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    Multiuser cyclic shift keying spread spectrum underwater acoustic communication by Cheng-bing HE, Shao-jing JING, Fei HUA, Rui XI, Rui-yu ZHANG, Wen-tao SHI, Qun-fei ZHANG

    Published 2017-07-01
    “…Aiming at the problem of low data rate and high receiver complexity of existing direct sequence spread spectrum code division multiple access (DS-CDMA),a novel code division multiple access (CDMA) using cyclic shift keying (CSK) signaling,namely CSK-CDMA,was proposed for multiuser underwater acoustic communication.The proposed method used the cyclic correlation characteristic of spread spectrum signals with M-ary modulation to provide a higher data rate than conventional.Passive time reversal technology was employed to suppress inter-code interference between users and the co-channel interference.The quasi-orthogonality of spread spectrum code was used to improve the processing gain.Multiuser communications are demonstrated with lake experimental recorded data under the condition of 5.27 km distance and complex multipath interference.The data rate is 39 bit/s/user for 6 users with bit error rate around 10<sup>-2</sup>~10<sup>-4</sup>.…”
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    Research and Prospect of Reservoir Landslide Mechanism and Risk Evaluation by GUAN Yanli, JIA Ronggu, LI Yuhong, WENG Yanmei, LI Jiayan, FENG Rui

    Published 2024-08-01
    “…Over the years, landslide disasters in mountainous reservoirs have caused multiple casualties and heavy economic losses worldwide, making it a key and difficult scientific and technological breakthrough in the prevention and control of geological disasters in reservoir areas. …”
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    Endogenous Security for the Space-Integrated-Ground Information Network in 6G by Xinsheng JI, Kaizhi HUANG, Jiangxing WU, Yajun CHEN, Wei YOU

    Published 2023-06-01
    “…The space-integrated-ground information network in 6G is facing security challenges due to its characteristics, such as the high exposure of the network, high-speed movement of nodes, limited computing resources.Moreover, new security issues are certainly introduced in the development of new architectures, new applications, new technologies and so on.It is urgent to propose new universal security theories to overcome safety and security threats by the integrated solutions.For this purpose, this paper first expounded the cyberspace endogenous security and proposed its endogenous security architecture.Then, under the guidance of the cyberspace endogenous security theory, the relevant security theory and practice norms were respectively discussed for onboard systems, 6G ground mobile networks, and satellite-ground links.Finally, the authentication and encryption mechanism of the communication and security integration from the aspects of security authentication and high security communication encryption, and the integration of traditional security technology and endogenous security were analyzed.…”
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    Biblioscope and the Variety of Disability Media: The Construction and Institutionalisation of a Swedish Reading Device for People with Physical Impairments, 1954&ndash;1966 by Erik Florin Persson

    Published 2024-12-01
    “…By analysing this now largely forgotten technology, the article makes several contributions to the field of disability media studies. …”
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