In order to identify radon-prone areas and evaluate radon risk level, a soil gas radon survey combined with gamma-ray spectrometry measurements was carried out in Shenzhen City, south China. Meanwhile, the statistical analysis was applied to evaluate the distribution of measured results. This paper presents the methodology of the radon risk assessment. A radon risk map was accomplished based on...

This paper mainly studies the order statistics of geometric distribution. The deduces joint frequency function and conditional statistics, and, obtain prove some important propositions Certain are different from also similar to corresponding exponential distribution.

We have investigated the population distribution of Chinese cities from 1997 to 2006. The rank-size distributions of Chinese cities deviate from the Pareto distribution. For city size distribution of each year we can find a population threshold Pc that characterizes the boundary of the deviation. The cities with population more than Pc follow the Pareto distribution, while the smaller cities de...

Several recent studies have proposed methods to accelerate the receipt of a file by downloading its parts from different servers in parallel. This paper formulates models for an approach based on receiving only one copy of each of the data packets in a file, while different packets may be obtained from different sources. This approach guarantees faster downloads with lower network use. However,...

Vertical distribution of aerosols in Mexico City during MILAGRO-2006 campaign P. A. Lewandowski, W. E. Eichinger, H. Holder, and J. Prueger IIHR-Hydroscience & Engineering, University of Iowa, Iowa City, Iowa 52242, USA Duke University, Rayleigh, NC, USA National Soil Tilth Laboratory, Ames, IA, USA Received: 8 February 2009 – Accepted: 18 February 2009 – Published: 11 March 2009 Correspondence...

This paper proposes a theory of city size distribution via a hierarchy approach rather than the popular random growth process. It does so by formalizing central place theory using an equilibrium entry model and specifying the conditions under which city size distribution follows a power law. Central place theory describes the way in which a hierarchical city system with different layers of citi...

Very often, when studying topological or dynamical properties of random scale-free networks, it is tacitly assumed that degree-degree correlations are not present. However, simple constraints, such as the absence of multiple edges and self-loops, can give rise to intrinsic correlations in these structures. In the same way that Fermionic correlations in thermodynamic systems are relevant only in...