2010
34
2
2
0
LIGHTLIKE RULED AND REVOLUTION SURFACES IN 3 1
2
2
In this paper lightlike ruled surfaces in 3 1=(3,dx2+dy2+dz2) are studied with respect to whetherruling curves are spacelike or null. It is seen that, in the first case the Gaussian curvature of the ruled surfacesvanishes. In the second case the Gaussian curvature of the ruled surfaces are negative. In the second caselightlike ruled surfaces are totally umbilical. Furthermore, lightlike surfaces of revolution are shown to beonly cones, and the second type lightlike ruled surface.
1

95
101


A.
ALTIN
Hacettepe University, Faculty of Science, Department of Mathematics, 06550 Beytepe, Ankara, Turkey
Hacettepe University, Faculty of Science,
Turkey


H.
KABADAYI
Ankara University, Faculty of Science, Department of Mathematics, 06100 Tandogan, Ankara, Turkey
Ankara University, Faculty of Science, Department
Turkey
kabadayi@science.ankara.edu.tr


A.
SABUNCUOGLU
Ankara University, Faculty of Science, Department of Mathematics, 06100 Tandogan, Ankara, Turkey
Ankara University, Faculty of Science, Department
Turkey
Lightlike surface
lightlike ruled surface
lightlike revolution surface
ON THE CASES OF EXPLICIT SOLVABILITY OF A THIRD ORDER PARTIAL DIFFERENTIAL EQUATION
2
2
In this paper, the Goursat problem of a third order equation on cases of explicit solvability isinvestigated, with the help of the Riemann function. Some results and one theorem are given concerning theexistence and uniqueness for the solution of the suggested problem.
1

103
112


A.
MAHER
Department of Mathematics, University College in Makkah, Pox: 2064, Umm AlQura Uni., KSA
Department of Mathematics, University College
United States
a_maher69@yahoo.com


YE. A.
UTKINA
Department of Differential Equations, Kazan State University, Russia
Department of Differential Equations, Kazan
Russian Federation
Third order partial differential equation
the Goursat problem
the Riemann function
REDUCED DIFFERENTIAL TRANSFORM METHOD FOR SOLVING LINEAR AND NONLINEAR WAVE EQUATIONS
2
2
Reduced differential transform method (RDTM) is applied to various wave equations. To assessthe accuracy of the solutions, we compare the results with the exact solutions and variational iteration method.The results reveal that the RDTM is very effective, convenient and quite accurate to systems of nonlinearequations.
1

113
122


Y.
KESKIN
Department of Mathematics, Science Faculty, Selcuk University, Konya 42003, Turkey
Department of Mathematics, Science Faculty,
Turkey
yildiraykeskin@yahoo.com


G.
OTURANC
Department of Mathematics, Science Faculty, Selcuk University, Konya 42003, Turkey
Department of Mathematics, Science Faculty,
Turkey
Reduced differential transform method
wave equation
TWODIMENSIONAL MAGMA FLOW
2
2
Exact solution for steady twodimensional flow of an incompressible magma is obtained. Themagmatic flow is studied by considering the magma as a second grade fluid. The governing partialdifferential equations are transformed to ordinary differential equations by symmetry transformations. Resultsare discussed through graphs to understand the rheology of the flowing magma
1

123
130


A.
MEHMOOD
Department of Mathematics (FBAS), International Islamic University Islamabad 44000, Pakistan
Department of Mathematics (FBAS), International
Pakistan
ahmerqau@yahoo.co.uk


A.
ALI
Department of Mathematics QuaidiAzam University 45320 Islamabad 44000, Pakistan
Department of Mathematics QuaidiAzam University
Pakistan
Magma flow
secondgrade fluid
symmetry analysis
exact solution
controlling eruption
ELECTRONIC AND STRUCTURAL PROPERTIES OF TIN DIOXIDE IN CUBIC PHASE
2
2
The electronic structure, energy band structure and electronic density of 2 SnO ceramic in cubicphase have been investigated using first principle full potentiallinearized augmented plane wave (FPLAPW)method within density functional theory (DFT). Local density approximation (LDA) and the generalizedgradient approximation (GGA), which are based on exchange correlation energy optimization were used.The band gap was 2.2 eV at point in the Brillouin zone within our approach. Calculations of the bandstructure and electronic structure of 2 SnO were in a good agreement with the previous experimental andtheoretical results with different approximations. Moreover, electronic density map shows that the bondingbetween Sn and O atoms is ionic.
1

