7,586 research outputs found

    Neural Architecture Search: Insights from 1000 Papers

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    In the past decade, advances in deep learning have resulted in breakthroughs in a variety of areas, including computer vision, natural language understanding, speech recognition, and reinforcement learning. Specialized, high-performing neural architectures are crucial to the success of deep learning in these areas. Neural architecture search (NAS), the process of automating the design of neural architectures for a given task, is an inevitable next step in automating machine learning and has already outpaced the best human-designed architectures on many tasks. In the past few years, research in NAS has been progressing rapidly, with over 1000 papers released since 2020 (Deng and Lindauer, 2021). In this survey, we provide an organized and comprehensive guide to neural architecture search. We give a taxonomy of search spaces, algorithms, and speedup techniques, and we discuss resources such as benchmarks, best practices, other surveys, and open-source libraries

    A Decision Support System for Economic Viability and Environmental Impact Assessment of Vertical Farms

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    Vertical farming (VF) is the practice of growing crops or animals using the vertical dimension via multi-tier racks or vertically inclined surfaces. In this thesis, I focus on the emerging industry of plant-specific VF. Vertical plant farming (VPF) is a promising and relatively novel practice that can be conducted in buildings with environmental control and artificial lighting. However, the nascent sector has experienced challenges in economic viability, standardisation, and environmental sustainability. Practitioners and academics call for a comprehensive financial analysis of VPF, but efforts are stifled by a lack of valid and available data. A review of economic estimation and horticultural software identifies a need for a decision support system (DSS) that facilitates risk-empowered business planning for vertical farmers. This thesis proposes an open-source DSS framework to evaluate business sustainability through financial risk and environmental impact assessments. Data from the literature, alongside lessons learned from industry practitioners, would be centralised in the proposed DSS using imprecise data techniques. These techniques have been applied in engineering but are seldom used in financial forecasting. This could benefit complex sectors which only have scarce data to predict business viability. To begin the execution of the DSS framework, VPF practitioners were interviewed using a mixed-methods approach. Learnings from over 19 shuttered and operational VPF projects provide insights into the barriers inhibiting scalability and identifying risks to form a risk taxonomy. Labour was the most commonly reported top challenge. Therefore, research was conducted to explore lean principles to improve productivity. A probabilistic model representing a spectrum of variables and their associated uncertainty was built according to the DSS framework to evaluate the financial risk for VF projects. This enabled flexible computation without precise production or financial data to improve economic estimation accuracy. The model assessed two VPF cases (one in the UK and another in Japan), demonstrating the first risk and uncertainty quantification of VPF business models in the literature. The results highlighted measures to improve economic viability and the viability of the UK and Japan case. The environmental impact assessment model was developed, allowing VPF operators to evaluate their carbon footprint compared to traditional agriculture using life-cycle assessment. I explore strategies for net-zero carbon production through sensitivity analysis. Renewable energies, especially solar, geothermal, and tidal power, show promise for reducing the carbon emissions of indoor VPF. Results show that renewably-powered VPF can reduce carbon emissions compared to field-based agriculture when considering the land-use change. The drivers for DSS adoption have been researched, showing a pathway of compliance and design thinking to overcome the ‘problem of implementation’ and enable commercialisation. Further work is suggested to standardise VF equipment, collect benchmarking data, and characterise risks. This work will reduce risk and uncertainty and accelerate the sector’s emergence

    TOWARDS AN UNDERSTANDING OF EFFORTFUL FUNDRAISING EXPERIENCES: USING INTERPRETATIVE PHENOMENOLOGICAL ANALYSIS IN FUNDRAISING RESEARCH

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    Physical-activity oriented community fundraising has experienced an exponential growth in popularity over the past 15 years. The aim of this study was to explore the value of effortful fundraising experiences, from the point of view of participants, and explore the impact that these experiences have on people’s lives. This study used an IPA approach to interview 23 individuals, recognising the role of participants as proxy (nonprofessional) fundraisers for charitable organisations, and the unique organisation donor dynamic that this creates. It also bought together relevant psychological theory related to physical activity fundraising experiences (through a narrative literature review) and used primary interview data to substantiate these. Effortful fundraising experiences are examined in detail to understand their significance to participants, and how such experiences influence their connection with a charity or cause. This was done with an idiographic focus at first, before examining convergences and divergences across the sample. This study found that effortful fundraising experiences can have a profound positive impact upon community fundraisers in both the short and the long term. Additionally, it found that these experiences can be opportunities for charitable organisations to create lasting meaningful relationships with participants, and foster mutually beneficial lifetime relationships with them. Further research is needed to test specific psychological theory in this context, including self-esteem theory, self determination theory, and the martyrdom effect (among others)

