ERU Research Symposium 2009: Accepted Papers

Dynamics of Four Legged Multipurpose Rope Climbing Robot
"N.D Hewapathirana, L. Uddawatta, and T. Nanayakkara "
Legged vehicles can walk on rough and uneven surfaces with a high degree of softness. This is one of the key reasons why legged machines have received more attention by the scientific community. The second fact is minimizing the overall cost for the practical usage of the robot to increase the applicability in various scenarios. This paper focuses on construction of a four legged multipurpose rope climbing robot and methods used to minimize the cost for the robot implementation.
Programmable Fault Path Indicator for Power Distribution Networks
"Narendra De Silva, Sisil Kumarawadu , Selvarasa A., Ratnayaka S.R.M.C.D., Ranawaka D.M.D., Kankanamge T.N. "
The increase in electricity demand and expansion of transmission and distribution system is leading to a more complex electrical network. As a result of complex networks, fault identification takes a longer time posing a disadvantage to both the utility and the consumer. The design of fault path indicator gives the fast indication of faults. The main objective is to identify and indicate the faulty segments of 11 kV overhead line distribution systems and inform the relevant people for fault clearance effectively and immediately. Fault path indicator is a flexible device and can be adapted to any network condition. The device indicates the fault condition in itself and notifies the central monitoring center.
De Silva
Power Electronic Starter for Wound Rotor Induction Motors
"W.H.I.D. Soysa, J.P. Karunadasa "
This paper presents a rotor based power electronic starter for a wound rotor three phase induction motor. The study was done for a 11kW motor and the successfulness of proposed starter was evaluated using Matlab-Simulink simulations, prior to the construction.
High Pulse Thyristor Converter for HVDC Applications
"L. B. Perera, J. P. Karunadasa, B.M.D.Perera, K.P.S.D.Perera, P.A.G.S.De Silva, M.C.Jayarathne "
Designing, simulation and implementation of a scaled down model of a High Pulse Thyristor ac / dc Current Source Converter (CSC) for HVDC applications based on a new concept of Multi Level Current reinjection are discussed. The fundamentals of the reinjection concept is discussed briefly which lead to the derivation of the ideal reinjection waveform for complete harmonic cancellation and approximations for practical implementation. Simulation analysis, implementation procedures, practical issues faced and the conclusions are comprehensively discussed.
High Pulse Voltage Source Inverter for Standalone Renewable Energy Systems
L.B Perera, J.P Karunadasa, K.A.P Chathuranga, D.M.K.M. Premathilake,I.N.W. Rathnayake and K.N. Senarathne
Designing, simulation and implementation of a 3kVA, 36 pulse voltage source inverter for standalone renewable energy systems based on the new concept of multi level voltage reinjection is discussed. Introduction to the inverters used in standalone energy systems, the concept of reinjection, power stage design and component selection, simulation analysis, control circuit design and the implementation procedure, practical issues faced and the conclusions are comprehensively discussed.
"Design and Development of Dye-sensitized Organic Semi Conductor Based Photo Electric System Utilizing Nanotechnology for Low Cost and Efficient Conversion of Solar Energy to Electricity "
C.I.F. Attanayake, B.A.J.K. Premachandra, A.A.P. De Alwis and G.K.R. Senadeera
Preliminary investigations on the identification of natural pigments in the dye-sensitization of nanocrystalline n-type TiO2 were carried out. Fresh extracts of Mangoostein, Rabutan, Mango, Tomato, Carrot, King coconut, Pumpkin, Red Bannana, and Beet root were employed as sensitizers in thin-layer sandwich-type photoelectrochemical solar cells. The dye extract obtained from the Mangoostein fruit showed better performances than the others.
Comparison of Heavy Metal Adsorption Using Bacterial Cellulose and Modified Bacterial Cellulose
"N.S Gamage, S.G Walliwala, T.R Dharmasena, F.M.Ismail, and A.A.P.De Alwis "
Adsorbent materials derived from various sources have been used to treat wastewater that is contaminated with heavy metals. Bacterial Cellulose (BC) is one such material that has the potential to use as an adsorbent. BC and modified BC (CM-BC) were examined for the removal of copper ions from aqueous solutions. CM-BC adsorbent proved to be a better adsorbent for copper ions in solution compared to BC.
Mathematical Modeling of Extraction of Chlorophyll from Alternanthera sessilis Cultivated in Sri Lanka
"M.A.M. Jinasena, D.M.M.B. Dissanayake, A.D.U.S. Amarasinghe, B.M.W.P.K. Amarasinghe, M.A.B. Prashantha "
Mass transfer modeling was used to study the extraction efficiency and the effect of temperature on solvent extraction of chlorophyll from. Alternanthera sessilis, which is a leafy vegetable cultivated in tropics and subtropics. Aqueous acetone with 80% (v/v) was used as the solvent and the chlorophyll concentration was analyzed spectrophotometrically. The experimental results were in good agreement with the model data for temperatures below 30°C. The degradation of chlorophyll beyond 30°C was found to be significant.
Study the Effect of Temperature on Extraction of Chlorophyll from Alternanthera sessilis cultivated in Sri Lanka
"M.A.M. Jinasena, A.D.U.S. Amarasinghe, B.M.W.P.K. Amarasinghe, M.A.B. Prashantha "
The effect of temperature on extraction of chlorophyll from Alternanthera sessilis cultivated in Sri Lanka was studied using buffered 80% aqueous acetone as the solvent. The yield increased with the increase of temperature up to 40ºC. At temperatures above 40ºC, the degradation of chlorophyll during the extraction was significant.
Comparison of Mechanical Oil Extraction vs. Solvent Extraction for Jatropah curcas
"S.H.P. Gunawardena, P. Jayasinghe, D. Hewa Walpita "
Jatropha curcas oil was found to be a good source for biodiesel the production. The effect of particle size and the temperature of Jatropha seeds on the extractability of oil were investigated in laboratory scale by mechanical pressing and solvent extraction. The results showed that the solvent extraction method is superior to mechanical pressing and expelling and a good oil yield can be obtained. Oil yield in both solvent extraction and manual pressing is high when the particle size is small and also when the seed particles are subjected to heat. However, cost of solvent extraction and the risk of operation are the limiting factors.
