Performance emulation and test for 5G massive MIMO base station by Xiaolong LIU, Guiming WEI, Xiang ZHANG, Yuxin REN, Jiamo JIANG

“…The new radio (NR) of 5G has gathered three main application scenarios and has broken the restrict of the air interface transmission,laying a solid foundation of the information science.Massive MIMO based base station (MMBS) has become the important fulcrum in the implementation deployment of 5G networks.In order to determine performance of the MMBS in sub 6 GHz band,the physical (PHY) layer techniques were firstly introduced,then,for providing a benchmark of the MMBS products,the evaluation method for upbound of the PHY performance and the PHY performance under the fast fading channel environment was given.Based on that,the current mainstream MMBS performance testing methods were analyzed,and a performance testing scheme was proposed which had been suitable for current commercial version of the MMBS.The proposed scheme can be used to test the function and performance of the products with 5G technique.By the end of 2019,there are many manufacturers of MMBS products have been tested by this solution.…”
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Power Flow in a Two-Stage Nonlinear Vibration Isolation System with High-Static-Low-Dynamic Stiffness by Ze-Qi Lu, Dong Shao, Hu Ding, Li-Qun Chen

“…Increasing both upper and lower nonlinear stiffness could bend the first resonant peak to the left. The isolation range in the power and the force transmissibility plot could be extended to the lower frequencies when the nonlinear stiffness is increased, but the rate of roll-off for the power transmissibility is twice the rate for the force transmissibility at each horizontal stiffness setting. …”
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A Novel Audio Cryptosystem Using Chaotic Maps and DNA Encoding by S. J. Sheela, K. V. Suresh, Deepaknath Tandur

“…The various types of analysis revealed that the algorithm is suitable for narrow band radio communication and real-time speech encryption applications.…”
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Research on Seismic Resistance of Precast Concrete Shear Walls with Bolt Splicing by XU Zhuang, ZHANG Ruigang

“…A design scheme of fully-assembled precast concrete shear walls with unit components spliced by bolts is proposed for the prefabricated unit residence system.An integral precast wall and two overlapped precast ones (consisting of two thin panels spliced horizontally by bolts) are designed,and low-cycle static loading tests of the walls under the bend-shear coupled loading mode are performed to study the seismic resistance of the structures.The research results indicate that the failure mode of the overlapped wall is the same as that of the integral one,and the crack development of the wall body is insufficient.The bearing capacity of the overlapped wall is equivalent to that of the integral one.The former is more ductile,whose displacement ductility factor is about 1.1 times that of the latter.The initial stiffness of the integral wall is larger than that of the overlapped one,but the former's stiffness degrades faster.In addition,the quantity and locations of bolts have little effect on the energy dissipation capacities of overlapped walls,and joint connection might be the only function of bolts for overlapped walls.…”
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The Chemistry of Mercury in the Stratosphere by Alfonso Saiz‐Lopez, A. Ulises Acuña, Anoop S. Mahajan, Juan Z. Dávalos, Wuhu Feng, Daniel Roca‐Sanjuán, Javier Carmona‐García, Carlos A. Cuevas, Douglas E. Kinnison, Juan Carlos Gómez Martín, Joseph S. Francisco, John M. C. Plane

“…This dichotomy arises due to the coincidence of the mercury absorption at 253.7 nm with the ozone Hartley band maximum at 254 nm. We also find that stratospheric Hg oxidation, controlled by chlorine and hydroxyl radicals, is much faster than previously assumed, but moderated by efficient photo‐reduction of mercury compounds. …”
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Blind source separation communication anti-jamming technology and practice by Fuqiang YAO, Miao YU, Pengcheng GUO, Miaomiao GU

“…Aiming at the threat of broad frequency band suppressing jamming and the inherent contradiction between spectrum resources and communication anti-jamming ability, a method was proposed to add the statistics domain dimension on the basis of spread spectrum anti-jamming, which promoted the transformation of communication anti-jamming from hard anti-jamming to accommodate the jamming.The statistical characteristics difference between communication signal and jamming signal was utilized by blind source separation (BSS) communication anti-jamming technology to separate signals, which could improve the communication anti-jamming ability without increasing spectrum resources.To understand and improve the development process of BSS communication anti-jamming (BSSCA) from theory and algorithm to engineering practice, the basic principle of BSSCA was described, the key technologies such as multi-channel BSS and single channel BSS were emphasized.The main characteristics and existing problems of BSSCA were analyzed.Finally, the development priorities of this field were pointed out.…”
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Fully Canonical Triple-Mode Filter with Source-Load Coupling for 5G Systems by Cristóbal López-Montes, José R. Montejo-Garai

“…This work presents the design of a novel fully canonical triple-mode filter with source–load coupling for 5G applications, exploiting its very compact size for the FR1 band. The design is carried out using circular waveguide technology to attain power handling and low insertion losses. …”
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Transient Dynamic Response of Delaminated Composite Rotating Shallow Shells Subjected to Impact by Amit Karmakar, Kikuo Kishimoto

