The influence of photovoltaics on roof thermal performance - an analysis of convective heat transfer coefficients

In a Mediterranean climate, given the absence of snow, flat roofs are typical of both vernacular and modern architecture. Thermal mass, cross ventilation and night time cooling are standard passive design aids that inhibit indoor temperature build-up on hot summer days. Such flat roofs provide a golden opportunity for free-orientation of PV (photovoltaic) panels, unlike pitched roofs. There is established scientific evidence that their presence on flat roofs also helps curtail surface temperatures of the heavy mass structure, by means of (i) solar shading and (ii) convective cooling at given angles. Both factors in turn lower the convective heat transfer coefficient (CHTC) of the roof structure, thus inhibiting early seasonal temperature build-up. This contributes to lower cooling loads, thus reducing both the carbon footprint of the building as well as lowering energy costs for the owners. Such a holistic contribution is deemed to uphold the social, environmental and economic challenges of today. This study purports to do just that. Through CFD (computational fluid dynamics) this study investigates the effect of flow fields over a typical flat roof building mass in a free field for a range of wind velocities. Results indicate that for a higher wind speed, the convective cooling is more significant than at lower wind speeds. This will in turn influence the elemental U-value of the roof structure, thus reducing cooling loads indoors.peer-reviewe

Using control flow analysis to improve the effectiveness of incremental mutation testing

Incremental Mutation Testing attempts to make mutation testing less expensive by applying it incrementally to a system as it evolves. This approach fits current trends of iterative software development with the main idea being that by carrying out mutation analysis in frequent bite-sized chunks focused on areas of the code which have changed, one can build confidence in the adequacy of a test suite incrementally. Yet this depends on how precisely one can characterise the effects of a change to a program. The original technique uses a naïve approach whereby changes are characterised only by syntactic changes. In this paper we propose bolstering incremental mutation testing by using control flow analysis to identify semantic repercussions which a syntactic change will have on a system. Our initial results based on two case studies demonstrate that numerous relevant mutants which would have otherwise not been considered using the naïve approach, are now being generated. However, the cost of identifying these mutants is significant when compared to the naïve approach, although it remains advantageous when compared to traditional mutation testing so long as the increment is sufficiently small.peer-reviewe

Automatic composition of music by means of Grammatical Evolution

This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in APL Quote Quad, http://dx.doi.org/10.1145/604444.602249Proceedings of the 2002 conference on APL: array processing languages: lore, problems, and applications (Madrid)This work describes how grammatical evolution may be applied to the domain of automatic composition. Our goal is to test this technique as an alternate tool for automatic composition. The AP440 auxiliary processor will be used to play music, thus we shall use a grammar that generates AP440 melodies. Grammar evolution will use fitness functions defined from several well-known single melodies to automatically generate AP440 compositions that are expected to sound like those composed by human musicians.This paper has been sponsored by the Spanish Interdepartmental Commission of Science and Technology (CICYT), project numbers TEL1999-0181 and TIC2001-0685-C02-1

Nomenclature updates resulting from the evolution of avian influenza A(H5) virus clades 2.1.3.2a, 2.2.1, and 2.3.4 during 2013-2014.

AIM: The A/goose/Guangdong/1/96-like hemagglutinin (HA) genes of highly pathogenic avian influenza (HPAI) A(H5) viruses have continued to rapidly evolve since the most recent update to the H5 clade nomenclature by the WHO/OIE/FAO H5N1 Evolution Working Group. New clades diverging beyond established boundaries need to be identified and designated accordingly. METHOD: Hemagglutinin sequences deposited in publicly accessible databases up to December 31, 2014, were analyzed by phylogenetic and average pairwise distance methods to identify new clades that merit nomenclature changes. RESULTS: Three new clade designations were recommended based on division of clade 2·1·3·2a (Indonesia), 2·2·1 (Egypt), and 2·3·4 (widespread detection in Asia, Europe, and North America) that includes newly emergent HPAI virus subtypes H5N2, H5N3, H5N5, H5N6, and H5N8. CONCLUSION: Continued global surveillance for HPAI A(H5) viruses in all host species and timely reporting of sequence data will be critical to quickly identify new clades and assess their potential impact on human and animal health.The Melbourne WHO Collaborating Centre for Reference and Research on Influenza is supported by the Australian Government Department of Health.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/irv.1232

Global mapping of highly pathogenic avian influenza H5N1 and H5Nx clade 2.3.4.4 viruses with spatial cross-validation.

