46 research outputs found

    Systematic Physics-Compliant Analysis of Over-the-Air Channel Equalization in RIS-Parametrized Wireless Networks-on-Chip

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    Wireless networks-on-chip (WNoCs) are an enticing complementary interconnect technology for multi-core chips but face severe resource constraints. Being limited to simple on-off-keying modulation, the reverberant nature of the chip enclosure imposes limits on allowed modulation speeds in sight of inter-symbol interference, casting doubts on the competitiveness of WNoCs as interconnect technology. Fortunately, this vexing problem was recently overcome by parametrizing the on-chip radio environment with a reconfigurable intelligent surface (RIS). By suitably configuring the RIS, selected channel impulse responses (CIRs) can be tuned to be (almost) pulse-like despite rich scattering thanks to judiciously tailored multi-bounce path interferences. However, the exploration of this "over-the-air" (OTA) equalization is thwarted by (i) the overwhelming complexity of the propagation environment, and (ii) the non-linear dependence of the CIR on the RIS configuration, requiring a costly and lengthy full-wave simulation for every optimization step. Here, we show that a reduced-basis physics-compliant model for RIS-parametrized WNoCs can be calibrated with a single full-wave simulation. Thereby, we unlock the possibility of predicting the CIR for any RIS configuration almost instantaneously without any additional full-wave simulation. We leverage this new tool to systematically explore OTA equalization in RIS-parametrized WNoCs regarding the optimal choice of delay time for the RIS-shaped CIR's peak. We also study the simultaneous optimization of multiple on-chip wireless links for broadcasting. Looking forward, the introduced tools will enable the efficient exploration of various types of OTA analog computing in RIS-parametrized WNoCs.Comment: 10 pages, 7 figures, submitted to an IEEE Journa

    Millimeter-wave power harvesting: a review

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    The broad spectrum available at millimeter-wave (mmWave) bands has attracted significant interest for a breadth of applications, with 5G communications being the main commercial drive for mmWave networks. Wireless power transmission and harvesting at mmWave bands have attracted significant attention due to the potential for minimizing the harvesting antenna size, allowing for more compact rectennas. For a fixed antenna size, the received power increases with frequency. Nevertheless, several challenges lie in realizing high efficiency antennas and rectifiers at mmWave bands. This article reviews the recent advances in mmWave rectenna design at a component- and system-level. Low-cost antennas and components for mmWave power harvesting, such as high efficiency scalable rectifiers on polymers and high radiation efficiency antennas on textiles, are reviewed. Both the antenna and rectifier can be realized using low-cost fabrication methods such as additively-manufactured circuits and packages, in addition to digital integrated circuits (ICs) for the rectifiers. Finally, this article provides an overview of future antenna design challenges and research directions for mmWave power harvesting

    Air Force Institute of Technology Research Report 2020

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    This Research Report presents the FY20 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs). Interested individuals may discuss ideas for new research collaborations, potential CRADAs, or research proposals with individual faculty using the contact information in this document

    Aeronautical engineering, a continuing bibliography with indexes

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    This bibliography lists 823 reports, articles, and other documents introduced into the NASA scientific and technical information system in November 1984

    Bibliography of Lewis Research Center technical publications announced in 1986

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    This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1986. All the publications were announced in the 1986 issues of Scientific and Technical Aerospace Reports (STAR) and/or International Aerospace Abstracts (IAA). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

    Large space structures and systems in the space station era: A bibliography with indexes (supplement 03)

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    Bibliographies and abstracts are listed for 1221 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1991 and June 30, 1991. Topics covered include large space structures and systems, space stations, extravehicular activity, thermal environments and control, tethering, spacecraft power supplies, structural concepts and control systems, electronics, advanced materials, propulsion, policies and international cooperation, vibration and dynamic controls, robotics and remote operations, data and communication systems, electric power generation, space commercialization, orbital transfer, and human factors engineering

    Aeronautical Engineering: A cumulative index to the 1984 issues of the continuing bibliography

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    This bibliography is a cumulative index to the abstracts contained in NASA SP-7037(171) through NASA SP-7037(182) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, foreign technology, contract, report number, and accession number indexes

