


Paper's Title:
Local Boundedness of Weak Solutions for Singular Parabolic Systems of pLaplacian Type
Author(s):
Corina Karim, Marjono
Department of Mathematics,
Universitas Brawijaya,
Indonesia.
Email: co_mathub@ub.ac.id,
marjono@ub.ac.id
Abstract:
We study the local boundedness of weak solutions for evolutional pLaplacian systems in the singular case. The initial data is belonging to Lebesgue space L^{∞} (0,T;W^{(1,p)} (Ω,R^{n} )). We use intrinsic scaling method to treat the boundedness of weak solutions. The main result is to make the local boundedness of weak solution for the systems wellworked in the intrinsic scaling.
Paper's Title:
Existence Results for Second Order Impulsive Functional Differential Equations with Infinite Delay
Author(s):
M. Lakrib, A. Oumansour and K. Yadi
Laboratoire de Mathématiques, Université Djillali
Liabées, B.P. 89 Sidi Bel Abbès 22000, Algérie
mlakrib@univsba.dz
oumansour@univsba.dz
Laboratoire de Mathématiques, Université Abou Bekr
Belkaid, B.P. 119 Tlemcen 13000, Algérie
k_yadi@mail.univtlemcen.dz
Abstract:
In this paper we study the existence of solutions for second order impulsive functional differential equations with infinite delay. To obtain our results, we apply fixed point methods.
Paper's Title:
Uniform Continuity and kConvexity
Author(s):
Adel Afif Abdelkarim
Mathematics Department, Faculty of Science,
J
erash University, Jerash
Jordan.
Abstract:
A closed arcwiseconnected subset A of R^{n} is called kconvex if for each positive number a and for all elements x and y in A there is a positive number b such that if the norm of xy is less than or equal to b then the length of the shortest curve l(x,y) in A is less than k times the norm of xy plus a. We show that a union of two non disjoint closed finite convex subsets need not be kconvex. Let f(x) be a uniformly continuous functions on a finite number of closed subsets A_{1},...,A_{n} of R^{n} such that the union of A_{j},...,A_{n},j=1,...,n1 is kconvex. We show that f is uniformly continuous on the union of the sets A_{i},i=1,...,n. We give counter examples if this condition is not satisfied. As a corollary we show that if f(x) is uniformly continuous on each of two closed convex sets A,B then f(x) is uniformly continuous on the union of A and B.
Paper's Title:
Some Properties of Cosine Series with Coefficients from Class of General Monotone Sequences Order r
Author(s):
Corina Karim, Moch. Aruman Imron
Department of Mathematics,
Universitas Brawijaya,
Indonesia.
Email: co_mathub@ub.ac.id
maimr@ub.ac.id
Abstract:
The coefficient of sine series from general monotone class has been generalized by Bogdan Szal to the new class which is called class of general monotone order r. This coefficient class is more general than class of general monotone introduced by Tikhonov. By special case, we study properties of cosine series with coefficient of sine series from the class of general monotone order r.
Paper's Title:
On a Problem on Periodic Functions
Author(s):
Adel A. Abdelkarim
Mathematics Department, Faculty of
Science,
Jerash Private University, Jerash,
Jordan.
Email:
adelafifo_afifo@yahoo.com
Abstract:
Given a continuous periodic real function f with n translates f_{1 },..., f_{n} , where f_{i}(x)=f(x+a_{i}), i=1,...,n. We solve a problem by Erdos and Chang and show that there are rational numbers r,s such that f(r)≥ f_{i}(r), f(s)≤ f_{i}(s), i=1,...,n. No restrictions on the constants or any further restriction on the function f are necessary as was imposed earlier.
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