Possibility of Using Waste Vegetable Oil as a Biodiesel Raw-Material
D.R.S. Hewa Walpita, P.R.A.U. Sampath, S.P.A.G.L. Samarakoon, F.M.Ismail and S.H.P. Gunawardena
WVO can be successfully and economically converted into biodiesel using a simple conversion process. The biodiesel produced using WVO shows physical properties which are compatible to those of standard biodiesel, and shows the possibility of using it in a conventional diesel engine.
Development of Adhesives from Rice and Cassava Starch
"H.S. Bhagya Manjaree, Sanja Gunawardena, Marliya Ismail "
A comparative study of the use of rice and cassava starches for the production of adhesives was investigated. Viscosity and tensile measurements were examined with varying alkali concentrations and the effect of standing time was also tested. Although rice starch based adhesives showed better adhesion characteristics than cassava starch, viscosity stability of rice starch based adhesives have to be improved further.
Synthesizing and Characterization of Alkyd Resins Using a Blend of Soya Oil (Glycine max) and Karawila Seed Oil (Momordica charantia) Cultivated in Sri Lanka
S.H.U.I. De Silva, B.A.J.K. Premachandra, A.D.U.S. Amarasinghe and M.A.B. Prashantha
The effectiveness of the blending of karawila seed oil with soya oil on the drying characteristic of the alkyd resins was studied. Monoglyceride process was used to synthesize the alkyd resins. The film properties of the alkyd resins were examined to find the optimum ratio of karawila oil to soya oil. A desired pencil hardness of 3H and a low drying time of 186 minutes were rendered for the blend of 30% karawila seed oil in soya oil
De Silva
Synthesizing and Characterization of Alkyd Resins Using a Blend of Nahar Seed Oil and Karawila Seed Oil
M.D.Y. Milani, J.K. Premachandra, A.D.U.S. Amarasinghe and M.A.B. Prashantha
Blend of Nahar (Mesua ferrea) seed oil and Karawila (Momordica charantia) seed oil (50:50 w/w %) as a potential source of fatty oil for manufacturing air drying long oil alkyd resins was investigated. The film properties of the alkyd resins prepared using different OH/COOH ratios were examined. Excellent set to touch and dry to touch drying times were observed for low OH/COOH ratios. However, chemical resistance was improved with the increase of OH/COOH ratio. Hardness, clarity and flexibility properties were comparable with the industrial reference and were not significantly varied with OH/COOH ratio.
Design of an Industrial Scale Biofiltration System
A J. Wijayawardhana, S.L.J. Wijekoon, S. Walpolage and A.D.U.S. Amarasinghe
An industrial scale waste gas treatment system was designed and constructed at a Tobacco Processing Factory. The treatment system consisted of three units namely: condenser, scrubber and bio filter, the latter acting as the major unit of the system. The major constituents of the foul smelling gas were found to be ammonia ( 400 – 500 ppm (v/v)) and hydrogen sulfide (> 100 ppm (v/v)). Complete removal of hydrogen sulfide and 95% removal of ammonia were achieved.
Full Scale Bio Filter Ammonia Removal Performance During Filter Maturation
A.J Wijayawardhana, S.L.J. Wijeyekoon, S. Walpalage and A.D.U.S. Amarasinghe
An industrial bio filter of 23 m3 in capacity, packed with a coconut fiber filter medium inoculated with compost of 12 m3 in volume was operated for a period of 45 days. Performance was monitored at gas flow rates of 1160 m3h-1 to 2100 m3h-1 to identify the removal efficiencies under varying conditions during filter maturation. Maximum elimination capacity of 5.9 gm-3h-1 was reached for an inlet loading of 1.8 gm-3h-1 for ammonia. Filter maturation periods were unexpectedly very short due to initial physical adsorption.
Comparative Performance of Bio Filter Packing Materials for Waste Gas Treatment
A J.Wijayawardhana, S. L. J.Wijeyekoon, S.Walpalage, A.D.U.S.Amarasinghe
A study was conducted to evaluate the removal efficiency of NH3 and H2S emitted from an industrial waste gas source by biofiltration. Four types of packing material were used and NH3 and H2S in the contaminated air stream ranged between 43-90 ppm and 70-100 ppm respectively. The experiments were carried out over an effective period of 45 days. Results indicate that 100% removal efficiencies of NH3 and H2S can be achieved for coconut fiber/tobacco compost and peat/wood chips mediums.
Chemical Recycling of PET from Waste Soft Drinks Bottles to Recover Terephthalic Acid.
"Udayakumara S.V., Gunapala P.Y., Gunapala O. "
This project aims to develop an efficient and low cost chemical recycling method to extract valuable terephthalic acid (TPA) from post consumer Poly (ethylene Terephthalate) ( PET) in Sri Lanka. PET waste from soft drink bottles was subjected to alkaline hydrolysis using NaOH to produce sodium terephthalate. Reaction was carried out under different hydrolysis conditions including varying Ethylene glycol to PET ratios, reaction temperature and time. After completing the reaction, mixture was diluted with sulfuric acid to precipitate TPA that was separated by filtration. Characterization and identification of purified TPA were performed using Fourier Transformation Infrared techniques.
Hydrodynamic Modelling for Stormwater Management for River Basin Planning: A Case Study of Welipenna River
" G.A.I.R.K Galhena and N.T.S Wijesekera "
Storm induced flash floods are very common in southern part of Sri Lanka especially in South-Western monsoon. The situation is more severe in Welipenna River, which faces around five major floods per annum. A model developed by HEC-RAS one dimensional hydrodynamic model with field assessment results and hydrologic analysis results was used to evaluate the stormwater management options. Furthermore, same model was used to assess the probable development scenarios Model results shows that calibration error was 35% and increasing the bridge span by one meter can reduce the water surface elevation by 3mm for spans of 50m to 100m.
