Housing Tenure in Ireland

This paper investigates the sources of the extremely high level of owner occupation in Ireland. After using census data to explore the evolution of this phenomenon, the paper makes a cross-country comparison of owner occupation within the EU-15. Explanations are found for the high level of owner occupation that go beyond fiscal privilege to include wider microeconomic factors, as well as historical factors. Within the EU-15, the Irish housing stock is exceptional not just in the high incidence of owner occupation, but also in the small number of dwellings relative to population.

Changes in Relative Consumer Prices and the Substitution Bias of the Laspeyres Price Index - Ireland, 1985-2001

This paper shows that Irish relative consumer prices have changed significantly, 1985- 2001, at the ten commodity-group level. A “true” cost-of-living index is derived from Madden’s (1993) parameter estimates for an Almost Ideal Demand System. Despite relative price changes, the substitution bias of a computed Laspeyres index is small, and the official Consumer Price Index tracks the computed index closely. Superlative indices are also constructed, but are not satisfactory cost-of-living indices in this context. Cost-of-living indices are computed for different income groups, and the impact of inflation in recent years is found to be negatively correlated with income.

Equilibrium and Rest Positions

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Issues and opportunities in space photovoltaics

Space power sources are becoming a central focus for determining man's potential and schedule for exploring and utilizing the benefits of space. The ability to search, probe, survey, and communicate throughout the universe will depend on providing adequate power to the instruments to do these jobs. Power requirements for space platforms are increasing and will continue to increase into the 21st century. Photovoltaics have been a dependable power source for space for the last 30 years and have served as the primary source of power on virtually all DOD and NASA satellites. The performance of silicon (Si) solar cells has increased from 10 percent air mass zero (AM0) solar energy conversion efficiency in the early 60's to almost 15 percent on today's spacecraft. Some technologists even think that the potential for solar photovoltaics has reached a plateau. However, present and near-future Air Force and NASA requirements show needs that, if the problems are looked upon as opportunities, can elevate the photovoltaic power source scientist and array structure engineer into the next technological photovoltaic growth curve

Preliminary aerodynamic investigation of small box-wing aircraft

This thesis explores the various aerodynamic aspects of the box-wing design - a non-planar aircraft configuration, which under certain conditions, displays reduced induced drag. The box-wing is similar to a biplane with wings that are joined at the tips by endplates, forming a box structure when viewed from the front.  As an unconventional planform, the fundamental capabilities and characteristic of the box-wing differ significantly from those of the conventional monoplane. Despite a recent increase in research focused on efficiency improvements utilising non-planar systems, including the box-wing, little of this has focused on application to small aircraft. Small, in the context of this thesis, being a maximum takeoff weight not exceeding fifty-seven hundred kilograms. In order to gain a great understanding of the potential for the reduction of induced drag of such aircraft, three interconnected investigations have been conducted. To conduct these investigations, a combination of analytical simulation and parametric analysis utilising vortex lattice method (VLM) are used. To assess the specific induced drag advantage of the box-wing configuration, a comparison aircraft is selected for reference. The geometric constraints of the reference aircraft are applied to the new box-wing, and the resulting aerodynamic characteristics are compared with those of the base aircraft. In the case of the third investigation, using parametric analysis within VLM, it was first necessary to create and validate a model of the reference aircraft

Note-based segmentation and hierarchy in the classification of digital musical instruments

The ability to automatically identify the musical instruments occurring in a recorded piece of music has important uses for various music-related applications. This paper examines the case of instrument classification where the raw data consists of musical phrases performed on digital instruments from eight instrument families. We compare the use of extracted features from a continuous sample of approximately one second, to the use of a systematic segmentation of the audio on note boundaries and using multiple, aligned note samples as input to classifiers. The accuracy of the segmented approach was greater than the one of the unsegmented approach. The best method was using a two-tiered hierarchical method which performed slightly better than the single-tiered flat approach. The best performing instrument category was woodwind, with an accuracy of 94% for the segmented approach, using the Bayesian network classifier. Distinguishing different types of pianos was difficult for all classifiers, with the segmented approach yielding an accuracy of 56%. For humans, broadly similar results were found, in that pianos were difficult to distinguish, along with woodwind and solo string instruments. However there was no symmetry between human comparisons of identical instruments and different instruments, with half of the broad instrument categories having widely different accuracies for the two cases

A Cosmic Variance Cookbook

Deep pencil beam surveys (<1 deg^2) are of fundamental importance for studying the high-redshift universe. However, inferences about galaxy population properties are in practice limited by 'cosmic variance'. This is the uncertainty in observational estimates of the number density of galaxies arising from the underlying large-scale density fluctuations. This source of uncertainty can be significant, especially for surveys which cover only small areas and for massive high-redshift galaxies. Cosmic variance for a given galaxy population can be determined using predictions from cold dark matter theory and the galaxy bias. In this paper we provide tools for experiment design and interpretation. For a given survey geometry we present the cosmic variance of dark matter as a function of mean redshift z and redshift bin size Dz. Using a halo occupation model to predict galaxy clustering, we derive the galaxy bias as a function of mean redshift for galaxy samples of a given stellar mass range. In the linear regime, the cosmic variance of these galaxy samples is the product of the galaxy bias and the dark matter cosmic variance. We present a simple recipe using a fitting function to compute cosmic variance as a function of the angular dimensions of the field, z, Dz and stellar mass m*. We also provide tabulated values and a software tool. We find that for GOODS at z=2 and with Dz=0.5 the relative cosmic variance of galaxies with m*>10^11 Msun is ~38%, while it is ~27% for GEMS and ~12% for COSMOS. For galaxies of m*~10^10 Msun the relative cosmic variance is ~19% for GOODS, ~13% for GEMS and ~6% for COSMOS. This implies that cosmic variance is a significant source of uncertainty at z=2 for small fields and massive galaxies, while for larger fields and intermediate mass galaxies cosmic variance is less serious.Comment: 8 pages, 4 figures, 5 tables, submitted to Ap