2024-03-29T09:37:33Z
https://ijsts.shirazu.ac.ir/?_action=export&rf=summon&issue=455
Iranian Journal of Science
ISTT
2731-8095
2731-8095
2010
34
2
LIGHTLIKE RULED AND REVOLUTION SURFACES IN 3 1
A.
ALTIN
H.
KABADAYI
A.
SABUNCUOGLU
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.
Lightlike surface
lightlike ruled surface
lightlike revolution surface
2010
10
10
95
101
https://ijsts.shirazu.ac.ir/article_2168_966d251fe029379c9662704899e31279.pdf
Iranian Journal of Science
ISTT
2731-8095
2731-8095
2010
34
2
ON THE CASES OF EXPLICIT SOLVABILITY OF A THIRD ORDER PARTIAL DIFFERENTIAL EQUATION
A.
MAHER
YE. A.
UTKINA
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.
Third order partial differential equation
the Goursat problem
the Riemann function
2010
10
10
103
112
https://ijsts.shirazu.ac.ir/article_2169_4c79b0a21011e167ffb9870fa6a0a4ab.pdf
Iranian Journal of Science
ISTT
2731-8095
2731-8095
2010
34
2
REDUCED DIFFERENTIAL TRANSFORM METHOD FOR SOLVING LINEAR AND NONLINEAR WAVE EQUATIONS
Y.
KESKIN
G.
OTURANC
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.
Reduced differential transform method
wave equation
2010
10
10
113
122
https://ijsts.shirazu.ac.ir/article_2170_2f253f0409a3300d7aa942dfd208a1c7.pdf
Iranian Journal of Science
ISTT
2731-8095
2731-8095
2010
34
2
TWO-DIMENSIONAL MAGMA FLOW
A.
MEHMOOD
A.
ALI
Exact solution for steady two-dimensional 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
Magma flow
second-grade fluid
symmetry analysis
exact solution
controlling eruption
2010
10
10
123
130
https://ijsts.shirazu.ac.ir/article_2171_81ef0cb3313dcbfedbe0b9308ae0f359.pdf
Iranian Journal of Science
ISTT
2731-8095
2731-8095
2010
34
2
ELECTRONIC AND STRUCTURAL PROPERTIES OF TIN DIOXIDE IN CUBIC PHASE
A.
ARYADOUST
SALEHI
H.
M.
FARBOD
The electronic structure, energy band structure and electronic density of 2 SnO ceramic in cubicphase have been investigated using first principle full potential-linearized augmented plane wave (FP-LAPW)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.
Lattice constant
bulk module
ceramic 2 SnO
electronic structure
electronic density distribution
2010
10
10
131
138
https://ijsts.shirazu.ac.ir/article_2172_316285dc18231f30cea718418d965276.pdf
Iranian Journal of Science
ISTT
2731-8095
2731-8095
2010
34
2
DISCRIMINANT ANALYSIS IN AR(p) PLUS DIFFERENT NOISES PROCESSES
B.
MANSOURI
R.
CHINIPARDAZ
G. A.
PARHAM
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.
Log-likelihood discrimination
AR(p) plus noise process
band matrix
pearson-curves
2010
10
10
139
150
https://ijsts.shirazu.ac.ir/article_2173_6dd1a5313b3be6c6f251bcafb9ba2a80.pdf
Iranian Journal of Science
ISTT
2731-8095
2731-8095
2010
34
2
JOHNSON AMENABILITY FOR TOPOLOGICAL SEMIGROUPS
M.
MAYSAMI SADR
A.
POURABBAS
–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.
amenability
crossed homomorphism
topological semigroup
2010
10
10
151
160
https://ijsts.shirazu.ac.ir/article_2174_2990e75e6c1a45f163ad031807c50123.pdf
Iranian Journal of Science
ISTT
2731-8095
2731-8095
2010
34
2
APPROXIMATE SOLUTION TO BOUNDARY VALUE PROBLEMS BY THE MODIFIED VIM
M.
HEYDARI
G. B.
LOGHMANI
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.
Variational iteration method
Chebyshev polynomials
boundary value problems
2010
10
10
161
167
https://ijsts.shirazu.ac.ir/article_2175_efbef62a60b71d2f6b575df55bbbc88d.pdf