Synthesis and Characterization of Stoving Alkyd Resin Based on Oil Blend of Karawila Seed Oil and Coconut Oil
D.K.B. Vitharana, J.K Premachandra, A.D.U.S. Amarasinghe and M.A.B. Prashantha
An alkyd/melamine resin mixture is the usual composition for the preparation of coating called Baking enamel or Stoving enamel cured through functional groups of the resin. This research focused on novel modified stoving alkyd resins having improved properties such as Film hardness, Adhesion and Gloss which are synthesized using blends of coconut oil and karawila seed oil. The alkyd resins were synthesized using monoglyceride process. The desired pencil hardness of 8H was obtained with the 10% of karawila seed oil blended with coconut oil.
Nutrient enrichment in Colombo Flood Detention Area wetlands
"S.Sharmili, M.N. Hettiararchchi, A.A.P. De Alwis "
Wetlands often serve as nutrient sinks, Wetlands microorganisms and wetlands plants; serve as environmental filters by trapping impurities such as toxins and excessive nutrients as water flows through the wetlands system. Although wetlands remove nutrients from inflows, the nutrients, once in the wetland, can cause substantial changes to the biological assemblages as well as to the overall functioning of the system. Although the term “enrichment” usu¬ally has positive connotation, it is causing substantial ecologi¬cal and economic problems across the Nation.
Prediction of Flexural Bond in Reinforced Concrete
I.R.A Weerasekera, A. A.D.I. Rasikamal, J.P.S. Chandrasiri and R.R. Attanayake
A method to forecast bond stresses by accounting for tension transmitted across radial cracks is presented. This phenomenon is known as cohesive cracking. When steel and uncracked concrete are present they are treated as isotropic materials. Concrete however behaves as an anisotropic material after radial cracks develop. Several factors are identified as parameters influencing bond stresses. Among them axial force in steel, area of the bar, concrete strength, and confinement are important. Results based on proposed method are discussed under a variety of practical situations.
Evaluation of Shear Design Procedures for Reinforced Concrete Beams without Shear Reinforcements
W.K.H.R.E. Wickramage and I.R.A. Weerasekera
Many structural concrete beams have been constructed without transverse reinforcements. The main objective of this paper is to review design procedures for slender beams. Five major codes namely: ACI, CSA, BS, Australian, Japanese and a procedure based on Shear Friction are considered. More than 500 slender beams without transverse reinforcements which have been exhumed from literature were used for the evaluation. Parameters influencing the accuracy of each and every procedure were studied using a Multinomial Logistic Regression Analysis.
Development of a Rational Procedure for Shear Design in Structural Concrete
V. Sureshkumar and I.R.A. Weerasekera
"Shear design equations for reinforced concrete beams are mostly empirical and are based on test results. But some mathematical models have also been developed over the years. The pursuit for a better model which gives a clearer representation of shear carrying mechanism in beams is still on. This paper explains a method based on Cohesive Cracking as a new approach to this ongoing search. The proposed model is giving promising results when compared with key codes of practice. "
Structural Performance of Reinforced Cement Stabilized Earth Masonry (CSEM) Subjected by In-Plane Lateral Loads
"Y.N.N. Sanjeewa, C.S. Lewangamage, M.T.R. Jayasinghe "
Various techniques have been developed to reinforce masonry structures and each of these methods has their pros and cons. The objective of the authors was to develop a method which is best suited for conditions prevailing in Sri Lanka incorporating structural performance, cost and ease of construction. In this study Cement Stabilized Soil Block masonry was selected to be tested for seismic performance due to its interlocking nature and ease of installation of vertical reinforcement. A sample house of CSEM was analysed for seismic performance using a computer model and the critical areas in the structure were identified. A wall with an opening was identified as critical location; it was reinforced and tested under in-plane lateral loads. Final Comparisons were done to check performances.
Review on Flexible Pavement Design Guidelines
"T.Janaraj and W.K.Mampearachchi "
"The primary objective of this research is to identify the proper design guideline in terms of strength of the structure that enable to last longer life span. Field testing was conducted to check performance of selected pavement design using AASHTO and TRL Road Note 31 guidelines. Finite Element Model was developed and validated with field data to analyze the performance of different pavement designs. Validated model was used to evaluate the structural performance of AASHTO and RN 31 Designs for different ESAL and Subgrade support conditions. "
Design and Fabrication of Cable Bolt for Excavation in a Fractured Rock
"Y.L.C. Dhanawardana, H.D.P.M. Siriwardana, S.H. Henderson, H.M.C.P. Kumara, K.A.S. Indika, PGR Dharmaratne, HS Welideniya and LPS Rohitha "
Most often in fractured rock masses, large excavations have an unsupported stand-up times less than the minimum time required to support the roof after the excavation. During past few years a wide variety of dowels and bolt types have been developed but most of them failed within a short period of time and the cost were high. Main objective of this research work was to design rock bolts using discarded cables at a low cost. The bolt consists of nearly 1.6m long cable and 16 cm of anchored part. Field data illustrated the amount of load that the bolt can carry as 5 KN . Suggestions were made to improve the design, which will enhance bolt performance. Field tests carried out at Bogala Graphite Lanka Ltd proved that cable bolts are effective in Sri Lankan conditions.
"Study on Gas Transport and Water Retention in Maharagama Land fill Cover soil "
"R.H.K. Ranasinghe, U.P. Nawagamuwa , K. Kawamoto "
In Sri Lanka there are few controlled landfills available and usual procedure is covering the waste layer with a good soil as a final cover. The Soil gas diffusion coefficient (Dp) and Air Permeability (Ka) govern the transport and emission of gases in unsaturated zone. In this study, Dp and Ka in soil which was used to construct Maharagama landfill site cover filling at different soil water matric potential were measured. With the soil air content, it is found that, Dp monotonically increases and Ka gradually increases.
Evaluating Suitability of Soil Stabilization Methods for Local Road Construction Industry
H.M.S.M.Herath, M.A.W.Kumara
Soil stabilization is not using in local road construction industry in major scale. Various reasons affects to non popularity and initial part this paper presents the result of questionnaire survey among the professionals who practice in road construction industry. Soil Sample collected from different places, used to determine the engineering properties (Sieve Analysis, Liquid Limit (LL), Plastic Limit (PL), California Bearing Ration (CBR) and Unconfined Compressive Strength (UCS)). Same soil has being used to determine the properties after stabilizing according to the available guideline, with locally available stabilizers ( Cement and Lime).Laboratory test results indicates that both stabilizer improve soil properties in considerable amount. Suitable stabilized criteria and quality controlling measures is to be established.
