Symposia and Conferences
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Item MATLAB Based Software Tool for Grain Classification and Their Quality Identification(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Atapattu, H.R.S.; Jayatissa, N.W.K.At present, the field of agriculture is the most prevalent and enduring industry in the world. Among the existing food crops, grain varieties have attracted more attention of farmers since they play a major role in providing daily nutritional rations of human beings. Hence, it is important to develop accurate, efficient and cost effective methodology for classification and identification of grain varieties in order to yield high quality products while boosting the profit of farmers. In this study, an attempt was made to develop a software tool based on MATLAB by using the techniques of image processing to classify grain varieties namely; green gram and rice grains into their sub varieties and identify foreign particlespresent and the percentage of broken grains in a given sample. The decisions in classification and identification of grains were taken based on their different morphological features extracted based on the still images acquired using a digital camera. Theimages acquired were initially conceded through several image pre-processing steps namely; RGB to gray conversion, gray to binary conversion, noise filtering and image erosion. The resulting binary images were then labeled and segmented based on the similarities that exist and the labels given. Subsequently, the features (area, perimeter, centroid, major axis length and minor axis length) of the segmented imageswere extracted and system decisions in classification of grain varieties and identification of the foreign particles & the percentage of broken grains were performed based on the features extracted with 95 % and 97 % accuracies respectively utilizing 35 training sets and 15 testing sets for each category. The subsequentprocessing steps were employed to convertnumerical values into string values and the final results were displayed and readout loud to enhance the user friendliness of the software tool developed. The graphical user interface of the software tool was also based on the MATLAB. Furthermore, the whole process tooka maximum of 5s execution time for one trail of grain classification or quality identification.Item Low Cost Method for Prototyping Printed Circuit Boards.(In: Proceedings of the International Postgraduate Research Conference 2017 (IPRC – 2017), Faculty of Graduate Studies, University of Kelaniya, Sri Lanka., 2017) Wanigasekara, R.M.G.; Agalawaththa, J.C.; Chrandrasena, B.G.D.R.; Jayatissa, N.W.K.Printed Circuit Boards (PCBs) are very commonly used in almost all of the electronic applications, due to ease of use. There are several modern methods of transferring circuit wiring diagrams to circuit board. Many of these methods are good for only producing large number of PCBs because making one or two PCB is very expensive. However, in an electronic research laboratory needed for producing various type of prototype boards is much needed. There are several difficulties in fulfilling this need; time to produce, cost of production, difficulty to produce large and complicated PCBs. The PCB drawing machine is designed to overcome these difficulties in prototyping PCBs for electronic laboratory use. The three dimensional axis of the designed machine is controlled by three independent stepper motors. A drawing pen holder is attached to the z-axis control and any permanent marker pen can be attached to the holder. The accuracy of the z-axis is 0.1 mm. Initially, the user designed circuit diagram (drawing) should be loaded to the computer which is connected to the drawing machine. The computer reads the drawing and replicate it on the copper board using the permanent marker pen. The total area of the x-y plane is 300mm x 200 mm. The required software for this operation is a development of an open source, which can send Gcode (RS-274) protocol commands to the device. Generally, RS-274 or G-code is known as numerical control (NC) programming language. This machine uses both computer numerical control (CNC) technique and CAD software to complete the task. The machine could also be used to remove the unwanted copper areas of a circuit board by connecting special carving bits to the machine instead of the pen. This method is much faster than the previous drawing method to replicate circuit to the copper board but more costly due to rapid wear of the milling bits. Finally, the designed drawing machine is able to draw 300 x 200 mm2 size circuit layouts with 0.1 mm line separations.Item Intelligent Window Controlling System(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Seneviratne, K.; Jayatissa, N.W.K.During the 21st century the global surface temperature has increased dramatically as a result of that, Air conditioners are often used to improve thermal comfort and indoor air quality. In both developed and developing countries, air conditioners increase the occupancy ratio of building areas. But air conditioners are expensive option for this issue. Because of that we need to optimize usage of air conditioners only in comfort zone. This research is conducted due to the growing energy management interest in the airconditioning industry. Most of the places outside air temperature and humidity drop down to human comfort levels during the night time. It may take considerable time to transfer these environmental conditions into the room. Insulated thermal envelope may be slowing this process furthermore. The objective of this research was to transfer the fresh outside air into the air conditioned room when the outside environment is in the comfort zone. Comfort zone is an area marked in the psychrometric chart which is comfortable for human being. The American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE’s) publication on thermal environmental conditions for human occupancy has defined the comfort zone with suitable temperature and relative humidity (RH) ranges. The specified temperature and humidity ranges for the designed system are 22 Celsius & 40 RH to 27 Celsius & 60 RH respectively. The designed controller detects the outside temperature and relative humidity every 15 minutes and opens the windows of the room if the outside fall into