15,239 research outputs found
Flight crew aiding for recovery from subsystem failures
Some of the conceptual issues associated with pilot aiding systems are discussed and an implementation of one component of such an aiding system is described. It is essential that the format and content of the information the aiding system presents to the crew be compatible with the crew's mental models of the task. It is proposed that in order to cooperate effectively, both the aiding system and the flight crew should have consistent information processing models, especially at the point of interface. A general information processing strategy, developed by Rasmussen, was selected to serve as the bridge between the human and aiding system's information processes. The development and implementation of a model-based situation assessment and response generation system for commercial transport aircraft are described. The current implementation is a prototype which concentrates on engine and control surface failure situations and consequent flight emergencies. The aiding system, termed Recovery Recommendation System (RECORS), uses a causal model of the relevant subset of the flight domain to simulate the effects of these failures and to generate appropriate responses, given the current aircraft state and the constraints of the current flight phase. Since detailed information about the aircraft state may not always be available, the model represents the domain at varying levels of abstraction and uses the less detailed abstraction levels to make inferences when exact information is not available. The structure of this model is described in detail
Welfare Reform and Lone Mothers Employment in the US
The Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA) of 1996 represents a dramatic change in the US welfare state. One of its key goals was to move lone mothers, even those with young children, from welfare to work. Early evidence suggests that, in concert with a strong economy, progress has been made - welfare caseloads have fallen dramatically and the employment rates of lone mothers have increased substantially. In addition to the federal reforms, state level welfare reforms played an important role prior to 1996 and are playing an even more important role subsequent to 1996 as PRWORA gives states unprecedented flexibility in designing and implementing their welfare systems. In this paper, we examine some key state-level reforms, using evidence from selected states, to illustrate the three major types of policies used in the US to move lone mothers from welfare to work: mandating work (Michigan); making work pay (Michigan and Minnesota); and helping families with child care (Illinois). We conclude that each of these policies has a role to play in moving lone mothers from welfare to work, but that further policies are needed if the US is to also to do a better job of reducing child poverty.welfare, lone mothers, employment
Residual Stress Mechanisms in Aluminum Oxide Films Grown by MOCVD
Residual stresses in amorphous aluminium oxide films were investigated with in situ wafer curvature measurements. The films were deposited from aluminium tri-isopropoxide, on sapphire substrates. Large tensile stresses of 1-2 GPa occurred during growth. These values are well above the fracture stress in bulk materials, but they are sustainable in thin film form. Subsequent heat treatment of these films produced additional tensile stress, even at low temperatures prior to crystallization. The mechanisms responsible for all of these stress contributions are discussed. The variety of operative mechanisms at low to moderate temperatures in these amorphous films suggests that different processing routes can be used to engineer significant differences in the final stress state of these materials
Evaluation of the implementation of the alert issued by the UK National Patient Safety Agency on the storage and handling of potassium chloride concentrate solution
Objectives: To assess the effectiveness of the response of NHS hospital trusts to an alert issued by the National Patient Safety Agency designed to limit the availability of concentrated potassium chloride in hospitals in England and Wales, and to determine the nature of any unintended consequences. Design: Multi-method study involving interviews and a physical inspection of clinical areas. Setting: 207 clinical areas in 20 randomly selected acute NHS trusts in England and Wales between 31 October 2002 and 31 January 2003. Participants: Senior managers and ward based medical and nursing staff. Main outcome measures: Degree of staff awareness of and compliance with the requirements of the national alert, withdrawal of concentrated potassium chloride solutions from non-critical areas, provision of pre-diluted alternatives, storage and recording in accordance with controlled drug legislation. Results: All trusts required that potassium chloride concentrate be stored in a separate locked cupboard from common injectable diluents (100% compliance). Unauthorised stocks of potassium chloride were found in five clinical areas not authorised by the trust (98% compliance). All trusts required documentation control of potassium chloride concentrate in clinical areas, but errors were recorded in 20 of the 207 clinical areas visited (90% compliance). Of those interviewed, 78% of nurses and 30% of junior doctors were aware of the alert. Conclusions: The NPSA alert was effective and resulted in rapid development and implementation of local policies to reduce the availability of concentrated potassium chloride solutions. The success is likely to be partly due to the nature of the proposed changes and it cannot be assumed that future alerts will be equally effective. Continued vigilance will be necessary to help sustain the changes
Mentoring to reduce antisocial behaviour in childhood
The effects of social interventions need to be examined in real life situations as well as studie
Symmetry-surfing the moduli space of Kummer K3s.
