Annual Research Symposium (ARS)
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Item Providing access to public health information via the institutional repository, Faculty of Medicine: A feasibility study based on medical undergraduates.(University of Kelaniya, 2013) Abeygunasekera, C.M.; Marasinghe, M.P.L.R.Community Medicine Clerkship and Community Attachment programs provide opportunity for medical undergraduates to learn how public health services are provided to the community. Their knowledge on health promotion, disease prevention, healthcare planning and management, demography and understanding epidemiology of diseases in the Sri Lankan context are very important. They are expected to read from diverse information sources to gain this knowledge, in addition to field based learning. As most of the recommended reading materials are considered grey literature sources, students are in a difficulty to access those resources within the library. Students face difficulties in accessing available online materials too, as some of the websites do not provide the information in a user friendly manner. With the understanding of possible barriers to access information, the Medical Library, University of Kelaniya, has developed a repository collection on ‘Public Health Information Resources,’ which are recommended as student reading materials for Community Medicine Clerkship and Attachment programs. This is under its online Institutional Repository (IR), developed using DSpace Software. This repository provides links to access a collection of resources published by different institutes. This is in addition to university libraries, which develop online digital repositories to preserve and distribute the intellectual scholarly information of the parent institute. A questionnaire and the User Guide to access the repository were given to a sample of fifty (50) students from Batch 21, who completed the Clerkship programme. Response rate to the questionnaire was 82% and more than 80% of students who were among the respondents ranked the collection as a useful resource which fulfilled their public health information needs. Barriers to information access were also assessed. Respondents have identified a list of difficulties they had in the past. Based on the feedback received, a resource collection inclusive of students’ suggestions is being planned to be introduced to the next batch of students.Item An Assessment of the Influence of Fundamental Factors on Share Prices in Sri Lanka,(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2008) Fernando, G.W.J. Sriyantha.This study analyses certain fundamental factors which are determinants of equity share prices in Sri Lanka. These factors are earning, growth, leverage, risk and company size. The literature review of the study have identified various aspects of equity share valuation. The theoretical and empirical studies have been used to formulate the foundation for the study. To assess above mentioned fundamental factors on share prices, multiple regression analyze was used with a log linear model as a cross section analyses related to the period 1993-2001. The sample for the study was selected from companies registered and listed in the Colombo Stock Exchange. The sample consisted of 40 companies from a group of239 companies in all industries. Result show that dividends appear to be a powerful influence in determining share prices than growth and retained earnings. Business risk and financial risk cannot be assessed because they are redundant variables. Company size is having a considerable influence on share prices and, accordingly large companies enj oy higher values for shares. On the basis of findings the following observation was made about the stock market in Sri Lanka. "The determinants of valuation of the share prices are not very clear. It goes mainly by considering dividend and company size factors which are readily measurable. However, factors like growth and risk cannot be measured with more certainty"Item On the systematic of anomalous absorption of partial waves by nuclear optical potential(Faculty of Graduate Studies, University of Kelaniya, 2008) Amarasinghe, D.; Munasinghe, J.M.; Piyadasa, R.A.D.An interesting phenomenon relating to the nuclear optical potential was discovered (Kawai M & Iseri Y,(1985)) [1] which is called the anomalous absorption of partial waves by the nuclear optical potential. They found, by extensive computer calculations, that, for a