Halfspaces or linear threshold functions are widely studied in complexity theory, learning theory and algorithm design. In this work we study the natural problem of constructing pseudorandom generators (PRGs) for halfspaces over the sphere, aka spherical caps, which besides being interesting and basic geometric objects, also arise frequently in the analysis of various randomized algorithms (e.g...

Planting of concrete piles on the soil surface must reach a layer rock/soil that is hard enough for building to stand firmly. Rock/soil layers can be studied through geoelectric resistivity log data. We require tools with high prices and need complicated process obtain such Therefore, mathematical model developed explore geological formations using space-time overcome these problems. The genera...

micro silica (ms) is an extremely fine, spherical powder that is used as an additive for improving concrete performance. it is obtained as a by product of silicon metal and ferrosilicon alloy production.  due to its pozzolanic nature, micro silica can be used to enhance the qualities of both  fresh  and  hardened  concrete. addition of micro silica into the concrete as a cement replacement, dec...

We present the first numerical model of the magnetohydrodynamical cosmic-ray (CR) driven dynamo of the type proposed by Parker (1992). The driving force of the amplification process comes from CRs injected into the galactic disk in randomly distributed spherical regions representing supernova remnants. The underlying disk is differentially rotating. An explicit resistivity is responsible for th...

The near-spherical AgCl micro-crystals were prepared by an ionic liquids-assisted hydrothermal method. The influence of ionic liquids (C(x)MimCl x = 4, 8, 12, 16) on (001) facet growth of AgCl was studied systemically. The composition of the as-prepared samples was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and FTIR spectra. The morphological structures were char...

In the resistive phase transition in VO2, temperature excursions taken from points on the major hysteresis loop produce minor loops. For sufficiently small excursions these minor loops degenerate into single-valued, nonhysteretic branches NHBs linear in log versus T and having essentially the same or even higher temperature coefficient of resistance TCR as the semiconducting phase at room tempe...

A versatile method for preparing spherical, micro- and macroporous (micro: 2-10 and macro: 150-550 microm pores), carbonated apatitic calcium phosphate (Ap-CaP) granules (2-4 mm in size) was developed by using NaCl crystals as the porogen. The entire granule production was performed between 21 and 37 degrees C. A CaP cement powder, comprising alpha-Ca3(PO4)2 (61 wt.%), CaHPO4 (26%), CaCO3 (10%)...