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5G Ultra-Dense Network Fingerprint Positioning Method Based on Matrix Completion

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China Communications 2023年第3期20卷 105-118页

作者： yuexia zhang Chong Liu Key Laboratory of Information and Communication Systems Ministry of Information IndustryBeijing Information Science and Technology UniversityBeijing 100101China Key Laboratory of Modern Measurement and Control Technology Ministry of EducationBeijing Information Science and Technology UniversityBeijing 100101China

The problem of high-precision indoor positioning in the 5G era has attracted more and more attention.A fingerprint location method based on matrix completion(MC-FPL)is proposed for 5G ultradense networks to overcome the high costs of traditional fingerprint database construction and matching ***,a partial fingerprint database constructed and the accelerated proximal gradient algorithm is used to fill the partial fingerprint database to construct a full fingerprint ***,a fingerprint database division method based on the strongest received signal strength indicator is proposed,which divides the original fingerprint database into several sub-fingerprint ***,a classification weighted K-nearest neighbor fingerprint matching algorithm is *** estimated coordinates of the point to be located can be obtained by fingerprint matching in a sub-fingerprint *** simulation results show that the MC-FPL algorithm can reduce the complexity of database construction and fingerprint matching and has higher positioning accuracy compared with the traditional fingerprint algorithm.

关键词： indoor positioning fingerprint matching matrix completion 5G UDN RSSI

Adaptive Time Slot Resource Allocation in SWIPT IoT Networks

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Computer Modeling in Engineering & Sciences 2023年第9期136卷 2787-2813页

作者： Yunong Yang yuexia zhang Zhihai Zhuo Key Laboratory of Information and Communication Systems Ministry of Information IndustryBeijing Information Science and Technology UniversityBeijing100101China Key Laboratory of ModernMeasurement&Control Technology Ministry of EducationBeijing Information Science&Technology UniversityBeijing100101China Beijing Advanced Innovation Center for Future Blockchain and Privacy Computing Beijing100101China

The rapid advancement of Internet of Things(IoT)technology has brought convenience to people’s lives;however further development of IoT faces serious challenges,such as limited energy and shortage of network spectrum *** address the above challenges,this study proposes a simultaneous wireless information and power transfer IoT adaptive time slot resource allocation(SIATS)***,an adaptive time slot consisting of periods for sensing,information transmission,and energy harvesting is designed to ensure that the minimum energy harvesting requirement ismet while the maximumuplink and downlink throughputs are ***,the optimal transmit power and channel assignment of the system are obtained using the Lagrangian dual and gradient descent methods,and the optimal time slot assignment is determined for each IoT device such that the sum of the throughput of all devices is *** results show that the SIATS algorithm performs satisfactorily and provides an increase in the throughput by up to 14.4%compared with that of the fixed time slot allocation(FTS)*** the case of a large noise variance,the SIATS algorithm has good noise immunity,and the total throughput of the IoT devices obtained using the SIATS algorithm can be improved by up to 34.7%compared with that obtained using the FTS algorithm.

关键词： Internet of Things simultaneous wireless information and power transfer adaptive time slot resource allocation

Discussion on evaluating the vulnerability of storm surge hazard bearing bodies in the coastal areas of Wenzhou

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Frontiers of Earth Science 2015年第2期9卷 300-307页

作者： yuexia zhang Jing GUO Zhumei CHE College of Environmental Science and Engineering Ocean University of China Qingdao 266000 China Marine Monitoring and Forecasting Center of Zhejiang Hangzhou 310007 China

Wenzhou is a region on the coast of China where storm surges are frequent and serious. Starting with society, economy, land utilization, and anti-disaster cap- ability, the vulnerability of each county in the coastal region of Wenzhou was evaluated. The counties were then divided into mild, moderate, heavy, and extremely heavy fragile areas by choosing 15 factors to establish an evaluation index system, using principal component analysis to set the weight of each factor. The results show that all of the counties fit into the categories of heavy and extremely heavy fragile areas except for Pingyang county, which is mild. There is no significant difference in storm surge vulnerability among all counties in the Wenzhou coastal region, which is highly associated with the general balance of socioeconomic development in the Zhejiang coastal region and the orientation of government policies. This research provides a method for evaluating vulnerability to storm surge. Evaluation results can provide the basis for responses to storm surge, contributing to disaster prevention and mitigation planning, and regional sustainable development planning.

