Research Topic: Numerical Simulation of Convective Heat Flaw in a Solar Water Heater

Group:- Dr. JK Wijeratne, Mrs. K Diana Nilmini Kumari

Introduction:

Solar energy became a vital interest in terms of green energy production. The power can be provided by solar energy without burning coal and other fossil fuels. Accordingly the byproducts that contribute to air pollution will be reduced. Solar energy is one of this our main focuses of green energy source which has a great potential in Sri Lanka. The most common uses of solar energy in Sri Lanka include drying, heating and electricity production. Solar water heaters are frequently used in hotel sector and can be used as a pre-heater source for industrial applications as well as home needs to save cost of energy. The second largest consumer of energy in most homes is for water heating and solar water heating system will typically provide 70-90% of the average domestic hot water needs over a year. However there can be several drawbacks with solar water heaters that may make them not worth the effect for many people. The initial investment in solar water heaters can be quite costly. The performance of solar water heaters depend on weather.

After the solar water heater system has paid, in addition to having free hot water it will be reduced utility bills and it can be assisted in reducing the country’s dependence on oil. The performance of a solar water heater is depended upon the collector and storage tank design and the weather conditions. As a tropical country, Sri Lanka receives an abundant supply solar radiation quite uniformly around the year. Therefore it is advisable to make use of mathematical modeling and simulation to identify and improve the efficiency of solar water heaters available in Sri Lanka.

Research Topic:Mathematical Analysis and Optimal Control of Dynamics of Dengue Transmission.

Group: Dr. S.S.N Perera, Mr. Dilruk Gallage

Introduction:

Dengue is one of the most prevalent viruses by mosquitoes where increasing incidence and severity claims it as a worrisome disease. This virus is common throughout the tropics and subtropics. Outbreaks have occurred in the US Virgin Islands, Cuba and Central America. Also it is increasing in Asia and Africa. According to the World Health Organization, there are an estimated 50 million cases of dengue fever with 500,000 cases of dengue hemorrhagic fever requiring hospitalization each year. Nearly 40% of the world’s population lives in an area endemic with dengue.

Dengue fever is caused by family of viruses that are transmitted by Aedes mosquitoes. Though its claim classic form causes flu-like symptoms and is not life-threatening, more severe forms as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) can be fatal, especially in children.

During the past few years, the characteristics of dengue in Sri Lanka appear to have changed. For instance, a decade ago, children were predominantly affected, but in recent years clinicians have seen increasing numbers of adult dengue patients, with both significant morbidity and increasing number of adult deaths due to dengue. Therefore, it is vital to investigate the changes of dengue transmission dynamics.

So it is important to have a solid idea about theoretical aspects of dengue transmission and their characteristics.

Research Topic: Mathematical optimization of space debris mitigation and Strategy analysis

Group:Dr. JK Wijeratne, Mr. C.R Rajapaksa.

Introduction:

Space activities conducted by humans on Earth orbit began with the first launch of the artificial satellite Sputnik1 in 1957.  Since then, orbital debris has increased with time and approximately 19,000 objects larger than 10cm and approximately 500,000 particles between 1 and 10 cm’s exist in space and probably tens of millions of particles smaller than 1cm roams in orbit today. U.S. Space Surveillance Network tracks larger orbital objects (> 10cm) and approximately 15,000 objects were in their catalogue as of 1st May 2010. Fifty percent of all orbital debris is vulnerable to collisions, which result in fragmentation of debris and that leads to a rise in the debris populations in the future even in the absence of future space launches.

    Mechanisms for Removing or reducing space debris

1)      Minimizing the break up potential during operational phases

2)      Limiting the accidental collision in orbit

3)      Avoiding intentional destructive and harmful operations (deliberate collisions) in orbit

4)      Limiting debris released during normal operations

5)      Limiting long-term presence of launch vehicle and the spacecraft in low earth orbit (LEO) region and geosynchronous (GEO) region after end of their missions

6)      Taking active measures to deorbit or move debris to alternative orbits

From the above mechanisms, the active measures to deorbit the debris object have been chosen for the suggesting study. The international space community has focused on debris mitigation measures that lasted a decade, and they have introduced policies and guidelines to address these issues.  In 2007, the United Nations adopted space debris mitigation guidelines. However, adopting these guidelines was not sufficient to stabilize the LEO debris environment, nevertheless active debris removal methods may help to control the situation. Moreover, active debris removal methods will enhance the reliability of future space systems. These methods need to address technological, financial and political constraints when being implemented. Furthermore, these systems should identify effective mitigation and removal strategies based on reliability, robust criteria and appropriate performance metrics. Previous studies used high-definition models of space debris environment to select these criteria and metrics on a relatively ad-hoc basis. Therefore, there is still a current requirement to identify a potentially optimal solution for space debris removal.

