This paper deals with the basic notions of k-tautimmersions . These notions come from two special cases; that is, tight and taut immersions. Tight and taut based on high and distance functions respectively and their basic notions are normal bundle, endpoint map, focal point, critical normal. We generalize hight and distance functions to cylindrical function and define basic notions of k-taut ...

‎in this work‎, ‎first the differential equation characterizing position vector‎ ‎of spacelike curve is obtained in lorentzian plane $mathbb{l}^{2}.$ then the‎ ‎special curves mentioned above are studied in lorentzian plane $mathbb{l}%‎‎^{2}.$ finally some characterizations of these special curves are given in‎ ‎$mathbb{l}^{2}.$‎

an important concern in rock mechanics is non-homogeneity as joints or fault. this noticeable feature of failures in rock is appearance of slip surfaces or shear bands, the characteristics of that are associated with deformation being concentrated in a narrow zones and the surrounding material remaining intact. adopting the joints as fractures, fractures are well known for their effects on the ...