special combinations of the total angular momentum (j) ,angular momentum(/) ,energy (E) and the target nuclei(A), the elastic S-matrix elements corresponding to nucleon elastic scattering become zero. This phenomenon is universal for light ion elastic scattering on composite nuclei. [2]. It is very interesting that this phenomenon occurs for the realistic nuclear optical potential and it exhibits striking systematic in various parameter planes. For example, all nuclei which absorb a partial l waves of a definite node lie along a straight in the plane (Re, A 3 ) as shown in the figure , where Re is the closest approach and A is mass number of the target nucleus. Theoretical description of this systematic has been actually very difficult, though attempts have been made by the Kyushu group in Japan. In this contribution, we explain mathematically the most striking systematic of this phenomenon. Explanation of the systematic Partial wave· u 1 ( k, r) of angular momentum I and incident wave number k satisfies the Schrodinger equation d21 + [ k2 _ l (l : l ) _ 21 {V(r)+iW(r)}] u,(k,r)= 0 dr r 1i , where V (r) is the total real part and W (r) is the total imaginary part of the optical potential. Starting from this equation , one obtains (1) lu1(k,r)I2=2 XI du, 12 -g(ru1(r2Jdr (2) dr dr 0 where g(r)= [k2-�� V(r)-l(l r:1)J. If u1(k, r) is the anomalously absorbed partial wave, the corresponding S-matrix element is zero and hence in the asymptotic region I u1(k,r) I is almost constant. Therefore [1;1' -g(ru1(k,rt ] o (3) for large r. Now, from (1) and (3), it is not difficult to obtain[3] the equation _1 !!I 12 -- g'( r) wh (r) 'Jw ( )J 12d (4) 2 u1 - ( ) + 2 h r,., u, r lu,l dr 2g r g(r u,l 0 166 Proceedings of the Annual Research Symposium 2008- Faculty of Graduate Studies University of Kelaniya which is valid for large r , and has been numerically tested in case of an anomalously absorbed partial waves , where Wh(r) =- 2 W(r) . If W(r) decays much more rapidly n than V(r) in case of a partial wave under consideration lu,l2 =- g'( ( r) ) and by lu,l dr 2g r integrating this equation with respect to r, we obtain I iu1 (k, r)i2 (g(r) 2 = C (5) ,where C is a constant, and the equation (5) is valid for large values of r. In case of anomalous absorption of the partial wave, I u 1 ( k, r ) I is constant in the asymptotic region and therefore g(r) is also constant. We have found that for all partial waves corresponding to a straight line of definite node, g(r) is constant at the respective I [l(l + 1)]2 closest approach. For example, at Re = k , g(r) is constant for all partial waves lying on a straight line in case of anomalous absorption of neutron partial waves by the nuclear optical potential. Therefore, neglecting the spin-orbit potential , we get -I I 21tV0[1+exp[([l(/+l)F -1.17A3)]/arr1 =C0 n2 k where V0 is depth of the real potential and A is the target mass and the optical potential parameter ar = 0.75 and C0 is a constant. Therefore, in case of neutron, we get the linear relation [I (I+ 1)]2 = 1.11 A + C1 k . (6) where C1 is again a constant. This relation has found to be well satisfied in the cases we have tested numerically. The equation (6) well accounts for the anomalous absorption of neutron partial waves by the Nuclear Optical Potential as shown in the figure below. : [:::::r�;;�����i����:::]::::::::::::::::::::::::] :::::::::--::::::::::::: 1 I I I I I I 7 L----------J------------L---------__ J _ ----------L----------- : ----- ------L----------- ::N :: 6 : ----------: ------------: -----------: _ ___________ :L _ -------i: --------..:---: ----------- ;::::" 5 ,1- ------ l l l : : ! - ---,------------r---- -------, ---- ------r--- --------,------------r----------- + : : : I : : : ::-::::: 4 :I- -----------;I ------ I I I I I ------:----- ---"t-------- ----:------------ 1------------:------------ 1....1 I I I I I I I 3 lI- ----------1I ------------I -----------1I ------------rI -----------1I ------------rI ----------- 2 ::- ----------1: ------------: -----------1: ------------: -----------1: ------------: ----------- I I I I I I I ,a , 2 3 4 5 6 All3 Gradient of straight line predicted by ( 6) is 1.1 7 and the actual value is 1.1828 . Very small discrepancy is due to the negligence of the spin-orbit potential.Item Coupling Shallow Water Equation with Navier-Stokes Equations: A viscous shallow water model(Faculty of Graduate Studies, University of Kelaniya, 2008) Karunathilake, N.G.A.The general characteristic of shallow