This field of research commenced more than twenty-five years ago and numerous methods were proposed to remove large debris.

Objectives of the research

It is suggested that when a single vehicle attempts to carry severaldeorbiting packages within different inclinations, even at same altitudes it requires a very high fuel mass and delta-v due to the plane changes that should be attended by the spacecraft. Equipped iron engines with satellites could also be used to direct debris back to the earth’s atmosphere. However, due to the high-energy requirements, this was also not worth being operational in the past. In addition, it requires a long-term power source and attitude control sub systems. This implies a practical approach to orbital debris removal process that needs to be developed more thoroughly to adopt a feasible system. This leads the main objective of the this research to find the best optimum solution to deorbit the debris to a position approximately below 100km of altitude to completely decay the debris object in the earth’s atmosphere. The optimum solution will be future analyzed to give out the best mission options in order to identify the most effective sequence of debris that needs to be de-orbited with priority. Technical communities have focused to obtain precise information about debris via the SGP4 model as it helps to predict these orbital debris objects more effectively. Consequently, the author of this study decides to use the SGP4(Simplified General Perturbation) model

Research Topic: A Mathematical Model to study dynamics of Dengue epidemics and controllability of transmission of Dengue

Group: Dr. S.S.N. Perera,Prof. Saroj Jayasinghe, Mr. W.P.T.M. Wickramaarachchi

Introduction:

Dengue is one of the most prevalent viruses by mosquitoes where increasing incidence and severity claims it as a worrisome disease. This virus is common throughout the tropics and subtropics. Outbreaks have occurred in the US Virgin Islands, Cuba and Central America. Also it is increasing in Asia and Africa. According to the World Health Organization, there are an estimated 50 million cases of dengue fever with 500,000 cases of dengue hemorrhagic fever requiring hospitalization each year. Nearly 40% of the world’s population lives in an area endemic with dengue.

During the past few years, the characteristics of dengue in Sri Lanka appear to have changed. For instance, a decade ago, children were predominantly affected, but in recent years clinicians have seen increasing numbers of adult dengue patients, with both significant morbidity and increasing number of adult deaths due to dengue. Each year the government of Sri Lanka spends a huge amount of money on the prevention of dengue and for the dengue infected people. Therefore, it is very important to investigate, how this virus spreads while considering their age, gender and other demographic factors with the attitudes of the government and people.

Research Topic: Developing and validating a Mathematical model to quantify air quality in Sri Lanka

Group : Dr. S. K. Boralugoda, Dr. S.S.N. Perera, Ms. Illangamge Thilini Sashika Piyatilake

Air pollution is now becoming a critical issue in both developed and developing countries. This issue has been seriously emerged in Sri Lanka with no difference in other Asian countries. Sri Lanka has witnessed the significant increase in the level of ambient air pollution due to urbanization and increasing levels of industrializations. The main ambient pollutants are Carbon Dioxide, Carbon Monoxide, Nitrogen Oxides, Sulphur Oxides, Lead and Environment Tobacco Smoke which cannot exist alone and produce a complex mixture of each of pollutants. The sources of these pollutants are spectrum of different sources which are broadly classified as stationary, vehicles and thermal power plants.

In Sri Lanka quality of the air has profound impacts on the economy as well. The most obvious of these impacts is related to health problems associated with poor air quality and the corresponding cost of medical care and treatments. Many of government and nongovernment bodies have been exercised on this problem in order to improve the quality of air. Therefore it is worthwhile to make use of mathematical illustrations to controlling measures of air pollution.

Our aim is to develop air quality models, which are mathematical descriptions of concentration of a mixture of ambient pollutants, ignoring the various underlying processes. Putting the problem in a more personal context, suppose that you live in a highly populated area, the place where the vehicular emission is high. In that kind of an environment what is the maximum concentration of CO in your surroundings according to the given standards (environmental factors, location etc).

Research Topic: Developing a mathematical model to study risk of Dengue transmission of Dengue.

Group: Dr. S.S.N. Perera,Dr.NC Ganegoda, Mrs. B.W.M.N.M De Silva

Introduction:

Dengue is one of the most prevalent viruses by mosquitoes where increasing incidence and severity claims severe social burden. This virus is common throughout the tropics and subtropics. Outbreaks have occurred in the US Virgin Islands, Cuba, Central America and many Asian and African countries. According to the World Health Organization, there are an estimated 50 million cases of dengue fever with 500,000 cases of dengue hemorrhagic fever requiring hospitalization each year. Nearly 40% of the world’s population lives in an area endemic with dengue.

