Covariance functions and variograms play a fundamental role in exploratory analysis and statistical modelling of spatial and spatio-temporal datasets. In this paper, we construct a new class of spatial covariance functions using the Fourier transform of some higher-order kernels. Moreover, we extend this class of spatial covariance functions to the spatio-temporal setting using the idea used in...

in this paper the minimum temperatures of 54 weather stations collected for a 31-year period were analyzed for zoning the frost regions in iran. the results of this study show that the average of the number of frost days per year was 62, and the average temperature was 3 degrees of centigrade below zero. dey the tenth month in the iranian calendar, december 22-january 20 with an average of 28, ...

geographic information and analysis provide a wide range of data and techniques to monitor and manage natural resources. as an important case, in arid and semi-arid areas, water management is critical for both local governance and citizens. as a result, the estimation of water potential brought by snowmelt runoff and rainfalls seems to be very useful and important for these areas. hydrological ...

objectives: the purpose of this study was to compare spatio-temporal gait parameters between elderly and young male subjects. methods & materials: 57 able-bodied elderly (72±5.5 years) and 57 healthy young (25±8.5 years) subjects participated in this study. a four segment model consist of trunk, hip, shank, and foot with 10 reflective markers were used to define lower limbs. kinematic data coll...

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...

sufficient measurements of effective parameters with suitable temporal and spatial distributions for all phenomena are needed. however, providing the data and informations are difficult and costly. so, temporal and/or spatial downscaling is of prime importance. by downscaling, one can generate data from available ones. there are diffent downscaling methods in literature but they are not compare...

A reliable dynamic simulator (based on a sound process model) is highly desirable for optimizing the performance of individual membrane modules and of entire desalination plants. This paper reports on progress toward development of a comprehensive model of the complicated physical-chemical processes occurring in spiral wound membrane (SWM) modules, that accounts for the...