673 research outputs found
Parachute Extraction of a Generic Store from a C-130; a CFD Proof of Concept
This thesis encompasses a feasibility analysis of a parachute extracted generic precision guided munition from the cargo bay of a C-130 aircraft in flight. This analysis utilizes the USAF Beggar code and incorporates full physics effects as well as aerodynamic loading assuming an inviscid aircraft and viscous store for a time-accurate solution. Both an immediate and time varying application of the parachute force are utilized as well as two different ordnance body styles at zero and 5 degrees AOA with the store placed on centerline and offset in the cargo bay. The time accurate parachute model is based on empirical data and more closely follows the force fall off as the parachute slows down during the extraction process. Both store body styles were successfully extracted from the cargo bay without contacting any portion of the delivery aircraft, following a safe trajectory down and away from all of the release conditions. The extraction took 1.7 seconds with the immediate application of the parachute force and 2.1 seconds when the time varying model was applied. The maximum roll seen during an extraction was 13 degrees, which was the largest movement on any axis
Consumer preferences for cultural heritage and tourism e-services: a case study of three European cities
This paper reports the results of a marketing study aimed at discovering consumer preferences for the e-services in European cultural destinations. Our results are central to eliciting potential consumers’ preferences for tourism and cultural heritage-related e-services. The paper is based on the analysis of user surveys conducted by the authors within the ISAAC EU-funded project in Amsterdam, Genoa and Leipzig in 2007-2009. Three types of consumers were contacted: residents, visitors and (cultural heritage) service providers. Our results provide a number of important recommendations for the design of e-tourism ICT platforms in European cities. The ICT platforms constitute a new market product, representing a novel approach to increasing the revenues from incoming tourism. The recommendations suggest priorities to ensure that the information system will most readily meet potential consumers’ needs
The Warwick-Edinburgh Mental Well-being Scale (WEMWBS) : development and UK validation
Background
There is increasing international interest in the concept of mental well-being and its contribution to all aspects of human life. Demand for instruments to monitor mental well-being at a population level and evaluate mental health promotion initiatives is growing. This article describes the development and validation of a new scale, comprised only of positively worded items relating to different aspects of positive mental health: the Warwick-Edinburgh Mental Well-Being Scale (WEMWBS).
Methods
WEMWBS was developed by an expert panel drawing on current academic literature, qualitative research with focus groups, and psychometric testing of an existing scale. It was validated on a student and representative population sample. Content validity was assessed by reviewing the frequency of complete responses and the distribution of responses to each item. Confirmatory factor analysis was used to test the hypothesis that the scale measured a single construct. Internal consistency was assessed using Cronbach's alpha. Criterion validity was explored in terms of correlations between WEMWBS and other scales and by testing whether the scale discriminated between population groups in line with pre-specified hypotheses. Test-retest reliability was assessed at one week using intra-class correlation coefficients. Susceptibility to bias was measured using the Balanced Inventory of Desired Responding.
Results
WEMWBS showed good content validity. Confirmatory factor analysis supported the single factor hypothesis. A Cronbach's alpha score of 0.89 (student sample) and 0.91 (population sample) suggests some item redundancy in the scale. WEMWBS showed high correlations with other mental health and well-being scales and lower correlations with scales measuring overall health. Its distribution was near normal and the scale did not show ceiling effects in a population sample. It discriminated between population groups in a way that is largely consistent with the results of other population surveys. Test-retest reliability at one week was high (0.83). Social desirability bias was lower or similar to that of other comparable scales.
Conclusion
WEMWBS is a measure of mental well-being focusing entirely on positive aspects of mental health. As a short and psychometrically robust scale, with no ceiling effects in a population sample, it offers promise as a tool for monitoring mental well-being at a population level. Whilst WEMWBS should appeal to those evaluating mental health promotion initiatives, it is important that the scale's sensitivity to change is established before it is recommended in this context
Development of an optimized converter layer for silicon carbide based neutron sensor for the detection of fissionable materials
Here, we describe the early stage design, construction and testing of a miniature silicon carbide diode neutron sensing instrument. It is intended that a more mature version of this instrument will be used as part of a robotic manipulator to investigate various parts of the stricken Fukushima nuclear power plant. Here, three such silicon carbide based proto-type sensors have been created, two of which have differing thicknesses of boron-10 deposited on, with the final one left bare. The thicknesses and materials chosen have been informed via Monte Carlo software (MCNP 6.2) which was also used to assess the suitability of two other potential converter materials – Lithium-6 and gadolinium-157. The work goes on to describe the design, construction and testing of the prototype device at two sites around the UK. The project is part of a UK/Japanese collaboration between Lancaster University and Kyoto University and is supported by an EPSRC grant via the UK Japan Civil nuclear research program
Optimal Evacuation-Decisions Facing the Trade-Off between Early- Warning Precision, Evacuation-Cost and Trust – the Warning Compliance Model (WCM)
In this article, we analyze the phenomenon of flood evacuation compliance from a both decision-theoretic and game-theoretic perspective presenting the Warning Compliance Model (WCM). This discrete decision model incorporates a Bayesian information system, which formalizes the statistical effects of a warning forecast based on the harmonious structure of a Hidden Markov Model (HMM). The game-theoretical part of the model incorporates the evacuation order decision of a local government and people’s compliance regarding their evacuation-decisions. The strengths of this novel approach lie in the joint consideration of probabilistic and communicative risk aspects of a dynamic setting, in the simultaneous consideration of escalation and de-escalation phases and of two differently exposed risk groups, which requires differential risk communication. For each scenario, we derive the explicit and generic solution of the model, which makes it possible to identify the scope for warning compliance and its effects independent from the parameter constellation. Applying empirical data from flood and risk studies yields plausible results for the escalation-scenario of the model and reveal the limits of compliance if people face a Black Swan flood event
Population Decline and Management Plan for the Peregrine Falcon
This library report summarizes the major works that have been carried out in the study of the peregrine falcon (Falco peregrinus) and outlines several management steps that may be effective in reversing the current decline in population levels that are presently occurring world wide. The peregrine falcon has experienced a world wide population crash during the years 1950 to 1965. The status of the present day populations is not widely agreed upon except that at least one and possibly two of the 12 subspecies is now extinct. Chlorinated hydorcarbons have effected an imbalance of the sex hormone endocrine system of these birds. This imbalance has led to thin eggshells, reduced fertility, and generally low reproductive rates, which were less than mortality rates and a population crash was the result. Management of the remaining peregrine populations can be in the form of absolute protection, purging adults systems free of pesticides, holding juveniles in captivity until two years of age and then releasing them, and by establishing captive breeding stocks to produce young which would be released to the wild to augment natural reproduction. Introduction of permanent wild populations by the use of alternative subspecies in areas where total extinction of the population has occurred may be possible after pesticides are eliminated from the world ecosystem and if habitat remains to support them.Natural Scienc
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