26,354 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

    The role of public energy advising in sustainability transitions– empirical evidence from Sweden

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    Public energy advising is a policy measure used to provide customized energy information and advice to energy end-users. It aims at encouraging and promoting decisions leading to reduced environmental impact from energy use. While the independent function of public energy advising is unique and important, in Sweden, the role of energy advisors is changing. With new and more complex client demands as well as increasing competition from other forms of advising, there is a need to examine the shift that public energy advising is facing. The aim is to provide an overview of the activities performed by public energy advisors in Sweden and to explore the roles that they play in the transition to a sustainable energy system. Based on a qualitative analysis of 129 activity reports from Swedish municipal energy advisors, this paper shows that public energy advisors do not only play a role on an actor-level, but also on a system-level, by undertaking activities connecting the target groups to other actors in society and translating national policy to the local level. These system-level roles represent an important potential for policies aimed at accelerating the energy transition, and thus they should be encouraged and maximized

    A co-criação enquanto impulsionadora de experiências enogastronómicas

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    Experiential tourism implies the central role given to tourists, perceived as key elements for the co-creation of value, within various tourist experiences, with particular emphasis on food & wine tourism. Theoretical and empirical research on tourism experience co-creation and food & wine tourism, particularly involving the interrelationship between both domains is still scarce, despite the emerging character and growth potential of both areas. This study is hence aimed to contribute to a better understanding of how co-creation can add value to food & wine tourism experiences. Regarding the methodological design of the study, two major stages should be highlighted: (i) the conceptual stage, involving an integrative literature review within the scope of experience co-creation in tourism and food & wine tourism, aimed at identifying the most representative dimensions of experience co-creation in the literature; and ii) the empirical stage, including two complementary qualitative studies, a netnography on food tour experiences in an urban destination and a multiple-case study involving food & wine experiences in two Portuguese wine regions, Bairrada and Dão, in order to analyse the perspective of visitors and agents of supply on the co-creation of value in these experiences. In the case of the netnography, 658 reviews of tourists’ food tour experiences with a food tour operator, shared on TripAdvisor, complemented with a semi-structured interview of the supply agent were analysed and, as for the multiple-case study, the perceptions of 38 visitors and of 6 supply agents of both regions were assessed through semi-structured interviews. The data were analysed by means of content analysis, implemented manually and with the support of qualitative data analysis software NVivo. The results showed the relevance of the role and the interrelationship between experience co-creation dimensions "interaction", "active participation", "involvement" (cognitive, emotional, and sensory), "personalization", and "authenticity" for the design of appealing, distinctive and memorable food & wine tourism experiences. The theoretical contributions of the study are synthesized in a proposed definition of experience co-creation in food & wine tourism and in a corresponding conceptual framework, that add to existing literature in the field for the range of dimensions considered and the interrelationships established, as well as for the holistic view of experience co-creation in food & wine tourism, given the role expected from tourists as co-creators of the experience provided. The practical implications of the study relate to value co-creation strategies to be considered by supply agents and destination management organizations in the design of food & wine experiences that cater to different tourist profiles visiting wine regions and that include an offer that preserves the identity of the region and simultaneously reinvents itself through sustainable practices. Limitations of the study and proposals for future research are also presented.O turismo de experiências centra-se no papel ativo do turista, enquanto elemento fundamental para a co-criação de valor, no âmbito de diversas experiências turísticas, com particular destaque para o turismo enogastronómico. Apesar do seu caráter emergente e potencial de crescimento, a co-criação de experiências em turismo e o turismo enogastronómico são áreas que carecem de investigação teórica e empírica, nomeadamente ao nível da sua relação. Este estudo visa, assim, contribuir para uma melhor compreensão da forma como a co-criação pode acrescentar valor a experiências de turismo enogastronómico. Relativamente ao desenho metodológico do estudo, destacam-se duas grandes etapas: i) a etapa conceptual, relativa a uma revisão integrativa da literatura ao nível da co-criação de experiências em turismo e turismo enogastronómico, com o intuito de identificar as dimensões da co-criação de experiências mais representativas na literatura; e ii) a etapa empírica, que contemplou dois estudos de natureza qualitativa complementares, uma netnografia relativa a experiências de roteiros gastronómicos num destino urbano, e um estudo de caso múltiplo, envolvendo experiências enogastronómicas em duas regiões de vinho portuguesas, a Bairrada e o Dão, com o intuito de analisar a perspetiva de visitantes e agentes da oferta acerca da co-criação de valor nestas experiências. No âmbito da netnografia, 658 comentários de turistas, deixados na plataforma TripAdvisor, acerca das suas experiências com um operador de roteiros gastronómicos foram analisados, complementados com uma entrevista semi-estruturada ao agente da oferta e, no âmbito do estudo de caso múltiplo, as perceções de 38 visitantes assim como de 6 agentes da oferta de ambas as regiões foram aferidas através de entrevistas semi-estruturadas. Os dados recolhidos foram sujeitos à análise de conteúdo, implementada manualmente e com o suporte do software de análise qualitativa de dados NVivo. Os resultados demonstraram a pertinência do papel e da interrelação das dimensões da co-criação de experiências “interação”, “participação ativa”, “envolvimento” (cognitivo, emocional e sensorial), “personalização” e “autenticidade” para a conceção de experiências em turismo enogastronómico apelativas, distintivas e memoráveis. Os contributos teóricos do estudo sintetizam-se numa proposta de definição de co-criação de experiências em turismo enogastronómico e de um modelo conceptual nesse âmbito, que se destacam pela abrangência de dimensões consideradas e pela forma como estas se interrelacionam, assim como pela visão holística da experiência de co-criação em turismo enogastronómico, atendendo ao papel do turista enquanto co-criador da experiência que lhe é proporcionada. As implicações práticas do estudo materializam-se em estratégias de co-criação de valor a serem consideradas pelos agentes da oferta e organizações de gestão de destinos no desenho de experiências enogastronómicas que atendam a diferentes perfis de turista que visitem regiões de vinho/ produtos locais e que incluam uma oferta que preserve as características identitárias da região e que, simultaneamente, se reinvente através de práticas sustentáveis. Limitações do estudo e propostas de investigação futura são igualmente apresentadas.Programa Doutoral em Turism