    Applications

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    Volume 3 describes how resource-aware machine learning methods and techniques are used to successfully solve real-world problems. The book provides numerous specific application examples: in health and medicine for risk modelling, diagnosis, and treatment selection for diseases in electronics, steel production and milling for quality control during manufacturing processes in traffic, logistics for smart cities and for mobile communications

    Applications

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    Volume 3 describes how resource-aware machine learning methods and techniques are used to successfully solve real-world problems. The book provides numerous specific application examples: in health and medicine for risk modelling, diagnosis, and treatment selection for diseases in electronics, steel production and milling for quality control during manufacturing processes in traffic, logistics for smart cities and for mobile communications

    Internet of Things (IoT): Societal Challenges & Scientific Research Fields for IoT

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    International audienceJust as the Internet radically reshaped society, the Internet of Things (IoT) willhave an impact on all areas of human life: from our homes, vehicles, workplacesand factories, to our cities and towns, agriculture and healthcare systems. It willalso affect all levels of society (individuals, companies and state-level), from urbanto rural and the natural world beyond. This makes it essential to have a properunderstanding of IoT and the challenges which relate to it. The primary aims ofthis document are to (i) determine the scope of IoT, its origins, current developments and perspectives, and (ii) identify the main societal, technical and scientific challenges linked to IoT.It seems inevitable that IoT will become increasingly omnipresent. Indeed, itis set to penetrate every aspect of all of our lives, connecting everything (billionsof new heterogeneous machines communicating with each other) and measuringeverything: from the collective action we take at a global level, right down to oursmallest individual physiological signals, in real-time. This is a double-edged sword,in that it simultaneously gives people cause for hope (automation, ­optimisation,innovative new functionalities etc.) and cause for fear (surveillance, dependency,cyberattacks, etc.). Given the ever-evolving nature of the IoT, new challenges linked to privacy, transparency, security appear, while new civil and industrialresponsibilities are starting to emerge.IoT is centred around an increasingly complex set of interlinked concepts andembedded technologies. At an industrial level, this growing complexity is makingthe idea of having full control over all components of IoT increasingly difficult, oreven infeasible. However, as a society, we must get to grips with the technologicalfoundations of IoT. One challenge for education will therefore be to graduallyincrease awareness of IoT, both in order to protect individuals’ sovereignty andfree will, and to initiate the training of our future scientists and technicians. Apublic research institute such as Inria can contribute towards understandingand explaining the technological foundations of IoT, in addition to preservingsovereignty in Europe.IoT will inevitably increase dependency on certain types of embeddedt ­ echno­logy. It is hence necessary to identify the new risks that entail, and todevise new strategies in order to take full advantage of IoT, while minimising theserisks. Similarly to the situation in other domains where one must continually seekto preserve ethics without hindering innovation, creating a legal framework forIoT is both necessary and challenging. It nevertheless seems clear already thatthe best way of facing up to industrial giants or superpowers is to take action atthe EU level, as shown by recent examples such as GDPR. Furthermore, given thegrowing influence of technological standards on society, playing an active rolein the process of standardising IoT technology is essential. Open standards andopen source – conceived as a common public good – will be pivotal for IoT, justas they have been for the Internet. Last but not least, massive use of IoT can helpbetter capture and understand the environmental challenges we are ­currentlyfacing – it is also expected IoT will help to mitigate these challenges. The goals inthis context are not only to reduce the quantities of natural resources consumedby IoT (for production, deployment, maintenance and recycling). We must alsoaim to more accurately evaluate the overall net benefit of IoT on the environment,at a global level. This requires determining and subtracting IoT’s environmentalcosts from its (measured) benefits, which is currently a challenge. The growingimpact of IoT underscores the importance of remaining at the cutting edge whenit comes to scientific research and technological development. This documenttherefore aims to (i) highlight the wide range of research fields which are fundamental to IoT, and(ii) take stock of current and future research problems in each of these fields. A number of links are made throughout the document to contributionsmade by Inria. These contributions are, by their nature, diverse (basic and appliedresearch, open source software, startup incubation) and concern the majority ofresearch fields on which IoT is based
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