bluuebunny/crossref_metadata_2025 huggingface dataset:
Note on modulational instability of Boussinesq wavetrains
Authors: Choudhury S. Roy
Published: September 2002

It is demonstrated that modulational instability may occur in Boussinesq wavetrains for wavenumbers k2 > 1, in contrast to the result found by Shivamoggi and Debnath. Both Whitham′s averaged Lagrangian formulation and the technique of Benjamin and Feir are used.
Surface water waves due to an oscillatory wavemaker in the presence of surface tension
Authors: Mandal B. N. , Banerjea S.
Published: September 2002

The initial value problem of generation of surface water waves by a harmonically oscillating plane vertical wavemaker in an infinite incompressible fluid under the action of gravity and surface tension is investigated. In the asymptotic evaluation of the free surface depression for large time and distance, the contribution to the integral by stationary phase method gives rise to transient component of the free surface depression while the contribution from the poles give rise to steady state component. It is observed that the presence of surface tension sometimes changes the qualitative nature of the transient component of free surface depression.
A majorant problem
Authors: Peretz Ronen
Published: September 2002

Let , a0 ≠ 0 be analytic in the unit disc. Any infinite complex vector θ = (θ0, θ1, θ2, …) such that |θk| = 1, k = 0, 1, 2, …, induces a function which is still analytic in the unit disc.

In this paper we study the problem of maximizing the p‐means:

urn:x-wiley:01611712:media:ijmm720382:ijmm720382-math-0003

over all possible vectors θ and for values of r close to 0 and for all p < 2.

It is proved that a maximizing function is and that r could be taken to be any positive number which is smaller than the radius of the largest disc centered at the origin which can be inscribed in the zero sets of f1. This problem is originated by a well known majorant problem for Fourier coefficients that was studied by Hardy and Littlewood.

One consequence of our paper is that for p < 2 the extremal function for the Hardy‐Littlewood problem should be .

We also give some applications to derive some sharp inequalities for the classes of Schlicht functions and of functions of positive real part.
A class of univalent functions with varying arguments
Authors: Padmanabhan K. S. , Jayamala M.
Published: September 2002

is said to be in V(θn) if the analytic and univalent function f in the unit disc E is nozmalised by f(0) = 0, f′(0) = 1 and arg an = θn for all n. If further there exists a real number β such that θn + (n − 1)β ≡ π(mod2π) then f is said to be in V(θn, β). The union of V(θn, β) taken over all possible sequence {θn} and all possible real number β is denoted by V. Vn(A, B) consists of functions f ∈ V such that

urn:x-wiley:01611712:media:ijmm453427:ijmm453427-math-0002

−1 ≤ A < B ≤ 1, where n ∈ NU{0} and w(z) is analytic, w(0) = 0 and |w(z)| < 1, z ∈ E. In this paper we find the coefficient inequalities, and prove distortion theorems.
On a nonlinear degenerate evolution equation with strong damping
Authors: Ferreira Jorge , Pereira Ducival Carvalho
Published: September 2002

In this paper we consider the nonlinear degenerate evolution equation with strong damping,

urn:x-wiley:01611712:media:ijmm603689:ijmm603689-math-0001

where K is a function with K(x, t) ≥ 0, K(x, 0) = 0 and F is a continuous real function satisfying

urn:x-wiley:01611712:media:ijmm603689:ijmm603689-math-0002

Ω is a bounded domain of Rn, with smooth boundary Γ. We prove the existence of a global weak solution for (*).
On a single‐server queue with fixed accumulation level, state dependent service, and semi‐Markov modulated input flow
Authors: Dshalalow Jewgeni H. , Russell Gary
Published: September 2002

The authors study the queueing process in a single‐server queueing system with state dependent service and with the input modulated by a semi‐Markov process embedded in the queueing process. It is also assumed that the server capacity is r ≥ 1 and that any service act will not begin until the queue accumulates at least r units. In this model, therefore, idle periods also depend upon the queue length.

The authors establish an ergodicity criterion for the queueing process and evaluate explicitly its stationary distribution and other characteristics of the system, such as the mean service cycle, intensity of the system, intensity of the input stream, distribution of the idle period, and the mean busy period. Various special cases are treated.
Measures on coallocation and normal lattices
Authors: Chan Jack-Kang
Published: September 2002

Let ℒ1 and ℒ2 be lattices of subsets of a nonempty set X. Suppose ℒ2 coallocates ℒ1 and ℒ1 is a subset of ℒ2. We show that any ℒ1‐regular finitely additive measure on the algebra generated by ℒ1 can be uniquely extended to an ℒ2‐regular measure on the algebra generated by ℒ2. The case when ℒ1 is not necessary contained in ℒ2, as well as the measure enlargement problem are considered. Furthermore, some discussions on normal lattices and separation of lattices are also given.
Matrix powers over finite fields
Authors: Acosta-De-Orozco Maria T. , Gomez-Calderon Javier
Published: September 2002

Let GF(q) denote the finite field of order q = pe with p odd. Let M denote the ring of 2 × 2 matrices with entries in GF(q). Let n denote a divisor of q − 1 and assume 2 ≤ n and 4 does not divide n. In this paper, we consider the problem of determining the number of n‐th roots in M of a matrix B ∈ M. Also, as a related problem, we consider the problem of lifting the solutions of X2 = B over Galois rings.
Solutions of the neutral differential‐difference equation αx′(t) + βx′(t − r) + γx(t) + δx(t − r) = f(t)
Authors: Chambers Ll. G.
Published: September 2002

