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1997

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Articles 211 - 240 of 240

Full-Text Articles in Mathematics

On The Solution Of The E.P.D. Equation Using Finite Integral Transformations, Neşe Dernek Jan 1997

On The Solution Of The E.P.D. Equation Using Finite Integral Transformations, Neşe Dernek

Turkish Journal of Mathematics

In this paper, a solution is given for the following initial boundary value problem: \Delta=u_{tt}+k/t+u_t+g(x, t) (t>0) u(0, t)=u(a, t)=0 u(x, 0)=f(x), u_t(x, 0)=0 where x, a \epsilon R^n, t is the time variable, k < 1, k ? -1, -2, -3, . . . is a real parameter, \Delta is the n dimensional Laplace operator, f and g real analytic functions. The equation in this problem is known as the nonhomogeneous Euler-Poisson-Darboux (E.P.D.) Equation. The solution is obtained using finite integral transformation technique and is the sum of two uniformly and absolutely convergent power series.


Characterization Of Some Rings By Functor Z*(.), Ayşe Çiğdem Özcan, Abdullah Harmanci Jan 1997

Characterization Of Some Rings By Functor Z*(.), Ayşe Çiğdem Özcan, Abdullah Harmanci

Turkish Journal of Mathematics

Let X = {M : Z*(M) = 0} and X* = {M : Q ]]] Keywords:


Augmented Graded Rings, Mashhoor Refai Jan 1997

Augmented Graded Rings, Mashhoor Refai

Turkish Journal of Mathematics

In this paper we study the augmented graded rings and give the ralationship between these rings and stronger properties of graded rings.


Integral Closure Of An Ideal Relative To A Module And \Delta-Closure, Yücel Tiraş Jan 1997

Integral Closure Of An Ideal Relative To A Module And \Delta-Closure, Yücel Tiraş

Turkish Journal of Mathematics

The aim in this paper is to give the relation between the \Delta-closure of an ideal I in a commutative Noetherian ring R, (see [3]), and the integral closure of the ideal i relative to a Noetherian R-module (see (1.1). Definition) and to give the closure cancellation law


On A Certain Family Of Linear Positive Operators, Ogün Doğru Jan 1997

On A Certain Family Of Linear Positive Operators, Ogün Doğru

Turkish Journal of Mathematics

In this study, a family of linear positive operators, which includes the sequence of linear positive operators built in a paper of A. D. Gadjiev and I. I. Ibragimov and later investigated by B. Wood and P. Radatz, is defined and using the some inequalities proved by P. J. Davis, results related to approximation properties of this family are obtained.


Unique Factorisation For Commutative Rings Without Identity, A. G. Ağargün, C.R. Fletcher Jan 1997

Unique Factorisation For Commutative Rings Without Identity, A. G. Ağargün, C.R. Fletcher

Turkish Journal of Mathematics

This paper concerns the unique factorisation property in commutative rings not necessarily with identity. We give a new definition of irreducibility and associates in a commutative ring with 1 (crwl), and define a UFR R in terms of a monomorphism from R into a crwl. This becomes equivalent to the definition in [3] when R has an identity. We generalize results on direct sums and direct summands. By our definition we have new members of the family of UFR's.


On The Theory Of A Certain Class Of Quadratic Pencils Of Matrices And Its Applications, G.Sh. Guseinov, G. Oturanç Jan 1997

On The Theory Of A Certain Class Of Quadratic Pencils Of Matrices And Its Applications, G.Sh. Guseinov, G. Oturanç

Turkish Journal of Mathematics

This paper is devoted to the study of the properties of eigenvalues and eigenvectors of quadratic pencil \lambda^2C - \lambdaR - J , where C is a positive diagonal matrix, R is an arbitrary real diagonal matrix, J is a ,, tridiagonal" real symmetric and positive matrix. The obtained results are then used to solve the corresponding system of differential equations with boundary and initial conditions. Kev Words: Quadratic pencijs, eigenvalues, eigenvectors.


Extension And Separation Of Vector Valued Functions, Zafer Ercan Jan 1997

Extension And Separation Of Vector Valued Functions, Zafer Ercan

Turkish Journal of Mathematics

It is proved that: If X is a paracompact Hausdorff space and E is a Frechet lattice then (X, E) has the separation property. This is employed to extend some varies of functions that are known for spaces of Banach lattice valued functions.


