Computer-aided liner optimization for broadband noise

In this article the attenuation of broadband noise in an acoustically-lined circular-section duct is investigated. The aim is to predict how an axially segmented liner influences the attenuation of broadband noise in an aero-engine intake. The sound field is modelled using a multi-modal representation, assuming an ensemble of uncorrelated modes over a wide range of frequencies. An optimization procedure based on a Response Surface Model is used to investigate the optimum uniform and axially-segmented acoustic liner that maximizes the attenuation of broadband noise. An approximate calculation of the Perceived Noise level (PNL) is used for the objective function. In this article the benefit of using an axially segmented liner instead of a uniform liner to attenuate broadband noise is demonstrated

On Resilient Behaviors in Computational Systems and Environments

The present article introduces a reference framework for discussing resilience of computational systems. Rather than a property that may or may not be exhibited by a system, resilience is interpreted here as the emerging result of a dynamic process. Said process represents the dynamic interplay between the behaviors exercised by a system and those of the environment it is set to operate in. As a result of this interpretation, coherent definitions of several aspects of resilience can be derived and proposed, including elasticity, change tolerance, and antifragility. Definitions are also provided for measures of the risk of unresilience as well as for the optimal match of a given resilient design with respect to the current environmental conditions. Finally, a resilience strategy based on our model is exemplified through a simple scenario.Comment: The final publication is available at Springer via http://dx.doi.org/10.1007/s40860-015-0002-6 The paper considerably extends the results of two conference papers that are available at http://ow.ly/KWfkj and http://ow.ly/KWfgO. Text and formalism in those papers has been used or adapted in the herewith submitted pape

PopFor : A new model for estimating poplar yields

Yield and soil data for this project has been supplied by Rainer Schlepphorst, Holger Hartmann and Dieter Murach from HNEE, Germany, from the BIODEM project. Soil water and groundwater data were supplied by Markus Schmidt, HNEE, Germany. We would like to thank Shell and the University of Aberdeen CLSM for funding this work with a studentship. The MiscanFor modelling was supported by UK NERC ADVENT (NE/1806209) and FAB-GGR (NE/P019951/1) project funding.Peer reviewedPostprin

East Asia and the global/transatlantic/Western crisis

This paper introduces the special collection on East Asia and the Global Crisis. After justifying why a focus on East Asia is appropriate, it draws out the main themes that run through the individual contributions. These are the extent to which the region is decoupling from the global economy (or the West), the increasing legitimacy of statist alternatives to neoliberal development strategies, and the impact of crises on the definition of ―region‖ and the functioning of regional institutions and governance mechanisms

Low risk management intervention? : Limited impact of remedial tillage on net ecosystem carbon balance at a commercial Miscanthus plantation

Acknowledgements The work was supported by Measurement and Analysis of bioenergy greenhouse gases (MAGLUE, EP/M013200/1). We were also supported by the Natural Environment Research Council award number NE/R016429/1 as part of the UK-SCAPE programme and the Ecosystem Land Use Modelling (ELUM) project which was commissioned and funded by the Energy Technologies Institute (www.elum.ac.uk). A.H. was additionally funded by the ADVENT project funded by the UK Natural Environment Research Council (NE/M019691/1) and ADVANCES funded by the UK Natural Environment Research Council (NE/M019691/1), EPSRC funded UKERC-4 and both A.H. and R.L.R were funded by BBSRC funded PCB4GGR project (BB/V011553/1). We would also like to thank theland owner for allowing access to their fields and the land owner and Terravesta Ltd for providing information on crop management.Peer reviewe

The Metal-Insulator Transition in \u3cem\u3eVO\u3csub\u3e2\u3c/sub\u3e\u3c/em\u3e Studied using Terahertz Apertureless Near-Field Microscopy

We have studied the metal-insulator transition in a vanadium dioxide (VO2) thin film using terahertz apertureless near-field optical microscopy. We observe a variation of the terahertz amplitude due to the phase transition induced by an applied voltage across the sample. The change of the terahertz signal is related to the abrupt change of the conductivity of the VO2 film at the metal-insulator transition. The subwavelength spatial resolution of this near-field microscopy makes it possible to detect signatures of micron-scale metallic domains in inhomogeneous VO2 thin films

CAD in mammography: lesion-level versus case-level analysis of the effects of prompts on human decisions

Object: To understand decision processes in CAD-supported breast screening by analysing how prompts affect readers’ judgements of individual mammographic features (lesions). To this end we analysed hitherto unexamined details of reports completed by mammogram readers in an earlier evaluation of a CAD tool. Material and methods: Assessments of lesions were extracted from 5,839 reports for 59 cancer cases. Statistical analyses of these data focused on what features readers considered when recalling a cancer case and how readers reacted to CAD prompts. Results: About 13.5% of recall decisions were found to be caused by responses to features other than those indicating actual cancer. Effects of CAD: lesions were more likely to be examined if prompted; the presence of a prompt on a cancer increased the probability of both detection and recall especially for less accurate readers in subtler cases; lack of prompts made cancer features less likely to be detected; false prompts made non-cancer features more likely to be classified as cancer. Conclusion: The apparent lack of impact reported for CAD in some studies is plausibly due to CAD systematically affecting readers’ identification of individual features, in a beneficial way for certain combinations of readers and features and a damaging way for others. Mammogram readers do not ignore prompts. Methodologically, assessing CAD by numbers of recalled cancer cases may be misleading