Estimation of Skin Friction on Bored and Cast In-situ Concrete Piles in Sand
D. Mohotti, and H. S. Thilakasiri
Bored and cast in-situ piles in Sri Lanka are design as end bearing piles and the skin friction contribution is generally neglected. Results of the high strain dynamic load tests are presented to show that a significant skin friction capacity is developed on bored and cast in-situ piles. The distribution of the skin friction along the pile shaft, obtained from high strain dynamic testing of piles, is used to investigate the accuracy of the commonly used skin friction capacity estimation methods.
Faster and Bouncier Cricket Pitches using Locally Available Clays
"Nawagamuwa U.P., Senanayake A.I.M.J., Silva S.A. and Sanjeewa D.M.I "
Reasons for the lack of ‘pace & bounce’ in Sri Lankan pitches has been a topic of debate for a long time. In order to address this problem from an engineering perspective, soil samples from Test venue in Colombo were gathered, analyzed and then compared to available data from other countries. Local pitches were found to have high silt content, low clay content and low plasticity due to a difference in clay mineralogy. Small scale model pitches were built and then tested to find the effect of adding commercially available clays on the pitch characteristics.
Managing Construction Site Material Waste: Web-Based Tool
"L.L. Ekanayake, D.A.S. Samarasinghe, M.S.M. Shamih and W.H.A.J. Jayakody "
Sri Lanka is a developing country which has considerable expanding infrastructure development projects. Hence, construction industry generates lots of waste which cause a significant environmental and social impact. It has been found that the construction waste management can be effectively addressed through a reliable waste database system. Therefore, this study sought to develop an applicable measurement tool to record the level of wastage on construction sites and to propose a construction waste management plan for the city of Colombo with “Nation Waste Database” concept.
"Assessment of the Stormwater Drainage Engineering in Expressway Design A Hydrologic and Hydrodynamic Analysis of Colombo-Katunayake Expressway using Hydrodynamic Modelling"
V.A.N. Soysa and N.T.S. Wijesekera
Road designs need to forecast the hydrologic system performance in order to implement effective solutions for proper stormwater management. Field assessment and hydrologic analysis were carried out in Kalu Oya catchment (54.5 km2) for the input data requirement of the hydrodynamic model. A satisfactory hydrodynamic model was developed using HEC-RAS with a calibration error of 55% and a verification error of 46%. Verified model was used to sensitivity analysis and management scenario modeling for achieving optimum expressway and hydrologic design.
Review the Guidelines of Overlay Design For Flexible Pavements
A.M.A.N.Karunarathne, W.K.Mampearachchi
This primary objective of this research is to compare the overlay design guidelines and verify the feasibility of them on Sri Lankan road network. This is focus on overlay design procedures for the flexible pavements. The study included the collection of required traffic and deflection data in several categories of Sri Lankan road network. Deflection data is needed to obtain the remaining structural capacity (Effective Structural Number- SNeff¬) of the pavement and can be collected through the related departments in Sri Lanka. Sub-grade strength parameters were found using the field and lab CBR (California Bearing Ratio) experiment.The main advantage of this comparison is to identify the most suitable design procedure of required structural overlay thickness according to the several traffic categories of traffic in Sri Lankan road network.
Field Assessment for Stormwater Drainage Modelling in Expressway Design
W.M.D.U.Wijesuriya and N.T.S. Wijesekera
Field assessment is important for storm water drainage engineering in expressway design. Such designs are carried out using hydrologic and hydraulic modeling which involves use of a significant number of empirical equations and site specific parameters .In this work field assessment consisted of identifying river channel parameters, land use, terrain details and flood inundations. The present study describes a methodology to be used to estimate the order of magnitude of flood flows and to carry out systematic field survey.
Design of a Phase Lead-Lag Controller for Servo Motors
T. Muralidaran, K.M.A. Nuwanpriya, A.I. Nagasinghe, N.A. Neydorff
Servo motors are used in diverse industrial applications in the world today. The main feature of these applications is that they require precise position or velocity controlling. In this research, we have come up with a robust and accurate design tools to control and diagnose Servo motor systems using Phase Lead-Lag technique. This Development Kit has a Manual Controller Design Tool to design Phase Lead-Lag Controllers. There is also an Automatic Controller Design and Diagnosis Tool as well.
Voice Based Automated Guided Vehicle
S.P. Kumarawadu, G.Yogalingam, M.A.D.S.Bandara, P.K.Wickramaarachchi, U.L.A.J.D.Perera.
The objective in this research is to present Voice based control of vehicles as an alternative to conventional methods. This represents a great reduction in infrastructure cost and improves flexibility of the system. The expectation is that the system is scaled up to cater to industrial applications and future applications in smart vehicles. This paper provides an introduction to the whole project and the research areas considered. Then it goes on to describe the methodologies used and the suggestions for future extensions of the system.
Swing Leg Kinematics for the Bipedal Walking Robots
M.G.A.P. Abeyratne, S.M. Welihinda, L. Udawatta, and J.P. Karunadasa
In this paper we demonstrate how the Robotic Technology theories are applied to solve the real world problem in bipedal walking of robots. Since there has been an increasing interest in bipedal locomotion, the modeling of swing leg is much important. The rhythm of the bipedal walking mainly depends on swing leg kinematics and condition of the walking path. Nowadays, the most interesting robot locomotion is ramp walking. In this paper we derived kinematics only for upward walking. The kinematics for downward walking could be derived effortlessly utilizing the same approach with some modifications
Evaluation of Effects of Design Parameters for the Performance of Fixed Bladed Small Scale Vertical Axis Wind Turbines
K.A.B. Pathirathna, H.E.D. De Silva, K.K.M.N.P. Samaraweera
The purpose of the paper is to evaluate the effects of design parameters such as solidity, Renold number, aspect ratio etc. for the performance of fixed bladed vertical axis wind turbines. Here theoretical modeling was done and software was developed by Java. Theoretical modeling was based on multiple streamtube model which was derived by the blade element theory. Support arm losses and finite span effect were included to the theoretical modeling and results compared with the literatures.
