Correspondence matching with modal clusters

The modal correspondence method of Shapiro and Brady aims to match point-sets by comparing the eigenvectors of a pairwise point proximity matrix. Although elegant by means of its matrix representation, the method is notoriously susceptible to differences in the relational structure of the point-sets under consideration. In this paper, we demonstrate how the method can be rendered robust to structural differences by adopting a hierarchical approach. To do this, we place the modal matching problem in a probabilistic setting in which the correspondences between pairwise clusters can be used to constrain the individual point correspondences. We demonstrate the utility of the method on a number of synthetic and real-world point-pattern matching problems

Non-invasive single-bunch matching and emittance monitor

On-line monitoring of beam quality for high brightness beams is only possible using non-invasive instruments. For matching measurements, very few such instruments are available. One candidate is a quadrupole pick-up. Therefore, a new type of quadrupole pick-up has been developed for the 26 GeV Proton Synchrotron (PS) at CERN, and a measurement system consisting of two such pick-ups is now installed in this accelerator. Using the information from these pick-ups, it is possible to determine both injection matching and emittance in the horizontal and vertical planes, for each bunch separately. This paper presents the measurement method and some of the results from the first year of use, as well as comparisons with other measurement methods.Comment: 10 pages, 10 figures; added figure, minor textual additions; To be resubmitted to Phys. Rev. ST-A

Studies of CMB structure at Dec=40. II: Analysis and cosmological interpretation

We present a detailed analysis of the cosmic microwave background structure in the Tenerife Dec=+40 degrees data. The effect of local atmospheric contributions on the derived fluctuation amplitude is considered, resulting in an improved separation of the intrinsic CMB signal from noise. Our analysis demonstrates the existence of common structure in independent data scans at 15 and 33 GHz. For the case of fluctuations described by a Gaussian auto-correlation function, a likelihood analysis of our combined results at 15 and 33 GHz implies an intrinsic rms fluctuation level of 48^{+21}_{-15} uK on a coherence scale of 4 degrees; the equivalent analysis for a Harrison-Zel'dovitch model gives a power spectrum normalisation of Q_{rms-ps} = 22^{+10}_{-6} uK. The fluctuation amplitude is seen to be consistent at the 68% confidence level with that reported for the COBE two-year data for primordial fluctuations described by a power law model with a spectral index in the range 1.0 \le n \le 1.6. This limit favours the large scale CMB anisotropy being dominated by scalar fluctuations rather than tensor modes from a gravitational wave background. The large scale Tenerife and COBE results are considered in conjunction with observational results from medium scale experiments in order to place improved limits on the fluctuation spectral index; we find n=1.10 +/- 0.10 assuming standard CDM with H_{0}=50 kms^{-1}Mpc^{-1}.Comment: 10 pages LaTeX, including 8 PostScript figures. Accepted for publication in MNRA

The Welfare Costs of Means Testing: Pensioner Participation in Income

We estimate parametric and semi-parametric binary choice models of benefit take-up by British pensioners and use a revealed preference argument to infer the cash-equivalent value of disutility arising from stigma or complexity of the claims process. These implicit costs turn out to be relatively small, averaging about £3-4 per week across Income Support recipients. Using the Foster-Greer-Thorbecke measure of poverty among pensioners, we find that allowing for implicit claim costs incurred by benefit recipients raises the measured degree of poverty by not more than 13%

Second-Order Latent Growth Models with Shifting Indicators

Second-order latent growth models assess longitudinal change in a latent construct, typically employing identical manifest variables as indicators across time. However, the same indicators may be unavailable and/or inappropriate for all time points. This article details methods for second-order growth models in which constructs’ indicators shift over time

Planning for Planning - Coal: Issues for the Eighties

This collaborative paper is based on a meeting held at IIASA in November 1980. The meeting was part of a sequence of discussions arranged by IIASA in conjunction with the Polish Academy of Sciences and the Polish Mining Industry. A previous meeting had been held at Szczyrk, Poland in November 1979, and the proceedings are available as IIASA Working/Collaborative Papers, WP-80-140, CP-80-23, and CP-80-24. These coal industry meetings were part of a research program at IIASA under the generic title "Issues for the Eighties" in which systems analysts and managers from a given industry met to exchange ideas and information, as well as to explore and develop a strategy of using systems analysis, rather than using it merely as a tool to be brought in for certain well-defined problems. The subject "Planning for Planning" was used as a shorthand to explore the use of systems analysis in the planning of new capacity for deep mining in hard coal. The discussions were attended by 17 representatives for 7 countries, and 13 papers were presented or tabled at the meeting. These are reproduced separately as IIASA Collaborative Paper CP-82-80. This paper, which summarizes the discussion, structures the planning process and discusses the place of systems analysis within it. It also presents a state-of-the-art account of the uses of systems analysis for major investment planning in the coal industry, and indicates areas for future research. The summaries have been prepared in conjunction with Bill Hancock and Mike Sadnicki of the Operational Research Executive, National Coal Board, UK

Public Support for Older Disabled People: Evidence from the English Longitudinal Study of Ageing on Receipt of Disability Benefits and Social Care Subsidy

In England, state support for older people with disabilities consists of a national system of non-means-tested cash disability benefits and a locally administered means-tested system of social care. Evidence on how the combination of the two systems targets those in most need is lacking. We estimate a latent factor structural equation model of disability and receipt of one or both forms of support. The model integrates the measurement of disability and its influence on receipt of state support, allowing for the socio-economic gradient in disability, and adopts income and wealth constructs appropriate to each part of the model. We find that receipt of each form of support rises as disability increases, with a strong concentration on the most disabled, especially for local-authority-funded care. The overlap between the two programmes is confined to the most disabled. Less than half of recipients of local-authority-funded care also receive a disability benefit; a third of those in the top 10 per cent of the disability distribution receive neither form of support. Despite being non-means-tested, disability benefits display a degree of income and wealth targeting, as a consequence of the socio-economic gradient in disability and likely disability benefit claims behaviour. The scope for improving income/wealth targeting of disability benefits by means testing them, as some have suggested, is thus less than might be expected

Opportunities in Molecular Biology: Enhancement of the Nutritional Value of Forages

Pasture plants, while producing a cost-effective source of feed for grazing ruminants, can frequently be less than optimal in meeting the animals’ nutrient requirements. Over the past half century, there has been a major effort to improve the quantity and nutritional quality of pasture plants using conventional plant breeding. Although considerable progress has been made in improving the quality and agronomic characteristics of our major pasture plants by this means, breeding can only be applied to plants capable of sexual crosses. This poses severe limitations both in terms of speed of progress and in the number of genes available for transfer (Ulyatt, 1991; Ulyatt et al., 1995)

Disability Costs and Equivalence Scales in the Older Population in Great Britain

We use a standard of living (SoL) approach to estimate older people's disability costs, using data on 8000 individuals from the U.K. Family Resources Survey. We extend previous research in two ways. First, by allowing for a more flexible relationship between SoL and income, the structure of the estimated disability cost and equivalence scale is not dictated by a restrictive functional form assumption. Second, we allow for the latent nature of disability and SoL, addressing measurement error in the disability and SoL indicators in surveys. We find that disability costs are strongly related to severity of disability, and vary with income in absolute and proportionate terms. Older people above the median disability level require an extra £99 per week (2007 prices) on average to reach the SoL of an otherwise similar person at the median. Costs faced by older people in the highest decile of disability average £180