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Research on Dielectric Focusing Lens Antenna for HPM Atmospheric Breakdown Experiments

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Chinese Journal of Electronics 2019年第1期28卷 202-206页

作者： YU Daojie CHAI Mengjuan ZHOU Dongfang ZHOU Changlin WEI Jinjin HU Junjie CAI Beibing ZHAO Tongcheng National Digital Switching System Engineering and technological Research center

To distinguish the dielectric surface breakdown from the atmospheric breakdown, one method for atmospheric breakdown experiment by loading dielectric focusing lens is proposed. The focusing characteristics of dielectric focusing lens are investigated for the microwave frequency on the order of 1.3GHz to 9.3GHz, the lens focal length on the order of 0.3m to 0.9m and the dielectric constant on the order of 0.3 to 0.9. Simulations show that higher frequency, shorter focal length, and fitter dielectric constant result in better focus effect that the rising and falling edges of electric field strength change faster near the focus which is closer to the theoretical value. A dielectric focusing lens for the S-band is optimally designed with the polytetrafluoroethylene of 0.32 m thickness, 0.6m diameter,and 0.4m focal length. The focus indicator of dielectric lens is measured and the atmospheric breakdown experiment is carried out. The experimental values of atmospheric breakdown are consistent with the theoretical values. The electric field strength with the lens at the focus is 5–6times greater than that without focusing lens. The image of atmospheric breakdown by the dielectric lens focusing method experiment is clearer than that by the direct radiation method.

关键词： HPM Atmospheric breakdown experiment Dielectric focusing lens antenna Near field Focusing effect

Moving target localization in distributed MIMO radar with transmitter and receiver location uncertainties

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Chinese Journal of Aeronautics 2019年第7期32卷 1705-1715页

作者： Yongsheng ZHAO Dexiu HU Yongjun ZHAO Zhixin LIU National Digital Switching System Engineering and technological Research center (NDSC)

In this paper, the problem of moving target localization from Bistatic Range(BR) and Bistatic Range Rate(BRR) measurements in a Multiple-Input Multiple-Output(MIMO) radar system having widely separated antennas is investigated. We consider a practically motivated scenario,where the accurate knowledge of transmitter and receiver locations is not known and only the nominal values are available for processing. With the transmitter and receiver location uncertainties,which are usually neglected in MIMO radar systems by prior studies, taken into account in the measurement model, we develop a novel algebraic solution to reduce the estimation error for moving target localization. The proposed algorithm is based on the pseudolinear set of equations and two-step weighted least squares estimation. The Cramer-Rao Lower Bound(CRLB) is derived in the presence of transmitter and receiver location uncertainties. Theoretical accuracy analysis demonstrates that the proposed solution attains the CRLB, and numerical examples show that the proposed solution achieves significant performance improvement over the existing algorithms.

关键词： Bistatic range Bistatic range rate Location uncertainty MIMO radar Target localization Two-step weighted least squares

Diagnostic approach to faecal incontinence:What test and when to perform?

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World Journal of Gastroenterology 2021年第15期27卷 1553-1562页

作者： Wisam Sbeit Tawfik Khoury Amir Mari Department of Gastroenterology Galilee Medical CenterNaharia 2210001Faculty of Medicine in the GalileeBar-Ilan UniversitySafedIsrael Gastroenterology and Endoscopy Unit The Nazareth HospitalEMMSNazareth 464000Faculty of Medicine in the GalileeBar-Ilan UniversitySafedIsrael

Faecal incontinence(FI)is a debilitating common end result of several diseases affecting the quality of life and leading to patient disability,morbidity,and increased societal *** the various causes of FI,it is important to assess and identify the underlying *** investigatory tools are available including high-resolution anorectal manometry,transrectal ultrasound,magnetic resonance imaging,and *** review article provides an overview on the causes and pathophysiology of FI and the author’s perspective of the stepwise investigation of patients with FI based on the available ***,high-resolution anorectal manometry should be the first investigatory tool for FI,followed by either transrectal ultrasound or magnetic resonance imaging for anal internal sphincter and external anal sphincter injury,respectively.