    Extreme Heat and COVID-19: The Impact on the Urban Poor in Asia and Africa

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    The research on which this report was based was funded by the UK Research and Innovation and the Global Challenges Research Fund through the Economic and Social Research Council (Award ES/T008091/1) and by the Scottish Funding Council as part of Cool Infrastructures, a multi-disciplinary project into life with heat in global cities. We also thank the Norwegian Red Cross and Norwegian Ministry of Foreign Affairs for publication support.The study provides substantial new data on the direct as well as indirect impacts of the COVID-19 pandemic, thermal comfort and heat-related illness, in Jakarta (Indonesia), Hyderabad (India), Karachi and Hyderabad (Pakistan) and Douala (Cameroon). These cities are home to very large or rapidly growing low-income populations dealing with extreme heat. Alongside data on heat exposure and symptoms associated with heat-related illness, the report supplies supplementary data points on access to electricity, water, food, health services, as well as income and food intake during the COVID-19 pandemic, that will be of use to policy makers and researchers. The report is intended for use by governmental and non-governmental organisations in these cities and countries as they work to fine-tune policy and programme responses to the COVID-19 pandemic and avoid heat-related health impacts. Its broader findings are intended to be of use to inform interventions in urban areas facing similar challenges across Sub-Saharan Africa, South Asia and South East Asia

    The Impact of a Play Intervention on the Social-Emotional Development of Preschool Children in Riyadh, Saudi Arabia

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    Practitioners working with children have emphasized that play is vital to children’s development, Links between children’s social-emotional development and play have been widely documented. However, rigorous research evidence of these links remains limited. This study’s objectives were to measure the impact of play on children’s social-emotional development in the kingdom of Saudi Arabia; identify teachers’ viewpoints around the use of play intervention; and understand the children’s experience of play intervention. Fifty-nine children aged between five and six years, with mean age of 5.5 (SD 3.376) and eight teachers participated in the study. The study used a mixed-method strategy including questionnaires, interviews, and focus group discussions. Children’s social-emotional development was measured by using the Strengths and Difficulties Questioner (SDQ). A pre-/post-test counterbalanced design was used to measure the impact of the play intervention on children’s development. Teachers’ perspectives on play were obtained by interviewing eight teachers. Children’s views were gathered through focus group discussions. Repeated measures ANOVA was conducted to determine the differences in the SDQ score over three time points. Results showed that using unstructured loose parts play had positively impacted children’s social-emotional development. After participation in the play intervention, scores from the SDQ indicated that children demonstrated significantly less problematic emotional, conduct and peer relationship issues. They also scored significantly higher in their positive prosocial behaviour. These positive effects were sustained after six weeks of stopping the intervention. The play intervention did not however impact children’s hyperactivity level. The interviews analysis illustrates four main themes: concept and characteristics of play, play functions, developmental benefits of play, and play and practice. Regarding children’s discussion, affordance emerged as a main theme; this includes emotional, social, and functional affordances. Unstructured loose parts play intervention was demonstrated to have positive impacts on children’s social-emotional development. The study’s findings support the view that play is a way to increase children’s development

    Socio-endocrinology revisited: New tools to tackle old questions

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    Animals’ social environments impact their health and survival, but the proximate links between sociality and fitness are still not fully understood. In this thesis, I develop and apply new approaches to address an outstanding question within this sociality-fitness link: does grooming (a widely studied, positive social interaction) directly affect glucocorticoid concentrations (GCs; a group of steroid hormones indicating physiological stress) in a wild primate? To date, negative, long-term correlations between grooming and GCs have been found, but the logistical difficulties of studying proximate mechanisms in the wild leave knowledge gaps regarding the short-term, causal mechanisms that underpin this relationship. New technologies, such as collar-mounted tri-axial accelerometers, can provide the continuous behavioural data required to match grooming to non-invasive GC measures (Chapter 1). Using Chacma baboons (Papio ursinus) living on the Cape Peninsula, South Africa as a model system, I identify giving and receiving grooming using tri-axial accelerometers and supervised machine learning methods, with high overall accuracy (~80%) (Chapter 2). I then test what socio-ecological variables predict variation in faecal and urinary GCs (fGCs and uGCs) (Chapter 3). Shorter and rainy days are associated with higher fGCs and uGCs, respectively, suggesting that environmental conditions may impose stressors in the form of temporal bottlenecks. Indeed, I find that short days and days with more rain-hours are associated with reduced giving grooming (Chapter 4), and that this reduction is characterised by fewer and shorter grooming bouts. Finally, I test whether grooming predicts GCs, and find that while there is a long-term negative correlation between grooming and GCs, grooming in the short-term, in particular giving grooming, is associated with higher fGCs and uGCs (Chapter 5). I end with a discussion on how the new tools I applied have enabled me to advance our understanding of sociality and stress in primate social systems (Chapter 6)

