the previous studies show that a high percentage of traffic accidents take place in two-lane rural highways and most of which happen at horizontal curves. meanwhile the horizontal alignment is often subject to hard topographic conditions where because of economic aspects designers are forced to design horizontal curves at grades. vertical angle of longitudinal slope reduces the normal force of ...

In this paper we discuss the variety of planar spiral segments and their applications in objects in both the real and artificial world. The discussed curves with monotonic curvature function are well-known in geometric modelling and computer aided geometric design as fair curves, and they are very significant in aesthetic shape modelling. Fair curve segments are used for two-point G1 and G2 Her...

the derakhte senged area is located in south of neishaboor town at khorasan razavi province. in this research, desertification intensity of derakht senged area was evaluated using imdpa, one of the newest method to assess desertification potential in arid and semi arid regions of iran. to evaluate desertification intensity, based on the primary research in this area, 4 criteria were selected in...

Article history: Received 2 October 2013 Accepted 16 February 2014 Available online 27 March 2014

Constraints can be used to specify and maintain spatial relationships among objects in a geometric design. In the 3-D geometric design domain , the diversity of possible relationships among objects makes it diicult for the designer to specify useful or intended relationships in a productive and intuitive manner. We have built a constraint-based 3D geometric editor called DEVI that infers possib...