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Distance-Targeting Mutation Operator for Evolutionary Design of 3D Structures
Get PDFEvolutionary design of 3D structures - an automated design by the methods of evolutionary algorithms - is a hard optimization problem. One of the contributing factors is a complex genotype-to-phenotype mapping often associated with the genetic representations of the designs. In such case, the genetic operators may exhibit low locality, i.e., a small change introduced in a genotype may result in a significant change in the phenotype and its fitness, hampering the search process. To overcome this challenge in evolutionary design, we introduce the Distance-Targeting Mutation Operator (DTM). The aim of this operator is to create offspring whose distance to the parent solution, according to a selected dissimilarity measure, approximates a predefined value. We compare the performance of the DTM operator to the performance of the mutation operator without parent-offspring distance control in a series of evolutionary experiments. We use different genetic representations, dissimilarity measures, and optimization goals, including velocity and height of active and passive 3D structures. The introduced DTM operator outperforms the standard one in terms of best fitness in most of the considered cases
Dilemmatic commitments following psychological contract breach and its contrasting implications for voluntary turnover and organizational citizenship behaviour
Get PDFDo Review Sessions Improve Exam Performance? Evidence from the UK
Get PDFOut-of-term classroom time to review exam-related material is widespread. However, despite the investment in organizing and running the review sessions, their causal effect on exam performance remains unknown. Using individual-level data from a quasi-experiment, this paper identifies the effect of a review session on exam performance in a large undergraduate economics course in the United Kingdom. Contrary to pedagogical priors, the effect is insignificant. It is not driven by selection bias and remains insignificant in a series of robustness checks. The puzzling irrelevance of review sessions is discussed. A low-cost response might be to schedule review sessions closer to the exam
Comparing advanced-era interferometric gravitational-wave detector network configurations:sky localization and source properties
Get PDFThe expansion and upgrade of the global network of ground-based gravitational wave detectors promises to improve our capacity to infer the sky-localization of transient sources, enabling more effective multi-messenger follow-ups. At the same time, the increase in the signal-to-noise ratio of detected events allows for more precise estimates of the source parameters. This study aims to assess the performance of advanced-era networks of ground-based detectors, focusing on the Hanford, Livingston, Virgo, and KAGRA instruments. We use full Bayesian parameter estimation procedures to predict the scientific potential of a network. Assuming a fixed LIGO configuration, we find that the addition of the Virgo detector is beneficial to the sky localization starting from a binary neutron star horizon distance of 20 Mpc and improves significantly from 40 Mpc onwards for both a single and double LIGO detector network, reducing the inferred mean sky-area by up to 95%. Similarly, the KAGRA detector tightens the constraints, starting from a sensitivity range of 10 Mpc. Looking at highly-spinning binary black holes, we find significant improvements with increasing sensitivity in constraining the intrinsic source parameters when adding Virgo to the two LIGO detectors. Finally, we also examine the impact of the low-frequency cut-off data on the signal-to-noise ratio. We find that existing 20 Hz thresholds are sufficient and propose a metric to monitor this to study detector performance. Our findings quantify how future enhancements in detector sensitivity and network configurations will improve the localization of gravitational wave sources and allow for more precise identification of their intrinsic properties
Transdisciplinary approaches to addressing factors that influence antimicrobial use in dairy cattle:A scoping review
Get PDFInterest in antimicrobial resistance (AMR) associated with livestock farming is increasing. During the 1990s, 30–40 academic papers a year on the use of antibiotics in dairy farming were indexed on the scientific database PubMed, but this has grown to more than 200 a year in the 2020s. Most (85%) of these papers are published in veterinary or livestock science journals. There has been a corresponding increase in social science interest in why responsible antibiotic stewardship in the livestock sector is so challenging. However, most social science insights are published in journals specific to the lead authors’ field(s), missing opportunities for knowledge translation to veterinary and animal science. This threatens to inhibit the transdisciplinary One Health approaches required to tackle the problem. Between 1 June and 31 December 2021, we undertook a scoping review of papers on the use of antibiotics in dairy farming indexed in PubMed, Scopus and Web of Science. Our aim was to identify studies that incorporate social science approaches and methodologies, and to note the main field of the journal in which these studies are published. Papers were most likely to be published in veterinary science, dairy science and/or livestock science journals (61, 29 and 18 respectively out of 127 papers) and were most likely to be concerned with antibiotic use, prescribing practice, and/or diagnosis (94%, 39% and 33% of included papers respectively). Only 27% of papers meeting our inclusion criteria included a qualitative approach to understanding reasons for antibiotic use. Even fewer acknowledged underlying drivers of behaviour, whereas such reasons are frequently highlighted in social science literature. Thus, to address the global health threat from antibiotic resistance, more work is needed to bring together the disparate but equally valid disciplines, methodologies and researchers working on antibiotic use in the livestock sector
More than meets the eye:hidden messages in the attribution of human-like values to product categories
Get PDFPurpose - This paper draws on values theory, associative network theory, and schemacongruity theory to examine how consumers attribute human-like values to productcategories and products, and how these attributions affect product evaluations.Design/methodology/approach - Study one randomly assigned 925 respondents to one ofthree product categories (cars, mobile phones, and vacations). They were asked about theirvalues, and to attribute values to an assigned product category. Study two randomly assigned919 respondents to one of four value-expressive car conditions. They were asked to attributevalues to the car, and then about their attitudes and purchase intentions.Findings – Respondents attributed human-like values to product categories and products thatwere distinct and reflected the motivational compatibilities and conflicts inherent in thecircular structure of human values. Moreover, multifaceted value congruity effects werefound to positively influence attitudes and intentions to purchase a car, including congruitywith (a) product category values-schema, (b) consumers’ personal values-schema, and (c) thestructure of human values.Originality – We demonstrate how a cognitive memory-based view can be used to betterunderstand the complexities of the attribution of human-like values to products and productcategories. Moving beyond the attribution of brand personality, this study demonstrates theimportance of not only understanding attributions of values to a product, but also consideringhow these attributions interact with the more abstract product category values, to influenceevaluations
Thirty Years of Progress in Our Understanding of the Nature and Influence of Fire in Carboniferous Ecosystems
Get PDFUntil the late 20th century, the idea of identifying wildfires in deep time was not generally accepted. One of the basic problems was the fact that charcoal-like wood fragments, so often found in sedimentary rocks and in coals, were termed fusain and, in addition, many researchers could not envision wildfires in peat-forming systems. The advent of Scanning Electron Microscopy and studies on modern charcoals and fossil fusains demonstrated beyond doubt that wildfire residues may be recognized in rocks dating back to at least 350 million years. Increasing numbers of studies on modern and fossil charcoal assemblages from the 1970s through the 1990s established the potential importance of wildfires in the fossil record, using Carboniferous examples in particular. Since the 1990s, extensive progress has been made in understanding modern wildfires and their byproducts. New techniques to study ancient charcoals have allowed considerable progress to be made to integrate modern and ancient fire studies, both before and after the evolution of mankind. Four important developments have made a reassessment of Carboniferous wildfires necessary: the recognition of the role of atmospheric oxygen in controlling the occurrence of wildfire; the development of new microscopical techniques allowing more detailed anatomical data to be obtained from charcoal; the integration of molecular studies with the evolution of fire traits; and new developments in or understanding of post-fire erosion/deposition systems
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