8,287 research outputs found

    Meso-scale FDM material layout design strategies under manufacturability constraints and fracture conditions

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    In the manufacturability-driven design (MDD) perspective, manufacturability of the product or system is the most important of the design requirements. In addition to being able to ensure that complex designs (e.g., topology optimization) are manufacturable with a given process or process family, MDD also helps mechanical designers to take advantage of unique process-material effects generated during manufacturing. One of the most recognizable examples of this comes from the scanning-type family of additive manufacturing (AM) processes; the most notable and familiar member of this family is the fused deposition modeling (FDM) or fused filament fabrication (FFF) process. This process works by selectively depositing uniform, approximately isotropic beads or elements of molten thermoplastic material (typically structural engineering plastics) in a series of pre-specified traces to build each layer of the part. There are many interesting 2-D and 3-D mechanical design problems that can be explored by designing the layout of these elements. The resulting structured, hierarchical material (which is both manufacturable and customized layer-by-layer within the limits of the process and material) can be defined as a manufacturing process-driven structured material (MPDSM). This dissertation explores several practical methods for designing these element layouts for 2-D and 3-D meso-scale mechanical problems, focusing ultimately on design-for-fracture. Three different fracture conditions are explored: (1) cases where a crack must be prevented or stopped, (2) cases where the crack must be encouraged or accelerated, and (3) cases where cracks must grow in a simple pre-determined pattern. Several new design tools, including a mapping method for the FDM manufacturability constraints, three major literature reviews, the collection, organization, and analysis of several large (qualitative and quantitative) multi-scale datasets on the fracture behavior of FDM-processed materials, some new experimental equipment, and the refinement of a fast and simple g-code generator based on commercially-available software, were developed and refined to support the design of MPDSMs under fracture conditions. The refined design method and rules were experimentally validated using a series of case studies (involving both design and physical testing of the designs) at the end of the dissertation. Finally, a simple design guide for practicing engineers who are not experts in advanced solid mechanics nor process-tailored materials was developed from the results of this project.U of I OnlyAuthor's request

    A holistic risk management framework for renewable energy investments

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    Private investments are critical enablers to achieving energy access for over 770 million people worldwide. Despite decreasing capital costs, investments in renewable energy (RE) projects in developing countries are low due to unattractive risk-return profiles. Through understanding key risks drivers and their interactions, actionable insights can be drawn to mitigate investment risks, making energy more accessible. This paper reviews RE risks and methods used for risk assessment and mitigation for developed and developing countries with a focus on Sub-Saharan Africa countries (SSA). The review finds that while risk analysis and evaluation mainly employed semi-quantitative multicriteria decision analysis (MCDA) and system dynamics (SD) methods for developing countries, qualitative methods were used to identify mitigations. The methods assessed technical and economic risks at a minimum, while MCDA and SD methods can assess social, political, and policy risks. The efficacies of mitigations were tested using SD and quantitative methods such as agent-based modelling and Monte Carlo simulation. The paper further introduces a ‘holistic multi-dimensional investor risk management framework’ which can be used to identify actions to improve investment risks in a structured manner. The framework addresses four fundamental limitations observed in the existing literature, recognising that RE risks are complex and involve multidisciplinary perspectives having interactions and feedbacks with other risks, actors, and their actions. This review provides a valuable reference to investors, policymakers, and researchers, providing a catalogue of risks, methods deployed in literature, including a framework to identify impactful actions to improve risk levels

    Existing technology and the one that is being used by insurance companies in the Iberian Peninsula A Gap Analysis

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    Dissertation presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Information Systems and Technologies ManagementThis Master’s Thesis dissertation focuses on the insurance sector, more precisely on the insurance companies present in the Iberian Peninsula and how new technologies are being used. New technology trends, digital transformation, and technology disruption are widely used terms nowadays; however, while it is quite common to use these terms, their practices and theories are not always applied by businesses. Several factors can be the cause of the failure to implement technological trends in insurance companies, either due to lack of expertise, high costs, or simply because the technologies are not mature enough and there is some fear of creating a bad reputation with customers. In order to investigate this gap between the existing technology and the technology that is being used by the insurance companies, a case study analysis was performed. Based on the technologies identified in the literature review, in-depth interviews were conducted with CIO’s, CTO’s, IT Directors, and Heads of IT of some insurance companies (from small insurance companies to market-leading insurance companies) and the results were analyzed in order to reach a valid conclusion about this gap and why it exists. After carrying out the case analysis and analyzing the answers given by the respondents, it is possible to identify that the technological gap exists and what the main reasons are for the lack of usage of the new technological trends in most insurance companies

