108 research outputs found

    Interleaved-MIMO DAS for Indoor Radio Coverage: Guidelines for Planning

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    The combination of distributed antenna systems (DAS) and multiple input multiple output (MIMO) schemes opens the way to a variety of coverage solutions for indoor environment. In this paperinterleaved-MIMO (i-MIMO) DASindoor coverage extension strategies are studied. Their performance in high-order MIMO cases is investigated in realistic conditions through LTE-A link-level simulations, based on statistical data extracted from radio channel measurements; the impact of the deployment strategy on performance is then evaluated and useful planning guidelines are derived to determine the optimum deployment for a given propagation environment

    A Multi-Frequency Investigation of Air-To-Ground Urban Propagation Using a GPU-based Ray Launching Algorithm

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    Unmanned Aerial Vehicles (UAV), also known as “drones”, are attracting increasing attention as enablers for many technical applications and services, and this trend is likely to continue in the next future. When compared to conventional terrestrial communications, those making use of UAVs as base- or relay-stations can definitely be more useful and flexible in reaction to specific events, like natural disasters and terrorist attacks. Among the many and different fields, UAV enabled communications emerge as one of the most promising solutions for next-generation mobile networks, with a special focus on the extension of coverage and capacity of mobile radio networks. Motivated by the air-to-ground (A2G) propagation conditions which are likely to be different than those experienced by traditional ground communication systems, this paper aims at investigating the narrowband properties of the air-to-ground channel for 5G communications and beyond by means of GPU accelerated ray launching simulations. Line of sight probability as well as path loss exponent and shadowing standard deviations are analysed for different UAV flight levels, frequencies and dense urban scenarios, and for different types of on board antennas. Thanks to the flexibility of the ray approach, the role played by the different electromagnetic interactions, namely reflection, diffraction and diffuse scattering, in the air-to-ground propagation process is also investigated. Computation time is reported as well to show that designing UAV communication networks and optimising their performances in a fast and reliable manner, might avoid exhausting – multiple - measurement campaigns

    Item level characterization of mm-wave indoor propagation

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    According to the current prospect of allocating next generation wireless systems in the underutilized millimeter frequency bands, a thorough characterization of mm-wave propagation represents a pressing necessity. In this work, an “item level” characterization of radiowave propagation at 70 GHz is carried out. The scattering properties of several, different objects commonly present in indoor environment are investigated by means of measurements carried out in an anechoic chamber. The measured data have been also exploited to tune some parameters of a 3D ray tracing model

    Strategies and Alliances into Action to Improve National Collaboration

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    The Italian NILDE network of libraries continues to grow through the use of the NILDE system and currently comprises more than 600 Italian librarians and about 10.000 registered end-users.The system allows to daily manage and to record all the Inter-Library-Loan (ILL) operations, with a high national coverage. This paper presents the NILDE network governance and evolution and the strategies that have been put into action to improve collaboration in resource sharing among the participants. These strategies include: − release of best practices and worst practices; − activities to promote the knowledge about the network; − cooperation with the Italian national catalogs and consortia; − data analysis about ILL and its performance, related to: turn around time, reciprocity factor, requested/supplied documents imbalance analysis, analysis of ILL requested serial titles and their relationship with consortial e-only acquisitions. The availability of such a high volume of ILL data has allowed for the first time to analyze the trends and gaps of ILL and to help future cooperative acquisitions planning

    Ray Tracing RF Field Prediction: An Unforgiving Validation

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    The prediction of RF coverage in urban environments is now commonly considered a solved problem with tens of models proposed in the literature showing good performance against measurements. Among these, ray tracing is regarded as one of the most accurate ones available. In the present work, however, we show that a great deal of work is still needed to make ray tracing really unleash its potential in practical use. A very extensive validation of a state-of-the-art 3D ray tracing model is carried out through comparison with measurements in one of the most challenging environments: the city of San Francisco. Although the comparison is based on RF cellular coverage at 850 and 1900 MHz, a widely studied territory, very relevant sources of error and inaccuracy are identified in several cases along with possible solutions

    The Rethinking Resource Sharing Initiative: the NILDE case study in the frame of Italian experiences

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    NILDE (Network for Inter-Library Document Exchange) is born at the CNR Bologna Research Area Library to provide an effective answer to the needs of libraries in order to guarantee information accessibility, sharing resources through Inter Library Loan (ILL) of returnable and non-returnable items (books and journal articles)

    HABITAT: An IoT solution for independent elderly

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    In this work, a flexible and extensive digital platform for Smart Homes is presented, exploiting the most advanced technologies of the Internet of Things, such as Radio Frequency Identification, wearable electronics, Wireless Sensor Networks, and Artificial Intelligence. Thus, the main novelty of the paper is the system-level description of the platform flexibility allowing the interoperability of different smart devices. This research was developed within the framework of the operative project HABITAT (Home Assistance Based on the Internet of Things for the Autonomy of Everybody), aiming at developing smart devices to support elderly people both in their own houses and in retirement homes, and embedding them in everyday life objects, thus reducing the expenses for healthcare due to the lower need for personal assistance, and providing a better life quality to the elderly users.In this work, a flexible and extensive digital platform for Smart Homes is presented, exploiting the most advanced technologies of the Internet of Things, such as Radio Frequency Identification, wearable electronics, Wireless Sensor Networks, and Artificial Intelligence. Thus, the main novelty of the paper is the system-level description of the platform flexibility allowing the interoperability of different smart devices. This research was developed within the framework of the operative project HABITAT (Home Assistance Based on the Internet of Things for the Autonomy of Everybody), aiming at developing smart devices to support elderly people both in their own houses and in retirement homes, and embedding them in everyday life objects, thus reducing the expenses for healthcare due to the lower need for personal assistance, and providing a better life quality to the elderly users

    Identification of the Bovine Arachnomelia Mutation by Massively Parallel Sequencing Implicates Sulfite Oxidase (SUOX) in Bone Development

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    Arachnomelia is a monogenic recessive defect of skeletal development in cattle. The causative mutation was previously mapped to a ∼7 Mb interval on chromosome 5. Here we show that array-based sequence capture and massively parallel sequencing technology, combined with the typical family structure in livestock populations, facilitates the identification of the causative mutation. We re-sequenced the entire critical interval in a healthy partially inbred cow carrying one copy of the critical chromosome segment in its ancestral state and one copy of the same segment with the arachnomelia mutation, and we detected a single heterozygous position. The genetic makeup of several partially inbred cattle provides extremely strong support for the causality of this mutation. The mutation represents a single base insertion leading to a premature stop codon in the coding sequence of the SUOX gene and is perfectly associated with the arachnomelia phenotype. Our findings suggest an important role for sulfite oxidase in bone development
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