关键词： Incontinence Manometry Ultrasound Rectal Magnetic resonance imaging Faecal

Overview of 5G security technology

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Science China(Information Sciences) 2018年第8期61卷 107-131页

作者： Xinsheng JI Kaizhi HUANG Liang JIN Hongbo TANG Caixia LIU Zhou ZHONG Wei YOU Xiaoming XU Hua ZHAO Jiangxing WU Ming YI National Digital Switching System Engineering & technological R&D center Zhengzhou 450002 China National Digital Switching System Engineering & technological R&D center

The 5 th-generation mobile communication system(5 G) has higher security requirements than previous systems. Accordingly, international standard organizations, operators, and equipment manufacturers are focusing extensively on 5 G security technology. This paper analyzes the security requirements of 5 G business applications, network architecture, the air interface, and user privacy. The development trends of5 G security architecture are summarized, with a focus on endogenous defense architecture, which represents a new trend in 5 G security development. Several incremental 5 G security technologies are reviewed, including physical layer security, lightweight encryption, network slice security, user privacy protection, and block chain technology applied to 5 G.

关键词： 5G security endogenous defense mimic defense physical layer security lightweight encryption network slice security user privacy preservation block chain

Treadmill exercise in combination with acousto-optic and olfactory stimulation improves cognitive function in APP/PS1 mice through the brain-derived neurotrophic factor-and Cygb-associated signaling pathways

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Neural Regeneration Research 2025年第9期20卷 2706-2726页

作者： Biao Xiao Chaoyang Chu Zhicheng Lin Tianyuan Fang Yuyu Zhou Chuxia Zhang Jianghui Shan Shiyu Chen Liping Li Department of Physiology and Pharmacology Health Science CenterNingbo UniversityNingboZhejiang ProvinceChina Ningbo Key Laboratory of Behavioral Neuroscience Health Science CenterNingbo UniversityNingboZhejiang ProvinceChina Key Laboratory of Addiction Research of Zhejiang Province NingboZhejiang ProvinceChina

A reduction in adult neurogenesis is associated with behavioral abnormalities in patients with Alzheimer's ***,enhancing adult neurogenesis represents a promising therapeutic approach for mitigating disease symptoms and ***,nonpharmacological interventions aimed at inducing adult neurogenesis are currently *** individual non-pharmacological interventions,such as aerobic exercise,acousto-optic stimulation,and olfactory stimulation,have shown limited capacity to improve neurogenesis and cognitive function in patients with Alzheimer's disease,the therapeutic effect of a strategy that combines these interventions has not been fully *** this study,we observed an age-dependent decrease in adult neurogenesis and a concurrent increase in amyloid-beta accumulation in the hippocampus of amyloid precursor protein/presenilin 1 mice aged 2-8 *** deposition became evident at 4 months,while neurogenesis declined by 6 months,further deteriorating as the disease ***,following a 4-week multifactor stimulation protocol,which encompassed treadmill running(46 min/d,10 m/min,6 days per week),40 Hz acousto-optic stimulation(1 hour/day,6 days/week),and olfactory stimulation(1 hour/day,6 days/week),we found a significant increase in the number of newborn cells(5'-bromo-2'-deoxyuridine-positive cells),immature neurons(doublecortin-positive cells),newborn immature neurons(5'-bromo-2'-deoxyuridine-positive/doublecortin-positive cells),and newborn astrocytes(5'-bromo-2'-deoxyuridine-positive/glial fibrillary acidic protein-positive cells).Additionally,the amyloid-beta load in the hippocampus *** findings suggest that multifactor stimulation can enhance adult hippocampal neurogenesis and mitigate amyloid-beta neuropathology in amyloid precursor protein/presenilin 1 ***,cognitive abilities were improved,and depressive symptoms were alleviated in amyloid precursor protein/presenilin 1 mice

关键词： acousto-optic stimulation adult neurogenesis Alzheimer's disease amyloid precursor protein/presenilin 1 mice amyloid-beta deposition brain cell apoptosis cognitive impairment depression-like behavior involuntary treadmill exercise olfactory stimulation serum metabolites

Uncovering network traffic anomalies based on their sparse distributions

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Science China(Information Sciences) 2014年第9期57卷 256-266页