Particular solutions and complementary functions are obtained for the functional equation αx′(t) + βx′(t − r) + γx(t) + δx(t − r) = f(t) in the forms of a convolution type integral and of infinite series.
A wave equation with discontinuous time delay
Authors: Wiener Joseph , Debnath Lokenath
Published: September 2002

The influence of certain discontinuous delays on the behavior of the solutions of the wave equation is studied.
Darcy‐Brinkman free convection about a wedge and a cone subjected to a mixed thermal boundary condition
Authors: Ramanaiah G. , Kumaran V.
Published: September 2002

The Darcy‐Brinkman free convection near a wedge and a cone in a porous medium with high porosity has been considered. The surfaces are subjected to a mixed thermal boundary condition characterized by a parameter m; m = 0, 1, ∞ correspond to the cases of prescribed temperature, prescribed heat flux and prescribed heat transfer coefficient respectively. It is shown that the solutions for different m are dependent and a transformation group has been found, through which one can get solution for any m provided solution for a particular value of m is known. The effects of Darcy number on skin friction and rate of heat transfer are analyzed.
A new approach to the problem of removal of soluble gaseous pollutants from the atmosphere and its correspondence with the existing approach
Authors: Chattopadhyay Soumitra , Mukherjee A. K.
Published: September 2002

A new approach has been developed using the kinetic theory for the dissolution of gaseous pollutants in cloud droplets. The existing theory, using the diffusion approach, assumes dissolving gas to be a continuous medium. This approach may not always be suitable; especially, as the mean free paths of the pollutant gases at the existing concentrations available at the atmosphere are of the same order as the diameter of the cloud droplets. We develop an equation by considering the mass of the gas molecules striking per unit area of the droplets. Equations are also developed for the rate of dissolution of gaseous air pollutants and an attempt has been made to find out the correspondence with the classical approach and the mass transfer process.
Testing the stability of regression parameters when some additional data sets are available
Authors: Radhakrishnan R. , Robinson Don R.
Published: September 2002

We consider the problem of testing the stability of regression parameters in regression lines of different populations when some additional, but unidentified, data sets from those populations are available. The standard test (T0) discards the additional data and tests the stability of the regression parameters using only the data sets from identified populations. We propose two test procedures (T1 and T2) utilizing all the available data, because the additional data may contain information about the parameters of the regression lines which are tested for stability. A power comparison among the tests is also presented. It is shown that T1 always has larger power than T0. In certain situations T2 has the largest power.
A theorem of differential mappings of Riemann surfaces
Authors: Hu Peichu , Yang Mingze
Published: September 2002

In this paper, we have extended S.S. Chern′s second basic theorem about holomorphic mapping between two Riemann surfaces to more general case, and also obtained two similar results.
On some regular and singular problems of Birkhoff interpolation
Authors: Jhunjhunwala N. , Prasad J.
Published: September 2002

Here we investigate the pure (0, 1, …, r − 2, r)‐interpolation problem on the zeros of , α > −1, where is the Jacobi polynomial of degree n with β = α.
A change of scale formula for Wiener integrals on abstract Wiener spaces
Authors: Yoo Il , Skoug David
Published: September 2002

In this paper we obtain a change of scale formula for Wiener integrals on abstract Wiener spaces. This formula is shown to hold for many classes of functions of interest in Feynman integration theory and quantum mechanics.
On certain Wallman spaces
Authors: Connell Roy
Published: September 2002

Several generalized Wallman type spaces are considered as well as various lattices of subsets therein. In particular, regularity of these lattices and consequences are investigated. Also considered are necessary and sufficient conditions for these lattices to be Lindelöf as well as replete, prime complete, and fully replete.
Existence and uniqueness of equilibrium states of a rotating elastic rod
Authors: Elgindi M. B. M.
Published: September 2002

A flexible rod is rotated from one end. The equilibrium equation is a fourth order nonlinear two‐point boundary value problem which depends on two parameters λ and α representing the importance of centrifugal effects to flexural rigidity and the angle between the rotation axis and the clamped end, respectively. Previous studies on the existence and uniqueness of solution of the equilibrium equation assumed α = 0. Among the findings of these studies is the existence of a critical value λc beyond which the uniqueness of the trivial solution is lost. The computations of λc required the solution of a nonlinear bifurcation problem. On the other hand, this work is concerned with the existence and uniqueness of solution of the equilibrium equation when α ≠ 0 and in particular in the computations of a critical value λc such that the equilibrium equation has a unique solution for each α ≠ 0 provided λ < λc. For small α ≠ 0 this requires the solution of a nonlinear perturbed bifurcation problem.
The meet of locally connected group topologies
Authors: Fox Dorene J.
Published: September 2002

The collection of all group topologies on a given group is a complete lattice partially ordered by inclusion. The purpose of this paper is to develop a convenient method of defining the meet of an arbitrary collection of group topologies and demonstrate that the meet of a collection of locally connected group topologies is also locally connected.
Certain integrals involving logarithmic and exponential functions
Authors: Chaudhry M. Aslam , Ahmad M.
Published: September 2002

In this paper we have evaluated the integrals

urn:x-wiley:01611712:media:ijmm603126:ijmm603126-math-0001

and

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for all n = 1, 2, 3, …. Some applications of the results are discussed and an open problem is posed.
A new class of infinite products, and Euler′s totient
Authors: Campbell Geoffrey B.
Published: September 2002