Dengue fever is caused by family of viruses that are transmitted by Aedesmosquitoes. Though its claim classic form causes flu-like symptoms and is not life-threatening, more severe forms as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) can be fatal, especially in children.

During the past few years, the characteristics of dengue in Sri Lanka appear to have changed. For instance, a decade ago, children were predominantly affected, but in recent years increasing numbers of adult dengue patients have been seen, with both significant morbidity and increasing number of adult deaths due to dengue. Therefore, it is very important to investigate, how this virus spreads while considering their age, gender and other demographic factors with the attitudes of the government and people.

There is no vaccination and standard treatment for dengue. Control the transmission of dengueis the only strategy to prevent the disease. Therefore, it is essential to know which factors to be controlled in what level and what strategies to be implemented.

Research Topic: Introduction Controllable Techniques for Portfolio Optimization

Group: Dr.S.S.N.Perera, Dr. JK Wijeratne, Prof N. Privault , Mr.Lakmal Prabash Ranasinghe

Introduction:

The main idea of portfolio optimization is to find the optimal asset allocation in order to find the maximum return with the minimum risk.

Since the beginning of modern investment theory, there has been constant controversy about the concept of risk, and increasing interest in ways to quantify it. This controversy has been accompanied by, the growth of investment industry in portfolio models based on sophisticated quantitative methods which require a huge computing power.

Markowitz portfolio theory is the most prominent and frequently used model. Based on Markowitz model many researches have been conducted and many extended models have been developed such as Black-litterman. Those extended models mainly target the expected return. This is better than in the Markowitz’s model and they blend with CAPM. There are some extensions for Black litterman model such as Theil’s mixed estimation and Idzorek’s extension.

The new concept of the proposed research is to introduce a control technique to the current portfolio optimization model. This controllability helps to allocate assets with the investors view. The difference between above extended models and proposed research is, Black litterman and robust have introduced a new combined return distribution (Implied return + Investor view = expected return), but the aim of the proposed research is to find a control technique along with other standard methodologies to find a better way of asset allocation.

Research Topic: Development of an information gain measure and a pre-selection criterion for decision tree algorithm

Group:  Dr. JK Wijeratne, Mr. Nimal Shantha Rathnayaka

Introduction:

Decision tree classification method is one of  most widely used data classification method in many fields such as medicine, manufacturing and production, financial analysis, education, astronomy, molecular biology, pattern recognition etc. One of most important part in a decision tree algorithm is to select, which attribute will become a splitting attribute in the tree. There are various algorithms for constructing a decision tree, like ID3, C4.5, and CART. These algorithms use the Information Gain, Gain ratio and Gini index to select the splitting attribute.As objectives of the research; studying existing decision tree algorithm with pre-selection measures and developing new pre-selection criterion in order to increase the prediction accuracy of the decision tree algorithm.

Research Topic:Development of mathematical model for risk assessment of plant species during deliberate introductions to Sri Lanka

Group: Dr. S.S.N. Perera, Dr. S.M.W. Ranwala, Ms.H.O.W. Peiris

Introduction:

Invasiveness of a species is recognized as the ability of a species to spread, establish beyond it’s origin while harming the biodiversity of the new environment. Invasive alien plants are therefore considered as a serious threat to the existence of various ecosystems as they alter physical, chemical and biological components of the environment. Over the past few years there has been a growing interest to minimize these threats by introducing and implementing various management strategies at various levels. Common approaches for management of invasive alien species encompass prevention, early detection, eradication, control and containment.

It is well known that increased trade and tourism, human travel and migrations facilitated intentional and unintentional introductions of species all over the world.Many deliberate introductions have later caused worrying problems as they have not been subjected to any risk assessment during their introduction. However at present impacts of species introductions are being seriously considered in the international trade and environmental policy agendas through a variety of international agreements. Thus risk assessments (RA)have beenincorporated into quarantine legislation and procedures at national borders to regulate the entry of species into new environments. In Sri Lanka several government agencies such as National Plant Quarantine Services, Seeds Certificate Centre of the Department of Agriculture conduct qualitative investigations on likelihood of the entry, establishment and spread of aquatic or terrestrial invasive plants. At present, a specific risk assessment procedure to regulate introduction in invasive alien species (IAS) has been suggested by the Ministry of Environment.