water flows is that the vertical characteristic scale D is essentially smaller than and typical horizontal scale L .i.e. £ := D << 1 . L In many classical derivations, in order to obtain the shallow water approximation of the Navier-Stokes's Equations, the molecular viscosity effect is neglected and a posteriori is added into the shallow water model to represent the efficient-viscosity ( a friction term through the Chezzy formula which involes empirical constants) at the bottom topography. However, the validity of this approach has been questioned in some applications as the models lead to different Rankine-Hugoniot curves (see e.g. [1]). Therefore, it can be useful to consider the molecular viscosity effect directly in the derivation of the shallow water model. On the other hand the classical shallow water models are derived under the assumption of slowly varying bottom topographies. Hence, for the description of incompressible shallow water laminar flow in a domain with a free boundary and highly varying bottom topography, the classical Shallow Water Equations are not applicable. The remedy consist of dividing the flow domain into two sub-domains namely, near field (sub domain with the bottom boundary) and far field (sub domain with the free boundary) with a slowly varying artificial interface and employ the Navier-Stokes Equations and Viscous Shallow Water Equations in the near field and far field, respectively. In this work, we derive a two-dimensional Viscous Shallow Water model for incompressible laminar flows with free moving boundaries and slowly varying bottom topographies to employ in the far field. In this approach, the effect of the molecular viscosity is retained and thereby corrections to the velocities and the hydrostatic pressure approximations are established. Coupling modified shallow water model with NSE has been carried out in a separate work. In order to derive the viscous shallow water model the two-dimensional Incompressible Navier-Stokes equations in usual notations au + au2 + auw + ap = ( 2v au) + (v au +V 8 w) , at ax az ax ax ax az az az aw + auw + 8w2 + ap =-g+ (vau +j.law) + ( 2vau), ---------------------------(1) at ax az az . ax az ax az az a-w+ a-w= 0. ax az are employed in the far field with the suitable boundary conditions. On the free surface, we assume that the fluid particle does not leave the free surface and we neglect the wind effect and the shear stress. On the artificial boundary we set the conditions according with the Navier-Stokes solution at the interface. On the lateral boundaries inflow and outflow conditions are employed. Rescaling the variables with the typical characteristic 151 Proceedings of the Annual Research Symposium 2008- Faculty of Graduate Studies University of Kelaniya scales L and D, the dimensionless form of the Navier-Stokes's equations for shallow water flows are obtained. Similarly, assuming that the bottom boundary is regular and the gradient of the free surface remains bounded we obtain the dimensionless boundary conditions. The second order terms with respect to & in the system are neglected and asymptotic analysis is carried out under the assumptions, the flow quantities admit linear asymptotic expansion to the second order with respect to & and the molecular viscosity of the water is very small. Then, rescaling the depth averaged first momentum equation of the resulting system and substituting the zeroth order solution for the velocity and the pressure in it the zeroth order first momentum equation which include the interface conditions is obtained. Again integrating the continuity equation of the dimensionless system from z1 to H(t, x ), a more detailed view of the vertical velocity component is established. Similarly, integrating the vertical momentum equation the dimensionless system from z1to H(t, x ) and replacing boundary conditions, the second order correction to the hydrostatic pressure distribution is derived. Then, dropping o(s2) in the system and switching to the variables with dimensions, the following results are established. Proposition: The formal second order asymp t ot ic ex p ansion of t he Navier-St okes Equat ions for t he shallow wat er laminarfl ow is given by ( z -z I ) ou . I ou 2 u(t, x, z) = u(t,x,z1) + I--- -(x, z1 ,t)(z-z1)---(x, z1 ,t)(z-z1) 2h oz 2h oz h(t,x)+z1 OU w(t,x,z)=w(t,x,z1)- f -d1] OX Z=Zt - ou ou p(t,x,z) = g(h+ z1 -z)-v-(t,x,z)-v-(x,t) ox ox wit h t he viscous shallow wat er equations ah + £(h)= ( w _ u az 1 ) , at ax ax z=Zt ( h) +£ {z h) + £( gh2 J = £( 4v h aJ -rl ' at ax 8x 2 ax 8x where r, [ p : +v: +v: -2v : : +u(u: -w) L,, and z z,(x, t ) is t he interface. Concluding remarks In the zeroth order expansion as well as in many classical shallow water models, the horizontal velocity does not change along with the vertical direction. In contrast, our first order correction gives a quadratic expansion to the vertical velocity components retaining more details of the flow. As many classical models we do not neglect the viscosity effect but just assume that it is very small. Also, the zeroth order hydrostatic pressure approximation has been upgraded to the first order giving a parabolic correction to the pressure distribution.Item The use of symbols and 'colour' for sports festivals.(Faculty of Graduate Studies, University of Kelaniya, 2008) Ramanyaka, Nilantha.The aim of this paper is to discuss the significance of 'Symbols'and the use of 'Colour' at national and international sporting events and festivals. Historical evidence reveals that the symbols and colors were used from the time of very early civilisations in the world. Some of the evidence is related with the development of human languages. However, with the development of civilizations and languages, verbal communication was placed forefront in order to present thoughts and feelings of the living elements of the universe. In the recent past the human interaction has resorted once again to non-verbal communication methods. In sport this phenomenon is widely used for a number of reasons and purposes. The use of emblems and colours in sporting events were initially done for promotional purposes. However emblems and colour were used to eonvey a powerful concept without the help of words. This study focuses on the importance of symbols and colours used in sporting events and the level of impact on the spectators. Based on data gathered from secondary sources this study hopes to discuss comparatively the use of symbols, and colours in national and international events held during the recent years. In most instances it is apparent that emblems are used in national sporting festivals as a showcase of the heritage of the respective country, in addition the emblems and colours are also used for the promotion of that event. Therefore the ability to reproduce this image on any number of products and surfaces would increase the viability of the emblem as well.Item Singularities of the elastic S-matrix element,(Faculty of Graduate Studies, University of Kelaniya, 2008) Jayasinghe, W.J.M.L.P.; Piyadasa, R.A.D.It is well known that the standard conventional method of integral equations is not able to explain the analyticity of the elastic S-matrix element for the nuclear optical potential including the Coulomb potential. It has been shown[1],[2] that the cutting down of the potential at a large distance is essential to get rid of the redundant poles of the S-matrix element in case of an attractive exponentially decaying potential. This method has been found [3] to be quite general and it does not change the physics of the problem. Using this method , analiticity and the singularities of the S-matrix element is discussed. Singularities of the elastic S-matrix element Partial wave radial wave equation of angular momentum l corresponding to elastic scattering is given by, [ d2 - 2 /(/+ 1)] 2p [ . ] 2 + k - 2 u1(k,r)=-2 V(r)+ Vc(r)+ zW(r) u1(k,r) M r n (1) where V (r) is the real part of nuclear potential, W (r) is the imaginary part of the optical potential · (r) is the Coulomb potential, and k is the incident wave number. Energy dependence of the optical potential is usually through laboratory energy E1ah and hence it depend on k2 and therefore k2- 2 [V(r) + Vc(r) + i W(r)] is depending on k n through e . It is Well known that . (r) is independent Of k Jn Order tO make U 1 ( k, r) an entire function of k , we impose k independent boundary condition at the origin . Now, we can make use of a well known theorem of Poincare to deduce that the wave function is an entire function of k2 and hence it is an entire function of k as well. We cut off the exponential tails of the optical potential at sufficiently large Rm and use the relation -1 --d u1 =.:u ;<--l -(k,-r)--s--'-r (--k,R--m----') u-'-;(+l--- ( k,-r) u, dr u/-l(k ,r)-sr(k,Rm) uj+l(k,r) (2) to define St(k,Rm),where u,<-l(k,r) and u,<+l(k,r) stand for incoming and outgoing Coulomb wave functions respectively which are given