When Einstein was thinking about the theory of general relativity based on the elimination of especial relativity constraints (especially the geometric relationship of space and time), he understood the first limitation of especial relativity is ignoring changes over time. Because in especial relativity, only the curvature of the space was considered. Therefore, tensor calculations should be to...

land cover mapping is important for many planning and management activities. today, satellite images and remote sensing techniques are extensively used in all sectors including agriculture and natural resources because they provide updated data and high analyzing abilities. in this study, in order to produce land cover map for the northern part of hamedan province , digital satellite data irsp6...

The major aim of processing satellite images is to prepare topical and effectivemaps. The selection of appropriate classification methods plays an important role. Amongvarious methods existing for image classification, artificial neural network method is ofhigh accuracy. In present study, TM images of 1987, and ETM+ images of 2000 and 2006were analyzed using artificial fuzzy ARTMAP neural netwo...

A nonlinear attitude model of a satellite with thrusters, gravity torquers and a reaction wheel cluster is developed. Then the linearized version of this satellite attitude model is derived for the attitude hold mode. For comparison purpose, various control methods are considered for attitude control of a satellite. We consider a proportional derivative controller which is actually used in the ...

Today, leisure time is changing by globalization and using of information technology. Most of people especially women prefer to spend their leisure time by modern technologies. Thus, they spend their leisure time to look up satellite programs and use of the internet. This research has done for sociological consideration of the globalization of communications (internet  & satellite) on leisure t...