Multidimensional stochastic approximation using locally contractive functions

A Robbins-Monro type multidimensional stochastic approximation algorithm which converges in mean square and with probability one to the fixed point of a locally contractive regression function is developed. The algorithm is applied to obtain maximum likelihood estimates of the parameters for a mixture of multivariate normal distributions

Analysis of payload bay magnetic fields due to dc power multipoint and single point ground configurations

An analysis of magnetic fields in the Orbiter Payload Bay resulting from the present grounding configuration (structure return) was presented and the amount of improvement that would result from installing wire returns for the three dc power buses was determined. Ac and dc magnetic fields at five points in a cross-section of the bay are calculated for both grounding configurations. Y and Z components of the field at each point are derived in terms of a constant coefficient and the current amplitude of each bus. The dc loads assumed are 100 Amperes for each bus. The ac noise current used is a spectrum 6 db higher than the Orbiter equipment limit for narrowband conducted emissions. It was concluded that installing return wiring to provide a single point ground for the dc Buses in the Payload Bay would reduce the ac and dc magnetic field intensity by approximately 30 db

Sail GTS ground system analysis: Avionics system engineering

A comparison of two different concepts for the guidance, navigation and control test set signal ground system is presented. The first is a concept utilizing a ground plate to which crew station, avionics racks, electrical power distribution system, master electrical common connection assembly and marshall mated elements system grounds are connected by 4/0 welding cable. An alternate approach has an aluminum sheet interconnecting the signal ground reference points between the crew station and avionics racks. The comparison analysis quantifies the differences between the two concepts in terms of dc resistance, ac resistance and inductive reactance. These parameters are figures of merit for ground system conductors in that the system with the lowest impedance is the most effective in minimizing noise voltage. Although the welding cable system is probably adequate, the aluminum sheet system provides a higher probability of a successful system design

Of sea anemones and clownfish: exploring a mutually beneficial approach to educational development through soft systems methodology.

This report presents a large scale exploration of the roles, practice and influence of members of staff in a central educational development department working alongside academic discipline-based teaching staff in a UK University. The project uses Soft Systems Methodology (SSM) for this exploration. The concept modelled within this doctoral project is one of developmental mentoring embedded in the management and design of an externally funded project – the Pathfinder Project. This includes using the characteristics of developmental mentoring and the five phases of the mentoring relationship. The concept model is compared to and discussed in a real-world situation of discipline-based teaching and learning. This activity takes place throughout the life span of the Pathfinder Project during the academic year 2007-08. This doctoral project heavily influenced the design and delivery of the Pathfinder Project although Pathfinder remains an entity in its own right. The doctoral project and the Pathfinder Project shared data however the analysis, findings, conclusions and recommendations are different. The work-based research questions which this doctoral project seeks to address are concerned with the means to develop ways for a central department to work most effectively with discipline-based teaching staff. The project outcomes offer a model for staff development that helps build staff capability and capacity. From a practitioner/researcher point of view, outcomes also suggest how the experiences and findings of this project can inform the work-based context for educational developers. This project report integrates project outcomes with a reflective critical commentary written in the first person. The project report includes original images throughout the text as could be expected from a user of SSM

The effect of heavy metals on differentiated neuronal and glial cells

Heavy metal poisoning poses a serious health risk among populations worldwide. The symptoms presented by exposure are varied and depend upon the species of the metal, the age of the individual and the exposure dose. All heavy metals have debilitating effects on the CNS. Children are especially sensitive to the neurological effects due to the intense growth and activity of a developing nervous system and inadequately developed defences. The aims of this study were to determine the effects of sub-lethal concentrations of numerous heavy metals on neuronal and glial cell differentiation. Using established cellular models, the toxicity of zinc, lead, mercury, methylmercury and thimerosal were investigated using assays of cell viability and morphology on differentiating N2a and C6 cells. Initial research revealed thimerosal, methylmercury and cadmium to be the most toxic compounds tested, in terms of their ability to inhibit the outgrowth of neurites in both cell lines at sub-lethal concentrations. Although cadmium chloride showed similar patterns of toxicity to the mercury compounds, thimerosal and MeHgCl were chosen for further investigation at a molecular level. Methylmercury chloride a common environmental pollutant and thimerosal; a preservative found in many medicines, were chosen for further investigation, as previous work has demonstrated the health risks posed by the two organic mercury compounds but little is known about non-lethal changes that occur in the nervous system, especially with thimerosal

Consistency of Consumer Valuation Under Different Information Sets: An Experimental Auction with Sweet Potatoes

We used a controlled, uniform 5th-price auction to elicit values for sweet potatoes—both when location is known and unknown, and before and after tasting and providing health information. Significant differences were found between pre- and post-consumption valuations and also found that there were significant effects for location of origin and health information. Interestingly, we also find that location of origin not only affects the level of bids, but also the marginal differences in bids between different potatoes. Overall, however, these results suggest little consistency in bid values across information sets, suggesting that attempting to elicit values of attributes in isolation may lead to erroneous results.Consumer/Household Economics, Demand and Price Analysis,

The Impacts of Taste, Location of Origin, and Health Information on Market Demand for Sweet Potatoes

Location of product origin is an often-used marketing device by retailers. This approach is based on the assumption that location of origin signals something to consumers about the underlying quality (or other attributes) of the product. This can be an effective strategy if the signal matches the consumer valuation of the product after consumption. In the same vein, health advertising is used to increase demand for a product that exhibits "healthy" dietary attributes. While there have been numerous studies examining the potential impacts of these attributes on demand, there have been few rigorous studies that examine the consistency of consumer valuations of location of origin before and after they have actually consumed the product (or before and after health advertising). Results show that knowledge of location of origin of sweet potatoes does have an impact on consumer valuation. It was also found that both the information from the taste attribute (experience) and the health attribute (credence) played a significant role in participant valuation.Food Consumption/Nutrition/Food Safety,

State Responses to the \u3ci\u3eWhren\u3c/i\u3e Decision

In Part I, this Article briefly discusses the Whren decision. Part II discusses the three states that have considered whether to divert from the Whren decision under their own state constitutions. This Article then concludes that while these states have made efforts to combat traffic stops initiated on unconstitutional grounds, such as racial profiling, these state courts are finding it hard to do in the absence of police admission of using a pretext. While this case law suggests that other means of addressing police use of pretext would be more effective than relying on state constitutional law remedies, the Washington mixedmotive test perhaps comes the closest to providing a reviewing court with the means to address whether a police officer has exercised her discretion appropriately