On Existence Of A Meromorphic Function With Infinitely Many Of Deficient Functions, Halil Ardahan Jan 1997

On Existence Of A Meromorphic Function With Infinitely Many Of Deficient Functions, Halil Ardahan

Turkish Journal of Mathematics

Let {a_n(z) : {a_n(z)}_n^w, 0 do not depend on r,0


The Linear Mean Value Of The Remainder Term In The Problem Of Asymptotic Behavior Of Eigenfunctions Of The Automorphic Laplacian, Zernişan Emi̇rleroğlu Jan 1997

The Linear Mean Value Of The Remainder Term In The Problem Of Asymptotic Behavior Of Eigenfunctions Of The Automorphic Laplacian, Zernişan Emi̇rleroğlu

Turkish Journal of Mathematics

The purpose of this paper is to obtain the estimate for the average mean value of the remainder term of the asymptotic formula for the quadratic mean value of the Fourier coefficients of the eigenfunctions over the discrete spectrum of the automorphic Laplacian.


Near Ultrafilters And Luc-Compactification Of Real Numbers, Mahmut Koçak Jan 1997

Near Ultrafilters And Luc-Compactification Of Real Numbers, Mahmut Koçak

Turkish Journal of Mathematics

In this work we will investigate some of the topological properties of the Luc compactification of real numbers R in terms of the concept of near ultrafilters.


On Hill's Equation With Piecewise Constant Coefficient, I. Yaslan, G.Sh. Guseinov Jan 1997

On Hill's Equation With Piecewise Constant Coefficient, I. Yaslan, G.Sh. Guseinov

Turkish Journal of Mathematics

In this paper the eigenvalues of the periodic and the semi-periodic boundary value problems associated with Hill's equation are investigated in the case of piecewise constant coefficient. As a corollary the asymptotic formula for the lengths of the instability intervals of Hill's equation is derived and it is shown that they increase beyond all bounds. Also, the conditions for coexistence of periodic and semi-periodic solutions are indicated.


A Characterization Of ^-Nc P-Groups, Ali Osman Asar Jan 1997

A Characterization Of ^-Nc P-Groups, Ali Osman Asar

Turkish Journal of Mathematics

In this work, presented is a partial characterization of a perfect locally nilpotent p-group in which every proper subgroup is nilpotent-by-Chernikov.


Immersions Preserved Under Rotations With Totally Reducible Focal Set, Rıdvan Ezentaş Jan 1997

Immersions Preserved Under Rotations With Totally Reducible Focal Set, Rıdvan Ezentaş

Turkish Journal of Mathematics

In [1] Carter and the author introduced the idea of an immersion f : Mm-+ Rn with totally reducible focal set (TRFS). Such an immersion has the property that, for all p E M, the focal set with base p is a union of hyperplanes in the normal plane to f(M) at f(p) . Here we show that if we take two immersions with TRFS then we can construct new immersions with TRFS. In particular, rotating an immersion with TRFS about an axis gives anew immersion with TRFS.


Quotients Of Real Algebraic Sets Via Finite Groups, Yıldıray Ozan Jan 1997

Quotients Of Real Algebraic Sets Via Finite Groups, Yıldıray Ozan

Turkish Journal of Mathematics

In this paper, we will study finite algebraic group actions on real algebraic sets and compare the topological quotient X/G with the algebraic quotient X/ /G. We will give a different and shorter proof of a result of Procesi and Schwarz, stating that if the order of the group G, acting algebraically on a real algebraic set X, is odd then X/G is equal to X/ /G. In the case of even order groups, we will a give sufficient condition ( and a necessary condition in the case G = Z_2 ) for the X / G to be equal …


Locally Nilpotent P-Groups Whose Proper Subgroups Are Nc-Groups, A.O. Asar, A. Yalincaklioğlu Jan 1997

Locally Nilpotent P-Groups Whose Proper Subgroups Are Nc-Groups, A.O. Asar, A. Yalincaklioğlu

Turkish Journal of Mathematics

Let G be a locally nilpotent p-group in which every proper subgroup is an NC-group. It is shown that G is itself an NC-group if either (i) the normal closure of every finite subgroup of G is a Chernikov extension of a CC-group or (ii) every proper normal subgroup of G is the union of an ascending chain of normal CCsubgroups.