    REDESIGNING THE COUNTER UNMANNED SYSTEMS ARCHITECTURE

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    Includes supplementary material. Please contact [email protected] for access.When the Islamic State used Unmanned Aerial Vehicles (UAV) to target coalition forces in 2014, the use of UAVs rapidly expanded, giving weak states and non-state actors an asymmetric advantage over their technologically superior foes. This asymmetry led the Department of Defense (DOD) and the Department of Homeland Security (DHS) to spend vast sums of money on counter-unmanned aircraft systems (C-UAS). Despite the market density, many C-UAS technologies use expensive, bulky, and high-power-consuming electronic attack methods for ground-to-air interdiction. This thesis outlines the current technology used for C-UAS and proposes a defense-in-depth framework using airborne C-UAS patrols outfitted with cyber-attack capabilities. Using aerial interdiction, this thesis develops a novel C-UAS device called the Detachable Drone Hijacker—a low-size, weight, and power C-UAS device designed to deliver cyber-attacks against commercial UAVs using the IEEE 802.11 wireless communication specification. The experimentation results show that the Detachable Drone Hijacker, which weighs 400 grams, consumes one Watt of power, and costs $250, can interdict adversarial UAVs with no unintended collateral damage. This thesis recommends that the DOD and DHS incorporates aerial interdiction to support its C-UAS defense-in-depth, using technologies similar to the Detachable Drone Hijacker.DASN-OE, Washington DC, 20310Captain, United States Marine CorpsApproved for public release. Distribution is unlimited

    Management Matters : Organizational Storytelling within the Anthroposophical Society in Sweden