We introduce some new infinite products, the simplest being

urn:x-wiley:01611712:media:ijmm924852:ijmm924852-math-0001

where ϕk is the set of positive integers less than and relatively prime to k, valid for |y|∧|qy| both less than unity, with q ≠ 1. The idea of a q‐analogue for the Euler totient function is suggested.
Generalized common fixed point theorems for a sequence of fuzzy mappings
Authors: Lee B. S. , Lee G. M. , Cho S. J. , Kim D. S.
Published: September 2002

We obtain generalized common fixed point theorems for a sequence of fuzzy mappings, which is a generalization of the result of Lee and Cho [6].
A proof of some Schützenberger‐type results for Eulerian paths and circuits on digraphs
Authors: Chwe Byoung-Song
Published: September 2002

This paper shows that the number of even Eulerian paths equals the number of odd Eulerian paths when the number of arcs is at least twice the number of vertices of a digraph.
The effect of Coriolis force on nonlinear convection in a porous medium
Authors: Riahi D. H.
Published: September 2002

Nonlinear convection in a porous medium and rotating about vertical axis is studied in this paper. An upper bound to the heat flux is calculated by the method initiated first by Howard [6] for the case of infinite Prandtl number.

For Ta ≪ 0(1), the rotational effect is not significant. For , the Nusselt number decreases with increasing Ta for a given Rayleigh number R. The flow has always a finite number of modes, but with increasing Ta in this region, the number of modes decreases. The functional dependence of the Nusselt number on R and Ta is found to have discontinuities as the number of modes N* reduces to N* − 1. For , the Nusselt number is proportional to . The stabilizing effect of rotation is so strong that the optimal solution has left with only one horizontal mode. For Ta = 0(R), the Nusselt number becomes 0(1) and the convection is inhibited entirely by rotation for .
Extremal problems for completely positive maps
Authors: Yang Mingze
Published: September 2002

In this note, we study the faces of some convex subsets of CPc(A, B(ℋ))(the continuous completely positive linear maps from pro‐C*‐algebra A to B(ℋ)).
On θ‐regular spaces
Authors: Kovár Martin M.
Published: September 2002

In this paper we study θ‐regularity and its relations to other topological properties. We show that the concepts of θ‐regularity (Janković, 1985) and point paracompactness (Boyte, 1973) coincide. Regular, strongly locally compact or paracompact spaces are θ‐regular. We discuss the problem when a (countably) θ‐regular space is regular, strongly locally compact, compact, or paracompact. We also study some basic properties of subspaces of a θ‐regular space. Some applications: A space is paracompact iff the space is countably θ‐regular and semiparacompact. A generalized Fσ‐subspace of a paracompact space is paracompact iff the subspace is countably θ‐regular.
Variational finite element approach to a heat flow problem in human limbs
Authors: Saxena V. P. , Gupta M. P.
Published: September 2002

An attempt has been made to study cross sectional temperature distribution in in‐vivo tissues of a human limb employing variational finite element approach. The outermost surface of the limb is assumed to be exposed to the atmosphere. The physiological and physical parameters like rate of metabolic heat generation (rmhg), blood mass flow rate (bmfr) and thermal conductivity are assumed to vary in the subregions independently. Numerical results have been obtained for various cases of practical interest.
Simulated annealing on uncorrelated energy landscapes
Authors: Goertzel Ben , Ananda Malwane
Published: September 2002

A function f : {0,1,2,L,a}n → R is said to be uncorrelated if Prob[f(x) ≤ u] = G(u). This paper studies the effectiveness of simulated annealing as a strategy for optimizing uncorrelated functions. A recurrence relation expressing the effectiveness of the algorithm in terms of the function G is derived. Surprising numerical results are obtained, to the effect that for certain parametrized families of functions {Gc,    c ∈ R}, where c represents the steepness of the curve G′(u), the effectiveness of simulated annealing increases steadily with c These results suggest that on the average annealing is effective whenever most points have very small objective function values, but a few points have very large objective function values.
Rotatory vibration of sphere of higher order viscoelastic solid
Authors: Sengupta P. R. , De (Das) Nibedita , Kar Manidipa , Debnath Lokenath
Published: September 2002

An attempt is made to investigate the rotatory vibration of a sphere of higher order viscoelastic solid considering higher order strain rate and stress rate. The general frequency equation is obtained for this type of vibration of a sphere. As a special case of this analysis, the frequency equations for the first order and the second order viscoelastic solids are derived. It is shown that the classical frequency equation for an isotropic elastic solid follows from this analysis.
Maximum principles for parabolic systems coupled in both first‐order and zero‐order terms
Authors: Zhou Chiping
Published: September 2002

Some generalized maximum principles are established for linear second‐order parabolic systems in which both first‐order and zero‐order terms are coupled.
Coordinate d‐dimension prints
Authors: Lee Hung Hwan , Baek In Soo
Published: September 2002

We define the coordinate d‐dimension print to distinguish sets of same fractal
dimension, and investigate its geometrical properties.
About the existence and uniqueness theorem for hyperbolic equation
Authors: Khalifa M. E.
Published: September 2002

In this paper we prove the existence and uniqueness theorem for almost everywhere
solution of the hyperbolic equation using the method of successive approximations [1].
q‐Analogue of a binomial coefficient congruence
Authors: Clark W. Edwin
Published: September 2002

We establish a q‐analogue of the congruence

urn:x-wiley:01611712:media:ijmm392186:ijmm392186-math-0001

where p is a prime and a and b are positive integers.
Around the Furuta inequality the operator inequalities
Authors: Wang Derming
Published: September 2002

For positive operators A and B with A invertible it is shown that implies
. The inequalities in the title for 0 ≤ B ≤ A are then derived as a conquence.
Hodographic study of plane micropolar fluid flows
Authors: Adluri Indrasena
Published: September 2002

