Ferdowsi University of MashhadIranian Journal of Numerical Analysis and Optimization2423-69771120080101On algebraic characterizations for finiteness of the dimension of EG1222439910.22067/ijnao.v1i1.616ENOlympiaTalelliDepartment of Mathematics, University of Athens
Panepistemiopolis, 15784 Athens - GreeceJournal Article19700101Certain algebraic invariants of the integral group ring ZG of a group G were introduced and investigated in relation to the problem of extending the Farrell-Tate cohomology, which is defined for the class of groups of finite virtual cohomological dimension. It turns out that the finiteness of these invariants of a group G implies the existence of a generalized Farrell-Tate cohomology for G which is computed via complete resolutions. In this article we present these algebraic invariants and their basic properties and discuss their relationship to the generalized Farrell-Tate cohomology. In addition we present the status of conjecture which claims that the finiteness of these invariants of a group G is equivalent to the existence of a finite dimensional model for EG, the classifying space for proper actions.https://ijnao.um.ac.ir/article_24399_5a1d6a9475aef57c33c2f263325f84df.pdfFerdowsi University of MashhadIranian Journal of Numerical Analysis and Optimization2423-69771120080101New classes of infinite groups23402440010.22067/ijnao.v1i1.617ENV.I.SenashovInstitute of Computational Modeling of Siberian Division of Russian Academy of SciencesV.P.ShunkovInstitute of Computational Modeling of Siberian Division of Russian Academy of SciencesJournal Article19700101In this article, we consider some new classes of groups, namely, Mp-groups, T0-groups,Ø-groups,Ø0-groups, groups with finitely embedded involution, which were appeared at the end of twenties century. These classes of infinite groups with finiteness conditions were introduced by V.P. Shunkov. We give some review of new results on these classes of groups.https://ijnao.um.ac.ir/article_24400_30fee98eaa7afc4be4ec3fa477ae082a.pdfFerdowsi University of MashhadIranian Journal of Numerical Analysis and Optimization2423-69771120080101Groups with soluble minimax conjugate classes of subgroups41502440110.22067/ijnao.v1i1.618ENFrancescoRussoMathematics Department, University of Wuerzburg, Wuerzburg, GermanyJournal Article19700101A classical result of Neumann characterizes the groups in which each subgroup has finitely many conjugates only as central-by-finite groups. If X is a class of groups, a group G is said to have X-conjugate classes of subgroups if G/coreG(NG(H)) 2 X for each subgroup H of G. Here we study groups which have soluble minimax conjugate classes of subgroups, giving a description in terms of G/Z(G). We also characterize FC-groups which have soluble minimax conjugate classes of subgroups.https://ijnao.um.ac.ir/article_24401_6df15ff724c0ef55fd1ece0d41224349.pdfFerdowsi University of MashhadIranian Journal of Numerical Analysis and Optimization2423-69771120080101A numerical solution for an inverse heat conduction problem51582440210.22067/ijnao.v1i1.619ENAbdollahShidfarDepartment of Mathematics, Iran University of Science and Technology
Narmak, Tehran-16, IranAliZakeriFaculty of Science, K.N. Toosi University of Technology, Tehran, IranJournal Article19700101In this paper, we demonstrate the existence and uniqueness a semianalytical solution of an inverse heat conduction problem (IHCP) in the form: ut = uxx in the domain D = {(x, t)| 0 < x < 1, 0 < t T}, u(x, T) = f(x), u(0, t) = g(t), and ux(0, t) = p(t), for any 0 t T. Some numerical experiments are given in the final section.https://ijnao.um.ac.ir/article_24402_d097ae55c225708c78265c9110687ab4.pdfFerdowsi University of MashhadIranian Journal of Numerical Analysis and Optimization2423-69771120080101Uniformly continuous 1-1 functions on ordered fields not mapping interior to interior59652440310.22067/ijnao.v1i1.620ENMojtabaMoniriDepartment of Mathematics,
Tarbiat Modarres University, TehranJafarS. EivazlooDepartment of Mathematics,
Tarbiat Modarres University, TehranJournal Article19700101In an earlier work we showed that for ordered fields F not isomorphic to the reals R, there are continuous 1-1 unctions on [0, 1]F which map some interior point to a boundary point of the image (and so are not open). Here we show that over closed bounded intervals in the rationals Q as well as in all non-Archimedean ordered fields of countable cofinality, there are uniformly continuous 1-1 functions not mapping interior to interior. In particular, the minimal non-Archimedean ordered field Q(x), as well as ordered Laurent series fields with coefficients in an ordered field accommodate such pathological functions.https://ijnao.um.ac.ir/article_24403_8abeb41e6281cf2da34670698078b0af.pdfFerdowsi University of MashhadIranian Journal of Numerical Analysis and Optimization2423-69771120080101Statistical inference based on k-records67822440410.22067/ijnao.v1i1.621ENJ.AhmadiDepartment of Statistics, Ferdowsi University of Mashhad, MashhadM.DoostparastDepartment of Statistics, Ferdowsi University of Mashhad, MashhadJournal Article19700101In this paper, an extension of record models, well known as k-records, is considered. Bayesian estimation as well as prediction based on k-records are presented when the underlying distribution is assumed to have a general form. The proposed procedure is applied to the Exponential, Weibull and Pareto models in one parameter case. Also, the two-parameter Exponential distribution, when both parameters are unknown, is studied in more details. Since the ordinary record values are contained in the k-records, by putting k = 1, the results for usual records can be obtained as special case.https://ijnao.um.ac.ir/article_24404_49e7a80b32455eeb6a7cee7719987b78.pdfFerdowsi University of MashhadIranian Journal of Numerical Analysis and Optimization2423-69771120080101Shrinkage estimation of the regression parameters with multivariate normal errors831002440510.22067/ijnao.v1i1.622ENM.ArashiDepartment of Statistics, Ferdowsi University of Mashhad, MashhadS. M. M.TabatabaeyDepartment of Statistics, Ferdowsi University of Mashhad, MashhadJournal Article19700101In the linear model y=XB+e with the errors distributed as normal, we obtain generalized least square (GLS), restricted GLS (RGLS), preliminary test (PT), Stein-type shrinkage (S) and positive-rule shrinkage (PRS) estimators for regression vector parameter \beta when the covariance structure in known. We compare the quadratic risks of the underlying estimators and propose the dominance orders of the five estimators.https://ijnao.um.ac.ir/article_24405_abdacfca87e72c9cfe6603b793285074.pdf