6,531 research outputs found
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Does the value of quality of life depend on duration?
The aims of this study are to investigate the feasibility of eliciting Time Trade Off (TTO) valuations using short durations; to determine the effect of contrasting durations on individualsâ responses to the TTO; to examine variations within and between respondentsâ values with respect to duration; and to consider the insights provided by participantsâ comments and explanations regarding their reaction to duration in the valuation task. 27 participants provided TTO values using short and long durations for three EQ-5D states. Feedback was sought using a series of open ended questions. Of the 81 opportunities to observe it, strict constant proportionality was satisfied twice. 11 participants had no systematic relationship between duration and value; 11 provided consistently lower valuations in long durations, while 5 had higher valuations in long durations. Comments provided by participants were consistent with the values they provided. Mean TTO values did not differ markedly between alternative durations. We conclude that it is feasible to elicit TTO values for short durations. There is considerable heterogeneity in individualsâ responses to the time frames used to elicit values. Further research is required to ensure that the values used in cost effectiveness analysis adequately represent preferences about quality and length of life
Minimum entropy restoration using FPGAs and high-level techniques
One of the greatest perceived barriers to the widespread use of FPGAs in image processing is the difficulty for application specialists of developing algorithms on reconfigurable hardware. Minimum entropy deconvolution (MED) techniques have been shown to be effective in the restoration of star-field images. This paper reports on an attempt to implement a MED algorithm using simulated annealing, first on a microprocessor, then on an FPGA. The FPGA implementation uses DIME-C, a C-to-gates compiler, coupled with a low-level core library to simplify the design task. Analysis of the C code and output from the DIME-C compiler guided the code optimisation. The paper reports on the design effort that this entailed and the resultant performance improvements
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A uniform Time Trade Off method for states better and worse than dead: feasibility study of the âlead timeâ approach
The way Time Trade Off (TTO) values are elicited for states of health considered âworse than being deadâ has important implications for the mean values used in economic evaluation. Conventional approaches to TTO, as used in the UKâs âMVHâ value set, are problematic because they require fundamentally different tradeoffs tasks for the valuation of
states better and worse than dead. This study aims to refine and test the feasibility of a new approach described by Robinson and Spencer (2006), and to explore the characteristics of the valuation data it generates. The approach introduces a âlead timeâ into the TTO, producing a uniform procedure for generating values either >0 or <0. We used this lead time TTO to value 10 moderate to severe EQ-5D states using a sample of the general public (n=109). We conclude that the approach is feasible for use in valuation studies, and appears to overcome the discontinuity in values around 0 evident in conventional methods. However, further research is required to resolve the issue of how to handle participants who âuse upâ all lead time; to develop ways of controlling for individual time preferences; and to better understand the implications for valuations of states better than dead
Restoration of star-field images using high-level languages and core libraries
Research into the use of FPGAs in Image Processing began in earnest at the beginning of the 1990s. Since then, many thousands of publications have pointed to the computational capabilities of FPGAs. During this time, FPGAs have seen the application space to which they are applicable grow in tandem with their logic densities. When investigating a particular application, researchers compare FPGAs with alternative technologies such as Digital Signal Processors (DSPs), Application-Specific Integrated Cir-cuits (ASICs), microprocessors and vector processors. The metrics for comparison depend on the needs of the application, and include such measurements as: raw performance, power consumption, unit cost, board footprint, non-recurring engineering cost, design time and design cost. The key metrics for a par-ticular application may also include ratios of these metrics, e.g. power/performance, or performance/unit cost. The work detailed in this paper compares a 90nm-process commodity microprocessor with a plat-form based around a 90nm-process FPGA, focussing on design time and raw performance. The application chosen for implementation was a minimum entropy restoration of star-field images (see [1] for an introduction), with simulated annealing used to converge towards the globally-optimum solution. This application was not chosen in the belief that it would particularly suit one technology over another, but was instead selected as being representative of a computationally intense image-processing application
