It is shown how the classical mathematical theory of sphere packing can be used to obtain bounds for a greedy heuristic for the bounded euclidean matching problem. In the case of 2 dimensions, bounds are obtained directly. For higher dimensions, an appeal is made to known bounds for the sphere packing problem that have appeared in the mathematical literature.

in common classical methods of cavity depth estimation through microgravity data, usually when a pre-geometrical model is considered for the cavity shape, the simple geometrical models of sphere, vertical cylinder and horizontal cylinder are commonly used. it is obviously an important fact that in real conditions the shapes of the cavities are not exactly sphere, horizontal cylinder or vertical...

Predicting time series necessitates choosing adequate regressors. For this purpose, prior knowledge of the data is required. By projecting the series on a low-dimensional space, the visualization of the regressors helps to extract relevant information. However, when the series includes some periodicity, the structure of the time series is better projected on a sphere than on an Euclidean space....

In this paper a transient free convection flow around a sphere with variable surface temperature and embedded in a porous medium has been considered. The temperature of the sphere is suddenly raised and subsequently maintained at values that varies with position on surface. The method of asymptotic expansions is applied for small Rayleigh numbers and then a finite-difference scheme is used to s...

focuses mostly on democracy (Arato 1981; Paxton 2002; Putnam 1993; Wuthnow 1991). This analysis investigates instead the relationship between associationism and authoritarianism. I explore how the strength of the associational sphere influenced the degree of regime hegemony in two cases of interwar European authoritarianism: the Italian fascist regime and the Spanish dictatorship of Miguel Prim...

This article focuses on the emerging online Arab public sphere that the web has enabled. It explores how the ‘‘local’’ interacts with the ‘‘global,’’ critically examining their implications on global politics. Specifically looking at online readers’ comments about the Swiss minaret ban the so-called ‘‘Ground Zero Mosque,’’ how does the Arab online public sphere respond to and frame these issues...