13,896 research outputs found

    Challenges in the Design and Implementation of IoT Testbeds in Smart-Cities : A Systematic Review

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    Advancements in wireless communication and the increased accessibility to low-cost sensing and data processing IoT technologies have increased the research and development of urban monitoring systems. Most smart city research projects rely on deploying proprietary IoT testbeds for indoor and outdoor data collection. Such testbeds typically rely on a three-tier architecture composed of the Endpoint, the Edge, and the Cloud. Managing the system's operation whilst considering the security and privacy challenges that emerge, such as data privacy controls, network security, and security updates on the devices, is challenging. This work presents a systematic study of the challenges of developing, deploying and managing urban monitoring testbeds, as experienced in a series of urban monitoring research projects, followed by an analysis of the relevant literature. By identifying the challenges in the various projects and organising them under the V-model development lifecycle levels, we provide a reference guide for future projects. Understanding the challenges early on will facilitate current and future smart-cities IoT research projects to reduce implementation time and deliver secure and resilient testbeds

    Eight Element MIMO Antenna Array with Tri-Band Response for Modern Smartphones

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    This article presents an eight-element tri-band Multiple Input Multiple Output (MIMO) antenna system for future handheld devices. The suggested antenna system consists of a main and sideboards. The feed lines are connected on the main board while the antennas are placed on sideboards, two on each side separately. The total dimension of the main board is 150Ă—75 mm2, and the sideboard is 150Ă—7 mm2. The antenna resonates at three distinct 5G allocated bands of 3.1-3.7 GHz, 4.47-4.91 GHz, and 5.5-6.0 GHz with impedance bandwidths of 600 MHz, 440 MHz, and 450 MHz, respectively. The antenna system provides pattern and spatial diversity characteristics with radiation and total efficiency of 78% and 62% and peak gain of 5.8 dBi. The MIMO system is fabricated, and the measured results are found to be in good agreement with the simulations. The isolation among radiating elements in all resonating bands is found to be >16 dB. The vital MIMO performance parameters such as envelope correlation coefficient (ECC) is less than 0.2 for any two antenna array meeting the required standard of less than 0.5 alongside the mean effective gain or MEG ratio of any two antenna meeting the required standard of less than 3 dB for power balance and optimal diversity. The Channel Capacity (CC) is found to be 41.1 bps/Hz, approximately 3 times that of 2Ă— 2 MIMO operations

    The Globalization of Artificial Intelligence: African Imaginaries of Technoscientific Futures

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    Imaginaries of artificial intelligence (AI) have transcended geographies of the Global North and become increasingly entangled with narratives of economic growth, progress, and modernity in Africa. This raises several issues such as the entanglement of AI with global technoscientific capitalism and its impact on the dissemination of AI in Africa. The lack of African perspectives on the development of AI exacerbates concerns of raciality and inclusion in the scientific research, circulation, and adoption of AI. My argument in this dissertation is that innovation in AI, in both its sociotechnical imaginaries and political economies, excludes marginalized countries, nations and communities in ways that not only bar their participation in the reception of AI, but also as being part and parcel of its creation. Underpinned by decolonial thinking, and perspectives from science and technology studies and African studies, this dissertation looks at how AI is reconfiguring the debate about development and modernization in Africa and the implications for local sociotechnical practices of AI innovation and governance. I examined AI in international development and industry across Kenya, Ghana, and Nigeria, by tracing Canada’s AI4D Africa program and following AI start-ups at AfriLabs. I used multi-sited case studies and discourse analysis to examine the data collected from interviews, participant observations, and documents. In the empirical chapters, I first examine how local actors understand the notion of decolonizing AI and show that it has become a sociotechnical imaginary. I then investigate the political economy of AI in Africa and argue that despite Western efforts to integrate the African AI ecosystem globally, the AI epistemic communities in the continent continue to be excluded from dominant AI innovation spaces. Finally, I examine the emergence of a Pan-African AI imaginary and argue that AI governance can be understood as a state-building experiment in post-colonial Africa. The main issue at stake is that the lack of African perspectives in AI leads to negative impacts on innovation and limits the fair distribution of the benefits of AI across nations, countries, and communities, while at the same time excludes globally marginalized epistemic communities from the imagination and creation of AI

    Beam scanning by liquid-crystal biasing in a modified SIW structure

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    A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium

    Activity-based costing technology adoption in Australian universities

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    Strategic cost management is vital to the Australian university sector’s performance, and activity-based costing (ABC) is a widely accepted and used accounting technology assisting with this. We examine the status of ABC technology adoption in two categories—adopters and non-adopters of the technology—informed by Technology Diffusion Framework, Social Cognitive Theory and Dynamic Theory of Strategy. The study collected data by sending a pilot-tested survey questionnaire to senior executives for electronic completion. From the 39 universities that elected to participate, 24 usable responses were received, representing a 61% response rate. The data were analyzed using cognitive characteristics supported by Social Cognitive Theory, and organizational characteristics supported by the Dynamic Theory of Strategy of universities ABC technology adopter and non-adopter status. Cognitive characteristics provide a qualitative explanation, but selected determinants show no statistical significance. Organizational characteristics also provide a qualitative explanation and show organizational revenue is the most significant determinant; followed by universities located outside the cities, and in the southern part of Australia, have more propensity for ABC technology adoption

    An empirical investigation of the relationship between integration, dynamic capabilities and performance in supply chains

