Browsing by Author "Dissanayake, R"

Now showing 1 - 13 of 13

item: Thesis-Full-text
Analysis of the relationship of stock market with exchange rate and spot gold price in Sri Lanka
Wickramasinghe, WTN; Dissanayake, R
Intention of this thesis is to analyze the interrelationship of stock market volatility with LKR/USD exchange rate and spot gold prices in Sri Lankan stock market. There are several statistical techniques used in this study, such as Unit Root Augmented Dickey Fuller test, Box-Pierce test, Ljung–Box test, ARCH LM test in order to identify the relationship between stock returns and macroeconomic variables. Daily data for All Share Price Index, Exchange rate and Spot gold prices were collected over six-year period from 4th Jan 2010 to 4th Mar 2016. EGARCH specification, which was proposed by Nelson was used to model the variables in order to derive an equation to forecast the future behavior of stock returns. Evidently, statistical model depicted a strong evidence on non-existence of relationship between stock returns and exchange rate but it was proven the strong negative relationship between stock returns and spot gold price returns.
item: Thesis-Full-text
The Behavior of sector return and volatility around budget : evidence from Colombo stock market
Bhashani, KLS; Dissanayake, R
The study examines the behavior of stock returns and volatility in Diversified Holdings (DIV) sector of CSE around three annual government budget announcements. The daily returns of the sector over a period of three years from 1st April 2015 to 29th March 2018 are tested using three types of conditional time varying models, namely GARCH, EGARCH and GJR-GARCH. Three cases are considered using the dummy variable for =5, 10 and 15 with three scenarios, number of days on pre- budget, pre and post budget, post- budget for each case. Seven models are fitted except pre-budget with n=10 and pre-budget with n=15. This study finds strong evidence for the presence of budget announcement effect in stock returns and volatility of the sector. Returns during all considered windows are significantly negative and it implies that significant reduction in return. This reduction is increasing when getting closer to the budget date. Due to this effect investors can earn an abnormal return by buying stocks before five days of the budget announcement or after five days of the budget announcement and selling stocks after 15 days from the budget date.
item: Thesis-Abstract
Factors influencing work life balance of G.C.E (O/L) and G.C.E.(A/L) teachers in Sri Lanka during COVID-19 pandemic a structural equation model
(2023) Edirisinghe, SI; Dissanayake, R
With conflicting responsibilities and commitments, maintaining a work-life balance in the office has grown to be a significant difficulty. The twenty-first century is characterized by constant change, uncertainty, and intense pressure to increase productivity. Today's high-tech world's fast-paced, multitasking lifestyle has created expectations for both personal and professional devotion. Working women are under a lot of stress because of their jobs, and they face many challenges and worries at work. At best, it can be challenging to strike a balance between one's personal goals and duties and one's professional obligations. Most previous research on juggling work and family revealed that women frequently shoulder more responsibility for both, making it more challenging for them to establish a balance at both ends. It is essential to consider how teachers' wellbeing affects students' experiences and achievements. This qualitative study examines the happiness of professors at public universities in Sri Lanka. The research takes place during the coronavirus disease (COVID-19) epidemic, when schools are strapped for cash and instructors are looking for a better work–life balance by working from home. Therefore, there is a theoretical gap between the previous research and the present study. The research uses a descriptive survey approach, positivism philosophy, and mixed method approach to identify the relationship between teach concerns and work life balance, job satisfaction mediating teacher concerns and work life balance, and job stress moderating teacher concerns and work life balance. Data was collected from 350 school teachers who teach Ordinary Level, and Advanced Level in government, semi-government, and private schools in Sri Lanka. According to this study, among instructors participating in COVID-19, family obligations may conflict with work obligations more frequently than the reverse. It was identified that because of the high workload and more urgent demands, one is forced to carry their job home with them, and demands of employment interfered with obligations to one's family. Additionally, the research identified that work-life balance is determined not only by the external pressures imposed by employers but also by the internal pressures brought on by the amount of motivation of the individual.Keywords: work-life balance, job satisfaction, Structural Equation modelling, job stress, COVID 19 Impact
item: Conference-Full-text
Importance of consistent cement quality for a sustainable construction
(2013-11-12) Priyadarshana, T; Dissanayake, R
The EN and SLS specifications for Portland cement have largely similar provisions on physical and chemical parameters of cement. However, consistency of cement within standards specifications is significantly high and it affect to standard deviation of concrete. In order to obtain good concrete quality, concrete users need to target a low standard deviation of concrete strength. In order to reduce the strength standard deviation of concrete strength, the material properties variations need to be lowered. This paper discusses variation in cement properties from 5 different cement suppliers. Cement from given suppliers varies between batches/ shipments. It is well understood that there are significant differences in mortar strength, chemical composition, fineness, setting times of same cement type (Type 1) from different suppliers. Experiments were conducted with 48 cement samples of 5 different cement suppliers collected over 10 months time from January 2011 to October 2011. It was found that as all cement brands comply with EN and SLS standards. However, coefficients of variation (COVs) of most parameters, especially strength, are significantly high. This paper answers two key questions; are all nominally similar cements the same? Does cement from same supplier always behave consistently? Finally it recommends cement users and specifies a systematic way to select a consistent cement supplier for an economical and sustainable construction.