A maximal subgroup of the Mathieu group M24 arises as the combined
holomorphic symplectic automorphism group of all Kummer surfaces whose Kaehler
class is induced from the underlying complex torus. As a subgroup of M24, this
group is the stabilizer group of an octad in the Golay code. To meaningfully
combine the symmetry groups of distinct Kummer surfaces, we introduce the
concepts of Niemeier markings and overarching maps between pairs of Kummer
surfaces. The latter induce a prescription for symmetry-surfing the moduli
space, while the former can be seen as a first step towards constructing a
vertex algebra that governs the elliptic genus of K3 in an M24-compatible
fashion. We thus argue that a geometric approach from K3 to Mathieu Moonshine
may bear fruit.Comment: 20 pages; minor changes; accepted for publication in the Proceedings
Volume of String-Math 201
On the Role of Density Matrices in Bohmian Mechanics
It is well known that density matrices can be used in quantum mechanics to
represent the information available to an observer about either a system with a
random wave function (``statistical mixture'') or a system that is entangled
with another system (``reduced density matrix''). We point out another role,
previously unnoticed in the literature, that a density matrix can play: it can
be the ``conditional density matrix,'' conditional on the configuration of the
environment. A precise definition can be given in the context of Bohmian
mechanics, whereas orthodox quantum mechanics is too vague to allow a sharp
definition, except perhaps in special cases. In contrast to statistical and
reduced density matrices, forming the conditional density matrix involves no
averaging. In Bohmian mechanics with spin, the conditional density matrix
replaces the notion of conditional wave function, as the object with the same
dynamical significance as the wave function of a Bohmian system.Comment: 16 pages LaTeX, no figure
Values and need satisfaction across 20 world regions
Poster Session F - Motivation/Goals: abstract F78Intrinsic valuing predicts the satisfaction of psychological needs (Niemiec, Ryan, & Deci, 2009). We conceptually replicate and extend this finding across 20 world regions. In multi-level models, Schwartz’s (1992) self-transcendence value was positively related to autonomy, competence, and relatedness satisfaction, even when controlling for the Big Five.postprin
Influence of Perfluorocarbons on Phanerochaete chrysosporium Biomass Development, Substrate Consumption and Enzyme Production
Limitations placed on aerobic cultures by dissolved oxygen can be alleviated by using oxygen-vectors such as perfluorinated organic oils. In this study, Phanerochaete chrysosporium was tested in batch cultures to evaluate the efficacy of perfluorinated oils in improving biomass development, nutrient consumption and extracellular enzyme production. The oils used in an emulsified form in this study were perfluorotripropylamine, perfluorooctyl bromide and bis-(perfluorobutyl) ethene, as they dissolve higher quantities
of oxygen compared to others. The surfactant used to stabilise the emulsion was Pluronic F 68, which was used at a concentration of 8.5 % (w/v). The addition of only the surfactant to the medium resulted in a 6.9-fold increase (1.38 mg mL–1) in biomass concentration of P. chrysosporium, while a biomass concentration of 0.82 to 1.53
mg mL–1 (4.1 to 7.6-fold increase) was observed in the PFC emulsions with an oil-phase fraction in the range of 0.1 to 0.3 (w/v), i.e. 10 to 30 % (w/v). The highest enzyme activity from crude samples was 307 and 410 U L–1 for LiP and MnP, respectively,
compared to <100 and <50 U L–1 enzyme activity for LiP and MnP obtained in control cultures, respectively. Ammonium and glucose utilisation was higher in emulsions with PFC concentrations of 10 % (w/v) for all the perfluorocarbons evaluated than at concentrations
of 20 % and 30 % (w/v). It was concluded that the use of the perfluorocarbon emulsions improved the performance of P. chrysosporium BKMF 1767 in terms of biomass development, nutrient consumption and enzyme production. Furthermore, PF 68
was found to have growth-promoting abilities for P. chrysosporium
Labor Trafficking Victimization among Farmworkers in North Carolina: Role of Demographic Characteristics and Acculturation
Human trafficking is a hidden domestic and international problem of unknown numbers and unsubstantiated estimates. Most research on labor trafficking has focused on known cases through conducting stakeholder interviews and reviewing police and court case files. This limited prior research suggests that demographic characteristics and level of acculturation may impact one’s risk for labor trafficking victimization. However, these relationships have not been consistently demonstrated. The current research explores two primary research questions: (1) how prevalent is labor trafficking and other labor exploitation among farmworkers in North Carolina; and (2) do individual-level characteristics or circumstances place a person at greater risk of labor trafficking or other labor exploitation. This was accomplished by conducting 380 inperson interviews with migrant farmworkers in North Carolina. We used three strategies to identify migrant farmworkers: (1) attendance at community events; (2) lists of labor camps known to advocacy organizations; and (3) other public venues farmworkers visit. Based on descriptive statistics and a logistic regression analysis, we present results on the extent of farmworker abuse and exploitation, and discuss future research in this area
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