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    This research aimed to develop an empirical understanding of the relationships between integration, dynamic capabilities and performance in the supply chain domain, based on which, two conceptual frameworks were constructed to advance the field. The core motivation for the research was that, at the stage of writing the thesis, the combined relationship between the three concepts had not yet been examined, although their interrelationships have been studied individually. To achieve this aim, deductive and inductive reasoning logics were utilised to guide the qualitative study, which was undertaken via multiple case studies to investigate lines of enquiry that would address the research questions formulated. This is consistent with the author’s philosophical adoption of the ontology of relativism and the epistemology of constructionism, which was considered appropriate to address the research questions. Empirical data and evidence were collected, and various triangulation techniques were employed to ensure their credibility. Some key features of grounded theory coding techniques were drawn upon for data coding and analysis, generating two levels of findings. These revealed that whilst integration and dynamic capabilities were crucial in improving performance, the performance also informed the former. This reflects a cyclical and iterative approach rather than one purely based on linearity. Adopting a holistic approach towards the relationship was key in producing complementary strategies that can deliver sustainable supply chain performance. The research makes theoretical, methodological and practical contributions to the field of supply chain management. The theoretical contribution includes the development of two emerging conceptual frameworks at the micro and macro levels. The former provides greater specificity, as it allows meta-analytic evaluation of the three concepts and their dimensions, providing a detailed insight into their correlations. The latter gives a holistic view of their relationships and how they are connected, reflecting a middle-range theory that bridges theory and practice. The methodological contribution lies in presenting models that address gaps associated with the inconsistent use of terminologies in philosophical assumptions, and lack of rigor in deploying case study research methods. In terms of its practical contribution, this research offers insights that practitioners could adopt to enhance their performance. They can do so without necessarily having to forgo certain desired outcomes using targeted integrative strategies and drawing on their dynamic capabilities

    Do consumers care about environmentally sustainable attributes along the food supply chain? —A systematic literature review

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    The agri-food market has shown a clear signal of "green" consumption that drives an increasing interest in studying consumers' willingness to pay (WTP) for food products with environmentally sustainable attributes, such as eco-friendly and carbon neutral. Whilst many existing studies have focused on a general idea of green attributes or on-farm practices that are regarded to be most relevant to the attributes, the agri-food industry has started to address consumers' concerns about the negative environmental impacts of agri-food production across the whole supply chain, including the processing, transportation, and consumption process. It is therefore the purpose of this study to conduct a systematic review of the existing literature on consumers' intentions of purchasing and WTP for food products with environmentally sustainable attributes, with a special interest in understanding the connections between consumer behaviours and different stages of the food supply chain. Results of the study revealed three main research gaps: the lack of clear definitions of environmentally sustainable attributes; ignorance of connections between the characteristics of environmentally sustainable attributes and different stages of the food supply chain; and lacking effective information processing among the key players along the supply chain, leading to inefficient communication between the supply and demand side. The findings of the study help form a conceptual framework for future studies to associate environmentally sustainable attributes to the whole food supply chain that helps the agri-food industry to effectively process market information, communicate with consumers, and satisfy the market demand

    Key technologies for safe and autonomous drones

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    Drones/UAVs are able to perform air operations that are very difficult to be performed by manned aircrafts. In addition, drones' usage brings significant economic savings and environmental benefits, while reducing risks to human life. In this paper, we present key technologies that enable development of drone systems. The technologies are identified based on the usages of drones (driven by COMP4DRONES project use cases). These technologies are grouped into four categories: U-space capabilities, system functions, payloads, and tools. Also, we present the contributions of the COMP4DRONES project to improve existing technologies. These contributions aim to ease drones’ customization, and enable their safe operation.This project has received funding from the ECSEL Joint Undertaking (JU) under grant agreement No 826610. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and Spain, Austria, Belgium, Czech Republic, France, Italy, Latvia, Netherlands. The total project budget is 28,590,748.75 EUR (excluding ESIF partners), while the requested grant is 7,983,731.61 EUR to ECSEL JU, and 8,874,523.84 EUR of National and ESIF Funding. The project has been started on 1st October 2019

    Future Visions for a Decolonized Future of Human-Computer Interaction: Thick descriptions of a survey created to discuss the colonization of imagination.

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    A forecast of a high-tech society often represents the visions of industry. The possible technological developments and innovations presented by tech companies promise a bright future, supposedly offering all a better quality of life. However, the ideas give protagonism of a particular style of life and reveal privileges that do not match the environmental and socio-economic tensions from the global south. We propose a discussion for the 'special interest groups' to analyze historical visions of the future commonly presented by companies. We started a 'proof of concept among us with an internet questionnaire and a form to allow participants to be proactive in proposing alternate visions by sending images. From this experience, we offer a thick description of the perspectives and feelings related to the questions submitted. This ethnography is a ground for future work where we aim to investigate how HCI literacy and knowledge of cultural studies impact the identification of biased content. Also, collecting data through questionnaires and forms can help participants increase awareness of image content on the internet and motivate them to present their voices proactively. For further actions, we aim to develop a platform able to provide quantitative data with diverse aesthetics for future visions, capable of adding diversity to the digital ecosystem

    The sustainability impact of a digital circular economy

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    Digital technologies — such as the Internet of Things, big data and advanced analytics, additive manufacturing and 3D printing, blockchain and online platforms — are regarded as key enablers for a circular economy. A systematic literature review and analysis of 48 scientific articles published in the last five years was conducted to identify the first-, second- and third-order sustainability effects of a digital circular economy. Second-order environmental effects such as improved resource efficiency and reduction of emissions, waste and material use in products and production processes are often envisaged. However, limited attention is given to social and economic impact, and rebound effects. Existing literature also lacks a solid assessment of actual (vs expected) impact, and a more balanced consideration of negative (vs positive) effects
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