Design and Development of a Payload Module for Rocket-borne Experiments for University Students (REXUS)
U.D.A.K. Ukwatta, U.P. Khangamage, P. Fernando
Sounding rockets are the most common medium that are used carry instruments to near space for various types of experiments such as microgravity experiments, upper atmospheric experiments etc. However, due to high acceleration and vibration occurred, most of the instruments tend to give inaccurate or imprecise results. Hence, there is a real need in developing a proper payload carrying unit, which can protect instruments from undesirable effects, in sounding rockets. This paper presents an improved design for a payload carrying module developed.
Detection of Vehicles using a Cascaded Classifier in Comparison to a Artificial Neural Network
Shehan Fernando, Lanka Udawatta
This paper describes the comparison of accuracy and performance of two machine learning approaches for visual object detection and tracking vehicles. The first is a neural network based approach. The classification was carried out with a multilayer feed forward neural network. The second approach is based on boosting It works by sequentially applying a classification algorithm to reweighed versions of the training data, followed by taking a weighted majority vote of the sequence of classifiers thus produced.
Mobile Healthcare Network and Distance Consulting on 3G
A. Amarasinghe, L.I.D. Kariyawasam, C.S. Rupasinghe, W.A.T. Ruwansiri and S.A.D. Dias
Continuous monitoring of patients is becoming increasingly important with the current progress of diagnosis and medical treatment techniques. When the available facilities and healthcare cost are considered, remote patient monitoring has the potential to relieve many inconveniences. To address this issue, a system has been developed, which has the ability to remotely view ECG, body temperature and stethoscope records of a patient. A hardware unit captures the signals bearing the above information, processes them appropriately and transfers to a mobile phone via Bluetooth. A mobile acquires this medical information and forwards them to a database via a mobile network. The patient or doctor can access the database using a web application which is developed as part of the system.
Comparison of Propagation Models for Fixed WiMAX System Based on IEEE 802.16-2004
K.C. Amarasinghe, K.G.A.B. Peiris, L.A.D.M.D. Thelisinghe, G.M. Warnakulasuriya and A.T.L.K. Samarasinghe
The study of empirical propagation models for mobile channels has been done extensively, but the applicability of those to a FWA System is not appropriately tested. The models include Hata-Okumura, COST231Hata, Walfisch-Ikegami and Erceg. From those, Erceg model seems to be the most suitable. In this paper field measurements are taken for the 3.5GHz Fixed WiMAX network in Katubedda, Sri Lanka. Those are used to validate the applicability of the above mentioned models in a Sri Lankan sub urban environment.
Software and Test Tool for Fixed WiMAX
K.C. Amarasinghe, K.G.A.B. Peiris, L.A.D.M.D. Thelisinghe, G.M. Warnakulasuriya and A.T.L.K. Samarasinghe
Planning and Optimizing IEEE 802.16d network need lot of effort and man power. In this paper we are presenting a tool which automates several aspects of these processes. This describes the hardware and the software components and telecommunication aspects of the design, and their integration as a complete system. A hardware tool is presented for gathering signal parameters at various location of the network for analyzing purposes. Measurements can be used to optimize the network to maintain better signal quality.
RFID Based Patient Identification and Management System
A.T.L.K Samarasinghe, A.A.C.N Athurugiriya, H.G.T.N Gamage, D.G Konara, W.A.P Suranjaya
The product provides a RFID based Patient Identification System to increase the efficiency and quality of the current hospital system. One of our main objectives is to avoid the misplacement or changing of Patient Record files and computerize the existing hospital management system currently used in Sri Lanka. This is a project that we are going to introduce as an efficient system for hospitals and done as a new product development.
Forecasting Critical Dry Spells in DL1 – A Case Study from Anamaduwa
S.C. Mathugama and T.S.G. Peiris
Daily rainfall data(1950-2005) in Anamaduwa were analysed and useful information on the lengths (LDS1-LDS4) and the starting dates (SD1-SD4) of four critical dry spells were obtained. The mean duration of LDS1- LDS4 were 37,35,46 and 50 days respectively. More than 75% of the fourth critical dry spell occurred prior to the period 12-18 December and continued up to 2-3 weeks in January. Regression models (p< 0.001) were developed to forecast starting dates of the second, third and fourth critical dry spells. Log normal distributions were fitted for the length of the four critical dry spells.
Measuring Volatility in Financial Data Series
This paper analyse relation between expected return and conditional variance, mainly whether it is time-varying or constant (and also linear). It is assumed that for specified period of time investors expect higher returns from assets with higher risk. However there is no agreement whether positive relation between expected returns and variance is 'dynamic'. Investment over short horizons may sometimes be influenced by portfolio balance and transaction cost consideration or by unexpected immediate consumption needs. All these factors may doubtful the risk and return relation in the short horizon. The risk and return relation may also be nonlinear or time varying. The author analyse this relation for 3 assets quoted on the Central Bank of Sri Lanka with the aim to provide additional insight into the nature of return volatility and its relation to expected returns. The GARCH(1,1) models with constant and time-varying parameter are implemented. For most assets there are no reasons to reject the hypothesis of no autocorrelation of returns. Observable higher serial correlations in portfolio returns are in agreement with the results of other investigations. According to the estimates of the parameters in the conditional variance, current information remains important for forecasts of the conditional variance for very long horizons.
Change Management in Lean Implementation: A Case Study in a Local Apparel Manufacturing Group
H.S.C. Perera, N.D. Abeytunge and G.D. Samarasinghe
Apparel industry is the main exporter and the contributor to the Sri Lankan economy. In order to stay competitive in the global market place, one major local apparel manufacturing group adopted lean manufacturing tool for its companies. The study explored how these apparel manufacturing companies managed the change process of transforming to a lean manufacturing culture. The study selected three companies of this group and adopted the case study method for investigating this situation. Based on the findings it developed a theoretical framework to understand how change process should be managed in implementing lean in the local apparel industry.
