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131 I Treatment : hospital discharge criteria
(University of Peradeniya, 2009-12-03) Loganathan, N.; Perera, K. A.; Hewawasam, R.
A case of juvenile active or aggressive ossifying fibroma(JAOF) in relation to the maxilla
(University of Peradeniya, 1998-11-07) Prabaharan, P. J.; Mendis, B. R. R. N.; Attygalla, A. M.
In the view of many pathologists and surgeons, the group of fibro-osseous lesions (FOL) occur by the replacement of the normal bone by fibrous tissue. Thereafter there is the formation of a new form of calcifying mass by the process of mataplasia. The FOL comprise of a diverse, interesting and challenging group of lesions that pose difficulty in classification and management. The FOL of the jaws may vary from asymptomatic lesions discovered by accident in routine radiographs to extensive, cosmetically and functionally disturbing lesions. Proper diagnosis of these lesions depend on a good correlation of the history, clinical findings, radiographic characteristics, and the histopathological appearances. Microscopically the lesion consists plump osteoblast like cells, surrounding areas of osteoid. The patient is a 18 years old male, from Vavuniya. He first reported to the Kandy General Hospital (Centre for sight), with a gradually progressing right sided proptosis and swelling in relation to the right eye. He had no pain but reduced vision on the right eye. He later reported to the Dental Hospital, Peradeniya with the same symptoms and an initial diagnosis of fibrous-dysplasia of bone was made. Further investigations such as like C.T Scans and histopathological observations reveals the diagnosis of Juvenile Active or Aggressive Ossifying Fibroma. Discussion A. JAOF is most often seen in the maxilla and the patients are in the first or second decade of life. This tumour is more cellular than any other fibro-osseous lesion. Some of these cells produce streams of osteoid that may bear some resemblance to the osteogenic sarcoma. B. According to the Johnson (1967) these lesions are aggressive and extend into antrum and approach the nasal septum and medial wall of the obit, causing proptosis and exopthalamos. Some of these lesions become osteogenic sarcomas while others mature into ossifying fibromas. JAOF may have an ancestral relationship to osteoblastoma because of the overlapping histological features of both lesions. Reed and Hagy (1965) also consider the JAOF and osteoblastoma to be the identical lesion.
A case of recurrent Central Giant Cell Granuloma in relation of the Maxilla
(University of Peradeniya, 1998-11-07) Attygalla, A. M.; Amaratunge, N. A. De S.; Mendis, A. R. R. N.
Central giant cell granuloma ( CGCG) of the jaws is an uncommon lesion which accounts for less than 7 percent of all benign lesions of the jaws. The CGCG is defined by the WHO as 'an intra osseous lesion consisting of a more or less cellular fibrous tissue containing multiple foci of haemorrhage, focal aggregations of multinuclear giant cells, and sometimes trabeculae of woven bone formation within the septa of more mature fibrous tissue that may traverse the lesion. The aetiology of the CGCG is unknown and its biological behaviour is poorly understood. In 1953, Jaffe identified these lesions as "giant cell reparative granulomas" to distinguish them from the giant cell turnours that are usually found in the epiphysial regions of the long bones. There are reports in the literature of CGCG behaving as slow growing neoplasms. The features of such lesions are gross bone destruction, displacement of teeth, enveloping and often erosion of roots, perforation of the cortex and also pathological fractures. A case of central giant cell granuloma of a 26-year-old Sinhalese woman is presented. The lesion was in relation to the left maxilla, involving the hard palate and extending from ~ crossing the midline. The occipitomental radiograph showed a mixed radiolucent lesion involving the left maxilla with ill-defined margins. The CT scan revealed a lobulated expanded lesion arising from the left maxilla which extends in to L nasal cavity, L maxillary and ethmoidal sinuses, L nasopharynx and infero medial aspect of L orbit. The management of this lesion and the difficulty of differentiating it from central giant cell tumour of bone are discussed. The comparisons of the CGCG and the Central Giant Cell tumour of Bone are given below. Detailed diagram is availble in the pdf
A case series of treatable causes of bronchiectasis
(The University of Peradeniya, 2013-07-04) Siribaddana, A.; Wickramasekara, K.; Illeperuma, S. K.; Punyajjeva, U. A. G.; Pathirana, G. G. P.
