Introduction: Image quality and accuracy of in vivo activity quantification in SPECT are affected by collimator penetration and scatter components, especially in high energy imaging. These phenomena highly depend on the collimator characteristic and photon energy. The presence of penetrated and scattered photons from collimator in SPECT images degrades spatial resolution, contr...

The concept of variable spatial resolution implies varying sized units at a given resolution level. The choise of the shape is a special matter. The square is particular handy if the process of creating the blocks of varying size is one of the decomposing space from a general level to more detail. For example, a polygon can be successively approximated by sets of blocks at different levels: If ...

purpose of this study is analysis of spatial auto-correlation of freezing changes of iran over the last half century. daily temperature data over the period 1340 - 1383 of esfezari database provided by doctor masoodian (to enhance the temporal resolution of the database, daily observations of temperature from 1383 to the end of 1390 using the same method and the same spatial resolution is added...

a considerable part of precipitation falls in the form of snow in golestan watershed. in turn, snowmelt plays a significant role in surface runoff, groundwater feeding and flood propagation in this area. snow cover area (sca) as an indicator of stored water can be implemented for temporal and spatial monitoring of snowmelt in the hydrological models. to monitor spatial and temporal variation of...