This paper defines a new class of L-fuzzy sets called r-L-fuzzy biconvex sets in (L; M)-fuzzy convex structures (X; C); where C is an (L; M)-fuzzy convexity on X; and some of their properties were studied. In addition, we introduce (L; M)-fuzzy topological convexity space and study some of its properties. Finally, we introduce locally (L; M)-fuzzy topology (L; M)-fuzzy convexity space and study some of its properties.

@ Faculty of Sciences and Mathematics, University of NIŠ, Serbia.

https://doi.org/10.2298/FIL1913151S

The current paper aims at studying soft Js-spaces and strong soft Js- spaces. It focuses on two related classes of spaces with certain basic defining features. The results indicate that in closed and perfect functions, soft J-spaces have natural categorizations. Furthermore, we prove that soft Js-spaces and strong soft Js- spaces coincide in the presence of soft local connectedness.

@2019 IEEE

 

The aim of this paper is to study some concepts in soft ideal topological spaces related to soft pre ideal open sets. Also, the concepts of a soft pre ideal neighborhood, a soft pre ideal limit point, a soft pre ideal frontier, a soft pre ideal exterior and a soft pre ideal border of a soft set are investigated.

 

In this paper, we apply the concept of soft sets to δ-open set and δ-closed set. The associated soft δ-topology in terms of soft δ-open sets were introduced and some properties of them were investigated. Moreover, the definitions, characterizations and basic results concerning soft δ-interior, soft δ-closure, soft δ-boundary and soft δ-exterior were given. Finally, the concept of soft pu-δ- continuity was defined and some properties of it were introduced.

©2018 Ramadhan A. Mohammed, O. R. Sayed, A. Eliow.
 

n this paper, differential properties of the one-parameter hyperbolic dual spherical kinematics are developed with explicit expressions independent of coordinates systems. We calculate Euler–Savary equations of spherical kinematics in the dual Lorentzian 3-space . Then from E. Study’s map new proofs are directly attained for the Disteli’s formulae and their spatial equivalents are examined in detail. Lastly for spherical and planar motions, the point trajectories theoretical expressions of the point trajectories are investigated with a certain value of acceleration and velocity, which are regarded as different forms of Euler–Savary equation form.

The main aim of this paper is the use of the rotation minimizing frame for the singularity type classification of timelike sweeping surface in Minkowski 3–Space . Then, we give conditions for a timelike sweeping surface to be developable ruled surfaces. To apply and illustrate the main results, some examples are given.%