关键词： storm surge disaster index system hazardbearing body vulnerability

Variations of Summer Phytoplankton Community Related to Environmental Factors in a Macro-Tidal Estuarine Embayment, Hangzhou Bay, China

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Journal of Ocean University of China 2015年第6期14卷 1025-1033页

作者： zhang yuexia YU Jun JIANG Zhibing WANG Qin WANG Hui College of Environmental Science and Engineering Ocean University of China Marine Monitoring and Forecasting Center of Zhejiang Key Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyState Oceanic Administration National Marine Environmental Forecasting Center

To explore the distribution and composition of phytoplankton community and their responses to environmental changes, summer net-collected phytoplankton and physicochemical parameters in the Hangzhou Bay during 2004–2010 were investigated. A total of four phyla and 84 species were identified, including 67 diatom and 12 dinoflagellate species. The dominant species con- stantly consisted of the diatoms, although the dominance of dinoflagellate and cyanobacteria increased recently. Due to great spa- tio-temporal variations in environmental factors(salinity, suspended solids, and nutrient concentration), significant heterogeneities in community compositions among different years and subregions(inner and middle sections, and bay mouth) were found based on the analyses of multidimensional scaling and similarity. Canonical correspondence analysis showed that salinity and Si/N were the main variables associated with algal assemblage. Compared with the historical data since the 1980 s, eutrophication(N, P, and N/P increased with decreasing Si/N) was exacerbated drastically. Moreover, climatic forcing and human activities resulted in a series of physical alterations, including sediment retention, temperature increase, and salinity decrease as well as reduction in water exchanges. All these changes induced obvious increases in cell density and Chl-a while decreases in species diversity and diatom-dinoflagellate ratio as well as the shifting of dominant species. Therefore, the long-term phytoplankton variations were closely related to anthropogenic and climatic perturbations in the Hangzhou Bay.

关键词： Hangzhou Bay phytoplankton long-term changes eutrophication Qiantang River Changjiang

Amperometric Biosensor for Detection of Phenolic Compounds Based on Tyrosinase, N-AcetyI-L-cysteinecapped Gold Nanoparticles and Chitosan Nanocomposite

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Chinese Journal of Chemistry 2017年第8期35卷 1305-1310页

作者： Wenjuan Dong Jiyan Han Jia Shi Wenting Liang yuexia zhang Chuan Dong Institution of Environmental Science College of Chemistry and Chemical Engineering Shanxi University Taiyuan Shanxi 030006 China Department of Laboratory Medicine College of Fenyang Shanxi Medical University Fenyang Shanxi 032200 China

A novel biosensor was fabricated based on the immobilization of tyrosinase and N-acetyl-L-cysteine-capped gold nanoparticles onto the surface of the glassy carbon electrode via the film forming by chitosan. The NAC-AuNPs （N-acetyl-L-cysteine-capped gold nanoparticles） with the average size of 3.4 nm had much higher specific surface area and good biocompatibility, which were favorable for increasing the immobilization amount of enzyme, retaining the catalytic activity of enzyme and facilitating the fast electron transfer. The prepared biosensor exhibited suitable amperometric responses at -0.2 V for phenolic compounds vs. saturated calomel electrode. The parameters of influencing on the working electrode such as pH, temperature, working potential were investigated. Under optimum conditions, the biosensor was applied to detect catechol with a linear range of 1.0 ×10^-7 to 6.0 × 10^-5 mol·L^-1 , and the detection limit of 5.0×10^-8mol·L^-1 （S/N=3）. The stability and selectivity of the proposed biosensor were also evaluated.

关键词： tyrosinase biosensor gold nanoparticles phenolic compounds

Parasitic plant dodder(Cuscuta spp.):a new natural Agrobacterium-to-plant horizontal gene transfer species

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Science China(Life Sciences) 2020年第2期63卷 312-316页

作者： yuexia zhang Delin Wang Yubin Wang Huirong Dong Yuge Yuan Wei Yang Daowan Lai Mingcai zhang Linjian Jiang Zhaohu Li State Key Laboratory of Plant Physiology and Biochemistry College of Agronomy and BiotechnologyChina Agricultural UniversityBeijing 100193China Key Laboratory of Pest Monitoring and Green Management Ministry of Agriculture and Rural AffairsDepartment of Plant PathologyCollege of Plant ProtectionChina Agricultural UniversityBeijing 100193China

Dear Editor,Horizontal gene transfer(HGT)has long been recognized as asexual means of DNA transfer between different *** HGT is common to prokaryotes,it remains uncommon in higher eukaryotic species(Beiko et al.,2005).

关键词： al. transfer spp.)

