ESTIMATING MARGINAL IMPLICIT PRICES FOR SELECTED QUALITY ATTRIBUTES OF HYBRID SEED CORN

The central objective of this study was to estimate the implicit marginal prices for the following attributes of hybrid seed corn: yield, moisture content, root lodging, stalk lodging, stand survival and ear drop. This study fills an existent gap in the application of a hedonic price technique to agricultural commodities. A hedonic price equation was constructed and estimated using characteristics data on hybrid corn varieties obtained from the Iowa State University Extension Service. Seed price data were solicited from seed companies for the same set of hybrids. In total, fifty-nine seed companies were asked for suggested retail prices for their hybrids. Forty companies responded with 1991 price information which was used in estimating the parameters of the formulated models. Six hypotheses relating the price paid for hybrid seed corn with the performance characteristics of interest were formulated and tested. Results indicate that the prices that farmers paid for hybrid seed corn were significantly related only to (1) the moisture content and (2) the root lodging characteristics of the resulting crop. Both results were significant at the 0.005 level. Surprisingly, seed price and yield were not significantly related. More research is needed to further analyze these relationships and to analyze farmer's response to the wide range of nonprice services provided by seed companies.Crop Production/Industries, Demand and Price Analysis,

A GA-based technique for the scheduling of storage tanks

YesThis paper proposes the application of a genetic algorithm based methodology for the scheduling of storage tanks. The proposed approach is an integration of GA and heuristic rule-based techniques, which decomposes the complex mixed integer optimisation problem into integer and real number subproblems. The GA string considers the integer problem, and the heuristic approach solves the real number problems within the GA framework. The algorithm is demonstrated for a test problem related to a water treatment facility at a port, and has been found to give a significantly better schedule than those generated using a heuristic-based approach

Roles, service knowledge and priorities in the provision of palliative care: a postal survey of London GPs

Objectives: To explore general practitioners' (GPs) current involvement in and attitudes towards the provision of palliative care in primary care. Methods: Postal survey of 356 London-based GPs, assessing attitudes towards palliative care provision, district nursing and specialist palliative care services, and priorities for future service development. Results: Currently, 65% of GPs were providing palliative care to patients on their list; 72% agreed or strongly agreed palliative care was a central part of their role; and 27% wanted to hand care over to specialists. Most GPs (66%) disagreed with the statement that 'palliative care is mainly district nursing (DN) work'. Many were unaware of out-of-hours DN and specialist palliative care services. Multi-variable analysis found four GP characteristics - larger practice size, more years experience as a GP, receipt of palliative care education, and current provision of palliative care - were associated with agreement that palliative care was central to a GP's role. Conclusion: A minority of NHS GPs in London would rather have no involvement in palliative care in primary care. Knowledge of current services for palliative care is generally poor among GPs. These findings highlight potential gaps in services, particularly in small practices. Specialists will need to consider these factors in working with GPs to develop primary palliative care and to enable greater access to specialist palliative care

GA/SA-based hybrid techniques for the scheduling of generator maintenance in power systems

YesProposes the application of a genetic algorithm (GA) and simulated annealing (SA) based hybrid approach for the scheduling of generator maintenance in power systems using an integer representation. The adapted approach uses the probabilistic acceptance criterion of simulated annealing within the genetic algorithm framework. A case study is formulated in this paper as an integer programming problem using a reliability-based objective function and typical problem constraints. The implementation and performance of the solution technique are discussed. The results in this paper demonstrate that the technique is more effective than approaches based solely on genetic algorithms or solely on simulated annealing. It therefore proves to be a valid approach for the solution of generator maintenance scheduling problem

Low noise charge injection in the CCD22

The inclusion of a charge injection structure on a charge coupled device (CCD) allows for the mitigation of charge transfer loss which can be caused by radiation induced charge trapping defects. Any traps present in the pixels of the CCD are filled by the injected charge as it is swept through the device and consequently, the charge transfer efficiency is improved in subsequently acquired images. To date, a number of different types of CCD have been manufactured featuring a variety of charge injection techniques. The e2v Technologies CCD22, used in the EPIC MOS focal plane instruments of XMM-Newton, is one such device and is the subject of this paper. A detailed understanding of charge injection operation and the use of charge injection to mitigate charge transfer losses resulting from radiation damage to CCDs will benefit a number of space projects planned for the future, including the ESA GAIA and X-ray Evolving Universe Spectrometry (XEUS) missions.The charge injection structure and mode of operation of the CCD22 are presented, followed by a detailed analysis of the uniformity and repeatability of the charge injection amplitude across the columns of the device. The effects of proton irradiation on the charge injection characteristics are also presented, in particular the effect of radiation induced bright pixels on the injected charge level

Zoning Law

The authors survey recent judicial and legislative developments in the Florida law of zoning, including the impact of mandatory comprehensive zoning, various flexible zoning methods, and discriminatory and confiscatory zoning. They also examine the taking issue in the zoning context and possible solutions through compensable regulation

Symmetric Vacua in Heterotic M-Theory

Symmetric vacua of heterotic M-theory, characterized by vanishing cohomology classes of individual sources in the three-form Bianchi identity, are analyzed on smooth Calabi-Yau three-folds. We show that such vacua do not exist for elliptically fibered Calabi-Yau spaces. However, explicit examples are found for Calabi-Yau three-folds arising as intersections in both unweighted and weighted projective space. We show that such symmetric vacua can be combined with attractive phenomenological features such as three generations of quarks and leptons. Properties of the low energy effective actions associated with symmetric vacua are discussed. In particular, the gauge kinetic functions receive no perturbative threshold corrections, there are no corrections to the matter field Kahler metric and the associated five-dimensional effective theory admits flat space as its vacuum.Comment: 22 pages, Late