418 research outputs found

    Resource Allocation in the Cognitive Radio Network-Aided Internet of Things for the Cyber-Physical-Social System: An Efficient Jaya Algorithm

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    Currently, there is a growing demand for the use of communication network bandwidth for the Internet of Things (IoT) within the cyber-physical-social system (CPSS), while needing progressively more powerful technologies for using scarce spectrum resources. Then, cognitive radio networks (CRNs) as one of those important solutions mentioned above, are used to achieve IoT effectively. Generally, dynamic resource allocation plays a crucial role in the design of CRN-aided IoT systems. Aiming at this issue, orthogonal frequency division multiplexing (OFDM) has been identified as one of the successful technologies, which works with a multi-carrier parallel radio transmission strategy. In this article, through the use of swarm intelligence paradigm, a solution approach is accordingly proposed by employing an efficient Jaya algorithm, called PA-Jaya, to deal with the power allocation problem in cognitive OFDM radio networks for IoT. Because of the algorithm-specific parameter-free feature in the proposed PA-Jaya algorithm, a satisfactory computational performance could be achieved in the handling of this problem. For this optimization problem with some constraints, the simulation results show that compared with some popular algorithms, the efficiency of spectrum utilization could be further improved by using PA-Jaya algorithm with faster convergence speed, while maximizing the total transmission rate

    Entropy and Energy Detection-based Spectrum Sensing over F Composite Fading Channels

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    In this paper, we investigate the performance of energy detection-based spectrum sensing over F composite fading channels. To this end, an analytical expression for the average detection probability is firstly derived. This expression is then extended to account for collaborative spectrum sensing, square-law selection diversity reception and noise power uncertainty. The corresponding receiver operating characteristics (ROC) are analyzed for different conditions of the average signal-to-noise ratio (SNR), noise power uncertainty, time-bandwidth product, multipath fading, shadowing, number of diversity branches and number of collaborating users. It is shown that the energy detection performance is sensitive to the severity of the multipath fading and amount of shadowing, whereby even small variations in either of these physical phenomena can significantly impact the detection probability. As a figure of merit to evaluate the detection performance, the area under the ROC curve (AUC) is derived and evaluated for different multipath fading and shadowing conditions. Closed-form expressions for the Shannon entropy and cross entropy are also formulated and assessed for different average SNR, multipath fading and shadowing conditions. Then the relationship between the Shannon entropy and ROC/AUC is examined where it is found that the average number of bits required for encoding a signal becomes small (i.e., low Shannon entropy) when the detection probability is high or when the AUC is large. The difference between composite and traditional small-scale fading is emphasized by comparing the cross entropy for Rayleigh and Nakagami-m fading. A validation of the analytical results is provided through a careful comparison with the results of some simulations.Comment: 30 pages, 11 figures, 1 table, Submitted to IEEE TCO

    The Global Risks Report 2016, 11th Edition

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    Now in its 11th edition, The Global Risks Report 2016 draws attention to ways that global risks could evolve and interact in the next decade. The year 2016 marks a forceful departure from past findings, as the risks about which the Report has been warning over the past decade are starting to manifest themselves in new, sometimes unexpected ways and harm people, institutions and economies. Warming climate is likely to raise this year's temperature to 1° Celsius above the pre-industrial era, 60 million people, equivalent to the world's 24th largest country and largest number in recent history, are forcibly displaced, and crimes in cyberspace cost the global economy an estimated US$445 billion, higher than many economies' national incomes. In this context, the Reportcalls for action to build resilience – the "resilience imperative" – and identifies practical examples of how it could be done.The Report also steps back and explores how emerging global risks and major trends, such as climate change, the rise of cyber dependence and income and wealth disparity are impacting already-strained societies by highlighting three clusters of risks as Risks in Focus. As resilience building is helped by the ability to analyse global risks from the perspective of specific stakeholders, the Report also analyses the significance of global risks to the business community at a regional and country-level

    Chernobyl's Radioactive Memory: Confronting the Impact of Nuclear Fallout

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    This dissertation examines the accretive violence wrought by nuclear power on bodies and spaces through a study of Chernobyl’s transnational memory. By examining this infamous disaster, I clarify the process by which power renders those impacts invisible, as well as the ways in which memory can assist in making the real impacts of nuclear power visible. I use the term ‘radioactive memory’ to explain the potential of these memories to combat dominant narratives of nuclear power that attempt to contain the disaster’s radioactive excess. The term also encompasses the potential of any engagement with Chernobyl to provoke a deeper understanding of how nuclear power affects communities and the environment. I show how memory of nuclear disaster is conditioned in a variety of ways through multimodal and multifaceted interactions and encounters with Chernobyl in film, literature, tourism, and memorial practices. I employ a wide variety of theoretical approaches and frameworks in order to account for the myriad of possible engagements with the disaster’s memory. This dissertation challenges the idea that Chernobyl is a singular and isolated event, and instead locates it within a constellation of nuclear violence that includes an expansive history of nuclear disaster. Recent examinations on Chernobyl nuclear disaster have centered on its historical Soviet context, which while valuable, do not account for the influence of states, the nuclear industry, and other vested institutions in maintaining the global nuclear apparatus. Memory offers a generative arena for revealing the human costs and risks of living in a nuclear-powered world. A close examination of Chernobyl’s memory reveals how its impacts, along with the impacts of all nuclear disasters, concern everyone, because radiation cannot be contained within set spatial and temporal boundaries. In bringing more awareness to the mechanisms of memory that offer evidence of nuclear power’s destructive consequences, we might then be able to take responsibility for the bodily and psychological trauma inflicted by our own complicity in allowing nuclear power to develop unchecked. In doing so, we might also be able to envision a non-nuclear alternative for the future.PHDSlavic Languages & LiteraturesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/162952/1/hallauri_1.pd

    Design a CPW antenna on rubber substrate for multiband applications

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    This paper presents a compact CPW monopole antenna on rubber substrate for multiband applications. The multi band applications (2.45 and 3.65 GHz) is achieved on this antenna design with better antenna performances. Specially this antenna focused on ISM band application meanwhile some of slots (S1, S2, S3) have been used and attained another frequency band at 3.65 GHz for WiMAX application. The achievement of the antenna outcomes from this design that the bandwidth of 520 MHz for first band, the second band was 76 MHz for WiMAX application and the radiation efficiency attained around 90%. Moreover, the realized gain was at 4.27 dBi which overcome the most of existing design on that field. CST microwave studio has been used for antenna simulation

    Transport 2040 : Impact of Technology on Seafarers - The Future of Work

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    https://commons.wmu.se/lib_reports/1091/thumbnail.jp

    Background Examples of Literature Searches on Topics of Interest

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    A zip file of various literature searches & some resources related to our work related to exposure after the Chernobyl accident and as we began looking at helping in Semey Kazakhstan----a collection of literature reviews on various topics we were interested in... eg. establishing a registry of those exposed for longterm follow-up, what we knew about certain areas like genetics and some resources like A Guide to Environmental Resources on the Internet by Carol Briggs-Erickson and Toni Murphy which could be found on the Internet and was written to be used by researchers, environmentalists, teachers and any person who is interested in knowing and doing something about the health of our planet. See more at https://archives.library.tmc.edu/dm-ms211-012-0060
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