Bronchiectasis is a chronic inflammatory lung disease which leads to permanent lung damage and significant morbidity. The underlying causes of bronchiectasis vary and in Sri Lanka the incidence of bronchiectasis and its causes are not known. This study was conducted to identify the patients with correctable causes of bronchiectasis who responded to appropriate therapy. Patients who presented with symptoms of bronchiectasis, to the respiratory unit 1, Teaching Hospital Kandy from October 2010 to December 2010, were investigated. Informed consent was taken from the patients before the clinical details were obtained. In all patients, except a child, the diagnosis of bronchiectasis was confirmed by High Resolution Computed Tomography of the chest. Chest X-ray was used to confirm the diagnosis in the child. All patients were investigated with full blood counts, X ray sinuses, serum proteins, serum immunoglobulin levels, sputum direct smears, culture for mycobacteria and skin prick tests for aspergillosis. Those with positive skin tests underwent antibody testing for Aspergillosis. Those who were diagnosed to have post tuberculosis bronchiectasis and concurrent pulmonary tuberculosis were excluded. There were 26 cases with a mean age of 31 years (range 8 to 56 years). 7 (27%) were found to have a correctable cause, which included, 4 cases of allergic broncho-pulmonary aspergillosis, 1 common variable hypogammaglobulinaemia, 1 relapsing polychondritis, and 1 case of myelodysplastic syndrome associated with leucopaenia. These patients were put on specific treatment which resulted in significant improvement in their symptoms and quality of life. Some patients were completely asymptomatic after specific therapy. We conclude that investigation for an underlying cause should be done in all patients diagnosed to have bronchiectasis.
A case study of water quality modelling in urban streams
(Unviersity of Peradeniya, Peradeniya, Sri Lanka, 1999-11-20) Weerakoon, S. B.
Urban streams receive more and more wastewater with the population growth, urban migration, industrial development and this results in the decrease of the environmental quality of the aquatic environment at an alarming rate specially in developing counties like Sri Lanka. Thus, maintaining water quality of urban streams to the desired standards is essential for health, bio-diversity preservation etc. through controlling waste water inflows with an understanding of the waste water assimilative capacity of the stream. A water quality model which describes the water quality parameters quantitatively along a stream is therefore an important tool in the planning of stream restoration schemes and also in the assessment of the influence of water quality changes brought by siting a new wastewater source. The present study has developed a one-dimensional, computational water quality model applicable for un-eutropic streams. The governing equations for the steady, stream water quality model are mass balance equation coupled with single-first order kinetic equation, 0=-U(dL/dx)-KL, for contaminant (N, P, BOD) concentrations and O=-U (dc/dx)- Kd L BOD exp(-K, x/U)+Ka(cs -c), for dissolved oxygen concentration where KN, KP, KBOD are decay rates, Ka. Kr Kd are aeration, total loss and deoxygenating rates. U is the stream velocity, Cs is the saturated DO concentration and x is measured from the upstream [Please refer to the downloaded abstract for the correct symbols]. The model was applied to the Meda-Ela (Mid Canal) which originates from the Kandy Lake and falls into the Mahaweli River at Getambe to assess the influence of alternate restoration proposals. By a field survey, wastewater sources were identified and pollutant loads received by this highly polluted canal along its path of about 4 km were quantified. It receives pollutants directly from restaurants, open markets of vegetables, fish, meat in the town, railway and bus stations, garages, slaughter houses, laundries, industries, treatment plant of the hospital, kitchens, some overflowing septic tanks and indirectly through subsurface migration from many septic tanks at the vicinity of the canal. Inflows were modelled as point sources at 50m intervals. The model predictions was verified with the field measurements of N,P,DO and BOD concentrations along the canal reported elsewhere as at present during dry weather period. The model was then applied to assess the influence of two different restoration proposals on the water quality along the canal: Phase I - direct inflows and 30% of septic tanks are absent and Phase II - Phase I with another 60% of septic tanks are absent. Predictions show that the canal could be restored to an environmentally acceptable level by Phase I which requires only the community participation and only a little capital investment. Phase II will bring the canal to much better level though it require a considerable capital investment.
