Volume 24, No. 2 (2014)
Articles
HYPERSURFACE FAMILY WITH A COMMON ISOGEODESIC
ERGIN BAYRAM(1) and EMIN KASAP(2)
In this paper, we study the problem of finding a hypersurface family from a given spatial geodesic curve in R4. We obtain the parametric representation for a hypersurface family whose members have the same curve as a given geodesic curve. Using the Frenet frame of the given geodesic curve, we present the hypersurface as a linear combination of this frame and analyze the necessary and sufficient conditions for that curve to be geodesic. We illustrate this method by presenting some examples.
COMMON FIXED POINT THEOREMS FOR CONTRACTIVE MAPPINGS WITH ALTERING DISTANCES IN METRIC AND ORDERED METRIC SPACES
SUMIT CHANDOK(1), MOHAMMAD SAEED KHAN(2) and BESSEM SAMET(3)
We derive some common fixed point theorems for three single valued mappings satisfying a nonlinear contractive condition involving altering distance functions in the setting of metric and ordered metric spaces. The results presented in this paper generalize and extend several well-known results in the literature. As application, we establish an existence result for a nonlinear first order differential equation. Some examples are also presented to illustrate our obtained results.
ON CERTAIN CLASS OF STARLIKE ANALYTIC FUNCTIONS ASSOCIATED WITH A DIFFERENTIAL OPERATOR
ENTISAR EL-YAGUBI(1) and MASLINA DARUS(2)
The aim of this paper is to introduce a new class of analytic functions in the unit disk, with negative coefficients, via a new generalized derivative operator. We prove coefficient inequalities for the new class of functions and for a subclass of it, as well as distortion theorems for functions in this subclass and for their derivatives. We determine the extreme points of the newly introduced subclass.
UPPER AND LOWER QUASI cl-SUPERCONTINUOUS MULTIFUNCTIONS
J. K. KOHLI(1), C. P. ARYA(2) and D. SINGH(3)
The notion of quasi cl-supercontinuity of functions is extended to the framework of multifunctions. Basic properties of upper (lower) quasi cl-supercontinuous multifunctions are studied and their place in the hierarchy of variants of continuity of multifunctions, that already exist in the literature, is elaborated. The class of upper (lower) quasi cl-supercontinuous multifunctions properly contains the class of upper (lower) cl-supercontinuous multifunctions and so includes all upper (lower) perfectly continuous multifunctions; and is strictly contained in the class of upper (lower) quasi z-supercontinuous multifunctions. The upper quasi cl-supercontinuity of multifunctions is preserved under compositions, union of multifunctions, restriction to a subspace and the passage to the graph multifunction. A sufficient condition for the intersection of two upper quasi cl-supercontinuous multifunctions to be upper quasi cl-supercontinuous is formulated. The lower quasi cl-supercontinuity of multifunctions is preserved under the shrinking and expansion of range, union of multifunctions and restriction to a sub-space.
COMMON FIXED POINT THEOREMS FOR A PAIR OF WEAKLY COMPATIBLE MAPPINGS IN FUZZY METRIC SPACES USING COMMON LIMIT IN THE RANGE PROPERTY
SAURABH MANRO(1), S.S. BHATIA(1), SANJAY KUMAR(2) and BRIAN FISHER(3)
The aim of this work is to establish some new common fixed point theorems for four self mappings satisfying an implicit contractive condition in fuzzy metric spaces by using common limit in range property and give some examples. Our results do not require the condition of closedness of range and so our theorems generalize, unify and extend many results in the literature.
ON UPPER AND LOWER m-ITERATE CONTINUOUS MULTIFUNCTIONS
TAKASHI NOIRI(1) and VALERIU POPA(2)
We introduce the notion of mIT-structures determined by operators mInt and mCl on an m-space . By using mIT-structures, we introduce and investigate the new classes of multifunctions called upper/lower mIT-continuous. As special cases of upper/lower mIT-continuity, we obtain upper/lower -M continuity [34] and upper/lower -M-precontinuity [35].
COMMON (E.A) - PROPERTY AND ALTERING DISTANCE IN METRIC SPACES
VALERIU POPA(1)
In this paper a general fixed point theorem for mappings satisfying an implicit relation is proved for two pairs of mappings with a common (E.A.) - property, which generalize the main results from [1]. In the last part of the paper, as applications we obtain some fixed point results for mappings satisfying contractive condition of integral type, for almost contractive mappings and for (ψ, φ) - weakly contractive mappings.
z-PERFECTLY CONTINUOUS FUNCTIONS AND THEIR FUNCTION SPACES
D. SINGH(1) and MANOJ KUMAR RANA(2)
A new class of functions called z-perfectly continuous functions is introduced, which properly includes the class of pseudo perfectly continuous functions [24] but turns out to be independent of continuity. Besides the study of the basic properties of z-perfectly continuous functions and the interplay with topological properties, sufficient conditions are outlined for their function spaces to be closed, respectively compact, in the topology of pointwise convergence.
REPLICATION METHODS IN DATA GRID: A SURVEY
ZAHRA MIROEI(1) and MARJAN KUCHAKI RAFSANJANI(2)
Today, scientific research and commercial applications generate large amounts of data. In such circumstances, storage and management of these data volume centrally is difficult or even impossible. Data Grid is a good solution for data management, storage resource management and execution of applications. In applications related to data, re-quired data transmission time is the main cause of delay in task execution. In order to decrease it, one method is to put the required data in places near task execution. On the other hand, one of the tasks of data grid is to share data and increase data availability and reliability. In order to reach these goals, one suitable solution is to replicate data in differ-ent parts of the system. In this method, not only required data for task execution are repli-cated near it and file transmission time and task execution time are decreased, also data availability is increased, system reliability is increased, fault tolerance is increased, system efficiency and scalability are increased. Benefits of data replication have led to many researchers to study in this field and propose many algorithms. In this paper the research-es done in this field are studied and compared.