    The Metaverse: Survey, Trends, Novel Pipeline Ecosystem & Future Directions

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    The Metaverse offers a second world beyond reality, where boundaries are non-existent, and possibilities are endless through engagement and immersive experiences using the virtual reality (VR) technology. Many disciplines can benefit from the advancement of the Metaverse when accurately developed, including the fields of technology, gaming, education, art, and culture. Nevertheless, developing the Metaverse environment to its full potential is an ambiguous task that needs proper guidance and directions. Existing surveys on the Metaverse focus only on a specific aspect and discipline of the Metaverse and lack a holistic view of the entire process. To this end, a more holistic, multi-disciplinary, in-depth, and academic and industry-oriented review is required to provide a thorough study of the Metaverse development pipeline. To address these issues, we present in this survey a novel multi-layered pipeline ecosystem composed of (1) the Metaverse computing, networking, communications and hardware infrastructure, (2) environment digitization, and (3) user interactions. For every layer, we discuss the components that detail the steps of its development. Also, for each of these components, we examine the impact of a set of enabling technologies and empowering domains (e.g., Artificial Intelligence, Security & Privacy, Blockchain, Business, Ethics, and Social) on its advancement. In addition, we explain the importance of these technologies to support decentralization, interoperability, user experiences, interactions, and monetization. Our presented study highlights the existing challenges for each component, followed by research directions and potential solutions. To the best of our knowledge, this survey is the most comprehensive and allows users, scholars, and entrepreneurs to get an in-depth understanding of the Metaverse ecosystem to find their opportunities and potentials for contribution

    Pretrained Embeddings for E-commerce Machine Learning: When it Fails and Why?