A case study to explore whether teachers use their computer literacy to enhance the effectiveness of teaching in secondary level classes
(The University of Peradeniya, 2013-07-04) Dawatawaththa, V. N.; Jayawardena, S. K. R.; Kallora, E. M. U. K.; Kandegedara, A. P.; Wanigasekara, W. S. M. B. S.; Ekanayake, T. M. S. S. K. Y.
It is recognized that Information Communication Technologies (ICT) have the potential to enhance the teaching process in various ways. Recognizing these potentials the Ministry of Education (MOE) initiated a number of programs to develop teachers’ computer literacy. For instance, during the last five years a large number of teachers were given a chance to attend trainings in computer technology such as Computer Assisted Learning (CAL), International Computer Driving License (ICDL), International Pedagogical Information and Communication Technology (IPICT) and Intel. The aim of this research is to evaluate the extent to which the teachers used their computer literacy and skills they acquired from CAL, ICDL, IPICT programs in their teachings of compulsory subjects such as English, Mathematics, Science, Sinhala, Buddhism and History in secondary level education. The mixed methods approach was used in this study. Eighteen teachers out of 15722 who followed the above mentioned computer trainings and who teach in the Kandy district were selected as the sample for this study. These 18 teachers represented different types of schools (Type 1 AB, 1 C, 2). First, the teachers were given a questionnaire and based on their answers further information was collected through semi-structured interviews. The data from the questionnaires were analysed using MS Excel and they were shown in ratios and percentages. The data gathered at interviews were transcribed and analysed using the thematic analysis technique. The findings of the study indicated that all teachers in the sample who taught Science and English integrated ICT into their teaching. Furthermore, only 33% of teachers who taught Mathematics and Sinhala used ICT in their teaching process. However, none of the teachers who taught Buddhism or History had integrated ICT into their teaching. Moreover, it was identified that a number of factors minimized the use of ICT by teachers in their teaching. The student - computer ratio is low in most of the schools. Furthermore, only 1 AB and 1C schools had internet facilities. According to the findings of the survey 94.44% of teachers had a positive attitude towards the use of computers in teaching and learning. Yet, only 72.22% used computers for their teaching. The study has further revealed that the lack of adequate time (33.35%), not having adequate computer knowledge (5.55%), lapses in the training provided by the Department of Education and the lack of proper supervision or feedback decreased ICT integration into teaching. However, this study has a limitation on generalizing the results as only 0.1% of the teachers who underwent the training were used as the sample.
A casestudy on password security evolution
(University of Peradeniya, Sri Lanka, 2006-11-30) Sandirigama, M.; Weragama, N. S
As the Internet and Mobile applications have been increasing in the recent past, the need for authentication over remote servers and telephones has become very important. The need of authentication is essential as the private data sent over the Internet have risk of being wiretapped. Existing password authentication schemes can be divided into two types, one requires only the weak password and the other must use the strong password. The main objective of this case study is to present a review on the evolution of the strong password protocols. Starting with the earliest password authentication protocols such as Lamport I, CINON and the PERM, the study comprehensively analyzes the most recent protocols such as SAS-2 and SPAPA. The newest protocol SPAPA stands for hash-based Strong Password Authentication Protocol with user Anonymity . The user's anonymity is highly required in a hostile environment as it prevents observing the user 's activity. Also, the SPAPA protocol is very simple and contains only hash functions and XOR operations as compared to the earlier versions, which are suitable for power and computation constrained smart card applications. The SPAPA protocol is tested and verified to be secure from Stolen Smart Card or Online Guessing Attack, Offline Guessing Attack, Stolen Verifier Attack, Replay Attack and Denial of Service (DoS) Attack. In addition, all the attacks performed on each of these protocols are covered in this case study as well. The common pattern in evolution and the details of the attacks that compromised the security measures in each of the protocol are taken into account.