131
138


A.
ARYADOUST
Department of Physics, Shahid Chamran University, Ahvaz, I. R. of Iran
Department of Physics, Shahid Chamran University,
Iran


SALEHI
H.
Department of Physics, Shahid Chamran University, Ahvaz, I. R. of Iran
Department of Physics, Shahid Chamran University,
Iran


M.
FARBOD
Department of Physics, Shahid Chamran University, Ahvaz, I. R. of Iran
Department of Physics, Shahid Chamran University,
Iran
Lattice constant
bulk module
ceramic 2 SnO
electronic structure
electronic density distribution
DISCRIMINANT ANALYSIS IN AR(p) PLUS DIFFERENT NOISES PROCESSES
2
2
The problem of discrimination between two stationary AR(p) plus noise processes is consideredwhen the noise process are different in two models. The discrimination rule leads to a quadratic form withcumbersome matrices. An approximate and analytic form is given to distribution of the discriminant. Thesimulation study has been used to show the performance of discrimination rule. The cumulants ofdiscriminant function are obtained and show them to be very close to the true values given in literature.
1

139
150


B.
MANSOURI
Department of Statistics, University of Shahid Chamran, Ahvaz, I. R. Iran
Department of Statistics, University of Shahid
Iran


R.
CHINIPARDAZ
Department of Statistics, University of Shahid Chamran, Ahvaz, I. R. Iran
Department of Statistics, University of Shahid
Iran
chinipardaz_r@scu.ac.ir,


G. A.
PARHAM
Department of Statistics, University of Shahid Chamran, Ahvaz, I. R. Iran
Department of Statistics, University of Shahid
Iran
Loglikelihood discrimination
AR(p) plus noise process
band matrix
pearsoncurves
JOHNSON AMENABILITY FOR TOPOLOGICAL SEMIGROUPS
2
2
–A notion of amenability for topological semigroups is introduced. A topological semigroup S iscalled Johnson amenable if for every Banach S bimodule E , every bounded crossed homomorphism fromS to E* is principal. In this paper it is shown that a discrete semigroup S is Johnson amenable if and only if1(S) is an amenable Banach algebra. Also, we show that if a topological semigroup S is Johnson amenable,then it is amenable, but the converse is not true.
1

151
160


M.
MAYSAMI SADR
Department of Mathematics, Institute for Advanced Studies in Basic Sciences, Zanjan, I. R. of Iran
Department of Mathematics, Institute for
Iran


A.
POURABBAS
Faculty of Mathematics and Computer Science, Amirkabir University of
Technology, 424 Hafez Avenue, Tehran 15914, I. R. of Iran
Faculty of Mathematics and Computer Science,
Iran
arpabbas@aut.ac.ir
amenability
crossed homomorphism
topological semigroup
APPROXIMATE SOLUTION TO BOUNDARY VALUE PROBLEMS BY THE MODIFIED VIM
2
2
This paper presents an efficient modification of the variational iteration method for solvingboundary value problems using the chebyshev polynomials. The proposed method can be applied to linearand nonlinear models. The scheme is tested for some examples and the obtained results demonstrate thereliability and efficiency of the proposed method.
1

161
167


M.
HEYDARI
Department of Mathematics, Yazd University, Yazd, I. R. of Iran
Department of Mathematics, Yazd University,
Iran


G. B.
LOGHMANI
Department of Mathematics, Yazd University, Yazd, I. R. of Iran
Department of Mathematics, Yazd University,
Iran
loghmani@yazduni.ac.ir
Variational iteration method
Chebyshev polynomials
boundary value problems