In a ground-breaking paper, Indyk and Woodruff (STOC 05) showed how to compute Fk (for k > 2) in space complexity O(poly-log(n,m) · n 2 k ), which is optimal up to (large) poly-logarithmic factors in n and m, where m is the length of the stream and n is the upper bound on the number of distinct elements in a stream. The best known lower bound for large moments is Ω(log(n)n 2 k ). A follow-up wo...

Existing symmetric encryption algorithms target messages consisting of elementary binary blocks of at least 64 bits. Some applications need a block cipher which operates over smaller and possibly nonbinary blocks, which can be viewed as a pseudo-random permutation of n elements. We present an algorithm for selecting such a random permutation of n elements and evaluating efficiently the permutat...

Abstract This study aims to evaluate Kharita gas reservoir enhance the production. The increase in water-cut ratio reduces left hydrocarbons’ amount behind pipe. Accurate determination of pore throats, pores connectivity and fluid distribution are central elements improved description. integration core logging data responses is often used draw inferences about lithology, depositional sequences,...

Noam Nisan constructed pseudo random number generators which convert O(S log R) truly random bits to R bits that appear random to any algorithm that runs in SPACE(S). D Sivakumar, demonstrated that a large class of probabilistic algorithms can be derandomized using Nisan’s construction. This class of algorithms is characterized by the fact that each probabilistic algorithm can thought of as a s...

the aim of this paper is to generalize the‎‎notion of pseudo-almost valuation domains to arbitrary‎ ‎commutative rings‎. ‎it is shown that the classes of chained rings‎ ‎and pseudo-valuation rings are properly contained in the class of‎ ‎pseudo-almost valuation rings; also the class of pseudo-almost‎ ‎valuation rings is properly contained in the class of quasi-local‎ ‎rings with linearly ordere...

The effect of porosity on the elastic behavior of cast steel is investigated experimentally, and an approach for including porosity effects in finite element analysis (FEA) simulations is presented. Porous cast steel specimens are mechanically tested having apparent elastic moduli reduced between 17 and 61 pct. Analysis of radiographs and tomography is used to measure and reconstruct the porosi...

We investigate the scaling relations between the supermassive black holes (SMBHs) mass (Mbh) and the host bulge mass in elliptical galaxies, classical bulges, and pseudo-bulges. We use two-dimensional image analysis software BUDDA to obtain the structural parameters of 57 galaxies with dynamical Mbh measurement, and determine the bulge K-band luminosities (Lbul,K), stellar masses (Ms), and dyna...

Continuous-fiber-reinforced ceramic matrix composites (CMC) have been proposed as candidates for high-temperature applications. Their architecture and network of porosity have a strong effect on the mechanical behavior. X-ray tomography is a non-destructive technique that allows studying the volume mesostructure of these porous materials. The volume porosity, the open porosity fraction, the con...