item: Article-Abstract
Lessons learned from tsunami damage in Sri Lanka
Dias, WPS; Dissanayake, R; Chandratilake, R
Around 300 000 people were killed by the tsunami that followed the Sumatra–Andaman earthquake on Boxing Day 2004, making it one of the worst disasters in modern history. Up to 40 000 died in Sri Lanka alone, where around 80 000 houses were also destroyed when waves up to 15 m high swept ashore. This paper reports on how coastal buildings and infrastructure in Sri Lanka behaved under various tsunami wave heights and the many lessons learned for reducing vulnerability to future events. In particular, newly published national guidelines for reconstruction emphasise the importance of tying down structures against upward and lateral loads as well as the need to anticipate and reduce soil scour around foundations, especially of backfilled earth.
item: Thesis-Abstract
Livelihood sustainability in post disaster resettlement
(2014-08-19) Dissanayake, R; Rameezdeen R
Natural disasters are very common today than ever in human history and the effect of diverse natural disasters are been increasing with rapid infrastructure development activities which harmfully effect on global ecological balances. The clear-cut results of socalled disasters are widespread human, material and environmental losses which exceed the ability of individuals and immediate communities to cope using only their own resources.
item: Thesis-Full-text
Modelling category wise tea export earnings in Sri Lanka : vector error correction model (VECM) approach
(2018) Chathurangi, AKDK; Dissanayake, R
Tea industry is a strong pillar in Sri Lankan economy in terms of foreign earnings and employment. Millions of people are employed directly and indirectly in the tea industry. Therefore, it is important to study about the behavior of tea export earnings and forecast tea export earnings for several months. This study is an attempt to identify predictive models to forecast category wise tea export earnings namely Bulk tea, Tea bags, Tea packets and Total exports using monthly data obtained from Sri Lanka Tea Board covering the period January 2003 to October 2017. The study employed the conventional augmented dickey fuller (ADF) test to test for stationarity among the four variables and Johensen co-integration technique to determine the co-integrating equation. All the series were found to be I(1) and two co-integrating relationships among these series were evident. Hence Vector Error Correction (VEC) model was fitted. For the validation of the VEC model, residual analysis was carried out using Residual plot, Correlogram, Residual portmanteau test for autocorrelation and Serial Correlation LM Test. The results indicated that model was satisfactory. Finally, Impulse Response Function (IRF) and Variance Decomposition (VDC) were employed in order to illustrate the importance of each variable to tea export earnings when a shock is imposed to the system. The analysis revealed that bulk tea earnings positively relate to tea packets earnings but negatively relate to total export earnings whereas tea bags earnings negative relate to tea packets earnings in long run. The results showed that tea packets earnings significantly and directly affect both bulk tea and tea bags earnings in the short run. The study also generated an out-of-sample forecast to analyze and compare the statistical results in order to determine the accuracy of the fitted model. The accuracy of the forecasts was tested using MAPE. Therefore, it can be concluded that the developed VEC model can be used to forecast tea export earnings in Sri Lanka with considerable accuracy.