The Influence of Whaler William Scoresby, Jr. on the Arctic Observations of Sir James Lamont
Scottish adventurer James Lamont led hunting expeditions to Svalbard (1858 and 1859) and to Svalbard and Novaya Zemlya (1869 to 1871), voyages chronicled in his two publications, Seasons with the Sea-horses (1861) and Yachting in the Arctic Seas (1876). These works were modeled on the English whaler William Scoresby, Jr.âs An Account of the Arctic Regions, with a History and Description of the Northern Whale-Fishery, Vol. 1, written in 1820. Scoresbyâs book, as well as a correspondence with evolutionary theorist, Charles Darwin, inspired Lamont to pursue science during an Arctic hunt. Lamontâs scientific endeavours included geographical surveys, the collection of geological specimens, and basic experiments in physical oceanography. However, most importantly, Lamont provided the first account of Arctic wildlife in the context of natural selection. Lamontâs legacy as an Arctic explorer linked the early sea-hunters like Scoresby to a later generation of Victorian hunter-explorers, such as Benjamin Leigh Smith, who followed Lamontâs lead and journeyed northward to hunt and conduct scientifically grounded explorations.James Lamont, aventurier Ă©cossais, a menĂ© des expĂ©ditions de chasse au Svalbard (en 1858 et en 1859) ainsi quâau Svalbard et Ă Novaya Zemlya (de 1869 Ă 1871). Il a racontĂ© ses expĂ©ditions dans ses deux publications, Seasons with the Sea-horses (1861) et Yachting in the Arctic Seas (1876). Ces oeuvres prenaient modĂšle sur celle de William Scoresby, fils, chasseur de baleines anglais qui a publiĂ© An Account of the Arctic Regions, with a History and Description of the Northern Whale-Fishery, Vol. 1, en 1820. Lâoeuvre de William Scoresby de mĂȘme que la correspondance avec Charles Darwin, thĂ©oricien Ă©volutionnaire, a inspirĂ© James Lamont Ă explorer lâaspect scientifique dâune de ses expĂ©ditions de chasse dans lâArctique. Ă cette occasion, il a fait des levĂ©s gĂ©ographiques, prĂ©levĂ© des Ă©chantillons gĂ©ologiques et rĂ©alisĂ© des expĂ©riences rudimentaires en ocĂ©anographie physique. Mais qui plus est, James Lamont a fait les premiers rĂ©cits sur la faune arctique dans le contexte de la sĂ©lection naturelle. Le travail effectuĂ© par James Lamont en tant quâexplorateur de lâArctique a permis de faire le pont entre les premiers chasseurs de baleines comme William Scoresby et une gĂ©nĂ©ration plus tardive dâexplorateurs-chasseurs victoriens, comme Benjamin Leigh Smith, qui a suivi les traces de Lamont vers le nord pour chasser et faire des explorations Ă caractĂšre scientifique
A Study of Marine Terrace Formation Along the California Central Coast
Marine terrace formation is in many instances attributed to wave action, and shore platforms are often called âwave-cutâ. However, alternative models for marine terrace formation suggest that other types of physical and chemical weathering have a more central role in the formation of marine terraces than is widely acknowledged. Roering and Retallack (2012) concluded that the roles of subaerial physical and chemical weathering are significant, and played a major role in the formation of the terraces. In this study, weathering of beach cliffs and shore platforms associated with marine terraces at eight sites in two different locations along the central California Coast is assessed, and results are compared to those of Roering and Retallack.
Findings for rock hardness along the profile of modern shore platform and cliff face are similar to the results from the Roering and Retallack study: the Schmidt rock hardness of cliff faces within the bottom 1.5 meters above the modern shoreline angle are significantly lower than the rock hardness of the shore platform. Oxidation color of shore platforms, assessed using a Munsell color and described in Munsell color notation, is consistently within the Gley 1 range in both study areas. Beach cliff oxidation color varied from Gley to colors indicating oxidation. Oxidation on beach cliffs was more prevalent within the upper half meter of the part of the beach cliff that was sampled, and oxidation within fractures and cracks was also apparent in some cliff faces
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Source-specific Fine Particulate Using Spatiotemporal Concentration Fields Developed using Chemical Transport Modelling and Data Assimilation
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