"Linking Supply Chain Management to Business performance: An empirical study on Sri Lankan firms"
K.C.S. Ekanayake and V.M. Wickramasinghe
Even though Supply Chain Management (SCM) has been identified as a strategic tool that expands a firm’s integrated behavior to incorporate customers and suppliers to be fully effective in today's competitive environment, so far very few companies have achieved this. As a result, the literature suggests seven strategic level activities that would gain increased performance by setting SCM in motion. Current research aimed to empirically validate this scenario by studying thirty Sri Lankan based firms while identifying industry best practices.
Prepaid Digital Energy Meter
A.T.L.K. Samarasinghe, L.L.S.I. Alwis, I.U. Perera, I.U. Samarathunga, M.K.L. Sandaruwan
Digital prepaid energy meter can be used to monitor the consumption of electricity in domestic needs and supports remote billing, recharging of account and web based account management functions. If the available credit is exhausted then the supply of electricity is automatically cut off by a relay. Therefore this leads to minimum human intervention and improved accuracy in the meter reading process. This product is low cost, reliable, easy to install and compact in design which makes this a marketable product.
FPGA-Based System-on-Chip Architecture for Real-Time Embedded Vision Systems
Mahendra Samarawickrama, Ajith Pasqual and Ranga Rodrigo
A single-chip FPGA implementation of a vision core is an efficient way to design fast and compact embedded vision systems from the PCB design level. The scope of the research is to design a novel FPGA-based parallel architecture entirely with on-chip FPGA resources. We designed it by utilizing block RAMs and IO interfaces on the FPGA. As a result, the system is compact, fast and flexible. We tested this architecture for spatial domain filtering algorithms using a Xilinx Virtex-2 Pro (XC2VP30) FPGA. Our algorithm uses a vision core with a 100 MHz system clock which supports image processing on a low-resolution image of 128×128 pixels up to 200 images per second. The results are accurate and fast as the fastest FPGA implementations reported to date. The performance of the algorithms could be substantially improved by applying sufficient parallelism.
Brain E-Learner
S. A. D. Dias, N. W. N. Dayananada, N. S. Ferdinand, K. Thivya, E. A. Udagedara, P.E. Weerathunga
The objective of this extended abstract is to present Brain e-Learning System which was developed and tested as a final year undergraduate project at the department of Electronic and Telecommunication Engineering, university of Moratuwa, Sri Lanka. The Brain e-Learning System is an integrated on-line system for remote education covering aspects of Medical Image Analysis, Remote patient monitoring, Video/Audio Conferencing and Brain E-Learning materials. It provides user-friendly web interface and optimized functionality with three different access levels: medical students, medical consultants and administrator.
Reinforcement of Natural Rubber Latex Films with Surface Modified Silica
N.M.V. Kalyani Liyanage, S. Walpalage, and M.C.W. Somaratne
The surface of silica particles was modified by treating with a polymer containing both hydrophilic and hydrophobic monomer units. Surface modification involved esterification of the surface hydroxyl groups with the carboxyl groups of the hydrophilic units of the polymer. Conversion of surface -OH groups to surface ester groups was confirmed by Fourier Transform Infrared Spectroscopy (FTIR). Tensile properties of natural rubber latex films containing modified silica fillers were compared with those of films containing unmodified filler and the outstanding reinforcing ability of surface modified filler was clearly evident.
The Effect of Dolomitic Lime and the Firing Temperature on the Properties of Pellets Produced from Dela Iron Ore
P.D.S.C. Dharmasiri, M.A. Aboonidhal, S.P. Guluwita, W.L.W. Fernando and R.G.N. De. S. Munasinghe
Iron ores and lime are two of the available raw materials in Sri Lanka for iron making. However, proven reserves of iron ore deposits in Sri Lanka have not been scientifically estimated as yet. There is no indication of the occurrence of coal deposits in Sri Lanka for the utilization to produce iron using the blast furnace. Therefore, it is important to investigate the possibility of producing high quality iron ore pellets using locally available resources for the utilization as a substitute for sponge iron, which is imported. In this study it is attempted to optimize the dolomitic lime content and firing temperature in producing high quality iron ore pellets.
"Reduction of Crack Susceptibility of Flash Butt Welded Joints in Rim Manufacturing"
S.P.K. Hewage, R.G.N. De S. Munasinghe
Flash butt welding is a well established and economical manufacturing process classified as a solid state welding process and mainly used in automobile wheel industry. The advantages of this process are economical in operation, suitable for mass production and high in joint strength. In contrast to that the major limitation is relatively high amount of scrap percentage due to welding cracks. This work is focus ed on the reduction of welding crack susceptibility of the flash butt welding joints in rim manufacturing. The parent material used was SS400 steel and it was found that with increasing advance velocity of the movable jaw will give better strength and ductility of the joints. In addition to that the reduction of welding time contributes to the refinement of the microstructure, which also contributes to a better quality of the joint.
Development of a Glazed Clay Body Suitable for Cookware
"J.T.S.T. Jayawardane, S.U. Adikary, U. Gunawardane "
Development of a glazed red clay cookware body with adequate thermal shock resistance was successfully done using locally available raw materials. Thermal compatibility of red clay and different fritted glazes were investigated using thermal expansion and thermal shock resistance of individual body/glaze components. Four clay body mixtures were prepared incorporating different proportion of quarts (10%, 20%, 30% and 40%) by dry weight to increase the thermal expansion and tested glazes. Suitable body compositions were selected and actual size cookware samples were fabricated and required properties were tested under actual domestic conditions. A kaolintic red clay body with 25% quartz having a coefficient of thermal expansion 60.31x10-7K-1 and thermal shock resistance 0.97kJm-1s-1 and the glazes having coefficient of thermal expansion in the range of (19-51) x 10-7 k-1 and thermal shock resistance in the range of (1.10-1.20) 97kJm-1s-1 could be effectively used to manufacture a glazed red clay cookware product.
