desertification is recognized as a serious environmental threat in iran because of its climatic-geomorphologicconditions. desertification and land degradation in arid, semi-arid, and dry sub-humid regions, is a globalenvironmental problem. accurate assessment of the status and trend of desertification is instrumental in developingglobal strategies to prevent and reverse this problem. the goal o...

It is well known that the set of P-matrices includes several important classes of matrices such as M-matrices and positive definite matrices. P-matrices arize in various theoretical and applied fields, for example in linear complementarity theory [9], in the analysis of the solution set of systems of linear interval equations [6], in the study of convex sets of matrices [5]. The class of M-mati...

abstract- according to article 44 of the i.r. of iran constitution, the iranian economy consists of three sectors; the state, the cooperative, and the private sectors. the aim of this study was to present a hierarchy of criteria for selecting the best economic sector for agricultural development. analytic hierarchy process (ahp) was used to calculate the relative importance of either criteria o...

We propose considering the problem of electronic cash i n the context of a network in which anonymous, untraceable commiinicatlon is assumed to be possible. We present a formal model for such a network, and define security criteria for an electronic cash system in such a setting. Finally, we show that there exists a remarkably simple electrortic cash system which meets the security criteria of ...

Nacrtak Sound development of forest infrastructure represents the backbone for sustainable forest management. However, planning forest roads, which nowadays must fulfill multiple conflicting objectives, is not an easy task. A GIS based model was developed for supporting decision making in forest road engineering. The tool allowed assessment of forest infrastructure scenarios based on multiple c...