A comparative analysis of the major schoos of Sinhala Literary criticism in the twentieth century
(University of Peradeniya, 2008-12-18) Kariyawasam, Senaratne
A comparative study of the concept of Ideal statesman as depicted in the Philosophy of Plato and in the early Buddhism
(University of Peradeniya, 2008-12-18) Samaratunge, Ayoma
A comparison of health habits, cancer risk and the use of screening tests for cancer between a migrant Sri Lankan population in the USA and their siblings/first cousins living in Sri Lanka
(The University of Peradeniya, 2013-07-04) Dissanayake, D. S.; Jones, L. A.
Comparing a migrant population with that of siblings and first cousins still living in the country of origin could explain how health habits have changed with acculturation to a new society. Cancer is the second leading cause of death in Sri Lanka. The aims of this study were to compare the health habits and other factors related to cancer, and the pattern of utilization of methods available for early detection of cancer, between Sri Lankan Sinhalese living in Houston, United States of America (USA) with that of their siblings and first cousins living in Sri Lanka. This cross sectional comparative study comprised Sri Lankan Sinhalese adults living in Houston, USA and their adult siblings and first cousins living in Sri Lanka. The 90 pairs studied were matched for sex and for age within ± 10 years. Data collection was carried out as telephone interviews using a questionnaire. Engaging in physical exercise was significantly lower among the subjects living in Sri Lanka (p=0.003). Having less than thirty minutes of moderate to vigorous physical exercise was reported by 41% of the group in Sri Lanka and 19% of the group in the USA. When compared to the study group in Sri Lanka, alcohol consumption was significantly higher in the USA group (p=0.006). Only 4% of the USA group and 5.5% of the group in Sri Lanka were heavy smokers. Frequent ‘bulath’ chewing with carcinogenic ingredients was reported among only those living in Sri Lanka (4%). A significantly higher percentage of the USA subjects had a high consumption of red meat (51%) compared to relatives in Sri Lanka (10%) (p< 0.001). Fruit and fruit juice intake was higher among US participants (p= 0.008, p< 0.001 respectively). Fish and vegetable consumption was higher among the participants in Sri Lanka (p< 0.001, p= 0.004 respectively). Type 2 diabetes mellitus was reported by 18% of participants from each country. Equally high proportions from both countries (73% in the USA and 72% in Sri Lanka) perceived as having moderate to high mental stress. Of the females aged 35 years or above (84% in USA and 11.9% in Sri Lanka) have been screened for breast cancer by a mammogram (p<0.001). The difference is highly significant. A significantly higher proportion of females living in the USA have been screened for pre-malignant lesions of the cervix by a Pap smear (p<0.001). Of the males aged over 50 years, a significantly higher proportion in the USA have been screened for prostate cancer (p< 0.001). The risk factors for cancer differed in the two groups indicating a change in lifestyle accompanying migration. Utilization of methods for early detection of cancer was poor among the group in Sri Lanka despite the high incidence of cancer in the country.
A comparison of larval feeds and the effect of sun light on theg growth of guppy (Poecillia Reticulata )
(Unviersity of Peradeniya, Peradeniya, Sri Lanka, 1999-11-20) Chamila Kumari, Y. A. A.; Edirisinghe, Udeni
Guppy (Poeillia reticulata) is the most widely distributed and firmly established aquarium fish in the world. The efficient management practices as well as the balanced larval feeds have a direct effect on the exporting quality. Three larval feeds were tested for growth and survival of guppy fry. Artemia salina eggs were hatched using 28-30 ppt saline water kept at 27 °C for 24 hours. Micro- worms (Anguillula silusiae) were cultured on bread and Soya flour mixture. A dry pelleted feed was formulated using intestines of layer chicken, shrimp head meal, tilapia head meal and Soya flour as protein sources. CRD with three replicates was used as the experimental design. Day old guppy fry were introduced to each tank at a stocking density of 64 fry/m². They were fed twice a day at 100g/10,000 fry. Weight gain was measured at 7-Day interval. Water quality parameters were recorded at 4-Day interval through out the experimental period. The effect of sun light on the growth rate, survival and colour development was determined by keeping one treatment exposed to the sunlight while the other unexposed. Post larvae fed with artemia and micro worms showed significantly higher (P0.05) in the three treatments and the values were within the tolerable range for guppy. Fish exposed to sun light showed significantly higher growth (P<0.05), and more attractive colour patterns. Fecundity was found to be directly related to the body weight. Results revealed that hatched artemia as well as micro-worms could be used as a larval feeds for guppy. After the first 14 days, formulated feed could be used to achieve higher performance. It could be concluded that sun light has a favourable effect on the growth rate development of attractive colour patterns, healthiness as well as fecundity.
