We analyze a directed variation of the book embedding problem when the page partition is prespecified and the nodes on the spine must be in topological order (upward book embedding). Given a directed acyclic graph and a partition of its edges into k pages, can we linearly order the vertices such that the drawing is upward (a topological sort) and each page avoids crossings? We prove that the pr...

Hyperoperations are mappings that assign a non-void subset of a set to each n-tuple of elements from the set. They present a fundamental notion for modeling non deterministic processes. Even though for each non deterministic automaton there is a language equivalent deterministic automaton, they do not have the same behavior. As behavior of concurrent processes took place in emerging fields of t...

This paper develops a mobility measure that combines desirable features of the relative and absolute approaches to measuring mobility. From the relative approach we borrow the idea that income growth accruing to the relatively poor is more to be valued than income growth to the relatively rich. From the absolute approach we take the idea that upward changes are to be valued, in and of themselve...

binaloud mountains formed during collision of iran and turan plate in the late triassic time and caused shortening of the sedimentary cover because of cimmerian and alpine orogeny. the thrust sheets with different generations formed as a results of the binalood and alborz fold- thrust belts. northeast of iran that was already south coast of the divergent margin of the paleothetys ocean at this ...

abstract background and aim: considering the widespread development of implants in dental treatment plans, linear measurements on panoramic radiography are of especial importance. in the present study we investigated the effect of head misalignment up to 15° around vertical and horizontal axes on the magnification rate of digital panoramic radiography in each part of upper and lower jaws. mater...