@article { author = {ALTIN, A. and KABADAYI, H. and SABUNCUOGLU, A.}, title = {LIGHTLIKE RULED AND REVOLUTION SURFACES IN 􀔹3 1}, journal = {Iranian Journal of Science}, volume = {34}, number = {2}, pages = {95-101}, year = {2010}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2010.2168}, abstract = {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.}, keywords = {Lightlike surface,lightlike ruled surface,lightlike revolution surface}, url = {https://ijsts.shirazu.ac.ir/article_2168.html}, eprint = {https://ijsts.shirazu.ac.ir/article_2168_966d251fe029379c9662704899e31279.pdf} } @article { author = {MAHER, A. and UTKINA, YE. A.}, title = {ON THE CASES OF EXPLICIT SOLVABILITY OF A THIRD ORDER PARTIAL DIFFERENTIAL EQUATION}, journal = {Iranian Journal of Science}, volume = {34}, number = {2}, pages = {103-112}, year = {2010}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2010.2169}, abstract = {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.}, keywords = {Third order partial differential equation,the Goursat problem,the Riemann function}, url = {https://ijsts.shirazu.ac.ir/article_2169.html}, eprint = {https://ijsts.shirazu.ac.ir/article_2169_4c79b0a21011e167ffb9870fa6a0a4ab.pdf} } @article { author = {KESKIN, Y. and OTURANC, G.}, title = {REDUCED DIFFERENTIAL TRANSFORM METHOD FOR SOLVING LINEAR AND NONLINEAR WAVE EQUATIONS}, journal = {Iranian Journal of Science}, volume = {34}, number = {2}, pages = {113-122}, year = {2010}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2010.2170}, abstract = {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.}, keywords = {Reduced differential transform method,wave equation}, url = {https://ijsts.shirazu.ac.ir/article_2170.html}, eprint = {https://ijsts.shirazu.ac.ir/article_2170_2f253f0409a3300d7aa942dfd208a1c7.pdf} } @article { author = {MEHMOOD, A. and ALI, A.}, title = {TWO-DIMENSIONAL MAGMA FLOW}, journal = {Iranian Journal of Science}, volume = {34}, number = {2}, pages = {123-130}, year = {2010}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2010.2171}, abstract = {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}, keywords = {Magma flow,second-grade fluid,symmetry analysis,exact solution,controlling eruption}, url = {https://ijsts.shirazu.ac.ir/article_2171.html}, eprint = {https://ijsts.shirazu.ac.ir/article_2171_81ef0cb3313dcbfedbe0b9308ae0f359.pdf} } @article { author = {ARYADOUST, A. and H., SALEHI and FARBOD, M.}, title = {ELECTRONIC AND STRUCTURAL PROPERTIES OF TIN DIOXIDE IN CUBIC PHASE}, journal = {Iranian Journal of Science}, volume = {34}, number = {2}, pages = {131-138}, year = {2010}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2010.2172}, abstract = {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.}, keywords = {Lattice constant,bulk module,ceramic 2 SnO,electronic structure,electronic density distribution}, url = {https://ijsts.shirazu.ac.ir/article_2172.html}, eprint = {https://ijsts.shirazu.ac.ir/article_2172_316285dc18231f30cea718418d965276.pdf} } @article { author = {MANSOURI, B. and CHINIPARDAZ, R. and PARHAM, G. A.}, title = {DISCRIMINANT ANALYSIS IN AR(p) PLUS DIFFERENT NOISES PROCESSES}, journal = {Iranian Journal of Science}, volume = {34}, number = {2}, pages = {139-150}, year = {2010}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2010.2173}, abstract = {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.}, keywords = {Log-likelihood discrimination,AR(p) plus noise process,band matrix,pearson-curves}, url = {https://ijsts.shirazu.ac.ir/article_2173.html}, eprint = {https://ijsts.shirazu.ac.ir/article_2173_6dd1a5313b3be6c6f251bcafb9ba2a80.pdf} } @article { author = {MAYSAMI SADR, M. and POURABBAS, A.}, title = {JOHNSON AMENABILITY FOR TOPOLOGICAL SEMIGROUPS}, journal = {Iranian Journal of Science}, volume = {34}, number = {2}, pages = {151-160}, year = {2010}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2010.2174}, abstract = {–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 if1(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.}, keywords = {amenability,crossed homomorphism,topological semigroup}, url = {https://ijsts.shirazu.ac.ir/article_2174.html}, eprint = {https://ijsts.shirazu.ac.ir/article_2174_2990e75e6c1a45f163ad031807c50123.pdf} } @article { author = {HEYDARI, M. and LOGHMANI, G. B.}, title = {APPROXIMATE SOLUTION TO BOUNDARY VALUE PROBLEMS BY THE MODIFIED VIM}, journal = {Iranian Journal of Science}, volume = {34}, number = {2}, pages = {161-167}, year = {2010}, publisher = {Springer}, issn = {2731-8095}, eissn = {2731-8109}, doi = {10.22099/ijsts.2010.2175}, abstract = {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.}, keywords = {Variational iteration method,Chebyshev polynomials,boundary value problems}, url = {https://ijsts.shirazu.ac.ir/article_2175.html}, eprint = {https://ijsts.shirazu.ac.ir/article_2175_efbef62a60b71d2f6b575df55bbbc88d.pdf} }