A hierarchical systems modelling approach based on neural networks for forecasting global waste generation: a case study of Chile

In this-first every study for Chile, a neural network based hierarchical modelling approach is proposed for forecasting domestic waste generation for the whole country. Over 30 global variables from the 342 communes (municipalities) in the country were analysed extensively using statistical tools that led to 5 significant explanatory variables: population, percentage of urban population, years of education, number of libraries and number of indigents. The five explanatory variables were used to develop a feedforward neural network for predicting volume of global waste generation for a particular year (2002 in this case) in Chile and assessing the contribution of variables. The model had validation R² of 0.82

The Delta-Delta Intermediate State in 1S0 Nucleon-Nucleon Scattering From Effective Field Theory

We examine the role of the Delta-Delta intermediate state in low energy NN scattering using effective field theory. Theories both with and without pions are discussed. They are regulated with dimensional regularization and MSbar subtraction. We find that the leading effects of the Delta-Delta state can be absorbed by a redefinition of the contact terms in a theory with nucleons only. It does not remove the requirement of a higher dimension operator to reproduce data out to moderate momentum. The explicit decoupling of the Delta-Delta state is shown for the theory without pions.Comment: 16 pages, 3 figures, uses harvma

Bound States and Power Counting in Effective Field Theories

The problem of bound states in effective field theories is studied. A rescaled version of nonrelativistic effective field theory is formulated which makes the velocity power counting of operators manifest. Results obtained using the rescaled theory are compared with known results from NRQCD. The same ideas are then applied to study Yukawa bound states in 1+1 and 3+1 dimensions, and to analyze when the Yukawa potential can be replaced by a delta-function potential. The implications of these results for the study of nucleon-nucleon scattering in chiral perturbation theory is discussed.Comment: 23 pages, eps figures, uses revte

Renormalization of Singlet NN-Scattering with One Pion Exchange and Boundary Conditions

We present a simple and physically compelling boundary condition regularization scheme in the framework of effective field theory as applied to nucleon-nucleon interaction. It is free of off-shell ambiguities and ultraviolet divergences and provides finite results at any step of the calculation. Low energy constants and their non-perturbative evolution can directly be obtained from experimental threshold parameters in a completely unique and model independent way when the long range explicit pion effects are removed. This allows to compute scattering phase shifts which are, by construction consistent with effective range expansion to a given order in the CM momentum and are free from finite cut-off artifacts. We illustrate how the method works in the $^1S_0$ channel for the One Pion Exchange potential.Comment: (Latex, epsfig) 7 pages, 2 figure

Causality, delocalization and positivity of energy

In a series of interesting papers G. C. Hegerfeldt has shown that quantum systems with positive energy initially localized in a finite region, immediately develop infinite tails. In our paper Hegerfeldt's theorem is analysed using quantum and classical wave packets. We show that Hegerfeldt's conclusion remains valid in classical physics. No violation of Einstein's causality is ever involved. Using only positive frequencies, complex wave packets are constructed which at $t = 0$ are real and finitely localized and which, furthemore, are superpositions of two nonlocal wave packets. The nonlocality is initially cancelled by destructive interference. However this cancellation becomes incomplete at arbitrary times immediately afterwards. In agreement with relativity the two nonlocal wave packets move with the velocity of light, in opposite directions.Comment: 14 pages, 5 figure

Consequences of high-technology economic development for African Americans in Georgia, 1990-2000

Issued as final reportUniversity System of Georgia. Board of Regent