Equations of steady flow of a plane micropolar fluid are transformed to the
hodograph plane by means of the Legendre transform function of the streamfunction. Results are
summarized in the form of a theorem, some flow problems are investigated as applications of this
theorem and exact solutions and geometry of the flow are obtained in each case.
Sequential point and interval estimation of scale parameter of exponential distribution
Authors: Govindarajulu Z.
Published: September 2002

Sequential fixed‐width confidence intervals are obtained for the
scale parameter σ when the location parameter θ of the negative exponential
distribution is unknown. Exact expressions for the stopping time and the
confidence coefficient associated with the sequential fixed‐width interval are
derived. Also derived is the exact expression for the stopping time of sequential
point estimation with quadratic loss and linear cost. These are numerically
evaluated for certain nominal confidence coefficients, widths of the interval and
cost functions, and are compared with the second order asymptotic expressions.
Norms for copulas
Authors: Darsow William F. , Olsen Elwood T.
Published: September 2002

We consider several norms on the span of the set C of all copulas. Dominance and
equivalence relationships among the norms are discussed, and completeness issues are addressed.
The motivation for the study is discussed. Applications to the study of one parameter semigroups
of copulas are also addressed.
Transcendentality of zeros of higher dereivatives of functions involving Bessel functions
Authors: Lorch Lee , Muldoon Martin E.
Published: September 2002

C.L. Siegel established in 1929 [Ges. Abh., v.1, pp. 209‐266] the deep results that
(i) all zeros of Jv(x) and are transcendental when v is rational, x ≠ 0, and (ii)
is transcendental when v is rational and x algebraic. As usual, Jv(x) is the
Bessel function of first kind and order v. Here it is shown that simple arguments permit one to
infer from Siegel′s results analogous but not identical properties of the zeros of higher derivatives
of x−uJv(x) when μ is algebraic and v rational. In particular, while all
other zeros of and all zeros of , v2 ≠ 1, x ≠ 0, are transcendental. Further,
while all other zeros of , x ≠ 0, and of , v ≠ 0, x ≠ 0, are
transcendental. All zeros of , x ≠ 0, are transcendental, n = 5, …, 18, when v
is rational. For most values of n, the proofs used the symbolic computation package Maple V
(Release 1).
On the numerical solution of perturbed bifurcation problems
Authors: Elgindi M. B. M. , Langer R. W.
Published: September 2002

Some numerical schemes, based upon Newton′s and chord methods, for the computations
of the perturbed bifurcation points as well as the solution curves through them, are presented. The
initial guesses for Newton′s and chord methods are obtained using the local analysis techniques and
proved to fall into the neighborhoods of contraction for these methods. In applications the perturbation
parameter represents a physical quantity and it is desirable to use it to parameterize the solution curves
near the perturbed bifurcation point. In this regard, it is shown that, for certain classes of the perturbed
bifurcation problems, Newton′s and chord methods can be used to follow the solution curves in a
neighborhood of the perturbed bifurcation point while the perturbation parameter is kept fixed.
Acoustic‐gravity waves in a viscous and thermally conducting isothermal atmosphere (part II: For small Prandtl number)
Authors: Alkahby Hadi Y.
Published: September 2002

In part one of these series we investigated the effect of Newtonian cooling on acoustic‐gravity
waves in an isothermal atmosphere for large Prandtl number. It was shown that the atmosphere
can be divided into two regions connected by an absorbing and reflecting layer, created by the exponential
increase of the kinematic viscosity with height, and if Newtonian cooling coefficient goes to infinity the
temperature perturbation associated with the wave will be eliminated. In addition all linear relations
among the perturbation quantities will be modified. In this paper we will consider the effect of Newtonian
cooling on acoustic‐gravity waves for small Prandtl number in an isothermal atmosphere. It is shown that
if the Newtonian cooling coefficient is small compared to the adiabatic cutoff frequency the atmosphere
may be divided into three distinct regions. In the lower region the motion is adiabatic and the effect of
the kinematic viscosity and thermal diffusivity are negligible, while the effect of these diffusivities is more
pronounced in the upper region. In the middle region the effect of the thermal diffusivity is large, while
that of the kinematic viscosity is still negligible. The two lower regions are connected by a semitransparent
reflecting layer as a result of the exponential increase of the thermal diffusivity with height. The two
upper regions are joined by an absorbing and reflecting barrier created but the exponential increase of the
kinematic viscosity. If the Newtonian cooling coefficient is large compared to the adiabatic cutoff frequency,
the wavelengths below and above the lower reflecting layer will be equalized. Consequently the reflection
produced by the thermal conduction is eliminated completely. This indicates that in the solar photosphere
the temperature fluctuations may be smoothed by the transfer of radiation between any two regions with
different temperatures. Also the heat transfer by radiation is more dominant than the conduction process.
Inclusions in elasto‐plastic solids under the influence of internal and external pressures
Authors: Das Tapan Kumar , Sengupta P. R. , Debnath Lokenath
Published: September 2002

An attempt is made to study the problems of spherical and circular inclusions in elasto‐plastic
solids under the action of internal increasing pressure and external constant pressure, taking into
consideration of the work‐hardening effect. Particular attention is given to the linear work hardening
effect on both problems. It is shown that results of this analysis are in good agreement with those of
ideal plastic solids.
A mixing dynamical system on the cantor set
Authors: Kim Jeong H.
Published: September 2002

