14,749 research outputs found

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

    Full text link
    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

    In-situ crack and keyhole pore detection in laser directed energy deposition through acoustic signal and deep learning

    Full text link
    Cracks and keyhole pores are detrimental defects in alloys produced by laser directed energy deposition (LDED). Laser-material interaction sound may hold information about underlying complex physical events such as crack propagation and pores formation. However, due to the noisy environment and intricate signal content, acoustic-based monitoring in LDED has received little attention. This paper proposes a novel acoustic-based in-situ defect detection strategy in LDED. The key contribution of this study is to develop an in-situ acoustic signal denoising, feature extraction, and sound classification pipeline that incorporates convolutional neural networks (CNN) for online defect prediction. Microscope images are used to identify locations of the cracks and keyhole pores within a part. The defect locations are spatiotemporally registered with acoustic signal. Various acoustic features corresponding to defect-free regions, cracks, and keyhole pores are extracted and analysed in time-domain, frequency-domain, and time-frequency representations. The CNN model is trained to predict defect occurrences using the Mel-Frequency Cepstral Coefficients (MFCCs) of the lasermaterial interaction sound. The CNN model is compared to various classic machine learning models trained on the denoised acoustic dataset and raw acoustic dataset. The validation results shows that the CNN model trained on the denoised dataset outperforms others with the highest overall accuracy (89%), keyhole pore prediction accuracy (93%), and AUC-ROC score (98%). Furthermore, the trained CNN model can be deployed into an in-house developed software platform for online quality monitoring. The proposed strategy is the first study to use acoustic signals with deep learning for insitu defect detection in LDED process.Comment: 36 Pages, 16 Figures, accepted at journal Additive Manufacturin

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

    Get PDF
    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

    Reinforcement Learning-based User-centric Handover Decision-making in 5G Vehicular Networks

    Get PDF
    The advancement of 5G technologies and Vehicular Networks open a new paradigm for Intelligent Transportation Systems (ITS) in safety and infotainment services in urban and highway scenarios. Connected vehicles are vital for enabling massive data sharing and supporting such services. Consequently, a stable connection is compulsory to transmit data across the network successfully. The new 5G technology introduces more bandwidth, stability, and reliability, but it faces a low communication range, suffering from more frequent handovers and connection drops. The shift from the base station-centric view to the user-centric view helps to cope with the smaller communication range and ultra-density of 5G networks. In this thesis, we propose a series of strategies to improve connection stability through efficient handover decision-making. First, a modified probabilistic approach, M-FiVH, aimed at reducing 5G handovers and enhancing network stability. Later, an adaptive learning approach employed Connectivity-oriented SARSA Reinforcement Learning (CO-SRL) for user-centric Virtual Cell (VC) management to enable efficient handover (HO) decisions. Following that, a user-centric Factor-distinct SARSA Reinforcement Learning (FD-SRL) approach combines time series data-oriented LSTM and adaptive SRL for VC and HO management by considering both historical and real-time data. The random direction of vehicular movement, high mobility, network load, uncertain road traffic situation, and signal strength from cellular transmission towers vary from time to time and cannot always be predicted. Our proposed approaches maintain stable connections by reducing the number of HOs by selecting the appropriate size of VCs and HO management. A series of improvements demonstrated through realistic simulations showed that M-FiVH, CO-SRL, and FD-SRL were successful in reducing the number of HOs and the average cumulative HO time. We provide an analysis and comparison of several approaches and demonstrate our proposed approaches perform better in terms of network connectivity

    Inovação, empreendedorismo e desenvolvimento económico em África: Uma abordagem pós-positivista e "topo da pirâmide" para Moçambique

