background: carpet weaving is an occupation that requires sufficient and appropriate lighting. the lighting in carpet weaving workshops affects the productivity and the physical and mental health of workers. therefore, the evaluation of the illumination and the identification of work stations requiring lighting modifications will be helpful in promotion of the health and safety of workers in ca...

in this paper, we give some characterizations for legendre spherical, legendre normal and legendre rectifying curves in the 3-dimensional sasakian space. furthermore, we show that legendre spherical curves are also legendre normal curves. in particular, we prove that the inverse of curvature of a legendre rectifying curve is a non-constant linear function of the arclength parameter.

introduction: nowadays,  considerable developments  in  the field  of  radiotherapy have  been  achieved.  they  include  the  advances  made  in  the  equipments  and  treatment  planning  techniques  which  require  highly complex calculations. such achievements have made it possible to treat cancer patients not only  with  higher  radiation  dose  but  also  with  higher  precision  and  con...

v. dannon showed that spherical curves in e4 can be given by frenet-like equations, and he thengave an integral characterization for spherical curves in e4 . in this paper, lorentzian spherical timelike andspacelike curves in the space time 41 r are shown to be given by frenet-like equations of timelike andspacelike curves in the euclidean space e3 and the minkowski 3-space 31 r . thus, finding...

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1-type and biharmonic curves by using laplace operator in lorentzian 3-space arestudied and some theorems and characterizations are given for these curves.