item: Conference-Full-text
Pervious concrete – a sustainable choice in civil engineering and construction
(2013-11-13) Priyadarshana, T; Jayathunga, T; Dissanayake, R
Pervious concrete (no-fines concrete) is a concrete containing little or no fine aggregate; it consists of coarse aggregate and cement paste. It seems pervious concrete would be a natural choice for use in structural applications in this age of ‘green building’. It consumes less raw material than normal concrete (no sand), it provides superior insulation values when used in walls, and through the direct drainage of rainwater, it helps recharge groundwater in pavement applications. The first pervious concrete has been used in Europe and the United Kingdom since 1930s for the building of single story and multistory houses, but had found little acceptance in rest of the world. In recent years, however, due to increased awareness of the need for conservation of nonrenewable mineral resources, increased consideration is being given to the use of pervious concrete in most countries. Even though, it is not yet widely used in Sri Lanka, pervious concrete is generally used for light-duty pavement applications, such as residential streets, parking lots, driveways, sidewalks, channel lining, retaining walls and sound walls. This paper discuss the art of pervious concrete; materials and possible mix proportions, properties such as compressive strength, flexural strength, shrinkage, permeability with initial tests done at Innovation & Application Center of Holcim (Lanka) Limited, and the principal advantages, major disadvantages and principal applications in Sri Lankan construction industry.
item: Conference-Full-text
Pilot study using fibre optics and corrosion sensors for condition monitoring of water pipes
(2013-11-13) Tran, H; Sidiroglou, F; Dissanayake, R; Setunge, S; Qing Li, C
The aging of water infrastructural pipelines and the needs to safely and economically extend the service life are the main drivers for real time monitoring of structural deterioration of water pipelines. Fiber optics sensors provide a means of detecting and monitoring pipeline defects in real time. A common application of fiber optics sensors is to measure the strain and temperature of pipelines by attaching the fiber sensors along the pipelines. Any abnormal change in temperature could be an indication of leak while any excessive change of strain is an indication of tampering or structural damage. This paper presents a pilot study which was aimed to investigate the fibre optics sensors and corrosion sensor as in-situ sensors to provide real time data on corrosion condition of pipelines. Such data would improve the targeting of inspection programs, and allow improved monitoring and decision making for pipe repair or replacement. Furthermore, the data could be used for development of improved deterioration models and thus enhance knowledge of pipe deterioration.
item: Thesis-Abstract
Portfolio optimization using quadratic programming
(2014-08-14) Ranasinghe, LP; Cooray, TMJA; Dissanayake, R
Investment analysis is concerned, portfolio optimization is very important in order to get maximum profit. In the proposed research the optimization will be done in two main steps. The first part is the modelling mean variance so called reward and risk. The second part is finding optimum solution. The data set published by the Colombo Stock Exchange was used for this research paper as the raw data. The following five companies are selected for the analysis without biases those are Commercial bank, John Keells, Lanka Hospital, The Sri Lanka Telecom and The United motors. These companies represent several fields in the Sri Lankan market such as banking, group of companies, health service, semi government companies, automobile sector. The objective of the research is to find the optimum allocation of the portfolio. The risk should be minimized and the reward should be maximized at the same time. As a strategy to do both of these simultaneously, the linear combination with controlling arbitrary constant is used. That particular linear combination is a convex quadratic function. In order to find the solution of this, the numerical method is used via MATLAB inbuilt'm file'. The developed model of the Markowitz portfolio optimization model1 could be formulated in order to find the optimum allocation of investment amounts for any number of investment channels. The model can be used by investment researchers and could be applied to gain an analytical idea about the efficient frontier. The model has a parameter that can change emphasis on risk minimization or reward maximization. The portfolio optimization finds the optimum allocation of money to be invested. The optimum allocation depends on several factors, according to Markowitz, the return as well as risk, should be considered simultaneously. The main model for this research is 'Markowitz Portfolio Selection Model'. The objective function of the above model consists a linear combination of risk and return. Since the risk is a quadratic expression, the objective function can also be considered as a quadratic function. Then the normal optimization cannot be applied and the non linear optimization (quadratic optimization) must be applied. The main constraint that can be identified is the budgetary constraint along with other limitations, such as boundary restraints. The model has the advantage of changing the budget at any time and the user can use the total budget as a unit, then the optimum allocation fractions, for each investment can be found. The optimization calculation is carried out through 'Matlab', computer aided calculation software. The output of the optimization model is the ratio of the total investment amount to be allocated, the allocated in the percentages of the total portfolio for Commercial Bank, John Keells, Lanka Hospital, Sri Lanka Telecom and United Motors respectively as 0%, 0%, 62%, 38%, and 0%. The minimum function value is - 0.0907, and the function stands for the linear combination of the risk and the reward.