“…An eight noded isoparametric plate bending element is employed in the finite element formulation incorporating rotary inertia and effects of transverse shear deformation based on Mindlin's theory. …”
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Co(II) Coordination in Prokaryotic Zinc Finger Domains as Revealed by UV-Vis Spectroscopy by Valeria Sivo, Gianluca D’Abrosca, Luigi Russo, Rosa Iacovino, Paolo Vincenzo Pedone, Roberto Fattorusso, Carla Isernia, Gaetano Malgieri

“…We show for the CysAspHis2 coordination an intense d-d transition band, blue-shifted with respect to the Cys2His2 sphere. …”
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Companding transform technique combined with iterative filtering for reducing PAPR of OFDM signals by Chao YANG, Yong WANG, Jian-hua GE

“…Considering the drawbacks of the traditional companding transforms，an efficient companding scheme combined with iterative filtering was proposed to reduce the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals.By introducing a joint optimization approach for PAPR and bit error rate (BER) performances along with remaining an unchanged average output power level，the scheme could achieve significant reduction in PAPR as well as an improved BER simultaneously.Moreover，by adaptively adjusting the transform parameters in the iterative process，more design flexibility in companding form and lower out-of-band radiation could also be given to satisfy various system requirements.The proposed scheme had a simple functional form and less computational complexity.The theoretical results regarding the transform gain and impact of companding distortion were derived.Simulation results show that this scheme can substantially offer better overall performances in terms of PAPR reduction，BER performance and bandwidth efficiency.…”
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Design and Implementation of Single-Layer 4 × 4 and 8 × 8 Butler Matrices for Multibeam Antenna Arrays by George A. Adamidis, Ioannis O. Vardiambasis, Melina P. Ioannidou, Theodoros N. Kapetanakis

“…Single-layer 4 × 4 and 8 × 8 Butler matrices (BMs) that operate in the L and S bands are implemented in this paper. Easy-to-fabricate microstrip layout topologies are designed and constructed; the final arrangement of the BMs allows realization without any crossovers. …”
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Combined simulation of fatigue crack nucleation and propagation based on a damage indicator by M. Springer, M. Nelhiebel, H. E. Pettermann

“…Finally, the proposed approach is exemplified by cyclic bending experiments in the Low Cycle Fatigue regime.…”
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Effect of acid pretreatments with various acid types on gelling properties and identification characteristics of pigskin gelatin by Zi-Xuan Yang, Xiao-Mei Sha, Hui Wang, Ting Fang, Sheng Shu, Zong-Cai Tu

“…The characteristic peptides digested from pigskin gelatin were studied by HPLC-MS/MS technique. The findings revealed that gelatin extracted from pigskin pretreated with acetic acid showed the most typical bands. …”
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Direct PCR for DNA barcoding of Bulbophyllum lobbii Lindl. based on rbcL sequence by Su’udi Mukhamad, Bahrul Ulum Fuad, Setyati Dwi

“…The results show that the lysate (after heating and briefly spun) is worthy of use as a template in PCR amplification, able to produce a thick single band with appropriate amplicon size (±600 bp). Further sequencing analysis confirms that the resulting sequence is highly readable with a clear chromatogram. …”
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Multiple Failure Modes，Causes and Prevention of Random Fracture for Hard Tooth Flank Gears by Xiaolu Zhu

“…For the most commonly used hard tooth flank gears today，the final bending failure of more than 70% of the gears is random fracture. …”
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Experimental Study on Pullout Behavior of Coir Geotextiles Based on Transparent Soil by Liangyong Li, Houyang Li, Weiqiang Cao

“…With the increase in normal stress, anchorage length, and pullout rate, the peak pullout force and the thickness of the shear band increase gradually.…”
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America is Dead. Long Live America! Political Affect in Days Gone by Soraya Murray

“…This essay models a method for understanding political affect in video games by analyzing the American action-adventure survival horror game Days Gone (SIE Bend Studio, 2019). Through an examination of its rendering of the Pacific Northwest landscape as ideology, much is revealed about a deeply troubled and oppositional worldview. …”
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Determining fracture energy parameters of concrete from the modified compact tension test by A. Fernández-Canteli, L. Castañón, B. Nieto, M. Lozano, T. Holušová, S. Seitl

“…The modified compact tension (MCT) test, though not yet recognized as a valid test for determining fracture energy of concrete, is believed to represent a plausible and suitable alternative versus other well established procedures, such as the wedge-splitting test (WST) and the three point (3PB) or four point bending (4PB) tests, due to its simplicity and low cost. …”
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A Comprehensive Flexural Analysis for Sustainable Concrete Structure Reinforced by Embedded Parts by Yuantian Sun, Junfei Zhang, Yunchao Tang, Yufei Wang, Junbo Sun, Xiangyu Wang

“…Later, the ultimate failure capacity by bending experiments was conducted and compared with the theoretically calculated results. …”
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A Review on Model and Control of Electromagnetic Active Engine Mounts by Henghai Zhang, Wenku Shi, Jun Ke, Guoyu Feng, Junlong Qu, Zhiyong Chen

“…The main purpose of this paper is to meet the needs of researchers and engineers engaged in electromagnetic AEM analysis and control.…”
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