16,995 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

    Strange bedfellows ngos and businesses move from conflict to cooperation

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    The struggle of NGOs to promote sustainable behavior from companies has successfully gained public sympathy, and has triggered a rising number of international voluntary agreements, public policy initiatives, and even state regulations. Some companies have worked their way out of stigmatization and tried to become responsible corporate citizens. While plenty of other companies are still trying to evade the CSR debate and the reporting standards therein, others have adjusted their structures to adopt them. Although this tends to raise costs on a short-term basis, most of the CSRfriendly companies have managed to economically outperform the deniers in the long run. Compliers have proven that they are able to adapt more swiftly to new market challenges, or state regulations. In addition, consumer patterns seem to reward CSR behavior. Within a decade business-NGO cooperation has become a mainstream issue, and has led to many synergetic dynamics and yielded creative solutions.Los esfuerzos de las ONG para promover entre las empresas comportamientos sostenibles han logrado ganar el apoyo del público y han llegado a producir un creciente número de acuerdos internacionales voluntarios, iniciativas de políticas públicas e incluso regulación estatal. Algunas compañías han trabajado para superar la estigmatización intentando convertirse en ciudadanos corporativos responsables. Mientras que muchas otras compañías aún están tratando de evadir el debate acerca de la RSC y sus estándares de reporte, otras han ajustado sus estructuras para adoptarlos. Aunque esto tiende a aumentar los costos a corto plazo, la mayoría de las compañías que aceptan la RSC han logrado tener un mejor desempeño económico que las que se niegan a largo plazo. Las que cumplen han demostrado que son capaces de adaptarse más rápidamente a nuevos desafíos del mercado o a la reglamentación estatal. Además, los patrones de consumo parecen remunerar este comportamiento. En el espacio de una década, la cooperación entre industrias y ONG se ha convertido en un tema corriente, ha llevado a dinámicas de sinergia y ha rendido soluciones creativas

    Hospitality Employers and Employees’ Perceptions Regarding Covid-19 Support Measures: The Case of the Algarve Region (Portugal)

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    This paper aims at investigating hospitality employers and employees’ perceptions regarding governmental policies and measures implemented during Covid 19 crisis, in the Algarve, one of the most tourist regions of Portugal. The methodological framework is associated with a case study based on a set of 51 interviews to Algarvean hospitality employers and employees. A content analysis of interviews on the effects of the pandemic on hospitality was carried using the software QSR NVivo 12. Covid 19 employment impacts were considered as ‘very high’ and ‘high’ in the Algarvean hospitality. Portuguese governmental intervention was classified as good, but more support should be enhanced, namely associated with four main policy areas such as ‘income-generating support measures’, ‘cost reductions’, ‘legal framework’, and ‘health and safety’

    A Design Science Research Approach to Smart and Collaborative Urban Supply Networks

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    Urban supply networks are facing increasing demands and challenges and thus constitute a relevant field for research and practical development. Supply chain management holds enormous potential and relevance for society and everyday life as the flow of goods and information are important economic functions. Being a heterogeneous field, the literature base of supply chain management research is difficult to manage and navigate. Disruptive digital technologies and the implementation of cross-network information analysis and sharing drive the need for new organisational and technological approaches. Practical issues are manifold and include mega trends such as digital transformation, urbanisation, and environmental awareness. A promising approach to solving these problems is the realisation of smart and collaborative supply networks. The growth of artificial intelligence applications in recent years has led to a wide range of applications in a variety of domains. However, the potential of artificial intelligence utilisation in supply chain management has not yet been fully exploited. Similarly, value creation increasingly takes place in networked value creation cycles that have become continuously more collaborative, complex, and dynamic as interactions in business processes involving information technologies have become more intense. Following a design science research approach this cumulative thesis comprises the development and discussion of four artefacts for the analysis and advancement of smart and collaborative urban supply networks. This thesis aims to highlight the potential of artificial intelligence-based supply networks, to advance data-driven inter-organisational collaboration, and to improve last mile supply network sustainability. Based on thorough machine learning and systematic literature reviews, reference and system dynamics modelling, simulation, and qualitative empirical research, the artefacts provide a valuable contribution to research and practice

