61 research outputs found

    Cognitive Radio Systems

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    Cognitive radio is a hot research area for future wireless communications in the recent years. In order to increase the spectrum utilization, cognitive radio makes it possible for unlicensed users to access the spectrum unoccupied by licensed users. Cognitive radio let the equipments more intelligent to communicate with each other in a spectrum-aware manner and provide a new approach for the co-existence of multiple wireless systems. The goal of this book is to provide highlights of the current research topics in the field of cognitive radio systems. The book consists of 17 chapters, addressing various problems in cognitive radio systems

    Multi-user beamforming on intelligent reflecting surface and networks

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    Full abstract available: pages i-iii. A new type of retrofitted low-cost material is recently proposed and made it possible to control (or program) part of the wireless channel around us. It is called the intelligent reflecting surface (IRS), also named reconfigurable intelligent surface (RIS) or metasurface. The metamaterial composed surface can realize selective EM properties by integrating artificially designed electronic elements that can be controlled by processors (e.g. field programmable gate array (FPGA)). Therefore, the wireless channel is controllable with such IRS posting on the ceiling and wall. Specifically, this functionality is realized by controlling the excitation and phase of each electronic element on the surface. The phase and amplitude of the EM wave impinging on the surface can be reflected in a designed manner of EM wave’s superposition. From this view, the wireless transmission can be enhanced by focusing the signal power while mitigating the interference power

    The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 1

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    These papers comprise a peer-review selection of presentations by authors from NASA, LPI industry, and academia at the Second Conference (April 1988) on Lunar Bases and Space Activities of the 21st Century, sponsored by the NASA Office of Exploration and the Lunar Planetary Institute. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics covered by this volume include (1) design and operation of transportation systems to, in orbit around, and on the Moon, (2) lunar base site selection, (3) design, architecture, construction, and operation of lunar bases and human habitats, and (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology

    Drones and Geographical Information Technologies in Agroecology and Organic Farming

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    Although organic farming and agroecology are normally not associated with the use of new technologies, it’s rapid growth, new technologies are being adopted to mitigate environmental impacts of intensive production implemented with external material and energy inputs. GPS, satellite images, GIS, drones, help conventional farming in precision supply of water, pesticides, fertilizers. Prescription maps define the right place and moment for interventions of machinery fleets. Yield goal remains the key objective, integrating a more efficient use or resources toward an economic-environmental sustainability. Technological smart farming allows extractive agriculture entering the sustainability era. Societies that practice agroecology through the development of human-environmental co-evolutionary systems represent a solid model of sustainability. These systems are characterized by high-quality agroecosystems and landscapes, social inclusion, and viable economies. This book explores the challenges posed by the new geographic information technologies in agroecology and organic farming. It discusses the differences among technology-laden conventional farming systems and the role of technologies in strengthening the potential of agroecology. The first part reviews the new tools offered by geographic information technologies to farmers and people. The second part provides case studies of most promising application of technologies in organic farming and agroecology: the diffusion of hyperspectral imagery, the role of positioning systems, the integration of drones with satellite imagery. The third part of the book, explores the role of agroecology using a multiscale approach from the farm to the landscape level. This section explores the potential of Geodesign in promoting alliances between farmers and people, and strengthening food networks, whether through proximity urban farming or asserting land rights in remote areas in the spirit of agroecological transition. The Open Access version of this book, available at www.taylorfrancis.com, has been made available under a Creative Commons 4.0 license

    2021-2022

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    Contains information on courses and class descriptions as well as campus resources at Collin College.https://digitalcommons.collin.edu/catalogs/1036/thumbnail.jp

    2020-2021

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    Contains information on courses and class descriptions as well as campus resources at Collin College.https://digitalcommons.collin.edu/catalogs/1035/thumbnail.jp

    2020-2021

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    Contains information on courses and class descriptions as well as campus resources at Collin College.https://digitalcommons.collin.edu/catalogs/1032/thumbnail.jp

    Towards Compelling Cases for the Viability of Silicon-Nanophotonic Technology in Future Many-core Systems

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    Many crossbenchmarking results reported in the open literature raise optimistic expectations on the use of optical networks-on-chip (ONoCs) for high-performance and low-power on-chip communications in future Manycore Systems. However, these works ultimately fail to make a compelling case for the viability of silicon-nanophotonic technology for two fundamental reasons: (1)Lack of aggressive electrical baselines (ENoCs). (2) Inaccuracy in physical- and architecture-layer analysis of the ONoC. This thesis aims at providing the guidelines and minimum requirements so that nanophotonic emerging technology may become of practical relevance. The key enabler for this study is a cross-layer design methodology of the optical transport medium, ranging from the consideration of the predictability gap between ONoC logic schemes and their physical implementations, up to architecture-level design issues such as the network interface and its co-design requirements with the memory hierarchy. In order to increase the practical relevance of the study, we consider a consolidated electrical NoC counterpart with an optimized architecture from a performance and power viewpoint. The quality metrics of this latter are derived from synthesis and place&route on an industrial 40nm low-power technology library. Building on this methodology, we are able to provide a realistic energy efficiency comparison between ONoC and ENoC both at the level of the system interconnect and of the system as a whole, pointing out the sensitivity of the results to the maturity of the underlying silicon nanophotonic technology, and at the same time paving the way towards compelling cases for the viability of such technology in next generation many-cores systems

    Audio for Virtual, Augmented and Mixed Realities: Proceedings of ICSA 2019 ; 5th International Conference on Spatial Audio ; September 26th to 28th, 2019, Ilmenau, Germany

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    The ICSA 2019 focuses on a multidisciplinary bringing together of developers, scientists, users, and content creators of and for spatial audio systems and services. A special focus is on audio for so-called virtual, augmented, and mixed realities. The fields of ICSA 2019 are: - Development and scientific investigation of technical systems and services for spatial audio recording, processing and reproduction / - Creation of content for reproduction via spatial audio systems and services / - Use and application of spatial audio systems and content presentation services / - Media impact of content and spatial audio systems and services from the point of view of media science. The ICSA 2019 is organized by VDT and TU Ilmenau with support of Fraunhofer Institute for Digital Media Technology IDMT
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