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Atmospheric Ducting Effect in Wireless Communications:Challenges and Opportunities

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Journal of Communications and Information Networks 2021年第2期6卷 101-109页

作者： Fangfang Liu Jiaxi Pan xiangwei zhou Geoffrey Ye Li Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and ConvergenceBeijing University of Posts and TelecommunicationsBeijing 100876China Louisiana State University Baton Rouge LA 70803USA Imperial College London London SW72AZU.K.

Atmospheric ducting has a significant impact on electromagnetic wave *** signals that are trapped and guided by the atmospheric duct can travel a much longer distance over the horizon with lower attenuation since the signal power does not spread isotropically through the *** ducting brings both challenges and opportunities to wireless *** one hand,the signals propagating in the atmospheric duct may interfere with a receiver far away as remote co-channel *** the other hand,a point-to-point link can be established directly through the atmospheric duct to enable beyond line-of-sight *** this article,the formation of the atmospheric duct and its effects on radio wave propagation are first *** solutions and standardization activities in the 3rd Generation Partnership Project(3GPP)to mitigate atmospheric duct induced remote interference are ***,the applications and design challenges of atmospheric duct enabled beyond line-of-sight communications are reviewed and future research directions are suggested.

关键词： atmospheric duct ducting channel modeling beyond line-of-sight remote interference management

The opportunistic relaying scheme design and symbol error rate analysis for PLC networks in smart homes

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Science China(Information Sciences) 2021年第8期64卷 250-252页

作者： Linlin SUN Jiahui YAN Yuwen QIAN Feng SHU xiangwei zhou The School of Electronic and Optical Engineering Nanjing University of Science and Technology The Division of Electrical and Computer Engineering Louisiana State University

Dear editor,Power line communication(PLC) is treated as a retrofit technology, transmitting messages via conductors without extra infrastructure, which reduces the cost of implementation and maintenance [1]. Therefore, PLC is extensively adopted in smart grid applications. However, PLC encounters a hostile communication environment caused by the fast signal attenuation and severe impulsive noise [2].

关键词： SER The opportunistic relaying scheme design and symbol error rate analysis for PLC networks in smart homes

Intelligent Wireless Communications Enabled by Cognitive Radio and Machine Learning

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China Communications 2018年第12期15卷 16-48页

作者： xiangwei zhou Mingxuan Sun Geoffrey Ye Li Biing-Hwang (Fred) Juang School of EECS Louisiana State University School of ECE Georgia Institute of Technology

The ability to intelligently utilize resources to meet the need of growing diversity in services and user behavior marks the future of wireless communication systems. Intelligent wireless communications aims at enabling the system to perceive and assess the available resources, to autonomously learn to adapt to the perceived wireless environment, and to reconfigure its operating mode to maximize the utility of the available resources. The perception capability and reconfigurability are the essential features of cognitive radio while modern machine learning techniques project great potential in system adaptation. In this paper, we discuss the development of the cognitive radio technology and machine learning techniques and emphasize their roles in improving spectrum and energy utility of wireless communication systems. We describe the state-of-the-art of relevant techniques, covering spectrum sensing and access approaches and powerful machine learning algorithms that enable spectrum and energy-efficient communications in dynamic wireless environments. We also present practical applications of these techniques and identify further research challenges in cognitive radio and machine learning as applied to the existing and future wireless communication systems.

关键词： cognitive radio energy efficiency machine learning reconfiguration spectrum efficiency

Toward Human-centered XAIin Practice:A survey

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Machine Intelligence Research 2024年第4期21卷 740-770页

作者： xiangwei Kong Shujie Liu Luhao Zhu Department of Data Science and Management Engineering School of ManagementZhejiang UniversityHangzhou 310058China

Human adoption of artificial intelligence(AI)technique is largely hampered because of the increasing complexity and opacity of AI *** AI(XAI)techniques with various methods and tools have been developed to bridge this gap between high-performance black-box AI models and human ***,the current adoption of XAI technique stil lacks"human-centered"guidance for designing proper solutions to meet different stakeholders'needs in XAI *** first summarize a human-centered demand framework to categorize different stakeholders into five key roles with specific demands by reviewing existing research and then extract six commonly used human-centered XAI evaluation measures which are helpful for validating the effect of *** addition,a taxonomy of XAI methods is developed for visual computing with analysis of method *** clearer human demands and XAI methods in mind,we take a medical image diagnosis scenario as an example to present an overview of how extant XAI approaches for visual computing fulfil stakeholders'human-centered demands in *** we check the availability of open-source XAI tools for stakeholders'*** survey provides further guidance for matching diverse human demands with appropriate XAI methods or tools in specific applications with a summary of main challenges and future work toward human-centered XAI in practice.

关键词： Artificial intelligence(AI)application explainable AI(XAI) human-centered design visual computing medical diagnosis.

Multi-Perspective Data Fusion Framework Based on Hierarchical BERT: Provide Visual Predictions of Business Processes

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Computers, Materials & Continua 2024年第1期78卷 1227-1252页

作者： Yongwang Yuan xiangwei Liu Ke Lu School of Mathematics and Big Data Anhui University of Science and TechnologyHuainan232001China School of Economics and Management Anhui University of Science and TechnologyHuainan232001China The Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji UniversityShanghai201804China

Predictive Business Process Monitoring(PBPM)is a significant research area in Business Process Management(BPM)aimed at accurately forecasting future behavioral *** present,deep learning methods are widely cited in PBPM research,but no method has been effective in fusing data information into the control flow for multi-perspective process ***,this paper proposes a process prediction method based on the hierarchical BERT and multi-perspective data ***,the first layer BERT network learns the correlations between different category attribute ***,the attribute data is integrated into a weighted event-level feature vector and input into the second layer BERT network to learn the impact and priority relationship of each event on future predicted ***,the multi-head attention mechanism within the framework is visualized for analysis,helping to understand the decision-making logic of the framework and providing visual ***,experimental results show that the predictive accuracy of the framework surpasses the current state-of-the-art research methods and significantly enhances the predictive performance of BPM.