A comparison of urinary β2 microglobulin levels in patients with chronic kidney disease of unknown aetiology and controls from Medawachchiya and Ja-ela
(The University of Peradeniya, 2013-07-04) Siriwardhana, E. A. R. I. E.; Perera, P. A. J.; Sivakanesan, R.; Abeysekera, D. T. D. J.
Chronic kidney disease of unknown aetiology (CKDu) has been reported in developing countries including Nicaragua, countries of Balkan region, Tunisia and Sri Lanka. Numerous studies carried out to date in these countries have failed to reveal the credible contributory factors for this disease. The objective of the present study was to compare the urinary β2 microglobulin (β2M) levels of CKDu subjects from Medawachchiya with those of normal subjects from Medawachchiya (Control M) and Ja-Ela (Control J). The test group consisted of 30 CKDu patients who were randomly selected from the CKDu patient register of Medawachchiya renal clinic. Normal age and sex matched individuals were selected as controls from the same division (Control M, n=30) and from Ja – Ela (Control J, n=30), an area which has been declared to be free from CKDu. Spot urine samples from all the subjects were collected and β2M estimated in duplicate using an ELISA test kit (BIOQUANT, B-2MG BQO10T, Germany). The mean urinary β2M level in CKDu patients (1.24 ± 0.71 μg/mL) was significantly higher (p<0.05) than that of control groups M (0.16 ± 0.05 μg/mL) and J (0.17 ± 0.05 μg/mL), while the control groups M and J had similar β2M levels. The urinary β2M levels between males and females of each of the three groups revealed no significant (p > 0.05) differences. Urinary β2M was significantly (p < 0.05) higher in males (1.31 ± 0.76 μg/mL) of the test group than of the males in the control groups (0.14 ± 0.04 μg/mL and 0.18 ± 0.05 μg/mL, respectively, in groups M and J). Similarly, significantly higher β2M concentration was seen in females of the test group (1.14 ± 0.65 μg/mL) than in females in the control groups (0.17 ± 0.05 μg/mL and 0.16 ± 0.05 μg/mL, respectively, in groups M and J). Renal tubular function based on urinary β2M showed a significant difference between those afflicted with CKDu and controls in the CKDu prevalent Medawachchiya Divisional Secretariat, as well as those from Ja-ela. Urinary β2M excretion is significantly higher in those affected with CKDu.
A computer based statistical tool to analyze the correlation among DNA sequences
(The University of Peradeniya, 2013-07-04) Jayarathna, P. G. S. S.; Sooriyapathirana, S. D. S. S.; Yapa, R. D.
DNA is the molecule of life. DNA sequence analysis is the key for understanding many biological questions. In bioinformatics, statistical techniques such as frequency distribution techniques, alignment algorithms, hypothesis testing, and clustering techniques are used to analyze the correlation among DNA sequences. Furthermore, comparing lengths, GC-content, AT/GC ratio, repetition of small sub-sequences and the analysis about restriction sites are the most basic analysis on the DNA sequences. Pie charts and the frequency tables can be used to analyze nucleotide distribution among DNA sequences. In DNA sequence analysis, sequence alignment is one of the most important steps to identify the similarity regions between DNA sequences, because it reflects functional, structural, or evolutionary relationships among them. Since the process of alignment algorithms like Smith-Waterman’s are very time consuming, the BLAST algorithm can be used as a time efficient procedure because it addresses the fundamental problems and the algorithm emphasizes speed over sensitivity. Cluster Analysis is also associated widely in DNA sequence analysis. The DNA analysis by using different statistical techniques requires several statistical tools and demands considerable expertise in statistics. Therefore, an attempt was made to design a user friendly computer based statistical tool to analyze one or more DNA sequences in different paths of statistics and make a sequence alignment efficiently. The DNA Sequence Analysis Tool (DSAT) was developed and implemented. by using vb.net programming language in Microsoft Visual Studio 8. MSChart and MSChartVisualStudioAddOn tools were used to display graphic outputs of the tool. An analysis can be conducted under five options named as Nucleotide Distribution Analysis, Basic Analysis (GC content, AT/GC ratio and repetitions), Multiple Analysis, Pair wise Analysis and Cluster Analysis. The DSAT contains a collection of several statistical techniques in one application and quick in aligning DNA sequences. This statistical tool can be used by biologists and students with limited statistical knowledge in quick time to get more detailed information about the correlation among DNA sequences.