In this paper we give mixing properties (ergodic, weak‐mixng and strong‐mixing)
to a dynamical system on the Cantor set by showing that the one‐sided ‐shift map is isomorphic
to a measure preserving transformation defined on the Cantor set
A note on finite codimensional linear isometries of C(X) into C(Y)
Authors: Takahasi Sin-Ei , Okayasu Takateru
Published: September 2002

Let (X, Y) be a pair of compact Hausdorff spaces. It is shown that a certain
property of the class of continuous maps of Y onto X is equivalent to the non‐existence of linear
isometry of C(X) into C(Y) whose range has finite codimension >0.
Heat transfer analysis of a second grade fluid over a stretching sheet
Authors: Maneschy C. E. , Massoudi M.
Published: September 2002

The heat tranfer and flow of a non‐Newtonian fluid past a stretching sheet is analyzed
in this paper. Results in a non‐dimensional form are presented here for the velocity and temperature
profiles assuming different kind of boundary conditions.
Fractional integration operator of variable order in the holder spaces Hλ(x)
Authors: Ross Bertram , Samko Stefan
Published: September 2002

The fractional integrals of variable order α(x) are
considered. A theorem on mapping properties of in Holder‐type spaces
Hλ(x) is proved, this being a generalization of the well known
Hardy‐Littlewood theorem.
Computation of Green′s matrices for boundary value problems associated with a pair of mixed linear regular ordinary differential operators
Authors: Bhaskar T. Gnana , Venkatesulu M.
Published: September 2002

An algorithm for the computation of Green′s matrices for boundary value problems
associated with a pair of mixed linear regular ordinary differential operators is presented and two
examples from the studies of acoustic waveguides in ocean and transverse vibrations in nonhomogeneous strings are discussed.
Common fixed points for nonexpansive type fuzzy mappings
Authors: Lee Byung Soo , Kim Do Sang , Lee Gue Myung , Cho Sung Jin
Published: September 2002

In this paper we define g‐nonexpansive and g‐nonexpansive type fuzzy mappings and
prove common fixed point theorems for sequences of fuzzy mappings satisfying certain conditions on
a Banach space. Thus we obtain fixed point theorems for nonexpansive type multi‐valued mappings.
General boundedness theorems to some second order nonlinear differential equation with integrable forcing term
Authors: Kroopnick Allan
Published: September 2002

In this note we present a boundedness theorem to the equation
x″ + c(t, x, x′) + a(t)b(x) = e(t) where e(t) is a continuous absolutely integrable function over the
nonnegative real line. We then extend the result to the equation x″ + c(t, x, x′) + a(t, x) = e(t). The
first theorem provides the motivation for the second theorem. Also, an example illustrating the theory is
then given.
Tilings with the neighborhood property
Authors: Fosnaugh Linda S. , Kramer Earl S.
Published: September 2002

The neighborhood N(T) of a tile T is the set of all tiles which meet T in at least one point. If for each tile T there is a different tile T1 such that N(T) = N(T1) then we say the tiling has the neighborhood property (NEBP). Grünbaum and Shepard conjecture that it is impossible to have a monohedral tiling of the plane such that every tile T has two different tiles T1, T2 with N(T) = N(T1) = N(T2). If all tiles are convex we show this conjecture is true by characterizing the convex plane tilings with NEBP. More precisely we prove that a convex plane tiling with NEBP has only triangular tiles and each tile has a 3‐valent vertex. Removing 3‐valent vertices and the incident edges from such a tiling yields an edge‐to‐edge planar triangulation. Conversely, given any edge‐to‐edge planar triangulation followed by insertion of a vertex and three edges that triangulate each triangle yields a convex plane tiling with NEBP. We exhibit an infinite family of nonconvex monohedral plane tilings with NEBP. We briefly discuss tilings of R3 with NEBP and exhibit a monohedral tetrahedral tiling of R3 with NEBP.
On barrelled topological modules
Authors: Pombo Dinamérico P.
Published: September 2002

Some of the main theorems concerning ultrabarrelled topological vector spaces are extended to the context of topological modules.
Generalized periodic rings
Authors: Bell Howard E. , Yaqub Adil
Published: September 2002

Let R be a ring, and let N and C denote the set of nilpotents and the center of R, respectively. R is called generalized periodic if for every x ∈ R\(N ⋃ C), there exist distinct positive integers m, n of opposite parity such that xn − xm ∈ N ⋂ C. We prove that a generalized periodic ring always has the set N of nilpotents forming an ideal in R. We also consider some conditions which imply the commutativity of a generalized periodic ring.
Magneto‐thermoelastic waves induced by a thermal shock in a finitely conducting elastic half space
Authors: Roychoudhuri S. K. , Banerjee (Mukhopadhyay) Santwana
Published: September 2002

The propagation of magneto‐thermoelastic disturbances produced by a thermal shock in a finitely conducting elastic half‐space in contact with vacuum is investigated. The boundary of the half‐space is subjected to a normal load. Lord‐Shulman theory of thermoelasticity [1] is used to account for the interaction between the elastic and thermal fields. Laplace transform on time is used to obtain the short‐time approximations of the solutions because of the short duration of ′second sound′ effects. It is found that in the half‐space the displacement is continuous at the modified dilational and thermal wavefronts, whereas the perturbed magnetic field, stress and the temperature suffer discontinuities at these locations. The perturbed magnetic field, is, however, discontinuous at the Alf′ven‐acoustic wavefront in vacuum.
On the Ricci tensor of real hypersurfaces of quaternionic projective space
Authors: Perez Juan De Dios
Published: September 2002