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    The Anthroposophical Society, founded by the Austrian polymath Rudolf Steiner, came to Sweden in 1913, but for the generation of present-day Swedish Anthroposophists whose voices are heard in this study, the great flowering of the movement occurred in the second half of the twentieth century. The movement had by then expanded into a large milieu with many largely independent enterprises and institutions, from the formal organization itself, to various schools, farms, shops, medical facilities, etc., all based on interpretations of Steiner’s legacy. Since then, many members of the movement feel, there has been a decline. A movement of this size and complexity can be seen as a large organization with a corporate-like structure. Taking its point of departure in ideas from the vast field of organization studies, and specifically in the study of storytelling as part of the creation of a corporate culture where many voices and many perspectives co-exist, this study investigates how Anthroposophists in Sweden, both rank and-file members and some who served in leadership positions, tell the story of the putative Golden Age, decline, and projected future of Anthroposophy in Sweden. Twenty-eight interviews were collected, recurrent themes identified, and the plots of the various individual stories analyzed by means of a version of the actantial model developed by the semioticist Algirdas Greimas. The basic storyline, of which the interviewees’ individual stories constitute variations, is that the Golden Age, when charismatic leaders could draw crowds of enthusiastic young people and a vibrant Anthroposophical milieu was built up, came to an end with the demise of those leaders. The present, i.e., the time at which the interviews were conducted, is narratively framed as a period of sharp decline. The vistas for the future come across in most stories as quite bleak. An actantial analysis reveals that the past, an epoch that is on one hand held up as a shining example is on the other hand also described as a time characterized by innumerable problems and conflicts. Disagreement is rampant regarding the reasons for the current decline, and a vast number of problems are identified in the individual narratives. The future is for some interviewees impossible to speculate about, whereas others have specific suggestions for change. These suggestions, when held up against each other, show that there is no unified vision of what the necessary changes might be or who must bring them about. The interviewees agree that Anthroposophy plays a vital role as a spiritual path. When asked how they would describe Anthroposophy and what it more specifically can offer, answers diverge, but substantive descriptions of core concepts or practices are rarely alluded to. Rather, their explanations of what Anthroposophy is are in almost all cases metaphorical or negative, i.e., they represent Anthroposophy as elusive or undefinable. Interviewees can suggest that the lack of a clear Anthroposophical “brand” is a major reason for its current perceived crisis. An analysis of the ways in which Rudolf Steiner is portrayed in the interview material shows that there are a variety of descriptions of him rather than a unified representation of a charismatic leader that members can rally around. This, the study suggests, is because four different forms of charisma can be distinguished on theoretical grounds, and the particular form that permeates the narratives collected for this study does not readily support the dissemination of a centralized, dominant narrative.Antroposofiska SĂ€llskapet, grundat av österrikaren Rudolf Steiner, kom till Sverige redan i 1913, men för den generation av nutida svenska antroposofer vars röster hörs i denna studie intrĂ€ffade rörelsens stora blomstringstid först under nittonhundratalets andra hĂ€lft. Vid det laget hade rörelsen expanderat och blivit till en omfattande miljö med mĂ„nga stort sett oberoende institutioner och verksamheter, frĂ„n sjĂ€lva det Antroposofiska SĂ€llskapet i strikt mening till olika skolor, lantbruk, butiker, kliniker, osv., som alla byggde pĂ„ tolkningar av arvet efter Steiner. MĂ„nga medlemmar i rörelsen menar att det sedan dess har skett en nedgĂ„ng. En rörelse med den storlek och komplexitet som det rör sig om i det aktuella fallet kan betraktas som en organisation med en företagsliknande struktur. Denna studie tar dĂ€rför sin utgĂ„ngspunkt i ett organisationsteoretiskt perspektiv, i synnerhet i den gren av organisationsteorin som studerar berĂ€ttande som ett led i hur en organisationskultur med mĂ„nga samexisterande röster skapas. I det aktuella fallet handlar det om berĂ€ttelser som antroposofer i Sverige, bĂ„de vanliga medlemmar och personer i ledarstĂ€llning, framför om den blomstringstid de menar rörelsen en gĂ„ng hade, den nedgĂ„ng de sĂ€ger sig uppleva och den framtid de förestĂ€ller sig att antroposofin i Sverige kommer att möta. TjugoĂ„tta intervjuer genomfördes och de berĂ€ttelser som förmedlas i dessa intervjuer analyserades med hjĂ€lp av en variant av den aktantmodell som utvecklats av semiotikern Algirdas Greimas. Den grundlĂ€ggande handling man Ă„terfinner i intervjupersonernas olika berĂ€ttelser Ă€r att blomstringstiden var en guldĂ„lder dĂ„ karismatiska ledare kunde samla stora grupper av entusiastiska ungdomar och en levande antroposofisk miljö byggdes upp, men att denna guldĂ„lder upphörde nĂ€r ledarna gick ur tiden. Nuet, alltsĂ„ den tid dĂ„ intervjuerna genomfördes, beskrivs i berĂ€ttelserna som en tid av förfall. Framtidsutsikterna som mĂ„las upp i de flesta berĂ€ttelser Ă€r dystra. Aktantanalysen visar att berĂ€ttelserna om det förflutna bĂ„de beskriver denna tid i mycket positiva termer och nĂ€mner otaliga problem och konflikter. Nuets pĂ„stĂ„dda förfall Ă„terkommer i de flesta berĂ€ttelser, men Ă„sikterna gĂ„r vitt isĂ€r nĂ€r det gĂ€ller vad nutidens problem Ă€r och vad som orsakat dem. Framtiden beskrivs av vissa intervjupersoner som omöjlig att spekulera nĂ€rmare om, medan andra har specifika förslag till förĂ€ndringar. Sammantaget visar analysen att det saknas en enhetlig förestĂ€llning om vad som behöver göras för att lösa rörelsens problem och vem som ska ta ansvar för dessa förĂ€ndringar. Intervjupersonerna Ă€r eniga om att antroposofin spelar en viktig roll. FrĂ„gan hur de skulle beskriva antroposofin och vad den har att erbjuda besvaras pĂ„ olika sĂ€tt, men sĂ€llan i termer av konkreta beskrivningar av för antroposofin centrala förestĂ€llningar eller praktiker. Tendensen Ă€r snarare att svara i metaforiska eller negativa termer, alltsĂ„ genom att berĂ€tta att de menar att antroposofin inte gĂ„r att definiera. Samtidigt kan intervjupersonerna förklara att bristen pĂ„ en tydlig antroposofisk identitet Ă€r ett huvudskĂ€l till vad de ser som rörelsens nuvarande kris. En analys av de sĂ€tt pĂ„ vilka Rudolf Steiner beskrivs i intervjumaterialet visar att det ocksĂ„ finns en rad divergerande uppfattningar av honom snarare Ă€n en sammanhĂ„llen beskrivning av en karismatisk ledare som medlemmarna kan samlas kring. Studien konkluderar att karisma pĂ„ teoretiska grunder kan delas in i fyra olika typer, och att den specifika form av karisma som intervjuerna Ă„terspeglar inte harmonierar sĂ€rskilt vĂ€l med spridandet av en centralt utformad dominerande berĂ€ttelse
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