item: Conference-Full-text
A review on utilization of c & dwaste for road and pavement construction in the international context and applicability of the findings to Sri Lanka
(Springer, 2021) Arandara, KP; Priyadarshana, ST; Paranavithana, GN; Dissanayake, R; Pasindu, HR; Bandara, S; Mampearachchi, WK; Fwa, TF
In this paper, the utilization ofC&D(Construction and Demolition)waste for roads and pavements construction is reviewed in the international context. Further, the results are assessed to see the relevance to Sri Lanka. The relevant references gathered from the databases are referred to this study. The different countries and regions including Asia, Australia, Middle-East, Europe, and the USA, are covered with 67 papers. Those references are critically reviewed by applying PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) methodology and key C & D waste types utilized for roads and pavements construction are found out. The paper discusses Recycled Concrete Aggregates (RCA), Crushed Clay Bricks (CCB), and Recycled Asphalt Pavement (RAP) as the C & D materials that commonly are used for roads and pavements construction. Also, policies, laws, regulations, and procedures adopted in multiple countries, applicable to the C & D waste sector are discussed in the paper. The findings are evaluated in the latter part of the paper and proposed applicability/rationales to Sri Lanka are examined simultaneously. The authors conclude that the specified three types of CDW based recycled materials could be utilized across the cross-section of roads and pavements through effective methods and applications in several counties and the same approach is applicable in Sri Lanka also. This study confirms that very significant policy support in terms utilization of CDWis evident in most countries and the particular learnings could be applied in Sri Lanka to improve the current state appropriately.
item: Conference-Full-text
Seismic drift demand on multi-storey buildings in Sri Lanka due to long-distant earthquakes
(2013-11-26) Gamage, P; Venkatesan, S; Dissanayake, R
Intra-plate seismic activities in Northern Indian Ocean region below Sri Lanka, can be a possible threat of seismic hazard in terms of large magnitude long-distant earthquakes. Hypothesized seismic events with magnitudes 8, 7.5, 7 and 6, have been simulated based on this source by using the stochastic approach with estimated parameters for the Sri Lankan region. The crustal rock stratigraphy of the country consists mostly of crystalline rocks of Precambrian age, which governs the estimation of seismo-geological parameters were found to compare well with the well-known `hard rock’ conditions. Seismic response of structures from two major cities (Colombo and Hambantota) in the country was evaluated in terms of drift demands and base shears. The study includes both rock and soil sites. The soil amplification was carried out using the Extended Component Attenuation Model (ECAM) developed for typical intra-plate regions. Results show that, the base shear demands are far more significant than the drift demands for structures directly supported on rocks. Soft storey buildings directly founded on soil may experience higher drifts greater than allowable limits in some codes of practice. This suggests that important structures may need to be assessed using proper standards.
item: Thesis-Full-text
A Study on identifying hidden factors associated with customer satisfaction levels of an airline
(2015-08-26) Deshani, KAD; Dissanayake, R; Attygalle, MDT
Air transportation plays an important role in the modern world as it is the easiest way to travel to any part of the world within a very short period of time. With the increasing number of passengers travelling through airlines, new airline companies have evolved with time. Due to the high competitiveness among the airline companies, retaining the existing customers seems a challenging task. Among such strategies, identifying the reasons behind their customers’ priorities for their choice of airline plays an important facet. This study is based on feedback of the passengers for a “Service and Performance Survey” conducted by a certain airline company. Among the few customer satisfaction survey results that have been published, possibly due to the confidentiality, the analyses are mainly based on descriptive analysis. This study was carried out to find out hidden factors or characteristics of the customers that are associated with their satisfaction level using Latent Class Analysis which was not done in the previously literature. The passengers were classified based their satisfaction levels and it was found out that the airline company has achieved their desired satisfaction level of 80% their passengers only to few attributes like crew friendliness, crew efficiency, overall crew satisfaction level, cabin lighting and cabin cleanliness. Inflight entertainment attributes (choice of movies, video quality, choice of music, headset quality and choice of newspaper/magazine) have very low satisfaction levels compared to other onboard services and must be improved a lot. More choices of meals should be provided and special attention should be paid for the choices of meals for the air planes taking more Middle Eastern people.