In the estimation of selectivity, many models assume that data is uniformly distributed, which is not true for many applications. In this paper, we discuss a generalized selectivity model, the so-called lαβ-model which is independent of the data distribution. The model predicts the fraction of a relation that should be selected in order to process a query. We have evaluated this model for diffe...

Complex cognitive behaviors, such as context-switching and rule-following, are thought to be supported by the prefrontal cortex (PFC). Neural activity in the PFC must thus be specialized to specific tasks while retaining flexibility. Nonlinear "mixed" selectivity is an important neurophysiological trait for enabling complex and context-dependent behaviors. Here we investigate (1) the extent to ...

the performance of msu-s and its forms modified with phosphotungstic acid (hpw) and nickel (ni) for the desulfurization and denitrogenation of model diesel fuel were studied. according to the results of the characteristic tests (n2 adsorption-desorption, xrd, sem, and nh3-tpd), heteropoly acid incorporation causes higher acidity along with a negligible loss of structural aspects, while ni impre...

T he main purpose of this paper is to analyze the performance of mutual funds in Iran by using Fama decomposition model (1972). Thus, daily data of 55 mutual funds during a four-year period from 21/3/2014 to 21/3/2018 were investigated. To achieve this goal, firstly, the performance of mutual funds was broken down into Fama components, and it was shown that the diversification perfor...

The development of direction selectivity in the visual system depends on visual experience. In the developing Xenopus retinotectal system, tectal neurons (TNs) become direction selective through spike timing-dependent plasticity (STDP) after repetitive retinal exposure to a moving bar in a specific direction. We investigated the mechanism responsible for the development of direction selectivity...

A method for the selective semiconducting single-walled carbon nanotube (SWCNT) growth over a continuous range from 67% to 98%, within the diameter range of 0.8-1.2 nm, by the use of a "catalyst conditioning process" prior to growth is reported. Continuous control revealed an inverse relationship between the selectivity and the yield as evidenced by a 1000-times difference in yield between the ...