Design of Conventional Extruder Die for Production of Semi Rigid PVC Pipe
O. Gunapala, P.Y.Gunapala,Uranga Tilakasena
The research was directed to design an extruder die for production of semi rigid poly-vinyl-chloride ( PVC) pipes widely used as an outlet pipe in washing machines, that are very popular not only at homes but in a number of factories located in Sri Lanka, belonging to certain industries including dyeing, protective clothing etc. Nevertheless extrusion dies for production of semi rigid pipes have been neither produced nor designed in Sri Lanka. Theoretical approach in the research project was based on rheology and thermodynamics of plasticized PVC melt that enabled design of the extrusion die considering the specialties of the selected material and processing limitations. The carried out research consisted of two parts. Firstly to come up with a general solution package that was used to derive the die dimensions when information about the input material and the expected output was given. Secondly, using the solution package to design the die for a special application of the desired dimensions. An Excel spread sheet was developed that embodied the theoretical aspects of the research project. Changing the indicated input parameters, spread sheet calculated and produced the dimension of the desired die. A sequence of calculations and AutoCAD diagrams were produced for the specific die requirements. With this information at hand, Sri Lankan industries can start manufacture of the extruder dies for production of plasticized PVC pipes on a good theoretical basis ensuring success, instead of importing .
Research on Motion Capture Technologies to Develop A Bionic Leg
V.P.C. Dassanayake, K.P.S. Dalpatadu, B.M.O. De Silva, A.N.E. Gamage
This paper explains how motion capture technology can effectively be used to detect, analyze and quantify human activities such as walking, standing, sitting and climbing stairs. This technology is expected to be used for active (eg: motor driven) knee replacements used by above knee amputees. A motion capture system is implemented using inertial sensors and force sensors which quantify gait parameters. The results are used to design a finite state control system for an active above knee prosthetic.
Control Platform for a Mobile Robot Team to Move in a Formation in an Indoor Environment
V.P.C. Dassanayake, D.S.De Z. Abeysiriwardena, S.W.H.M.T.D. Lalitharatne, K.A.A.P. Wimalarathne
The purpose of this paper is to explain the approach taken and results achieved in an attempt made to develop a mobile robot team which can move in formation in an indoor environment. A trilateration system is implemented using RF and ultrasonic signals for localization. Two PID control loops are used to maintain the formation parameters and control the driving motors.
Simulation of a Poly-Bag Manufacturing System
R.A.R.C. Gopura, T.S.S. Jayawardene and K.G.A.H. Amarasena
Poly bag manufacturing entrepreneurs face many challenges due to frequent fluctuation and continuous increasing trend of material prices of poly bags. Further legal restrictions imposed on some types of polythene products made the situation aggravated. With the purview of optimizing the poly bag manufacturing process, authors attempted to model and simulate the poly bag manufacturing process in the light of posed challenges. This paper presents a modeling method and a simulation study of a poly bag manufacturing system.
Development of an Efficient Drying Method for Large Scale Timber Drying
P.M.T.S.S. Bandara, B.M.H.S.K. Basnayake, D.M.M.C. Dissanayake and U.P. Kahangamage
The purpose of this paper is to elaborate on how to overcome the problematic issues the Sri Lankan timber drying industry is currently facing with and to assure the future sustenance of the industry. In order to achieve the desired outcomes a field survey and an energy audit were carried out. Using those results improvements to a selected conventional timber drying kiln were done. A conceptual energy efficient timber drying method suitable for the Sri Lankan industry was also developed.
Evaluate the Potential of Alternative Air Conditioning Systems in Place of Conventional Vapor Compression for Industrial Buildings in Sri Lanka
A.M.N.S. Abeynayake, A.M.A.B. Amarakoon, D.G.O. Weerasinghe
This research evaluates the potential of alternative air conditioning techniques for industrial buildings in Sri Lanka. In order to assess the applicability of selected alternatives, a life cycle cost analysis was performed for a selected case and alternatives. CO2 emissions from the air conditioning systems were calculated to assess the ecological feasibility. The results indicate that biomass fueled, vapor absorption system is a viable option compared with the conventional vapor compression system.
Development of Low Cost Evaporative Cooler Unit to Suit Industrial Environment
R.A. Attalage, G.P.T.K. Abeysekara, K.H.H.G. Ketanwila, K.A.P. Vithana
The purpose of this paper is to demonstrate the adaptability of evaporative cooling technology to Sri Lankan environment. Desiccant cooling technology is initiated to control the relative humidity level of the environment. A generic model of the evaporative cooler is constructed using direct evaporative cooling method and solid desiccant dehumidification method. The model was installed in the testing environment. The results show that the evaporative cooler is provided the sufficient level of thermal comfort to the people changing relative humidity slightly.
Challenges and Common Failures in Implementing Lean manufacturing
P. P. G. Vilasini
Lean is a management philosophy which delivers many benefits such as waste reduction, cycle time reduction, inventory reduction, improvement in quality, delivery in time, high customer satisfaction etc. But up to 80% Lean implemented programs will fail to achieve those benefits. However, many of the problems that lead to failure could be predicted and dealt with prior to the start of the improvement process. The purpose of this paper is to find out failure factors of lean implementation and strategies to overcome those failures.
Enhancement of Students’ Learning Experience through Introduction of Innovative Methods of Conducting and Assessing Laboratory Classes: A Case Study
R.A.M.P. Ranaweera, J.R. Gamage, U.P. Kahangamage, V.P.C Dassanayake
This paper elaborates a successful attempt made for improved way of conducting and assessing of laboratory classes. The key aims were to improve the quality & effectiveness of laboratory classes, promote team work and increase the relevance of the undergraduate practical programme that suits the industrial environment. In the design stage, problems of the existing methods, industrial requirements and expert views were carefully analysed. Finally it has shown considerable improvement in quality and effectiveness of the practical programme and team working ability of students.
CFD Simulation of Flow around Ceiling Fan
M.C. Kodikara, S.A.D.H. Samarasinghe, M.S. Chandrasiri, A.G.T. Sugathapala
This manuscript consists of the computation of the aerodynamic performances of flow around ceiling fan of symmetrical blade profiles ceiling fans by computational fluid mechanics (CFD) methods, developing a methodology for analysis of the flow pattern generated by ceiling fan with CFD methods. The aerodynamic performances of the generated flow are evaluated using Star-CD software for different fan speeds and for the different ceiling gaps. The results of these computations are presented in the graphs to identify the patterns of the flow field generated and the behavior and the reasons for the results were discussed.
