Massive MIMO LEO Satellite Communications System by Kexin LI, Li YOU, Xiqi GAO

“…Extending massive multiple-input multiple-output (MIMO) technique to low earth orbit (LEO) satellite communication systems enables satellites to implement fl exible beamforming, which can make full use of the spatial degrees of freedom of massive MIMO and signifi cantly improve the spectral effi ciency and energy effi ciency of LEO satellite communication systems.Several related issues in massive MIMO-based LEO satellite communication systems were studied.The characteristics of massive MIMO LEO satellite channels were analyzed.The important diff erences between them and terrestrial wireless channels were revealed.With the aim of addressing the problems on channel information acquisition, multi-user transmission and user scheduling in massive MIMO LEO satellite communication, the main difficulties faced by the current work were discussed, and how to use the characteristics of massive MIMO LEO satellite channels to design tailored solutions with low implement complexity was conceived.…”
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Cross-layer scheduling and dynamic resource allocation for MIMO-OFDMA/SDMA systems with multi-service by ZHONG Chong-xian1, LI Chun-guo1, YANG Lv-xi1

“…Cross-layer scheduling and dynamic resource allocation problems were investigated for downlink MIMO-OFDMA/SDMA systems with multi-service.Firstly,a mathematical formulation of the optimization problem was provided with the objective of maximizing the total system throughput under various constraints.Secondly,a user group-ing scheme was proposed utilizing clustering analysis method based on the type of services and the spatial compatibility of multiple users with multiple receive antennas.Thirdly,a new cross-layer scheduling and dynamic resource allocation algorithm was developed based on the proposed user grouping scheme combined with the priorities of different service,which maximizes the total system throughput by maximizing the throughput of each subcarrier.Simulation results show that compared with the existing schemes,the proposed algorithms obtain reasonable throughput performance while provide better QoS requirement for each user of different services.…”
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Delayed Diagnosis of McCune–Albright Syndrome by Bereket Fantahun, Seblewongel Desta

“…She had pathological fractures at multiple sites and had raised thyroid hormones since the age of 3½ years. …”
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Élize Féron, Wartime Sexual Violence Against Men: Masculinities and Power in Conflict Zones. by Selina Palm

“…The book highlights the lived experiences of male survivors and male perpetrators in multiple settings, enabling her theoretical analysis of how violence is understood, narrated, and addressed to emerge from concrete contexts of experience. …”
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Correlation calculation decrypting for BSS-based image cryptosystem by LIN Qiu-hua, DANG Jie, YIN Fu-liang

“…For a blind source separation （BSS） based method for encrypting multiple images, the multiple decrypted im- ages by BSS may have changed order and reversed pixel values. …”
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Retracted: Image Recognition Technology Based on Neural Network by Jianqiu Chen

“…For the calculation of classification results, a multi-region test method is used. By calculating multiple regions of the image during the test, the accuracy of image recognition can be improved. …”
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Job satisfaction, life orientation and perception of family role - Comparison between women employed in public sector and in economy by Eva Boštjančič

“…This study seeks to determine the connection between their multiple roles, life orientation, and life satisfaction. …”
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Design of precoding matrices in MIMO full duplex two-way security communication system by Weijia LEI, Yang ZHOU, Xianzhong XIE, Hongjiang LEI

“…The design of precoding matrices was studied in the multiple input multiple output (MIMO) full-duplex two-way security communication system where legitimate nodes transmit the confidential information accompanied by the artificial noise while receiving information.For the scenario where the perfect channel state information (CSI) of legitimate channels and eavesdropping channels was available,the difference of concave/convex (DC) programming was used to optimize the precoding matrices of the information signal and the artificial noise for the maximization of the secrecy sum rate.For the scenario where the CSI was imperfect,the channels were modeled by using worst-case criterion and the weighted minimum mean square error algorithm was used to get the robust precoding matrices of the information signal and the artificial noise.The simulation results prove that the proposed algorithm can effectively promote the secrecy sum rate of the system.…”
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Crescere nella migrazione. Generi e sessualità fra gli adolescenti di origine straniera by Federica Tarabusi

“…Grounded on an ethnographic work carried out in the context of Bologna and surrounding area, the paper investigates the symbolic construction of gender and sexuality among the teenagers of foreign origin. Exploring their multiple biographical trajectories, the research reveals a pattern of resources, subjective desires, imaginaries largely shared with the younger generations, but also their multiple attempts to negotiate and challenge both parent’s expectations and Italian society’s request of “assimilation”. …”
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« Et que fais-tu de cinq cents millions d’étoiles ? » by Samuel Challéat, Thomas Poméon

“…In reaction to this, territories are organising the protection of these “objects of nature” that have become precious, thus activating their multiple values. Feet on the ground and head in the stars, we look at values that are emerging from the starry sky industry and from the multiple services and activities it valorises, not only monetarily. …”
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Research on multi-access selection mechanism for multi-mode terminals in heterogeneous wireless networks by Wen-hao FAN, Yuan-an LIU, Fan WU