We study some conditions on the Ricci tensor of real hypersurfaces of quaternionic projective space obtaining among other results an improvement of the main theorem in [9].
Fixed point theorems in metric spaces and probabilistic metric spaces
Authors: Cho Yeol Je , Park Keun Saeng , Chang Shih-Sen
Published: September 2002

In this paper, we prove some common fixed point theorems for compatible mappings of type (A) in metric spaces and probabilistic metric spaces Also, we extend Caristi′s fixed point theorem and Ekeland′s variational principle in metric spaces to probabilistic metric spaces.
On a class of exact locally conformal cosymlectic manifolds
Authors: Mihai I. , Verstraelen L. , Rosca R.
Published: September 2002

An almost cosymplectic manifold M is a (2m + 1)‐dimensional oriented Riemannian
manifold endowed with a 2‐form Ω of rank 2m, a 1‐form η such that Ωm Λ η ≠ 0 and a vector field ξ
satisfying iξΩ = 0 and η(ξ) = 1. Particular cases were considered in [3] and [6].

Let (M, g) be an odd dimensional oriented Riemannian manifold carrying a globally defined vector
field T such that the Riemannian connection is parallel with respect to T. It is shown that in this case
M is a hyperbolic space form endowed with an exact locally conformal cosymplectic structure. Moreover
T defines an infinitesimal homothety of the connection forms and a relative infinitesimal conformal
transformation of the curvature forms.

The existence of a structure conformal vector field C on M is proved and their properties are
investigated. In the last section, we study the geometry of the tangent bundle of an exact locally conformal
cosymplectic manifold.
On the basis of the direct product of paths and wheels
Authors: Al-Rhayyel A. A.
Published: September 2002

The basis number, b(G), of a graph G is defined to be the least integer k such that
G has a k‐fold basis for its cycle space. In this paper we determine the basis number of the direct product
of paths and wheels. It is proved that P2∧Wn,is planar, and b(Pm∧Wn) = 3, for all m ≥ 3 and n ≥ 4.
The fifth‐order Korteweg‐de Vries equation
Authors: Adomian G.
Published: September 2002

Decomposition is applied to the 5th‐order KdV equation.
Anisotropic nonlinear diffusion with absorption: existence and extinction
Authors: Lair Alan V. , Oxley Mark E.
Published: September 2002

The authors prove that the nonlinear parabolic partial differential equation

urn:x-wiley:01611712:media:ijmm347450:ijmm347450-math-0001

with homogeneous Dirichlet boundary conditions and a nonnegative initial condition has a nonnegative generalized solution u. They also give necessary and sufficient conditions on the constitutive
functions φij and f which ensure the existence of a time t0 > 0 for which u vanishes for all t ≥ t0.
Maximal ideals in algebras of vector‐valued functions
Authors: Kitchen J. W. , Robbins D. A.
Published: September 2002

Subsuming recent results of the authors [6,7] and J. Arhippainen [l], we investigate
further the structure and properties of the maximal ideal spaces of algebras of vector‐valued functions.
Exotic structures on quotient spaces of S3‐actions
Authors: Astey L. , Micha E. , Pastor G.
Published: September 2002

A correct version of some results by A. Rigas regarding S3 actions on S7 × S3 and on
the symplectic group Sp2 with quotients exotic seven‐spheres is presented.
Some results on [n,m]‐paracompact and [n,m]‐compact spaces
Authors: Hdeib Hasan Z. , Ünlü Yusuf
Published: September 2002

Let n and m be infinite cardinals with n ≤ m and n be a regular cardinal. We prove
certain implications of [n, m]‐strongly paracompact, [n, m]‐paracompact and [n, m]‐metacompact
spaces. Let X be [n, ∞]‐compact and Y be a [n, m]‐paracompact (resp. [n, ∞]‐paracompact), Pn‐space
(resp. wPn‐space). If we prove that X × Y is [n, m]‐paracompact (resp. [n, ∞]‐paracompact
Multiplication operators on weighted spaces in the non‐locally convex framework
Authors: Khan L. A. , Thaheem A. B.
Published: September 2002

Let X be a completely regular Hausdorff space, E a topological vector space, V a
Nachbin family of weights on X, and CV0(X, E) the weighted space of continuous E‐valued functions
on X. Let θ : X → C be a mapping, f ∈ CV0(X, E) and define Mθ(f) = θf (pointwise). In case E is
a topological algebra, ψ : X → E is a mapping then define Mψ(f) = ψf (pointwise). The main purpose
of this paper is to give necessary and sufficient conditions for Mθ and Mψ to be the multiplication
operators on CV0(X, E) where E is a general topological space (or a suitable topological algebra) which
is not necessarily locally convex. These results generalize recent work of Singh and Manhas based on the
assumption that E is locally convex.
A strong version of Poisson summation
Authors: Petulante Nelson
Published: September 2002

We establish a generalized version of the classical Poisson summation formula. This
formula incorporates a special feature called “compression”, whereby, at the same time that the
formula equates a series to its Fourier dual, the compressive feature serves to enable both sides of
the equation to converge.
Exact solutions of steady plane MHD aligned flows using (ξ, ψ)‐ or (η, ψ)‐coordinates
Authors: Labropulu F. , Chandna O. P.
Published: September 2002

A new approach for the determination of exact solutions of steady plane infinitely
conducting MHD aligned flows is presented. In this approach, the (ξ, ψ)‐ or the (η, ψ)‐
coordinates is used to obtain exact solutions of these flows where ψ = (x, y) is the streamfunction
and w = ξ(x, y) + iη(x, y) is an analytic function of z = x + iy.
Boundary value problems for the diffusion equation with piecewise continuous time delay
Authors: Wiener Joseph , Debnath Lokenath
Published: September 2002