作者： CHENG GuoZhen CHEN HongChang CHENG DongNian ZHANG Zhen LAN JuLong National Digital Switching System Engineering and technological Research center

Characterizing network traffic with higher-dimensional features results in increased complexity of most detectors and classifiers for identifying traffic *** key observations from existing studies confirm that network anomalies are typically distributed in a sparse way,with each anomaly essentially characterized by its lower-dimensional *** on this important finding,we exploit sparsity in designing a novel detection method for anomalies that ignores redundancies that are dynamically filtered from the feature sets and accurately classifies *** of our method with three well known techniques shows a10%improvement in accuracy with an O(n)complexity of the classifier.

关键词： anomaly detection feature filtering multi-resolution analysis sparse distribution

Dual-Threshold Based Secure On-Off Transmission Scheme for Dense HCNs with Imperfect CSI

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China Communications 2019年第3期16卷 132-142页

作者： Yunjia Xu Kaizhi Huang Yi Zou Xin Hu National Digital Switching System Engineering & technological Research center

In this paper, we propose a dual-threshold based secure On-Off transmission scheme, where signals are transmitted only if the channel condition can guarantee secure and reliable communication. First, we present a dynamic access strategy to increase access efficiency, which provides an access region for the intended user. Then, we propose an emission control policy to transmit signals according to the current channel condition, which declines the influence of channel estimation errors and guarantees qualities of communication links. Furthermore, we give a comprehensive performance analysis for the proposed scheme in terms of connection outage probability(COP) and secrecy outage probability(SOP), and present a dual-threshold optimization model to further support the performance. Numerical results verify that the secure On-Off transmission scheme can increase the system secure energy efficiency and guarantee reliable and secure communication.

关键词： physical layer security imperfect CSI dense heterogeneous cellular networks On-Off transmission secure energy efficiency

Texture Pattern Generation Using Clonal Mosaic

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Journal of Computer Science & Technology 2006年第2期21卷 173-180页

作者：张厚健黄国长 center for Graphics and Imaging Technologies School of Computer EngineeringNanyang Technological University Singapore

In this paper, an effective system for synthesizing animal skin patterns on arbitrary polygonal surfaces is developed. To accomplish the task, a system inspired by the Clonal Mosaic （CM） model is proposed. The CM model simulates cells＇ reactions on arbitrary surface. By controlling the division, mutation and repulsion of cells, a regulated spatial arrangement of cells is formed. This arrangement of cells shows appealing result, which is comparable with those natural patterns observed from animal skin. However, a typical CM simulation process incurs high computational cost, where the distances among ceils across a polygonal surface are measured and the movements of cells are constrained on the surface. In this framework, an approach is proposed to transform each of the original 3D geometrical planes of the surface into its Canonical Reference Plane Structure. This structure helps to simplify a 3D computational problem into a more manageable 2D problem. Furthermore, the concept of Local Relaxation is developed to optimally enhance the relaxation process for a typical CM simulation. The performances of the proposed solution methods have been verified with extensive experimental results.

关键词： procedural texture clonal mosaic pattern synthesis geometry processing

A Self-Adaptive Programming Mechanism for Reconfigurable Parsing and Processing

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China Communications 2016年第S1期13卷 87-97页

作者： DUAN Tong SHEN Juan WANG Peng LIU Shiran National Digital Switching System Engineering & technological Research center

In this paper, we present a self-adaptive programming mechanism(SAP) that targets programming hardware devices of reconfigurable parsing and processing. The SAP programming system locates in software of network data plane and has three features:(1) programmable packet parsing: the packet header format can be customized and new header type can be added;(2) reconfigurable packet processing: the match fields to be handled in each match table can be specified;(3) function-adaptive control: any function control systems can determine the packet processing flow independently without the need of knowing the specifics of the underlying hardware. Finally, we implement a prototype on NetF PGA-10 G together with two representative function control systems(router and Open Flow switch) to demonstrate how SAP works. We believe the data plane of reconfigurable parsing and processing will lead to future switches that provide greater flexibility, and unlock the potential of network function innovation.

关键词： programming mechanism selfadaptive reconfigurable network data plane Net FPGA