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    The use of pretrained embeddings has become widespread in modern e-commerce machine learning (ML) systems. In practice, however, we have encountered several key issues when using pretrained embedding in a real-world production system, many of which cannot be fully explained by current knowledge. Unfortunately, we find that there is a lack of a thorough understanding of how pre-trained embeddings work, especially their intrinsic properties and interactions with downstream tasks. Consequently, it becomes challenging to make interactive and scalable decisions regarding the use of pre-trained embeddings in practice. Our investigation leads to two significant discoveries about using pretrained embeddings in e-commerce applications. Firstly, we find that the design of the pretraining and downstream models, particularly how they encode and decode information via embedding vectors, can have a profound impact. Secondly, we establish a principled perspective of pre-trained embeddings via the lens of kernel analysis, which can be used to evaluate their predictability, interactively and scalably. These findings help to address the practical challenges we faced and offer valuable guidance for successful adoption of pretrained embeddings in real-world production. Our conclusions are backed by solid theoretical reasoning, benchmark experiments, as well as online testings

    Marketing Through Microcultures on Social Media: An Examination of BookTok and Independent Bookstores

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    This thesis explores the role of microcultures in social media marketing, by focusing on the BookTok microculture and its significant role in the marketing strategies of independent bookstores. The research includes an examination of microcultures and their impact on businesses, the effectiveness of the key social media marketing tactics used on TikTok, what BookTok is, how independent bookstores engage with BookTok, and an interview with an independent bookstore on their uses of BookTok

    Anuário científico da Escola Superior de Tecnologia da Saúde de Lisboa - 2021

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    É com grande prazer que apresentamos a mais recente edição (a 11.ª) do Anuário Científico da Escola Superior de Tecnologia da Saúde de Lisboa. Como instituição de ensino superior, temos o compromisso de promover e incentivar a pesquisa científica em todas as áreas do conhecimento que contemplam a nossa missão. Esta publicação tem como objetivo divulgar toda a produção científica desenvolvida pelos Professores, Investigadores, Estudantes e Pessoal não Docente da ESTeSL durante 2021. Este Anuário é, assim, o reflexo do trabalho árduo e dedicado da nossa comunidade, que se empenhou na produção de conteúdo científico de elevada qualidade e partilhada com a Sociedade na forma de livros, capítulos de livros, artigos publicados em revistas nacionais e internacionais, resumos de comunicações orais e pósteres, bem como resultado dos trabalhos de 1º e 2º ciclo. Com isto, o conteúdo desta publicação abrange uma ampla variedade de tópicos, desde temas mais fundamentais até estudos de aplicação prática em contextos específicos de Saúde, refletindo desta forma a pluralidade e diversidade de áreas que definem, e tornam única, a ESTeSL. Acreditamos que a investigação e pesquisa científica é um eixo fundamental para o desenvolvimento da sociedade e é por isso que incentivamos os nossos estudantes a envolverem-se em atividades de pesquisa e prática baseada na evidência desde o início dos seus estudos na ESTeSL. Esta publicação é um exemplo do sucesso desses esforços, sendo a maior de sempre, o que faz com que estejamos muito orgulhosos em partilhar os resultados e descobertas dos nossos investigadores com a comunidade científica e o público em geral. Esperamos que este Anuário inspire e motive outros estudantes, profissionais de saúde, professores e outros colaboradores a continuarem a explorar novas ideias e contribuir para o avanço da ciência e da tecnologia no corpo de conhecimento próprio das áreas que compõe a ESTeSL. Agradecemos a todos os envolvidos na produção deste anuário e desejamos uma leitura inspiradora e agradável.info:eu-repo/semantics/publishedVersio

    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

    Discreetly Exploiting Inter-session Information for Session-based Recommendation

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    Limited intra-session information is the performance bottleneck of the early GNN based SBR models. Therefore, some GNN based SBR models have evolved to introduce additional inter-session information to facilitate the next-item prediction. However, we found that the introduction of inter-session information may bring interference to these models. The possible reasons are twofold. First, inter-session dependencies are not differentiated at the factor-level. Second, measuring inter-session weight by similarity is not enough. In this paper, we propose DEISI to solve the problems. For the first problem, DEISI differentiates the types of inter-session dependencies at the factor-level with the help of DRL technology. For the second problem, DEISI introduces stability as a new metric for weighting inter-session dependencies together with the similarity. Moreover, CL is used to improve the robustness of the model. Extensive experiments on three datasets show the superior performance of the DEISI model compared with the state-of-the-art models
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