A critical study of the insecurity dilemma of Sri Lanka
(University of Peradeniya, 2010-12-16) Kumara, J. S.
A culture-specific emotion vocabulary
(University of Peradeniya, 2010-12-16) Appuhamilage, U. M. H.
A design of low cost working model of wind turbine for battery charging purpose
(Unviersity of Peradeniya, Peradeniya, Sri Lanka, 1999-11-20) Obeyesekara, B. R. K.
The paper discusses that how to make a cost effective wind battery charger for rural community. Wind battery chargers are becoming popular among the rural communities as they can generate electricity capacity of which can be vary from 50 watts to 250 watts. As it is shown in the studies that power generated by the wind battery charger directly proportionate to area which is swept by the rotor blades of the wind turbine. In other words to increase the power out put, it is necessary to increase the radius of the wind blades. Subsequently increasing the overall size of the wind rotor, which is needed to be optimized with a base function of, cost analysis. Two-blade designs of wind battery chargers are the most cost-effective designs among the wind energy converters for battery charging. And also it is essential to have three-blade design to minimize the vibration to increase the overall plant efficiency relative to Blitz criteria. The faculty of engineering has designed a low cost-wind energy converter for battery charging purpose with the help of computer simulation. Airfoil of the wind blade is selected from NACA airfoil designs. Rated wind speed is taken; as 5 m/s, Furling is 18 m/s. Diameter of the wind blade is 3.2 m. Angle of attack is taken as 17 degrees. Speed ratio of multiplication is 10: J .And Hub of the wind rotor is designed in such away to hold the blades at Constant pitch. Materials for wind blades are used as treated wood planks and components such as hub. housing of multiplicator, cover & rudder of the plant are made out of waste materials of steel and other metals. Cost per l Ou-watt plant is approximately Rs. 48000.00. This is 1/3 rd of the cost reduction of available wind battery chargers. Assemble of wind energy converter for battery charging is fabricated in the faculty of engineering and made several trials to investigate the behavior of the plant according to different wind climates. Below: Assembling process of the wind energy converter.
A design of solar energy crop dryer
(University of Peradeniya, 1998-11-07) Obeyesekara, B. R. K.; Elankathir, A.
This paper discusses how to improve the qualitative characteristics of cereals by utilizing the Solar Energy Ventilating systems. As the economy of the rural community of developing countries is mainly based on their agricultural crops, securing the quality of the product would be one of the main and essential aspect in agricultural industry. As harvest of the various crops is reaped in different time during the year, it requires the necessity to keep the crops for longer period of time without causing any damages to them. Damage can be caused by insects, fungal, thermal etc. High quality of agricultural crops such as cereals, make available to draw foreign currency in to the country in to the country and also crops will be marketed as high quality product by maintaining its moisture content, color shape, sizes and so on. In village community, the farmers who deal with cereals in small scale, finally sale to the whole sale dealers. At most of the time, the product itself shows poor quality subjected to different undefined techniques of drying. As a result of this most of the cereals end up with fungal attacks and discolour of products as they are exposed to the moisture environment and the direct sunlight. Hence the total quality of the cereals naturally falls down. Further the paper discusses the methodology to solve this problem. It is suggested to have a Solar collector system, hot air of which passes to a chamber in which the cereals are kept for further drying after initial drying of direct sun light. As the experimental study is new in this nature (crop drying) and it gives couple of recommendations and values of parameters of the geometrical configuration of the Solar Energy ventilator for different types of cereals. The temperature and the flow of hot air can be controlled by changing the geometry of the solar collector. Further the experimental study shows that serious limitations for the diameters of inlet and out let of solar collector ducts. This new mathematical models show how to control the flow and temperature of the air flow inorder to run with maximum gain more heat. A design of solar energy collector is now been constructed at the Nawa Nilambe Estate for drying of 1000 kg. of Pepper, Coffee, etc.