GPX4 Promoter Hypermethylation Induced by Ischemia/Reperfusion Injury Regulates Hepatocytic Ferroptosis

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Journal of Clinical and Translational Hepatology 2024年第11期12卷 917-929页

作者： Chen Bai Peilun Xiao Yuting Chen Fangfang Chu Yue Jiao Jiaqi Fan yuexia zhang Jiao Liu Jiying Jiang Shuna Yu Department of Anatomy School of Basic Medical SciencesShandong Second Medical UniversityWeifangShandongChina

Background and Aims:Glutathione peroxidase 4(GPX4)is a key factor in ferroptosis,which is involved in ischemia-rep-erfusion ***,little is known about its role in he-patic ischemia-reperfusion injury(HIRI).This study aimed to investigate the role of GPX4 methylation in ferroptosis during ***:For the in vitro experiments,an oxygen and glucose deprivation cell model was *** the in vivo experiments,an ischemia-reperfusion model was created by subjecting mice to simulated *** occurrence,GPX4 promoter methylation,and global methylation levels were then ***:Ferroptosis was observed in oxygen and glucose deprivation,characterized by a signifi-cant decrease in cellular viability(P<0.05),an increase in lipid peroxidation(P<0.01),iron overload(P<0.05),and down-regulation of GPX4(P<0.05).This ferroptosis was ex-acerbated by GPX4 knockdown(P<0.01)and mitigated by exogenous glutathione(P<0.01).Similarly,ferroptosis was evident in mice subjected to HIRI,with a down-regulation of GPX4 mRNA and protein expression(all P<0.01),and an upregulation of acyl-CoA synthetase long-chain family mem-ber 4 mRNA and protein(all P<0.01),as well as prostaglan-din-endoperoxide synthase 2 mRNA and protein expression(all P<0.05).Methylation levels increased,evidenced by upregulation of DNA methylation transferase expression(P<0.05)and down-regulation of Ten-eleven translocation fam-ily demethylases(P<0.01),along with an upregulation of GPX4 promoter ***:Ferroptosis may be the primary mode of cell death in hepatocytes following ischemia-reperfusion *** methylation of the GPX4 promoter and elevated levels of global hepatic methylation are involved in the regulation of ferroptosis.

关键词： Glutathione peroxidase 4 Promoter Methylation Oxygen and glucose deprivation cell model Hepatic ischemia-reperfusion injury Ferroptosis Lipid peroxidation Iron overload

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物联网双层耦合动力学信息传播模型研究

电子与信息学报 2024年第8期46卷 3165-3173页

作者：张月霞常凤德北京信息科技大学现代测控技术教育部重点实验室北京100020 高动态导航北京市实验室北京100020

信息传播模型的研究是物联网领域的重要组成部分,它有助于提高物联网系统的性能和效率,促进物联网技术的进一步发展,针对物联网通信中影响信息传播的因素复杂且不稳定的问题,该文提出一种双层耦合信息传播模型SIVR-UAD,通过分析物联网... 详细信息

信息传播模型的研究是物联网领域的重要组成部分,它有助于提高物联网系统的性能和效率,促进物联网技术的进一步发展,针对物联网通信中影响信息传播的因素复杂且不稳定的问题,该文提出一种双层耦合信息传播模型SIVR-UAD,通过分析物联网中不同状态的设备和用户对信息传播的影响,建立了6种耦合状态,并利用马尔科夫方法分析耦合节点的状态变化过程,找到信息传播平衡点,最后通过理论分析证明了模型的平衡点的唯一性以及稳定性。仿真结果表明,在3组不同的初始耦合节点数下,SIVR-UAD模型中的6种耦合节点数量变化始终趋向同一稳定水平,证明了该模型的平衡点和稳定性。

关键词：物联网通信 SIVR-UAD 双层耦合信息传播模型稳定性证明

基于能量阈值的双参数阈值函数在生理信号降噪中的应用

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兵工学报 2024年第4期45卷 1264-1272页

作者：赵薇卓智海张月霞北京信息科技大学信息与通信工程学院北京100101

针对弱生理信号在采集过程中易被噪声淹没,传统小波去噪算法存在去噪效果差和信号提取失真的问题,根据小波系数的能量分布特点,提出一种改进的小波阈值去噪算法。通过计算各层小波系数的能量来确定阈值,避免阈值计算的不平衡性,同时提... 详细信息

针对弱生理信号在采集过程中易被噪声淹没,传统小波去噪算法存在去噪效果差和信号提取失真的问题,根据小波系数的能量分布特点,提出一种改进的小波阈值去噪算法。通过计算各层小波系数的能量来确定阈值,避免阈值计算的不平衡性,同时提高自适应性和弱信号的保真度;采用一种改进的可调节的双参数阈值函数对小波系数进行处理,在小波系数压缩程度可控的同时可以自由调节阈值函数的变化趋势。实验结果表明:改进的小波阈值去噪算法相较于两种传统去噪算法(经验模态分解算法和滤波器算法)以及12种传统小波阈值和阈值函数组合算法,在信噪比、均方根百分比和均方根误差上都具有明显的优势,并且在实测生理信号中取得了最小的平均相对误差和最小的波动性。

关键词：小波变换能量梯度阈值改进阈值函数生理信号去噪