Weight Equations For Binary Linear Codes And Their Applications, Ersan Akyildiz, İsmai̇l Ş. Güloğlu, Masatoshi Ikeda Jan 1997

Weight Equations For Binary Linear Codes And Their Applications, Ersan Akyildiz, İsmai̇l Ş. Güloğlu, Masatoshi Ikeda

Turkish Journal of Mathematics

Some combinatorial problems concerning binary vector spaces are solved by applying the techniques developed in [1]. These illustrate that they are effective tools for such purposes.


Some New Sequence Spaces Defined By A Sequence Of Moduli, Ayhan Esi̇ Jan 1997

Some New Sequence Spaces Defined By A Sequence Of Moduli, Ayhan Esi̇

Turkish Journal of Mathematics

In this paper we introduce and exaamine some properties of three sequence spaces defined by using a sequence of moduli.


Locally Finite Barely Transitive Permutation Group With Almost Nilpotent Point Stabilizers, Mahmut Kuzucuoğlu Jan 1997

Locally Finite Barely Transitive Permutation Group With Almost Nilpotent Point Stabilizers, Mahmut Kuzucuoğlu

Turkish Journal of Mathematics

We show that the groups mentioned in the title are solvable. Moreover, a point stabilizer H of the locally finite barely transitive group G is almost nilpotent, whenever the indices H : H \cap H^g (g \in G) have a finite upper bound.


On Univalent Functions With Three Preassigend Values, Y. Avci, E. Zlotkiewicz Jan 1997

On Univalent Functions With Three Preassigend Values, Y. Avci, E. Zlotkiewicz

Turkish Journal of Mathematics

In this paper, univalent functions with three preassigend values are studied. The sharp bounds for the first coefficient are obtained. Moreover, the coefficient problem for a subclass of such functions is completely solved.


On High Order Riesz Transformations Generated By Generalized Shift Operator, İsmai̇l Eki̇nci̇oğlu, İ. Kaya Özkin Jan 1997

On High Order Riesz Transformations Generated By Generalized Shift Operator, İsmai̇l Eki̇nci̇oğlu, İ. Kaya Özkin

Turkish Journal of Mathematics

In this paper, we determine high order Riesz transformations by using generalized shift operators and giving some of their properties.


Particle Modeling Of Liquid Drop Formation On A Solid Surface In 3-D, Mark Korlie Jan 1997

Particle Modeling Of Liquid Drop Formation On A Solid Surface In 3-D, Mark Korlie

Department of Mathematics Faculty Scholarship and Creative Works

Using a molecular aggregate approach and classical Newtonian dynamics, we show how to simulate a liquid drop formation on a horizontal solid surface in three-dimensional space. We use sets of quasi-molecular particles which interact in accordance with classical molecular-type formulas. For application, the liquid is taken to be water while the solid surface is taken to be graphite. The resulting dynamical equations for the particles are large systems of second-order, nonlinear, ordinary differential equations which must be solved by a numerical method. Computer simulations of the results and related contact angle calculations are presented and discussed. The results are in …


Particle Simulation Of Carbon Dioxide Bubbles In Water, Mark Korlie, D. Greenspan Jan 1997

Particle Simulation Of Carbon Dioxide Bubbles In Water, Mark Korlie, D. Greenspan

Department of Mathematics Faculty Scholarship and Creative Works

Using a molecular aggregate approach and classical molecular dynamics type formulas, a method that can be used to simulate the motion of fluid drops within fluids is described through a detailed study of a prototype problem, the motion of carbon dioxide bubbles in water. The resulting equations are solved numerically. The rise of the bubbles and the motion of the water near the bubbles are described.


On The Dynamic Behaviour Of A Thermoviscoelastic Body In Frictional Contact With A Rigid Obstacle, Kenneth Kuttler, K. T. Andrews, M. Shillor Jan 1997

On The Dynamic Behaviour Of A Thermoviscoelastic Body In Frictional Contact With A Rigid Obstacle, Kenneth Kuttler, K. T. Andrews, M. Shillor

Faculty Publications

We consider the dynamic behaviour of a thermoviscoelastic body which may come into frictional contact with a rigid obstacle. The frictional contact is modelled by general contact and friction laws which include as special cases the power law normal compliance condition and the corresponding generalization of Coulomb's law of dry friction. The stress-strain constitutive relation is assumed to be of Kelvin-Voigt type and the frictional heat generation on the contact surface is taken into account. In this setting we establish the existence of a solution to a weak version of the energy-elasticity system which consists of a parabolic equation coupled …