“…Aiming at further promoting the multi-mode terminal’s transmission performance and service continuity,a multi-access selection mechanism for multi-mode terminals which exploits the multi-radio transmission diversity of the heterogeneous wireless networks for accessing multiple networks simultaneously and executing parallel transmission was designed.The mechanism applied exponential smoothing method to process the measured parameters;used state transition models to manage access selection strategies of terminal’s multiple network interface cards;adopted utility functions to dynamically balance terminal’s power consumption and transmission speed.Simulation results demonstrate the decrease of unnecessary re-selections,the enhancement of transmission energy efficiency under the premise of the guarantee of terminal’s power consumption and throughput compared with the traditional switched access selection.…”
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Physical-layer network coding in k-users MIMO-Y two-way relay channels by Tao WANG, Yong WANG, Yue ZHANG

“…In order to exchange information among k users using the technology of physical-layer network coding in the multiple input multiple output Y two-way relay channels,the GSA-GSA scheme was proposed,using the technology of general signal alignment during the uplink and the downlink.The signals were exchanged between every source node align in a transformed subspace,rather than the direct subspace.This was realized by jointly designing the precoding matrices at all source nodes and the processing matrix at the relay.The constraints of the number of sending and receiving antennas and the sum rate of proposed scheme were analyzed.In simulation,it can figure out that the proposed scheme needs fewer antennas in the whole system and can improve the achievable system sum rate under the same SNR and degrees of freedom.…”
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Efficient Convex Optimization of Reentry Trajectory via the Chebyshev Pseudospectral Method by Chun-Mei Yu, Dang-Jun Zhao, Ye Yang

“…Numerical results and a comparison study reveal that the proposed method is efficient and effective to solve the problem of reentry trajectory optimization with multiple constraints.…”
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An Analytical Multimodulus Algorithm for Blind Demodulation in a Time-Varying MIMO Channel Context by Steredenn Daumont, Daniel Le Guennec

“…This paper addresses the issue of blind multiple-input multiple-output (MIMO) demodulation of communication signals, with time-varying channels and in an interception context. …”
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Research on Architecture of LEO Satellite Internet of Things and Key Technologies by Xiaojin DING, Tao HONG, Rui LIU, Wentao PENG, Gengxin ZHANG

“…First, we analyzed the composition and demand characteristics of LEO satellite IoTs, and designed an architecture of LEO satellite IoTs.Second, to extracted characteristics of electromagnetic environment and channel, we studied electromagnetic environment and channel sensing methods through constructing neural network model.Then, we investigated an active terminal-identifi cation method for detecting active terminals.Finally, considered multiple-input multiple-output as the main approach to improved the capacity of terrestrial mobile communication systems, we explored a pair of algorithms of mining satellite spatial resources for realizing the collision mitigation and capacity improvement of LEO IoT terminals.Simulation results showed that the designed method sofmining spatial-domain resources could mitigated eff ectively signal collisions among IoT terminals, and improved signifi cantly the concurrent accessing number of LEO satellite IoT terminals.…”
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Intelligent and open new generation telecom service architecture and its key technologies by Jianxin LIAO, Hao ZHANG, Tong XU, Lingfei NI, Jingyu WANG, Wenfu WU

“…For complex heterogeneous networks,IOTSA (intelligent and open telecom service architecture) based on the comprehensive decoupling of service systems was proposed,as well as core mechanisms such as intelligent scheduling of network resources,dynamic service orchestration and combination,and intelligent monitoring of abnormal behavior.Through the establishment of a three-level interface and four-layer capability opening architecture,multi-granular capability opening and comprehensive resource sharing were realized,which met the needs of multiple scenarios.Key technologies such as low-risk and low-cost rapid decoupling of service systems and dynamic coordination of multiple services were proposed.These achievements had formed a series of international standards and had been applied on a large scale on existing networks.By providing a large number of ultra-fine-grained capabilities,396 atomic capabilities,and flexible composite capabilities,the development of operator and third-party services and applications were strongly supported.…”
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Ombres et transparences, de Vinci aux calques numériques by Marie-Madeleine Martinet

“…Studies of reflexion ranged from mirror-images to sets of multiple contiguous spots of light; form/texture relationships changed over the centuries from the gradual recomposition of motifs – as in multiple-colour printing– to decomposition –as in camouflage. …”
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A crítica pós-moderna: analítica da interação e da sociabilidade by Carlos A. Gadea

“…As one attempts to approach the multiple dimensions of modernity and its nexus with contemporary theoretical debates, one should not omit the different contributions made by the so-called post-modern critique. …”
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Heterogeneous multi-layer mobile edge computing for 6G by Pengfei WANG, Boya DI, Lingyang SONG, Zhu HAN

“…With the development of the Internet of things,multiple real-time applications will emerge in future 6G communication network.Driven by demands on low-latency services of multiple real-time applications,mobile edge computing (MEC) will become an important technology to improve the user experience and reduce the network cost.However,the computing capacity of a single MEC server is limited,which induces that it is difficult to meet the low-latency requirement of data processing for the computation-intensive applications.A heterogeneous multi-layer mobile edge computing (HetMEC) network architecture was proposed to jointly utilize the computing and transmission resources of both the cloud computing center and multi-layer MEC servers.By reasonably dividing and offloading computing tasks,reliable and efficient computing services were provided for edge applications.Simulation results show that the proposed algorithm could effectively reduce the processing latency,improve the network processing rate and robustness.…”
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Design of Highly Isolated Compact Antenna Array for MIMO Applications by Tiancong Huang, Yantao Yu, Lijun Yi

“…When implemented in a size limited platform, the multiple antenna arrays suffer from strong mutual coupling between closely spaced array elements. …”
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