iran is one of the world's arid regions and exposed to dust particles in the air. this is important in spatial and temporal terms as well as the affects human health. in this paper a day when due to the amount of dust particles visibility reduces to 5,000 m is considered the dusty day. in the spatial and temporal analysis of dusty days 38 synoptic stations were studied. in order to conduct data...

Policy evaluation is a process to determine whether a request submitted by a user satisfies the access control policies defined by an organization. Modality conflict is one of the main issues in policy evaluation. Existing modality conflict detection approaches do not consider complex condition attributes such as spatial and temporal constraints. An effective authorization propagation rule is n...

In this paper, we develop a random process theory to explain the laser speckle phenomena. The relation between the probability distribution of speckle's integrated intensity random process Y(t) and the relative velocity v(t) is derived. Based on the random process theory, traditional spatial or temporal laser speckle contrast analysis (i.e. spatial or temporal LASCA) can be derived as the spati...

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...

objectives: this study was designed to evaluate the effectiveness of a modified floor reaction ankle foot orthosis (frafo) design on gait performance in children with cerebral palsy. methods: eight children with cerebral palsy wore a modified frafo bilaterally for six weeks. motion analysis was used to assess the immediate effectiveness of the orthosis on improving gait and also following six w...

introduction: the accuracy of analyzing functional mri (fmri) data is usually decreases in the presence of noise and artifact sources. a common solution in for analyzing fmri data having high noise is to use suitable preprocessing methods with the aim of data denoising. some effects of preprocessing methods on the parametric methods such as general linear model (glm) have previously been evalua...

abstract  background: the brain response to temporal frequencies (tf) has been already reported, but with no study reported for different tf with respect to various spatial frequencies (sf).  materials and methods: fmri was performed by 1.5t ge-system in 14 volunteers during checkerboard, with tfs of 4, 6, 8 and 10hz in low and high sfs of 0.5 and 8cpd.  results: average percentage bold signal ...

 Fitting a suitable covariance function for the correlation structure of spatial-temporal data requires de-trending the data. In this article, some potential models for spatial-temporal trend are presented. Eventually the best model will be announced for de-trending tropospheric ozone concentration data for the city of Tehran (Capital city of Iran). By using the selected trend model, some ...