Refrigerated Three-Wheeler Truck
C. Sandamali, N. G. K. S. N. Senevirathne, M. P. G. Sirimanna, M. A. R. V. Fernando
The mobile fish sellers in Sri Lanka used bicycles, motor bicycles and three wheelers to distribute fish. Refrigerated three-wheeler truck was developed targeting mobile food sellers. A prototype was fabricated which consists of an Electrolux vapour absorption system fitted to a specially designed cool box to suit commonly used three-wheelers. The waste heat in exhaust gas of vehicle is used as the power source. The heat available is sufficient to cater for around 140W unit.
Analysis and Design of Garbage Compacting Tractor Trailer for Sri Lanka
Nandana Wanigasinghe, Ananda Wijesinghe, M. A. R. V. Fernando ,T. A. Piyasiri
Low efficiency in collection and transportation of garbage and environmental pollution with the currently available vehicles such as open dump trucks, tractor trailers are two of the main problems encountered in solid waste management in Sri Lanka. This paper proposes an innovative design using a currently available tractor trailer to improve above problems. The capacity of waste transported is improved by compacting the garbage using a hydraulic system. A closed body is built with safe unloading system to overcome the environmental pollution.
Development of Die & Mould Making Industry in Sri Lanka though Tripartite Collaboration of University-Industry-Government
"S. W. M. A. I. Senevirathne, U. P. Kahangamage, K H J Mangala "
Most of the Sri Lankan Die & mould makers are Small and Medium Enterprises. UDe to various constraints they manage to cater only for 20% of the local die & mould demand. One of the reasons is the high technological gap between SMEs and large scale mould makers. The local SME mould makers need financial and technological support to increase production volume and the quality. Considering the strengths and weaknesses of different parties, a tripartite approach that involves the industry, government and the academic institute has been proposed to uplift this industry. This paper presents a proposed working model for a tripartite approach and its successful implementation being carried out at University of Moratuwa.
A Study of Information Literacy Skills of Engineering Undergraduates at University of Moratuwa
"T. M. Seneviratne and V. Wickramasinghe "
This research was conducted to investigate the status of information literacy skills of the undergraduates of Engineering Faculty of University of Moratuwa. Survey questionnaire was the main method of data collection and it was administered to stratified random sample of 189 Level 4 Engineering undergraduates representing all academic departments. The findings and implications of the research will be discussed.
Development of an Effective Communication Skill Development Program Embedded in Engineering Study Program
R.A.M.P. Ranaweera, U.P. Kahangamage
This paper presents a successful and innovative approach for improving presentation skills of undergraduates by incorporating PowerPoint presentation to laboratory practical assessments. The key aims were to improve oral presentation skills, to enhance the knowledge of undergraduates about the state of the art technologies and to improve the effectiveness of laboratory practical assessments. After completion of the first “presentation coursework” session, a noteworthy improvement in presentation skills and enthusiasm among undergraduates for making presentations was clearly seen.
Investigation of Effectiveness of Carbonized Rice Husk in Oily Water Treatment
W.A.J. Anurangi, B.M.W.P.K. Amarasinghe, A.A.P. De Alwis
In this study, agricultural waste, rice husk was used as an adsorbent in the oil pollution management. Thermally treated rice husk, prepared by carbonizing rice husk at 600 0C for 3 hrs, were tested for oil removal from aqueous mixtures. Solution pH, adsorbent dose and mixing time affect the degree of oil removal. COD removal efficiencies of 99% were achieved.
"Treatment of Soak Wastewater Resulting from Paddy Parboiling Process: Combined Methods Approach"
H.W.G.I. Karunaratne and M.Y. Gunasekera
Parboiling is a process used to improve the milling characteristics of paddy. The wastewater generated from soaking operation in parboiling process has pollutant levels higher than the discharge standards. Lab scale experiments were carried out to remove Chemical Oxygen Demand (COD) in soak water resulting from hot soaking of a red rice variety named LD 356. Combined treatment of this wastewater using biological treatment with aeration and coagulation was able to remove 95.48% COD while coagulation and adsorption collectively removed 92.58%. The combination of adsorption and aquatic plant based treatment removed 90.64% COD in which adsorption alone removed 90%.
Shape Prior based Image Segmentation using a Log Distance – Theta model
Janaka Senarathna and Ranga Rodrigo
Image segmentation is a popular topic in computer vision. Incorporation of prior shape knowledge into this process and the subsequent extraction of objects demonstrating shape characteristics similar to the priors are being extensively researched. Major challenges include the judgment of parameters such as scale and rotation as well as tolerating object distortions such as occlusions and noise. This paper proposes a novel framework to successfully overcome these by using a log distance-theta domain mapping which greatly simplifies rotation, scaling and provides an opportunity to incorporate a decision threshold.
Control of Electrical Appliances from Hand Tracking
"Nalin Wickramarachchi, H.M.S.L.G Bandara, K.H.E.H Jayarathna, P.M.A.U Karunapala, M.R.K.C Senevirathne "
Control of Electrical appliances from hand tracking is our final year project and mainly based on newly emerging image processing technology. Image grabbed by the camera will be processed by PC and if it is identified any new gesture it will given to the microcontroller. Microcontroller will generate the correct control signal for that gesture and it will be transmitted to the receiver through transmitter. Receiver unit will identify the control signal correctly and it will provide the relevant output for the control circuit of the appliance.

On behalf of the Engineering Research Unit-Symposium 2009's Editorial Board, we Congratulate the authors. We thank all the authors who submitted papers, and invite them to consider submitting their work for upcoming symposia as well.


ERU Reserach Symposium 2011, the official research symposium of the Faculty of Engineering, will be held on December 22, 2011.

List of paper accepted for oral presentation at the ERU Reserach Symposium 2011.

List of reviewers for ERU Symposium 2011.


ERU Symposium 2011

Paper submission deadline is now over. Authors hoave been notified teh decision.

Authors' Resources