Global disease suitability models are essential tools to inform surveillance systems and enable early detection. We present the first global suitability model of highly pathogenic avian influenza (HPAI) H5N1 and demonstrate that reliable predictions can be obtained at global scale. Best predictions are obtained using spatial predictor variables describing host distributions, rather than land use or eco-climatic spatial predictor variables, with a strong association with domestic duck and extensively raised chicken densities. Our results also support a more systematic use of spatial cross-validation in large-scale disease suitability modelling compared to standard random cross-validation that can lead to unreliable measure of extrapolation accuracy. A global suitability model of the H5 clade 2.3.4.4 viruses, a group of viruses that recently spread extensively in Asia and the US, shows in comparison a lower spatial extrapolation capacity than the HPAI H5N1 models, with a stronger association with intensively raised chicken densities and anthropogenic factors

Lady Gaga as (dis)simulacrum of monstrosity

Lady Gaga’s celebrity DNA revolves around the notion of monstrosity, an extensively researched concept in postmodern cultural studies. The analysis that is offered in this paper is largely informed by Deleuze and Guattari’s notion of monstrosity, as well as by their approach to the study of sign-systems that was deployed in A Thousand Plateaus. By drawing on biographical and archival visual data, with a focus on the relatively underexplored live show, an elucidation is afforded of what is really monstrous about Lady Gaga. The main argument put forward is that monstrosity as sign seeks to appropriate the horizon of unlimited semiosis as radical alterity and openness to signifying possibilities. In this context it is held that Gaga effectively delimits her unique semioscape; however, any claims to monstrosity are undercut by the inherent limits of a representationalist approach in sufficiently engulfing this concept. Gaga is monstrous for her community insofar as she demands of her fans to project their semiosic horizon onto her as a simulacrum of infinite semiosis. However, this simulacrum may only be evinced in a feigned manner as a (dis)simulacrum. The analysis of imagery from seminal live shows during 2011–2012 shows that Gaga’s presumed monstrosity is more akin to hyperdifferentiation as simultaneous employment of heterogeneous and potentially dissonant inter pares cultural representations. The article concludes with a problematisation of audience effects in the light of Gaga’s adoption of a schematic and post-representationalist strategy in the event of her strategy’s emulation by competitive artists

Quantifying uncertainty due to fission-fusion dynamics as a component of social complexity.

Groups of animals (including humans) may show flexible grouping patterns, in which temporary aggregations or subgroups come together and split, changing composition over short temporal scales, (i.e. fission and fusion). A high degree of fission-fusion dynamics may constrain the regulation of social relationships, introducing uncertainty in interactions between group members. Here we use Shannon's entropy to quantify the predictability of subgroup composition for three species known to differ in the way their subgroups come together and split over time: spider monkeys (Ateles geoffroyi), chimpanzees (Pan troglodytes) and geladas (Theropithecus gelada). We formulate a random expectation of entropy that considers subgroup size variation and sample size, against which the observed entropy in subgroup composition can be compared. Using the theory of set partitioning, we also develop a method to estimate the number of subgroups that the group is likely to be divided into, based on the composition and size of single focal subgroups. Our results indicate that Shannon's entropy and the estimated number of subgroups present at a given time provide quantitative metrics of uncertainty in the social environment (within which social relationships must be regulated) for groups with different degrees of fission-fusion dynamics. These metrics also represent an indirect quantification of the cognitive challenges posed by socially dynamic environments. Overall, our novel methodological approach provides new insight for understanding the evolution of social complexity and the mechanisms to cope with the uncertainty that results from fission-fusion dynamics