Fast Calculation of the Radiative Opacity of Plasma

Plasma opacity calculations play an important role in solar modelling and many plasma physics and inertial confinement fusion experiments. This thesis is focussed on the fast calculation of opacity from first principles. The existing average atom (AA) opacity code IMP [1] is used alongside experimental data and detailed atomic physics to develop new models; the results show that simple models can give an excellent description of plasma spectra for a large range of conditions. The results are significant for the development of fast opacity codes which necessarily use the AA approach. The application of fast models to very large scale calculations is considered and an efficient approach to these developed; this allows the fast description of experimental data that would not have otherwise been possible [2]. Analysis of this data then allows the accuracy of the IMP model to be further discussed. The atomic model is also considered, and an improved approach implemented. These improvements makes little difference to the description of experiment provided electron exchange is included. The range of applicability of the IMP model is then extended to higher density by adding a fast description of line broadening by electrons. This gives an excellent agreement with both experiment and more advanced opacity codes. The treatment of atomic term structure can represent a significant portion of code runtime. A good compromise between detail and efficiency is the unresolved transition array (UTA) formulation; a consistent theory of UTAs is developed, and various models introduced. The accuracy of these is systematically tested. It is found that within the validity range of the UTA approach, a good description of the opacity can be gained using a simple model provided that the linewidth is correct. Various simplified calculations of this width are tested, and found to be inaccurate [3]

1991 NCCD Prison Population Forecast: The Impact of Declining Drug Arrests (FOCUS)

According to the National Council and Crime and Delinquency (NCCD), prison populations will increase by 35 percent over the next five years under the current criminal justice policies. This rate of growth is significantly lower than NCCD's 1989 estimates of a 60 percent increase over five years. The principal reason for the lower growth rate is a 20 percent reduction in drug arrests, which in turn is reducing projected jail and prison admissions. The declining number of drug arrests are related to the fiscal crisis of state and local governments, drug asset and seizure laws, and lower drug use. However, prison populations will continue to grow despite reductions in admissions due to the passage of mandatory minimum sentencing statutes and lengthier prison terms for certain crimes. Assuming that the 16 states researched are representative of trends that are on-going in other states and the Federal Prison System, the nation's prison population will reach 1 million inmates by 1994

How New York City Reduced Mass Incarceration: A Model for Change?

In this report, leading criminologists examine the connection between New York City's shift in policing strategies and the dramatic decrease in the City's incarcerated and correctional population

Nomenclatural faux pas for Speyeria atlantis greyi Moeck, 1950 (Lepidoptera: Nymphalidae)

Nomenclatural errors associated with the nymphalid butterfly, Speyeria atlantis greyi Moeck, have persisted in the literature and electronic databases. We present here a synonymy of the various combinations and misspellings associated with it and clearly indicate the correct name and spelling based on Moecks (1950) original description. Additionally, color images of the holotype and allotype specimens are published herein for the first time

Direct QR factorizations for tall-and-skinny matrices in MapReduce architectures

The QR factorization and the SVD are two fundamental matrix decompositions with applications throughout scientific computing and data analysis. For matrices with many more rows than columns, so-called "tall-and-skinny matrices," there is a numerically stable, efficient, communication-avoiding algorithm for computing the QR factorization. It has been used in traditional high performance computing and grid computing environments. For MapReduce environments, existing methods to compute the QR decomposition use a numerically unstable approach that relies on indirectly computing the Q factor. In the best case, these methods require only two passes over the data. In this paper, we describe how to compute a stable tall-and-skinny QR factorization on a MapReduce architecture in only slightly more than 2 passes over the data. We can compute the SVD with only a small change and no difference in performance. We present a performance comparison between our new direct TSQR method, a standard unstable implementation for MapReduce (Cholesky QR), and the classic stable algorithm implemented for MapReduce (Householder QR). We find that our new stable method has a large performance advantage over the Householder QR method. This holds both in a theoretical performance model as well as in an actual implementation

Escalating the Use of Imprisonment: The Case Study of Florida (FOCUS)

During the past five years, Florida has embarked on a policy of incarcerating massive numbers of drug offenders. This policy has accelerated an increase in usage of early release, not only for drug offenders, but also for inmates convicted of violent crimes and those with violent criminal histories. Florida today has the highest rate of prison admissions and the shortest length of stay of any prison system in the country. In addition, its already high crime rate has not been reduced but has increased slightly. A more cost-effective alternative, which the state could utilize, would be placing prison admissions in less expensive and more effective community based programs. Such a policy would result in initiating necessary levels of supervisions and services that many drug offenders and other inmates require, reduce costs to taxpayers, and increase public safety

America's Growing Correctional-Industrial Complex

America faces an enormous public policy dilemma. On one hand we are expending a greater portion of our public dollars on incarcerating, punishing, treating, and controlling persons who are primarily from the lower economic classes in a futile effort to reduce crime. On the other hand, we have set in motion economic policies that serve to widen the gap between the rich and the poor and produce yet another generation of impoverished youths who will likely end up under the control of the correctional system. By escalating the size of the correctional system, we are also increasing the tax burden and diverting billions of dollars from those very public services (education, health, transportation, and economic development) that would reduce poverty, unemployment, crime, drug abuse, and mental illness. Until the long-term consequences of such a controversial and deliberating public policy are recognized and reversed, the hope for a "kinder and gentler" America will be yet another "unmet promise.

The design and application of associative memories for scene analysis

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis investigates a novel scene analysis system that determines the identity and the relative positions of unconstrained objects within a natural three dimensional grey scale image. Images may be of 'block filled' or 'line drawn' occluded shapes. It utilises the occluding information to discover the relative depth of objects in the scene. The system incorporates associative memories, the N tuple pattern recognition process, movable multiple resolution windows and edge detection. The structure and performance of the system and its subsystems is reported. The associative memory incorporates a novel recall procedure which has uses outside the application given here. The work incorporates ideas from the neurophysiology of the human visual system to overcome some of the problems encountered.Funding was obtained from the South Eastern Regional College (SERC)