A study is made of partial differential equations with piecewise constant arguments.
Boundary value problems for three types of equations are discussed delayed; alternately of advanced and
retarded type; and most importantly, an equation of neutral type (that is, including the derivative at
different values of time t).
On subordination for certain subclass of analytic functions
Authors: Jinlin Liu
Published: September 2002

In the present paper the class Pn[α, M] consisting of functions ,
which are analytic in the unit disc E = {z : |z| < 1} and satisfy the condition |f′(z) + αzf″(z) − 1| < M
is introduced. By using the method of differential subordination the properties of the class Pα[α, M] are
discussed.
The Paley‐Wiener‐Levinson theorem revisited
Authors: García A. G.
Published: September 2002

In this paper a new proof of the Paley‐Wiener‐Levinson theorem is presented.
This proof is based upon the isometry between the Paley‐Wiener space and that of the square‐integrable
functions in [−π, π], on one hand, and a Titchmarsh′s theorem which allows recovering
bandlimited, entire functions from their zeros, on the other hand.
On a conjecture of Vukman
Authors: Deng Qing
Published: September 2002

Let R be a ring A bi‐additive symmetric mapping d : R × R → R is called a symmetric
bi‐derivation if, for any fixed y ∈ R, the mapping x → D(x, y) is a derivation. The purpose of this paper
is to prove the following conjecture of Vukman.

Let R be a noncommutative prime ring with suitable characteristic restrictions, and let
D : R × R → R and f : x → D(x, x) be a symmetric bi‐derivation and its trace, respectively. Suppose
that fn(x) ∈ Z(R) for all x ∈ R, where fk+1(x) = [fk(x), x] for k ≥ 1 and f1(x) = f(x), then D = 0.
Commutativity of one sided s‐unital rings through a Streb′s result
Authors: Quadri Murtaza A. , Jacob V. W. , Ashraf M.
Published: September 2002

The main theorem proved in the present paper states as follows “Let m, k, n and s be
fixed non‐negative integers such that k and n are not simultaneously equal to 1 and R be a left
(resp right) s‐unital ring satisfying (resp ) Then R is
commutative.” Further commutativity of left s‐unital rings satisfying the condition xt[xm, y] − yr[x, f(y)]xs = 0 where f(t) ∈ t2Z[t] and m > 0, t, r and s are fixed non‐negative integers, has been
investigated Finally, we extend these results to the case when integral exponents in the underlying
conditions are no longer fixed, rather they depend on the pair of ring elements x and y for their values.
These results generalize a number of commutativity theorems established recently.
Outer measure analysis of topological lattice properties
Authors: Wibisono Setiawati
Published: September 2002

Let X be a set and ℒ a lattice of subsets of X such that ∅, X ∈ ℒ. A(ℒ) is the algebra
generated by ℒ, M(ℒ) the set of nontrivial, finite, normegative, finitely additive measures on A(ℒ) and
I(ℒ) those elements of M(ℒ) which just assume the values zero and one. Various subsets of M(ℒ) and
I(ℒ) are included which display smoothness and regularity properties.

We consider several outer measures associated with dements of M(ℒ) and relate their behavior
to smoothness and regularity conditions as well as to various lattice topological properties. In addition,
their measurable sets are fully investigated. In the case of two lattices ℒ1, ℒ2, with ℒ1 ⊂ ℒ2, we present
consequences of separation properties between the pair of lattices in terms of these outer measures, and
further demonstrate the extension of smoothness conditions on ℒ1 to ℒ2.
Matrix spread sets of p‐primitive semifield planes
Authors: Cordero M.
Published: September 2002

In this article we present the matrix spread sets of the p‐primitive planes of order p4
where p = 3, 5, 7, 11.
Thermoelastic waves in an infinite solid caused by a line heat source
Authors: Dhaliwal Ranjit S. , Majumdar Samir R. , Wang Jun
Published: September 2002

The generalized thermoelasticity theory recently developed by Green and
Naghdi is employed to investigate thermoelastic interactions caused by a continuous line
heat source in a homogeneous isotropic unbounded solid. Hankel‐Laplace transform
technique is used to solve the problem. Explicit expressions, for stress and temperature
fields, are obtained for small time approximation. Numerical values are displayed
graphically. Our results show that this theory predicts an infinite speed for heat
propagation in general, and includes the second sound phenomena as a special case.
A Schur method for the solution of the matrix Riccati equation
Authors: Razzaghi Mohsen
Published: September 2002

This paper is concerned with an analytic solution of the finite‐time matrix Riccati equation.
The solution to the Riccati equation is given in terms of multiple of two matrices. These matrices
are found using a Schur‐type decomposition for Hamiltonian matrices. Simple examples illustrating the
method are presented.
On the strong law for arrays and for the bootstrap mean and variance
Authors: Hu Tien-Chung , Taylor R. L.
Published: September 2002

Chung type strong laws of large numbers are obtained for arrays of rowwise
independent random variables under various moment conditions. An interesting application of
these results is the consistency of the bootstrap mean and variance.
A remark on operating groups
Authors: Wang Yanming
Published: September 2002

Let G be a finite group and H be an operator group of G. In this short
note, we show a relationship between subnormal subgroup chains and H‐invariant subgroup
chains. We remark that the structure of H is quite restricted when G has a special H‐invariant
subgroup chain.
On maps: continuous, closed, perfect, and with closed graph
Authors: Garg G. L. , Goel Asha
Published: September 2002