by I (±l(k )-+· [r(/+ l+i 17) ]2 [J[2"+iU+nJ w (-2 'u1 ,r - _l . e 1 1k r ) r(Z+I-z17) +i,,/+2 (3) where Ware the Whittaker functions. In the limit Rm oo St (k,Rm) ,the nuclear part of the S-matrix element , becomes St { k) and the redundant poles removed[1 ],[2].Now, the nuclear S-matrix element , in terms of the Whittaker functions is given by 143 Proceedings of the Annual Research Symposium 2008- Faculty of Graduate Studies University of Kelaniya where w' 1 (2ikr)-(k,r) W I (2ikr) IIJ, 1+-2 in'" 1+-2 , ,r 2 Rm W. 1 (-2ikr)-(-k,r)W 1 (-2ikr) -IIJ, I+-2 -ill ' 1+-2 P1(k,r) = u;(k,r) ,and St (k) has an essential singularity at k = 0, which u1(k,r) , (4) is apparent from the Wister's definition of the Gamma function l(z) smce z= l+ 1 ±i lJ .However, this singularity has no any physical meaning and is an outcome of treating 21Jk as well defined quantity for all k including k = 0 in the corresponding r Schrodinger equation .The infinite number of zeros and poles of S- matrix element due to the Gamma functions associated with S - matrix element have to be interpreted 1 carefully. S;'(k)=O at the zeros of ---- f(l+1+i1J ) and then the total wave function reduces to [ . ] I J( '7 +i(/+I)ZZ"j uj-l(k,r)=-i f(l+1-'7) e l 2 2 W (2ikr) f(l+1+zlJ) i11,1+l2 which is also zero. Even though the corresponding energies of these states are negative since the corresponding wave number is given by ? k= z · z,z2 e- 2 n= 0' 1' 2 , ... 11 (n+l+1) they are not physically meaningful bound states as found in[1],[2] long ago. These states are unphysical since poles are redundant poles. This fact is clearly understood by the fact that all these poles are absent in the physically meaningful total S - matrix element. For large 1k1, Sin' (k) (- ) { e-21k r S(k), where S(k) = [-ik+(k)] • +2k [ik-(-k)]. smce W = e- " for large k. Therefore the S-matrix element has an essential singularity at infinity, which is on the imaginary axis. It is clear that there are no redundant poles in the total S-matrix element is free from redundant poles sinceSJ (k) =SeS t , where Se = f(l + 1 + i7J) f(l+1-i1]) .Item A metric which represents a sphere of constant uniform density comprising electrically counterpoised dust,(Faculty of Graduate Studies, University of Kelaniya, 2008) Wimaladharma, N.A.S.N.; De Silva, Nalin.ABSTRACT Following the authors who have worked on this problem such Bonnor et.al 1•2 , Wickramasuriya3 and we write the metric which represents a sphere of constant density p = -1-, with suitable units, as ds2 = 47Z" (e(: ))2 c2 dt2 - ( e(r )Y ( dr2 + r2 dQ 2) ds2 = ( 1 B)' c'dT' - ( D + !)' (dR' + R2dQ') D+-R Ora A .!!! = e(a) dT (1+ ) (i) -2 ( ) -2 ( B (e(a) )3 B' a cdt = ) ( B )3 -7 cdT 1+-A => _dt = _-_B--'(,e(-'-a-- )Y---=----�(ii) dT A'B'(a{l + )' (1+ B => dr A ) -=-dR --B(a) _____ (iii) 154 Proceedi11gs of the A1111Ua/ Research Symposium 2008- Faculty of Graduate Studies U11iversity of Kela11iya From (i) and (ii), we have e(a1 = - B (B(a )Y 3 (t+ A) A'll'(a{l+ ) (1+ B ) From (iv), ( ) = !!_ (vi) Ba A __ (v) Using equation (vi) in equation (v), we have B -A'(:: } '(a) -a2ll'(a ) . Substituting the value of B in equation (iv), B(a )a = ( 1 + ) A = A+ B =A- a2B'(a) =>A= aB(a)+ a2B'(a) . Then the metric becomes ds2 = 1 c2 dt2 - (e( )Y (dr2 + r2 dQ2) (e(r )Y r dsz = 1 cz dT z - (1- (a2B '(a))J 2 ( dRz + R z dQ z ) (t _(a'(a))J' R where A=(ae(a )+ a2B'(a ))Item The Executive Presidency and the Seventeenth Amendment(Faculty of Graduate Studies, University of Kelaniya, 2007) Mudalige, PriyanthaJ. R. Jayawardene and his United National Party (UNP) were able to get five upon six majority at the general election held in July 1977. According to the prevailing constitution, Mr. Jayawardene was elected as the Prime Minister of Sri Lanka. In 1978 he brought an amendment to the existing 1972 first republic constitution of Sri Lanka. With the amendment he introduced the executive presidency. In the same year he and his party brought another amendment to repeal the 1972 constitution and introduced a new constitution which is a combination of presidential government system and Westminster Government system. Therefore this constitution is <;:onsidered as a dual executive system. The dual executive contains the president and the cabinet. Therefore we can say that both the president and the cabinet have a great responsibility in maintaining the government system. The President is chosen from a presidential election and he plays the main role in the government . The