    Get PDF
    Esta tese desenvolve uma investigação abrangente sobre o empreendedorismo africano, revisitando o seu quadro concetual tradicional e posicionando-o enquanto elemento fundamental das estratégias de desenvolvimento para a África Subsariana (ASS). Explorados os diferentes impactos do empreendedorismo de oportunidade e do empreendedorismo de necessidade na região, efetuou-se uma pesquisa sobre a situação dos vários países da ASS que participaram no Global Entrepreneurship Monitor na última década, com vista a compor o status quo hipotético do empreendedorismo regional, ao qual juntámos um estudo empírico original e com elementos metodológicos inovadores sobre a atividade empreendedora em Moçambique. O alcance das estratégias empreendedoras implementadas na ASS é avaliado através de um estudo dos polos africanos de inovação tecnológica e do empreendedorismo digital que neles tem vindo recentemente a emergir, a que juntámos um levantamento original do tech hub de Maluana. Por fim, a partir destes casos e de uma leitura política das opções económicas do estado moçambicano com impacto sobre o ecossistema empreendedor, desenvolve-se uma proposta de teoria da mudança, numa lógica pós-positivista, para suportar medidas de política pública desejáveis para a eclosão de um empreendedorismo de “topo da pirâmide” em Moçambique.This thesis develops a comprehensive investigation of African entrepreneurship, revisiting its traditional conceptual framework and positioning it as a fundamental element in development strategies for Sub-Saharan Africa (SSA). Exploring the different impacts of opportunity entrepreneurship and necessity entrepreneurship in the region, an analysis was carried out on the situation of the various SSA countries that participated in the Global Entrepreneurship Monitor in the last decade, with a view to composing the hypothetical status quo of the entrepreneurship in the region, to which we added an original empirical study with innovative methodological elements on entrepreneurial activity in Mozambique. The reach of entrepreneurial strategies implemented in the SSA is assessed through a study of the African tech hubs, or innovation hubs, and the digital entrepreneurship that has recently emerged there, to which we have added an original survey of the Maluana tech hub. Finally, based on these cases and on a political reading of the economic options of the Mozambican government with an impact on the entrepreneurial ecosystem, a proposal for a theory-of-change is developed, within a post-positivist approach, to support desired public policy measures for the emergence of a “top of the pyramid” entrepreneurship in Mozambique

    Market capitalization shock effects on open innovation models in e-commerce: Golden cut q-rung orthopair fuzzy multicriteria decision-making analysis

    Get PDF
    This research paper analyzes revenue trends in e-commerce, a sector with an annual sales volume of more than 340 billion dollars. The article evaluates, despite a scarcity of data, the effects on e-commerce development of the ubiquitous lockdowns and restriction measures introduced by most countries during the pandemic period. The analysis covers monthly data from January 1996 to February 2021. The research paper analyzes relative changes in the original time series through the autocorrelation function. The objects of this analysis are Amazon and Alibaba, as they are benchmarks in the e-commerce industry. This paper tests the shock effect on the e-commerce companies Alibaba in China and Amazon in the USA, concluding that it is weaker for companies with small market capitalizations. As a result, the effect on estimated e-trade volume in the USA was approximately 35% in 2020. Another evaluation considers fuzzy decision-making methodology. For this purpose, balanced scorecard-based open financial innovation models for the e-commerce industry are weighted with multistepwise weight assessment ratio analysis based on q-rung orthopair fuzzy sets and the golden cut. Within this framework, a detailed analysis of competitors should be made. The paper proves that this situation positively affects the development of successful financial innovation models for the e-commerce industry. Therefore, it may be possible to attract greater attention from e-commerce companies for these financial innovation products.Ministry of Education and Science of the Russian Federatio

    Big Tech and research funding: A bibliometric approach

    Get PDF
    Dissertation presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Business AnalyticsTechnology companies have radically transformed our daily life in the recent years with help of the wide usage of internet. While transforming our lives, these companies also have grown up even bigger in the recent times and have become more powerful not only financially, but also in terms of computing power and data. Although there have been lots of research done on the influence of large digital economy players (Big Tech) in different fields, the academic influence of these companies is little understood. By drawing on 130,000 academic papers for which there is evidence of support by the Big Tech, the present work applies bibliometric approaches (on the metadata) and text mining techniques (on the contents) to shed a light on the outcomes of this relationship. In particular, we take into consideration research funding (direct strategies) and conference sponsorships (indirect strategies) to empirically explore this relatively unexplored side of Big Tech’s influence in contemporary society. While developing the analysis a key limitation was the scarcity of prior work exploring the connections between digital platforms and the scientific enterprise. There are several results that come to light from such a perspective, one of these findings is that among the research supported by Big Tech companies, there is big gap between the number of outcomes with the content about the technical perspectives (like machine learning or artificial intelligence) than the content about reflexive (say ethical or environmental) dimensions of innovation, ladder being very small. These findings may stimulate further inquiries into identifying the possible risks, if any, are generated from the direct and indirect financial support by corporate informational giants to academia. The causes and consequences of this non-market activity by companies with big market power may require further attention and research in this field
    corecore