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 ...

the improvement in the temporal resolution of seismic data is a critical issue in hydrocarbonexploration. it is important for obtaining more detailed structural and stratigraphic information. manymethods have been introduced to improve the vertical resolution of reflection seismic data. eachmethod has advantages and disadvantages which are due to the assumptions and theories governingtheir issu...

The improvement in the temporal resolution of seismic data is a critical issue in hydrocarbon exploration. It is important for obtaining more detailed structural and stratigraphic information. Many methods have been introduced to improve the vertical resolution of reflection seismic data. Each method has advantages and disadvantages which are due to the assumptions and theories governing their ...

many recent researches have been devoted to investigating the connection between seismic activity and ionospheric variations. it has been shown that the behavior of characteristic parameters of the ionosphere can be used as temporal and spatial precursors of strong earthquakes ( ). in the present work variations of critical frequency of ionospheric f2 layer as a temporal precursor for the qom e...