A device made to measure and control bite force of human subjects in recording EMG activity of muscles of mastication
(University of Peradeniya, 2000-12-16) Pallegama, L. N.; Pallegama, R. W.; Sitheeque, M. A. M.; Weerasinghe, V.S.; Ranasinghe, A.W.; Somaratne, A.P.N.
Electromyographic activity (EMG) of muscles of mastication is recorded for various research and clinical activities related to masticatory complex. Integrated EMG activity· as well as the degree of biting force generated depend on the number of motor units involved in contraction of the muscles. Therefore, in recording EMG activity of muscles of mastication the bite force has to be controlled. Further, subjects must have a visual feedback to control and maintain the bite force during the recording period. The objective of the present study was to design and prepare a reusable and reliable electronic device that can be used to control and measure the bite force of human subjects in recording EMG activity of muscles of mastication. This prepared transducer consists of a stainless steel bite piece that can withstand the bite force of humans within the elastic limit of the material. A strain gauge (KFG-I 0-120-C I L5 M3 S) was attached to the outer surface of the stainless steel bite piece to measure the strain that is directly proportional to the bite force. The strain gauge was connected to a bridge circuit and the resultant signal was passed through an amplifier and then fed to an analogue multimeter. The multimeter reading provided the visual feedback required by the subject. The EMG activity of masseter and anterior temporalis was recorded in ten dentulous young adults while maintaining the bite force with this transducer. The visual feedback given through the multimeter was sufficient for subjects to maintain the bite force during the recording period The bite piece of the transducer was placed in between upper and lower incisors on each subject and they were asked to maintain four different loads using the visual feedback. The EMG activity was recorded under four different loads in all subjects. The recorded EMG activity was proportional (y = 0.9) to the bite force and it can be concluded that with the aid of this device the bite force of human subjects can be satisfactorily controlled in recording EMG activity of muscles of mastication.
A fuzzy based approach for condition monitoring of engine oil
(University of Peradeniya, 2010-12-16) Marasinghe, L.; Ratnaweera, D.A.A.C.
A greedy agent to solve the minesweeper game
(The University of Peradeniya, 2013-07-04) Damunugalla, Salinda; Walgampaya, Chamila
Minesweeper is a one-person game which looks deceptively easy to play, but where average human performance is far from optimal. Playing the game requires logical, arithmetic and probabilistic reasoning based on spatial relationships on the board. At the beginning, the player is presented with a board containing NxM squares which are all blank. Hidden among the tiles are mines distributed uniformly at random on the board. The task of the player is to uncover all the tiles which do not contain a mine. At each turn the player can select one of three actions (moves): to mark a tile as a mine; to unmark a tile; and to uncover a tile. Game play continues until the player has uncovered each and every square that does not hide a mine, while successfully avoiding all of the mines. In our research, minesweeper game has been redesigned as a key board controlled shooting game. While it can be played by human users we have developed a software player, which we called a greedy agent, to play the minesweeper game. Greedy agent is a rule based agent that uses prior acquired knowledge to achieve specified tasks. The agent stores acquired knowledge in the form of sentences. New sentences are derived from prior sentences during the goal seeking process. At each move the greedy agent collects the following information: Flagged cell count around the current cell, Mines Count in current cell, and the Uncovered Cell Count around the current cell. According to the collected information the agent can make sentences such as “If mine count of current cell is equal to unvisited or flagged cell count of eight neighbors of current cell then all those unvisited cells contain mines.” During the exploration, if a mine is found and flagged, the agent will look for a safe cell to move. If a safe cell is not found then greedy approach is used to find a safer direction to move. The agent calculates the probability of having a mine in each neighboring cell. Once the cell with the least probability to have a mine is found the agent moves in that direction. In situations where two or more directions have the same probability value, the agent chooses the direction randomly. We have simulated the game with different mines counts and our results show that the agent performs better when the mines count is large.

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