This paper gives relationships between continuous maps, closed maps, perfect maps, and
maps with closed graph in certain classes of topological spaces.
Some properties and characterizations of A‐normal functions
Authors: Xiao Jie
Published: September 2002

Let M be the set of all functions meromorphic on D = {z ∈ ℂ : |z| < 1}.
For a ∈ (0, 1], a function f ∈ M is called a‐normal function of bounded (vanishing) type or
, if supz∈D(1 − |z|) af#(z) < ∞ (lim|z | → 1(1 − |z|) af#(z) = 0). In this paper
we not only show the discontinuity of Na and relative to containment as a varies, which
shows ∪0<a<1Na ⊂ UBC0, but also give several characterizations of Na and which are real
extensions for characterizations of N and N0.
On viscous and resistive dissipation of Alfvén waves in an isothermal atmosphere
Authors: Alkahby Hadi Yahya
Published: September 2002

In this article we will investigate reflection and dissipation of Alfvén waves, resulting
from a uniform vertical magnetic field, in a viscous, resistive and isothermal atmosphere. It is shown that
the atmosphere may be divided into two distinct regions connected by an absorbing and reflecting
transition layer. In the transition layer the reflection, dissipation and absorption of the magnetic energy of
the waves take place and in it the kinematic viscosity changes from small to large values. In the lower
region the effect of the resistive diffusivity and kinematic viscosity changes from small to large values. In
the lower region the effect of the resistive diffusivity and kinematic viscosity is negligible and in it the
solution can be represented as a linear combination of two, incident and reflected, propagating waves
with different wavelengths and different dissipative factors. In the upper region the effect of the resistive
diffusivity and kinematic viscosity is large and the solution, which satisfies the prescribed boundary
conditions, will behave as a constant. The reflection coefficient, the dissipative factors are determined
and the conclusions are discussed in connection with solar heating.
A generalization of Hermite interpolation
Authors: Sun Xie-Hua , Xie Tingfan
Published: September 2002

We introduce a new interpolation at Chebyshev nodes. The usual Hermite interpolation is
the limit case of our new interpolation as h → 0
n‐Color partitions with weighted differences equal to minus two
Authors: Agarwal A. K. , Balasubrananian R.
Published: September 2002

In this paper we study those n‐color partitions of Agarwal and Andrews, 1987, in which
each pair of parts has weighted difference equal to −2 Results obtained in this paper for these
partitions include several combinatorial identities, recurrence relations, generating functions, relationships
with the divisor function and computer produced tables. By using these partitions an explicit expression
for the sum of the divisors of odd integers is given. It is shown how these partitions arise in the study of
conjugate and self‐conjugate n‐color partitions. A combinatorial identity for self‐conjugate n‐color
partitions is also obtained. We conclude by posing several open problems in the last section.

Corrigendum to
“A note on selfe-conjugate n-color partitions”dx.doi.org/10.1155/S0161171298000957
Comultiplication on monoids
Authors: Arkowitz Martin , Gutierrez Mauricio
Published: September 2002

A comultiplication on a monoid S is a homomorphism m : S → S∗S (the free
product of S with itself) whose composition with each projection is the identity homomorphism.
We investigate how the existence of a comultiplication on S restricts the structure of S. We show
that a monoid which satisfies the inverse property and has a comultiplication is cancellative and
equidivisible. Our main result is that a monoid S which satisfies the inverse property admits a
comultiplication if and only if S is the free product of a free monoid and a free group. We call
these monoids semi‐free and we study different comultiplications on them.
Notes on (α, β)‐derivations
Authors: Aydin Neşet
Published: September 2002

Let R be a prime ring of characteristic not 2, U a nonzero ideal of R and 0 ≠ da(α, β)‐derivation of R where α and β are automorphisms of R. i) [d(U), a] = 0 then a ∈ Z ii) For a, b ∈ R,
the following conditions are equivalent (I) α(a)d(x) = d(x)β(b), for all x ∈ U
(II) Either
α(a) = β(b) ∈ CR(d(U)) or CR(a) = CR(b) = R′ and a[a, x] = [a, x]b (or a[b, x] = [b, x]b) for all
x ∈ U. Let R be a 2‐torsion free semiprime ring and U be a nonzero ideal of R iii) Let d be a (α, β)‐derivation of R and g be a (γ, δ)‐derivation of R. Suppose that dg is a (αγ, βδ)‐derivation and g
commutes both γ and δ then g(x)Uα−1d(y) = 0, for all x, y ∈ U iv) Let Ann(U) = 0 and d be an
(α, β)‐derivation of Rand g be a (λ, δ)‐derivation of R such that g commutes both γ, and δ. If for all
x, y ∈ U, β−1(d(x))Ug(y) = 0 = g(x)Uα−1(d(y)) then dg is a (αγ, βδ)‐derivation on R.
A Unif: A common supercategory of pMET and Unif
Authors: Lowen R. , Windels B.
Published: September 2002

In order to have a topological category that contains both pMET and Unif in a
nice way (and therefore combines quantitative and uniform concepts), approach uniformities are
introduced. Approach uniformities uniformize the so‐called approach spaces, introduced in Lowen
[8]. Different characterizations of approach uniformities are formulated. Some natural examples
are presented, such as function spaces, hyperspaces, spaces of measures, and an example concerning
theoretical computer science.
Derivations of higher order in semiprime rings
Authors: Luh Jiang , Ye Youpei
Published: September 2002

Let R be a 2‐torsion free semiprime ring with derivation d. Supposed d2n

is a derivation of R, where n is a positive integer. It is shown that if R is (4n − 2)‐torsion free
or if R is an inner derivation of R, then d2n−1 = 0.