Analysis Of Repeated Measures Data Under Circular Covariance, Andrew Montgomery Hartley Jan 1997

Analysis Of Repeated Measures Data Under Circular Covariance, Andrew Montgomery Hartley

Mathematics & Statistics Theses & Dissertations

Circular covariance is important in modelling phenomena in epidemiological, communications and numerous physical contexts. We introduce and develop a variety of methods which make it a more versatile tool. First, we present two classes of estimators for use in the presence of missing observations. Using simulations, we show that the mean squared errors of the estimators of one of these classes are smaller than those of the Maximum Likelihood (ML) estimators under certain conditions. Next, we propose and discuss a parsimonious, autoregressive type of circular covariance structure which involves only two parameters. We specify ML and other types of estimators …


The Rank And The Crank Modulo 5, A. Bülent Eki̇n Jan 1997

The Rank And The Crank Modulo 5, A. Bülent Eki̇n

Turkish Journal of Mathematics

Let p(n) denote the number of partitions of n . Ramanujan's partition congruences are p(5n + 4) , p(7n + 5) and p(11n + 6) = mod 5, 7, and 11, respectively. These have been proved in number of ways. Atkin and Swinnerton-Dyer proved the congruences and some more relations about partition İn the case of mod5 and 7 in terms of rank, Garvan proved them in three cases in terms of crank. In this study, we give an another proof of their results in the case of mod5 by using the theory of modular forms. Although our method is …


About Some Normal Subgroups Of Hecke Groups, İsmail Naci Cangül Jan 1997

About Some Normal Subgroups Of Hecke Groups, İsmail Naci Cangül

Turkish Journal of Mathematics

In this work we study the suucture of some special normal subgroups of Hecke groups. Particwarly those of genus O and 1 are studied by means of the regwar map theory which has been a growing subject in recent years. As a nice application, we calcwate the total number of genus 1 normal subgroups for a given index.


A Dual Approach To Constrained Interpolation From A Convex Subset Of Hilbert Space, Frank Deutsch, Wu Li, Joseph D. Ward Jan 1997

A Dual Approach To Constrained Interpolation From A Convex Subset Of Hilbert Space, Frank Deutsch, Wu Li, Joseph D. Ward

Mathematics & Statistics Faculty Publications

Many interesting and important problems of best approximationare included in (or can be reduced to) one of the followingtype: in a Hilbert spaceX, find the best approximationPK(x) to anyxXfrom the setKCA−1(b),whereCis a closed convex subset ofX,Ais a bounded linearoperator fromXinto a finite-dimensional Hilbert spaceY, andbY. The main point of this paper is to show thatPK(x)isidenticaltoPC(x+A*y …


Hartogs' Phenomenon For Polyregular Functions And Projective Dimension Of Related Modules Over A Polynomial Ring, W. W. Adams, P. Loustaunau, V. P. Palamadov, Daniele C. Struppa Jan 1997

Hartogs' Phenomenon For Polyregular Functions And Projective Dimension Of Related Modules Over A Polynomial Ring, W. W. Adams, P. Loustaunau, V. P. Palamadov, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we prove that the projective dimension of Mn = R^4/(An) is 2n -1, where R is the ring of polynomials in 4n variables with complex coefficients and (An) is the module generated by the columns of a 4x4n matrix which arises as the Fourier transform of the matrix of differential operators associated with the regularity condition for a function of n quaternionic variables. As a corollary we show that the sheaf R of regular functions has flabby dimension 2n -1, and we prove a cohomology vanishing theorem for open sets in the space Hn of quaternions. We …


An Invariance Property Of Common Statistical Tests, N. Rao Chaganty, A. K. Vaish Jan 1997

An Invariance Property Of Common Statistical Tests, N. Rao Chaganty, A. K. Vaish

Mathematics & Statistics Faculty Publications

Let A be a symmetric matrix and B be a nonnegative definite (nnd) matrix. We obtain a characterization of the class of nnd solutions Σ for the matrix equation AΣA = B. We then use the characterization to obtain all possible covariance structures under which the distributions of many common test statistics remain invariant, that is, the distributions remain the same except for a scale factor. Applications include a complete characterization of covariance structures such that the chisquaredness and independence of quadratic forms in ANOVA problems is preserved. The basic matrix theoretic theorem itself is useful in other characterizing …