Prime Minister is appointed by the president. The Prime Minister and the cabinet have to support the president in all terms. According to the constitution 1978 in article 4 (b) the executive power of people, including the defence of Sri Lanka, shall be exercised by the president of the republic elected by the people. In article 43 (I) there shall be a cabinet of ministers charged with the direction and control of the government of the republic which shall be collectively responsible and answerable to parliament. In article 43 (3) the president shall appoint as Prime Minister the member of parliament who in his opinions is most likely to command the confidence of parliament. According to the above mentioned factors the executive president of Sri Lanka has a great power in ruling the country. There is a criticism that the power of the president has exceeded the judicial and legislative power and therefore many have suggested to eliminate the executive presidency or to reduce and control the power of the president. In this regard an important legislative action took place in October 200l.That was the unanimous approval of the seventeenth amendment of the 1978 constitution. By this amendment a constitutional council was established and as a result of this the judicial service and the public service have been able to be saved from politicalization. Because 6f thi�� amendment the monopolistic power of the president of appointing higher officials of state is controlled. As we all know the seventeenth amendment was brought with the intention of reducing the executive power of the president. However by considering the current situation, It is necessary to inquiry whether the seventeenth amendment was successful or not. Secondary data was collected through the constitution amendments of constitution and other related acts and literature .Also particular attention is given to qualitative methodology.Item Future prospects of value added tea sector of Sri Lanka: comparative study,(University of Kelaniya, 2006) Wanninayake, W.M.C.B.; Dissanayake, D.M.R.Sri Lanka has been position in the world as one of leading tea manufactures and it has more than 100 years of experience for Sri Lankan tea industry. The world tea market has been rapidly growing with newly emerging customer needs. Specially it could be identified that the relative importance of unbranded (basic) tea consumption is being decreased among those high end segments all over the world. Although Sri Lankan tea industry had been mainly focused on bulk tea from the beginning now, Sri Lankan tea sector is being diversified into value added trends with some value added strategies in terms of new product levels, value features, branding and packaging too. But again, the major international tea competitors such as Kenya, China, India, Indonesia, Vietnam and Argentina are also aggressively following those value added strategies to penetrate and capture the potential markets. With this background Sri Lankan value added tea sector has to scan the existing and potential competitive forces to develop effective competitive strategies for having sustainable marketing results. Here, this research focuses on identifying the present competitive situation of Sri Lankan value added tea sector compared to international competition and further it discusses the existing strategies followed by this sector in terms of international brand development. The research has been broadly based on secondary data published by Central Bank of Sri Lanka, Sri Lankan Tea board, web site published articles, journals and news papers. Further some primary data has been collected through unstructured personal interviews. Finally researchers have found following major findings. The relative importance of value added tea in Sri Lankan tea industry has been growing tremendously. It has achieved relatively higher net gain by Sri Lankan value added tea than other competitive countries. Sri Lankan tea sector is following tea import strategy and re-export them with added values successfully. The overall brand development in Sri Lankan tea industry should be further developed so that it can acquire a higher competitive share. Here the researchers have concluded some recommendations for competitive development in Sri Lankan value added tea sectorItem The causal relations among stock prices and the macro economic variables: Evidence from Sri Lanka(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2002) Tilakasiri, K.K.