo

Sonnadara, D.U.J.; Jayewardene, D.R. (Springer Vienna, 2015)

The hypothesis that the wet and dry patterns of daily precipitation observed in Colombo can be modeled by a first order Markov chain model was tested using daily rainfall data for a 60-year period (1941–2000). The probability ...

Estimating separability of magnetisation signals by fast implementation of Bloch equation simulations across multiple tissues and distance correlation function

Iddagoda, M; Jayaweera, H H E; Wansapura, J (Faculty of Science, University of Kelaniya, Sri Lanka, 2020)

Magnetic Resonance Fingerprinting (MRF) is an emerging field in Magnetic Resonance Imaging (MRI) where tissues to be identified are subjected to a series of magnetic pulses. The resulting magnetisation signal is governed ...

Calibration of the rolling angle of a Quadrant Photo Detector mounted in the image plane of a dark-field passive LIDAR system

Abeywickrama, S S; Perera, H E; Jayaweera, H H E (Faculty of Science, University of Kelaniya, Sri Lanka, 2020)

Passive Light Detection and Ranging (LIDAR) has successfully been used for observing insects and their activities. It was reported that such techniques are more efficient compared to traditional approaches. Quadrant Photo ...

Implementation of a wireless distributed node-based system for monitoring, controlling and data logging of a Parabolic Trough Concentrator

Viraj, M P S; Perera, H E; Kumara, P D C; Jayaweera, H H E (Faculty of Science, University of Kelaniya, Sri Lanka, 2020)

Solar thermal energy harnessing through a Parabolic Trough Concentrator (PTC) type plant is the most efficient and cheapest technique in the field of renewable energy harnessing. Near real time performance monitoring and ...

Use of Google Earth Engine to monitor surface water: A case study in water tanks located in the dry zone of Sri Lanka

Perera, H. E; Jayaweera, H H E (Faculty of Science, University of Kelaniya, Sri Lanka, 2020)

Water is a valuable and limited resource that needs to be managed properly. The amount of surface water changes over time due to a variety of reasons including rainfall, temperature, wind patterns and agricultural usage. ...

High speed optical observations of cloud flashes

SPA Vayanganie; Mahendra Fernando; Sonnadara, D.U.J.; DC Perera; Vernon Cooray (IEEE, 2014)

Abstract—Luminosity variations of natural cloud lightning channels were studied using high speed video recordings in Sri Lanka in the tropic. Five cloud flashes were selected for the study, which were recorded with 5000 ...

Electric field signatures of narrow negative bipolar pulse activities from lightning observed in Sri Lanka

T.A.L.N. Gunasekara; U. Mendis; M. Fernando; Sonnadara, D.U.J.; V. Cooray (IEEE, 2014)

Abstract - Isolated Narrow Bipolar Pulses (NBP) have been observed in the past in sub tropical and tropical regions. This study presents detail electric field characteristics of NBP pulses observed in Sri Lanka in the ...

An assessment of the impacts of Sri Lanka’s Programme for School Improvement on students’ academic progress

Aturupane, H.; Glewwe, P.; Ravina, R.; Sonnadara, D.U.J.; Wisniewski, S. (Taylor & Francis, 2014)

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