    Technologies and Applications for Big Data Value

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    This open access book explores cutting-edge solutions and best practices for big data and data-driven AI applications for the data-driven economy. It provides the reader with a basis for understanding how technical issues can be overcome to offer real-world solutions to major industrial areas. The book starts with an introductory chapter that provides an overview of the book by positioning the following chapters in terms of their contributions to technology frameworks which are key elements of the Big Data Value Public-Private Partnership and the upcoming Partnership on AI, Data and Robotics. The remainder of the book is then arranged in two parts. The first part “Technologies and Methods” contains horizontal contributions of technologies and methods that enable data value chains to be applied in any sector. The second part “Processes and Applications” details experience reports and lessons from using big data and data-driven approaches in processes and applications. Its chapters are co-authored with industry experts and cover domains including health, law, finance, retail, manufacturing, mobility, and smart cities. Contributions emanate from the Big Data Value Public-Private Partnership and the Big Data Value Association, which have acted as the European data community's nucleus to bring together businesses with leading researchers to harness the value of data to benefit society, business, science, and industry. The book is of interest to two primary audiences, first, undergraduate and postgraduate students and researchers in various fields, including big data, data science, data engineering, and machine learning and AI. Second, practitioners and industry experts engaged in data-driven systems, software design and deployment projects who are interested in employing these advanced methods to address real-world problems

    Gender and Sport

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    This volume covers current issues, cutting-edge debates and new knowledge on women and sport. The range of topics extends from female coaches and women in sport to sexual harassment, from snowboarders to schoolgirls, and from physical education to football. The aim of this book is to provide an overview of the current debates on gender and sport from a women’s perspective, to share new knowledge about important issues, in particular about gender (in)equalities, and to present insights into the causes and effects of the debates and developments in the arena of women’s sport. A special focus in all chapters will be on the perspective of change, and backgrounds, reasons and effects of gender arrangements will be analyzed by scholars who made major contributions to the development of a new gender order in sport and society. Other authors are younger scholars with new perspectives and approaches – who represent the new generation of gender researchers

    Defining Service Level Agreements in Serverless Computing

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    The emergence of serverless computing has brought significant advancements to the delivery of computing resources to cloud users. With the abstraction of infrastructure, ecosystem, and execution environments, users could focus on their code while relying on the cloud provider to manage the abstracted layers. In addition, desirable features such as autoscaling and high availability became a provider’s responsibility and can be adopted by the user\u27s application at no extra overhead. Despite such advancements, significant challenges must be overcome as applications transition from monolithic stand-alone deployments to the ephemeral and stateless microservice model of serverless computing. These challenges pertain to the uniqueness of the conceptual and implementation models of serverless computing. One of the notable challenges is the complexity of defining Service Level Agreements (SLA) for serverless functions. As the serverless model shifts the administration of resources, ecosystem, and execution layers to the provider, users become mere consumers of the provider’s abstracted platform with no insight into its performance. Suboptimal conditions of the abstracted layers are not visible to the end-user who has no means to assess their performance. Thus, SLA in serverless computing must take into consideration the unique abstraction of its model. This work investigates the Service Level Agreement (SLA) modeling of serverless functions\u27 and serverless chains’ executions. We highlight how serverless SLA fundamentally differs from earlier cloud delivery models. We then propose an approach to define SLA for serverless functions by utilizing resource utilization fingerprints for functions\u27 executions and a method to assess if executions adhere to that SLA. We evaluate the approach’s accuracy in detecting SLA violations for a broad range of serverless application categories. Our validation results illustrate a high accuracy in detecting SLA violations resulting from resource contentions and provider’s ecosystem degradations. We conclude by presenting the empirical validation of our proposed approach, which could detect Execution-SLA violations with accuracy up to 99%

    Does Rosie like riveting? Male and female occupational choices

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    Occupational segregation and pay gaps by gender remain large, while many of the constraints traditionally believed to be responsible for these gaps seem to have weakened over time. We explore the possibility that women and men have different tastes for the content of the work that they do. We relate job satisfaction and job mobility to measures that proxy for the content of the work in an occupation, which we label ‘people’, ‘brains’ and ‘brawn’. The results suggest that women value jobs high on ‘people’ content and low on ‘brawn’. Men care about job content in a similar fashion, but have much weaker preferences. High school students show similar preferences in a discrete choice experiment and indicate that they make their choices based mainly on preferences for the work itself. We argue that the more pronounced preferences of women can account for occupational sorting, which often leads them into careers with large pay penalties for interruptions due to childbearing

    Impact of climate change on yields and output supply responses of selected cereal crops in Ethiopia

