The Loomis-Whitney inequality, and the more general Uniform Cover inequality, bound the volume of a body in terms of a product of the volumes of lowerdimensional projections of the body. In this paper, we prove stability versions of these inequalities, showing that when they are close to being tight, the body in question is close in symmetric difference to a box. Our results are best possible u...

Introduction: Accurate calculation of equal square field size is important in radiation therapy and A factor, in the Vadash formula must be determine by considering collimator exchange effect. Therefore, the purpose of this study was to determine the best A factor, for calculation of equal square field size in treatment planning   Materials and Methods: A new...

We analyze three-body decays of and . Under the factorization approach, there are tree level diagrams for these decay modes and the transition matrix element of decay is factorized into a form factor multiplied by decay constant and form factor multiplied into weak vertices form factor. The transition matrix element of decay is also factorized into a form factor multiplied into weak vertic...

Complexity/Cost We stated last time that for a system of n equations in n unknowns (represented by an N × N matrix A), both LU and QR-factorization take time proportional to the cube of n (O(n3)). LU-factorization takes less time by a constant factor of around 2 as n gets large, this constant factor is dwarfed by the third power of the matrix dimension, however. Note that the theoretical “best-...

this study was carried out to determine regression equations for prediction of apparent metabolizable energy corrected by nitrogen (amen) using 11 barley cultivar (valfajr, karon, bahman, aras, dasht, afzal, zarjo, kavir, reihani, makui and yousef) the seeds obtain from alborz province, iran. all of the cultivar were analyzed based on proximate analysis, starch, ndf and adf. result showed that ...

In this paper, we study the replica placement problem on trees and present a constant factor approximation algorithm (with an additional additive constant factor). This improves the best known previous algorithm having an approximation ratio dependent on the maximum degree of the tree. Our techniques also extend to the partial cover version. Our algorithms are based on the LP rounding technique...

It is shown that the minimum cut ratio is within a factor of O(log k) of the maximum concurrent flow for k-commodity flow instances with arbitrary capacities and demands. This improves upon the previously best-known bound of O(log k) and is existentially tight, up to a constant factor. An algorithm for finding a cut with ratio within a factor of O(log k) of the maximum concurrent flow, and thus...

We derive an indefinite quadrature formula, based on a theorem of Ganelius, for Hp functions, for p > 1, over the interval (−1, 1). The main factor in the error of our indefinite quadrature formula is O(e−π √ ), with 2N nodes and 1 p + 1 q = 1. The convergence rate of our formula is better than that of the Stenger-type formulas by a factor of √ 2 in the constant of the exponential. We conjectur...

springs are the  mechanical parts which have many application in industries. static and dynamic forces cause relaxation in these parts so that they lose some of their free length and reaction force. springs constant are very important in airplane and vailway industry since constant and variable forces are applied to them in period time, therefore it is necessary to avoid decreasing in spring co...