comfort zone. When the windows are opened the air conditioner is switched off by the controller at the same time. The designed system consists of three separate items such as outdoor unit, indoor unit and actuator driver. Relative humidity and temperature of the outside air are measured and transmitted to the room via radio frequency (RF) communication system by the outdoor unit. The indoor unit receives the transmitted signal from the outdoor unit, process it and produce appropriate signals to both actuator driver and air conditioner. Therefore, actuator driver is controlled the window according to the outside environmental conditions. The designed system is commissioned in Thailand and it is proven that the device is significantly saving the energy in the residential sector.Item UV absorption properties of natural solutions(University of Kelaniya, 2008) Wijesiri, W.D.S.; Jayatissa, N.W.K.; Jayakody, J.R.P.Electromagnetic radiation is classified into types according to the frequency of the waves such as radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. UV radiation is a part of the electromagnetic spectrum emitted by the sun, and is divided according to wavelength into three regions known as UVA, UVB and UVC. The UVC is completely absorbed by the atmospheric ozone, water vapor, oxygen and carbon dioxide. However, both UVA and UVB are of major importance to human health. These radiations may penetrate into the skin and eyes, causing the adverse health effects, such as skin cancers, cataracts and immune suppression. The objective of this work is to support the mankind to prevent from the kind of threats and conflicts that they will face due to the harmful solar radiation using natural and available materials. Initially the study is focused to identify the UV absorption properties of natural materials. In order to achieve this goal several fruit juices, vegetable juices and plant leaf extractions are analyzed by using UV /VIS spectrum. The sample path length (1 Omm) and concentration (0.75mol/l & pH = 2.3) are kept constant during the experiment. The Citrus family exhibited interesting UV absorption behavior compared with the other tested materials. The experiments are carried out using both distilled water and isopropyl alcohol as solvents. Especially chlorophyll of the plant extract is removed by dissolving it in isopropyl alcohol and filtering it through activated carbon. When electromagnetic radiation passes through the compound, energy from the radiation is used to promote an electron from a bonding or non-bonding orbital into one of the empty anti-bonding orbital. The electron jump can be occurred or absorption takes place only when the energy associated with the particular wavelength is provided. In terms of Chemistry, Flavonoides are water soluble Polyphenolic molecules containing fifteen Carbon atoms. The Flavonoides, belongs to the polyphenol family, are found in most plant material and dietary sources. It is presumed that absorptions occurred in the citrus family due to the double bonds of the Flavonoides. Energy of the incident radiation is promoted electron jumps ( n:-+n:*, n-+n*, n-+a*) which caused to the absorption spectrum as discussed earlier. It is clearly illustrated that lime juice absorbed the wavelength from 290nm to 400nm where UV-B and UV-A radiations exist. Zero transmittance of incident radiation in between 290 and 400nm's for lime juice is observed in the experiment. It is interesting to find the optimal path length for zero transmittance and it determines the minimum thickness of the filter. One of the interesting applications of this finding is it can be converted any moisturizing cream into a moisturizing plus sunscreen by adding natural Flavonoides, just before the application.Item Construction and performance-analysis of a 'Solar-light" for efficient use of daylight(University of Kelaniya, 2008) Jayatissa, N.W.K.; Punyasena, M.A.A pleasant and appealing environment, excellent color rendering, natural interior, and significant energy saving are the major advantages of using the daylight compared to the artificial lighting. Glare and heat radiation are the main drawbacks of utilizing direct sunlight for building illumination. This 'solar-light', a newly designed unit, can be used only during the day time and is operated from natural solar radiation with no additional power being required at all. It acts as a light guide which transfers the filtered visible spectrum of solar radiation from outside into the interior of the building. Solar-light that illuminates building interiors more efficiently with natural daylight, has been constructed and tested for its performance. The unit has been designed to reduce substantially the heat component of solar radiation with an IR-filter so that the building interior does not get heated up by increased cooling load due to lighting. This would considerably reduce the air-condition load of the building. The UV component of the solar spectrum is eliminated with a UV-filter installed inside the unit, thus only the filtered harmless visible spectrum is taken into the interior of the building. The Solar-light has a cylindrical shape (to minimize the internal reflection losses) with a height of 80 cm and a diameter of 26 cm. The transparent window at the top of the unit has a hemispherical shape in order to increase the effective area of the solar radiation input into the interior of the building. The small air gap between outer cylinder and reflective cylinder creates a convection path for heated air. A light-reflective coating is applied at the interior surface of the cylinder to minimize the loss of illumination. The filtered radiation finally is sent through a light diffuser also with the same diameter at the bottom of the unit before the light is finally delivered into the building. The performance of the unit has been tested in real environment and a maximum of 170 Lux was measured at the desktop height inside the building with the daylight. Diameter of the illuminated area is about 5-6 m of which the intensity variation is minimal within the . . mner regwn. A series of these solar-light units can be installed on the roofs of large buildings (ex: garments factories, ware houses etc.) to illuminate the interiors in place of fluorescent bulbs to save energy substantially reducing the electricity bill.