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    Climate change affects agricultural production and productivity in sub-Saharan Africa, including Ethiopia, where it poses some threats to sustainable economic growth and ag-ricultural development. As studies conducted on the impact of climate change on crop production are limited, this study analyzed the impacts of the changes in climate on yields and output supply responses of teff, wheat and maize crops in Ethiopia. The study employed time series secondary data on selected variables over the period of 1981 to 2018. The data were collected from various reputable sources such as the Ethio-pian CSA, NMA, and FAO data set (FAOSTAT). The study adopted Cobb-Douglas Pro-duction Function and Autoregressive Distributed Lag (ARDL) modeling approaches. The impacts of climate change on crop yields and output was estimated using key cli-mate parameters (minimum and maximum temperature and short- and long- season rainfalls). The results of Production Function analysis on the impact of climate variables on yield of cereal crops revealed that long-season rainfall have negative (-0.352, -0.498, and -0.429) and significant (at 1% and 5% levels) impact on yields of teff, wheat and maize crops, respectively. Maximum temperature also had negative (-2.810 & -3.681) and sig-nificant (at 10% level) impact on the yields of wheat and maize crops while it had posi-tive (0.372) and significant (at 10% level) impact on teff yield. Equally, the impact of climatic variables on crop output supply responses was estimated based on crop season temperature and short- and long-season rainfalls. The results indi-cated that changes in short- and long-season rainfalls had negative (-0.453 and -0.077) and significant (at 1% level) impact on wheat and maize outputs in their first lag order. The results also demonstrated that crop growing period mean temperature had negative (-2.88 and -10.70) and significant (at 1% and 5% levels) impacts on wheat and maize outputs in their first lag orders. Although temperature and long-season rainfall parame-ters showed negative impact on teff output, their impacts were minimal as they were statistically insignificant. Conversely, carbon dioxide (CO2) showed positive (4.76 and 2.256) and significant (at 5% and 1% level) impact on teff and wheat outputs in their first lag orders. This signified that teff and wheat outputs were positively responsive to an increase in CO2 concentration. Forecasted future changes in temperature and rainfall variables showed increasing trend in mean temperature (rise from -4.850C to 0.1950C by 2080) in teff growing belt while future changes in rainfall (both short- and long-season rainfalls) showed a decreasing trend in teff (from -0.06mm to -1.58mm), wheat (from -0.11mm to -1.3mm), and maize (from -0.01mm to -0.17mm) growing belts by 2080. However, the projected future changes in the yields of wheat, maize and teff are positive over the selected scenarios. By 2080, yield of wheat would increase by 237% while those teff and maize would increase by48% and 10% respectively. In conclusion, rainfall and temperature parameters were found to increase yield level and variability for wheat crop. However, rainfall and temperature parameters were indi-vidually found to have adverse effects on yield of teff and maize crops. Unless some abatement measures are taken on increasing CO2 emission, the rise in temperature and the decrease in seasonal rainfall will continue and this will negatively affect cereal crop yields. It is therefore recommended that there is the need to design and implement adap-tation strategies that reverse and mitigate the risks of changing climate. Development of early maturing and stress tolerant crop varieties as well as supporting research and ex-tension tasks becomes imperative.Agriculture and  Animal HealthPh. D. (Agriculture

    Conscience and Consciousness: British Theatre and Human Rights.

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    This research project investigates a paradigm of human rights theatre. Through the lens of performance and theatre-making, this thesis explores how we came to represent, speak about, discuss, and own human rights in Britain. My framework of ‘human rights theatre’ proposes three distinctive features: firstly, such works dramatise real-world issues and highlights the role of the state in endangering its citizens; secondly, ethical ruptures are encountered within and without the drama, and finally, these performances characteristically aspire to produce an activist effect on the collective behaviours of the audience. This thesis interrogates the strategies theatre-makers use to articulate human rights concerns or to animate human rights intent. The selected case-studies for this investigation are ice&fire’s testimonial project, Actors for Human Rights; Badac Theatre; Jonathan Holmes’ work as director of Jericho House; Cardboard Citizens’ youth participation programme, ACT NOW; and Tony Cealy’s Black Men’s Consortium. Deliberately selecting companies and performance events that have received limited critical attention, my methodology constellates case-studies through original interviews, durational observation of creative working methods and proximate descriptions of practice. The thesis is interested in the experience of coming to ‘consciousness’ through human rights theatre, an awakening to the impacts of rights infringements and rights claiming. I explore consciousness as a processual, procedural, and durational happening in these performance events. I explore the ‘éffect’ of activist art and examine the ways in which makers of human rights theatre aim to amplify both affective and effective qualities in their work. My thesis also considers the articulation of activist purpose and the campaigning intent of the selected theatre-makers and explores how their activism is animated in their productions. Through the rich seam of discussion generated by the identification and exploration of the traits of a distinctive human rights theatre, I affirm the generative value of this typological enquiry
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