Dr. Stanley Changnon has done extensive work in climatological studies that included tornado frequency. He studied these frequencies using tornado statistics across Illinois using data from storms that occurred between 1916 and 1980 (Changnon, 1982). He also guided work done at the Illinois State Water Survey on the significance of long-track tornadoes (Wilson and Morgan, 1971). One of the conc...

. clicking here colleagues, clients, or customers by , you can order high-quality copies for your If you wish to distribute this article to others . here following the guidelines can be obtained by Permission to republish or repurpose articles or portions of articles (this information is current as of April 13, 2010 ): The following resources related to this article are available online at www....

To assess the significance of modern climate change, it is essential to place recent observed changes in a longer-term context. This review assesses the evidence from both “proxy” climate data and theoretical climate model simulations with regard to the nature and causes of climate variability over a time interval spanning roughly the past two millennia. Evidence is reviewed for changes in temp...

We consider the problem of minimizing the differential delay in a virtually concatenated Ethernet over SONET (EoS) system by suitable path selection. In such a system, a service provider can dynamically add virtual channels to or drop them from a Virtually Concatenated Group (VCG). A new virtual channel can be added to the VCG provided that the differential delays between the new channel and th...

We introduce a new method of Bayesian wavelet shrinkage for reconstructing a signal when we observe a noisy version. Rather than making the usual assumption that the wavelet coefficients of the signal are independent, we assume that they are locally correlated in both location (time) and scale (frequency). This leads us to prefer a novel prior structure to which is, unfortunately, analytically ...

The paper is concerned with the Bayesian analysis of point processes which are observed with noise. It is shown how to produce exact samples from the posterior distribution of the unobserved true point pattern given a noisy observation. The algorithm is a perfect simulation method which applies dominated Coupling From The Past (CFTP) to a spatial birth-and-death process. Dominated CFTP is made ...

We introduce a new method of Bayesian wavelet shrinkage for reconstructing a signal when we observe a noisy version. Rather than making the usual assumption that the wavelet coefficients of the signal are independent, we allow for the possibility that they are locally correlated in both location (time) and scale (frequency). This leads us to a prior structure which is, unfortunately, analytical...

This paper studies the implementation of the coupling from the past (CFTP) method of Propp and Wilson (1996) in the setup of two and three component mixtures with known components. We show that monotonic-ity structures can be exhibited in both cases, but that CFTP can still be costly for three component mixtures. We conclude with a simulation experiment exhibiting an almost perfect sampling sch...

We study the generation of uniformly distributed linear extensions using Markov chains. In particular we show that monotone coupling from the past can be applied in the case of linear extensions of two-dimensional orders. For width two orders a mixing rate of O(n 3 log n) is proved. We conjecture that this is the mixing rate in the general case and support the conjecture by empirical data. On t...