    People make Places

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    For centuries Glasgow, as a bucolic fishing village and ecclesiastical centre on the banks of the River Clyde, held little of strategic significance. When success and later threats came to the city, it was as a consequence of explosive growth during the industrial era that left a significant civic presence accompanied by social and environmental challenges. Wartime damage to the fabric of the city and the subsequent implementation of modernist planning left Glasgow with a series of existential threats to the lives and the health of its people that have taken time to understand and come to terms with. In a few remarkable decades of late 20th century regeneration, Glasgow began to be put back together. The trauma of the second half of the 20th century is fading but not yet a distant memory. Existential threats from the climate emergency can provoke the reaction “what, again?” However, the resilience built over the last 50 years has instilled a belief that a constructive, pro-active and creative approach to face this challenge along with the recognition that such action can be transformational for safeguarding and improving people’s lives and the quality of their places. A process described as a just transition that has become central to Glasgow’s approach. Of Scotland’s four big cities, three are surrounded by landscape and sea only Glasgow is surrounded by itself. Even with a small territory, Glasgow is still the largest of Scotland’s big cities and by some margin. When the wider metropolitan area is considered, Glasgow is – like Birmingham, Manchester and Liverpool – no mean city. People make Places begins with a review of the concept and complexities of place, discusses why these matter and reviews the growing body of evidence that place quality can deliver economic, social and environmental value. The following chapters focus on the history and evolution of modern Glasgow in four eras of 19th and early 20th century industrialisation, de- industrialisation and modernism in mid 20th century, late 20th century regeneration and a 21st century recovery towards transition and renaissance, and document the process, synthesis and the results of a major engagement programme and to explore systematic approaches to place and consensus building around the principal issues. The second half of the work reflects on a stocktaking of place in contemporary Glasgow, looking at the city through the lenses of an international, metropolitan and everyday city, concluding with a review of the places of Glasgow and what may be learned from them revealing some valuable insights presented in a series of Place Stories included. The concluding chapter sets out the findings of the investigation and analysis reviewing place goals, challenges and opportunities for Glasgow over the decades to 2030 and 2040 and ends with some recommendations about what Glasgow might do better to combine place thinking and climate awareness and setting out practical steps to mobilise Glasgow’s ‘place ecosystem’

    Creating an Information System with a Social Purpose - The Case of Re-Food

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    Project Work presented as the partial requirement for obtaining a Master's degree in Statistics and Information Management, specialization in Information Analysis and ManagementNowadays, with the evolution of technology, the strategies of information management are constantly improving to create faster and more efficient methods of analyzing and displaying data. At the same time, the users, considering the amount of information they access every day, search for simpler, faster and cleaner ways to interact with information. These strategies with simpler designs are important, now more than ever, to help social organizations, such as Re-Food, improve their work and show to communities that they impact directly and indirectly the importance of eco-sustainability and solidarity projects. This project proposes to build an information system capable of structuring data from Re-Food resources, create faster and more efficient solutions to improve the centers’ management and show to the rest of the community the impact this organization, and the ones alike have on society

    Redefining Community in the Age of the Internet: Will the Internet of Things (IoT) generate sustainable and equitable community development?

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    There is a problem so immense in our built world that it is often not fully realized. This problem is the disconnection between humanity and the physical world. In an era of limitless data and information at our fingertips, buildings, public spaces, and landscapes are divided from us due to their physical nature. Compared with the intense flow of information from our online world driven by the beating engine of the internet, our physical world is silent. This lack of connection not only has consequences for sustainability but also for how we perceive and communicate with our built environment in the modern age. A possible solution to bridge the gap between our physical and online worlds is a technology known as the Internet of Things (IoT). What is IoT? How does it work? Will IoT change the concept of the built environment for a participant within it, and in doing so enhance the dynamic link between humans and place? And what are the implications of IoT for privacy, security, and data for the public good? Lastly, we will identify the most pressing issues existing in the built environment by conducting and analyzing case studies from Pomona College and California State University, Northridge. By analyzing IoT in the context of case studies we can assess its viability and value as a tool for sustainability and equality in communities across the world

    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

    Universal Challenges of Policing Rooted in Colonialism in the United States and Nigeria

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    Growing awareness regarding police brutality has generated a massive shift in public views on police institutions and the need for reform. The universal challenges of police authority, abuse, and impunity plague policing institutions across the globe. The roots of many of these contemporary challenges can be traced to European colonization. This paper explores policing structures, abuse, and impunity in the United States and Nigeria
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