Browsing by Author "Tennakoon, S"

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item: Conference-Abstract
Automatic Sinhala news text summarizer
(National Language Processing Centre University of Moratuwa Sri Lanka, 2020) Tennakoon, S; Thayasivam, U; Rathnayaka, C
With the present explosion of news circulating the digital space, which consists mostly of unstructured textual data, there is a need to absorb the content of news easily and effectively. While there are many Sinhala news sites out there, no site facilitates recommendation despite the popularity of recommender systems in the current age and day. Therefore, it is effective if the news were presented in a summarized version which tally with the user preferences as well. Our research aims to fill this gap by providing a centralized news platform which recommends news to its users clearly and concisely. The news articles were collected using web scraping and after performing categorization it will be presented in a summarized context. Also, we expect to detect the grey sheep users and to provide separate recommendations to them in order to minimize errors in recommendation. Here the grey sheep users refer to the user group who have special tastes and they may neither agree nor disagree with majority of users. By implementing the proposed system, we hope to provide appropriate solutions to the mentioned requirements and build a user-friendly Sinhala news platform. Considering about the application, manually creating a summary can be time consuming and tedious. The main idea behind building an automatic text summarization is to distinguish the highest significant information from the given content, decrease of the offered text to fewer sentences without leaving the fundamental thoughts of the first content and present it to the end-readers. Implementation of a specific summarizer for Sinhala Language is a major requirement to develop such an application because there is no Sinhala news platform available which presents summarized and categorized news text to the users. The objective is to produce a brief and exact outline of voluminous news messages while focusing on the key thoughts that convey beneficial information without losing the general significance. The research aims to build the summarizer with the use of PyTeaser algorithm. Even though PyTeaser can not be directly used for Sinhala Language, by using language specific modifications, PyTeaser is made available for Sinhala. The logic behind the PyTeaser includes assigning a total score to each sentence based on four features: Title Score, Keyword Frequency, Sentence Length and Sentence Position. Total score is computed by weighting the mentioned features and those weights are constants. Then the sentences with the highest scores are selected to produce the summary. The quality of the summary is evaluated using F Measure, with the use of human-generated summaries which are produced by Sinhala experts. The research focuses to compute the F Measure for all the possible weight combinations made out with original weights of PyTeaser and choose the optimized weight vector which provides the best quality news summary. The summaries for the proposed application are generated using the derived weight set and then those news are expected to recommend to endusers via the recommender system, according to user preferences.
item: Conference-Full-text
Development of a numerically controlled hot wire foam cutting machine for wing mould construction
(IEEE, 2016-04) Abeysinghe, A; Abeysiriwardena, S; Nanayakkarawasam, R; Wimalsiri, W; Lalitharatne, TD; Tennakoon, S; Jayasekara, AGBP; Bandara, HMND; Amarasinghe, YWR
The foam mould making for Unmanned Aerial Vehicles should be efficient and accurate to improve research and manufacturing. Hot wire cutting is a widely used method in foam cutting. In hot wire cutting, accuracy and quality of the foam cut mainly depends on the variable cutting parameters which affect the cutting process. To perform a proper cut with required quality the cutting parameters should be set precisely and accurately. This research is done to identify the variations and inter dependency of cutting parameters. It is important to estimate appropriate cutting parameter values before the actual cut. The results of this research aid to improve the hot wire foam cutting by solving the limitations and drawbacks to select best cutting parameters of the Computer Numerically Controlled machine which is in progress.
item: Article-Abstract
Flicker Attenuation—Part I: Response of Three-Phase Induction Motors to Regular Voltage Fluctuations
Tennakoon, S; Perera, S; Robinson, D
Voltage fluctuations leading to lamp flicker that originate in one place in a power system tend to propagate to other parts of the network with some level of attenuation depending on the network impedances and the loads connected. Numerous subsynchronous- type frequency components exist in these voltage fluctuations that are responsible for lamp flicker. The rudimentary theory and the experimental measurements support the idea that industrial load bases, which contain a large percentage of mains-connected induction motors, tend to attenuate flicker better compared to residential load bases having mainly passive loads. This paper reports on the response of three-phase induction motors of several sizes when subjected to low-frequency voltage fluctuations: 1) the case where a balanced single-frequency component is superimposed on the mains voltage and 2) the case where the mains voltage is sinusoidally amplitude modulated, a scheme that is frequently used in the flicker-related work. Small-signal models are presented that will enable systematic understanding of the behavior which is verified using large signal models
item: Article-Abstract
Flicker Attenuation—Part II: Transfer Coefficients for Regular Voltage Fluctuations in Radial Power Systems With Induction Motor Loads
Tennakoon, S; Perera, S; Robinson, D
Electromagnetic compatibility standards and guidelines used for planning of flicker allocation at various busbars of a power system requires some knowledge of the manner in which voltage fluctuations and hence the flicker propagate and how various loads respond to them. The current rudimentary approach taken for the determination of the load response to voltage fluctuations is based on network impedance values and hypothetical dynamic impedance values of the connected loads. Practical results and recently developed theory on the subsynchronous behavior of induction machines suggest that where there is a large base of induction machine exists on a power system the flicker attenuation is significant. This paper reports on a methodology to include the influence of induction machine behavior in flicker propagation and attenuation studies. The work is based on small-signal models to describe induction machine and system behavior which are utilized for the development of a flicker transfer coefficient. A systematic approach for the practical application of the methodology for flicker related work is included