关键词： Business process prediction monitoring deep learning attention mechanism BERT multi-perspective

Molten salt construction of core-shell structured S-scheme CuInS_(2)@CoS_(2)heterojunction to boost charge transfer for efficient photocatalytic CO_(2)reduction

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Chinese Journal of Catalysis 2024年第8期63卷 190-201页

作者： Fulin Wang xiangwei Li Kangqiang Lu Man zhou Changlin Yu Kai Yang School of Chemistry and Chemical Engineering Jiangxi University of Science and TechnologyGanzhou 341000JiangxiChina School of Pharmacy Gannan Medical UniversityGanzhou 341000JiangxiChina School of Chemical Engineering Key Laboratory of Petrochemical Pollution Process and ControlGuangdong ProvinceGuangdong University of Petrochemical TechnologyMaoming 525000GuangdongChina

Weak redox ability and severe charge recombination pose significant obstacles to the advancement of CO_(2)*** tackle this challenge and enhance the CO_(2)photoconversion efficiency,fabricating well-matched S-scheme heterostructure and establishing a robust built-in electric field emerge as pivotal *** pursuit of this goal,a core-shell structured CuInS_(2)@CoS_(2)S-scheme heterojunction was meticulously engineered through a two-step molten salt *** approach over the CuInS_(2)-based composites produced an internal electric field owing to the disparity be-tween the Fermi levels of CoS_(2)and CuInS_(2)at their ***,the electric field facili-tated the directed migration of charges and the proficient separation of photoinduced *** resulting CuInS_(2)@CoS_(2)heterostructure exhibited remarkable CO_(2)photoreduction performance,which was 21.7 and 26.5 times that of pure CuInS_(2)and CoS_(2),*** S-scheme heterojunc-tion photogenerated charge transfer mechanism was validated through a series of rigorous anal-yses,including in situ irradiation X-ray photoelectron spectroscopy,work function calculations,and differential charge density ***,in situ infrared spectroscopy and density functional theory calculations corroborated the fact that the CuInS_(2)@CoS_(2)heterojunction substan-tially lowered the formation energy of*COOH and**** study demonstrates the application potential of S-scheme heterojunctions fabricated via the molten salt method in the realm of ad-dressing carbon-related environmental issues.

关键词： S-scheme heterojunction Molten salt CuInS_(2)CoS_(2) CO_(2)photoreduction

The Static Stability Region of an Integrated Electricity-Gas System Considering Voltage and Gas Pressure

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Engineering 2024年第5期36卷 132-145页

作者： Yunfei Mu Zhibin Liu xiangwei Guo Hongjie Jia Kai Hou Xiaodan Yu Bofeng Luo Hairun Li Key Laboratory of Smart Grid of Ministry of Education Tianjin UniversityTianjin 300072China State Grid Tianjin Electric Power Company Tianjin 300201China China Southern Power Grid Digital Grid Research Institute Co. Ltd.Guangzhou 510700China

In an integrated electricity-gas system(IEGS),load fluctuations affect not only the voltage in the power system but also the gas pressure in the natural gas *** static voltage stability region(SVSR)method is a tool for analyzing the overall static voltage stability in a power ***,in an IEGS,the SVSR boundary may be overly optimistic because the gas pressure may collapse before the voltage ***,the SVSR method cannot be directly applied to an *** this paper,the concept of the SVSR is extended to the IEGS-static stability region(SSR)while considering voltage and gas ***,criteria for static gas pressure stability in a natural gas system are proposed,based on the static voltage stability criteria in a power ***,the IEGS-SSR is defined as a set of active power injections that satisfies multi-energy flow(MEF)equations and static voltage and gas pressure stability constraints in the active power injection space of natural gas-fired generator units(NGUs).To determine the IEGSSSR,a continuation MEF(CMEF)method is employed to trace the boundary point in one specific NGU scheduling direction.A multidimensional hyperplane sampling method is also proposed to sample the NGU scheduling directions *** obtained boundary points are further used to form the IEGSSSR in three-dimensional(3D)space via a Delaunay triangulation hypersurface fitting ***,the numerical results of typical case studies are presented to demonstrate that the proposed method can effectively form the IEGS-SSR,providing a tool for IEGS online monitoring and dispatching.

关键词： Integrated electricity-gas system Static stability region Continuation multi-energy flow Multidimensional hyperplane sampling

Greenhouse gas emissions from Daihai Lake,China:Should eutrophication and salinity promote carbon emission dynamics?

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Journal of Environmental Sciences 2024年第1期135卷 407-423页

作者： xiangwei Li Ruihong Yu Jun Wang Heyang Sun Xinyu Liu Xiaohui Ren Shuai Zhuang Zhiwei Guo Xixi Lu Inner Mongolia Key Laboratory of River and Lake Ecology School of Ecology and EnvironmentInner Mongolia UniversityHohhot 010070China Key Laboratory of Mongolian Plateau Ecology and Resource Utilization Ministry of EducationHohhot 010070China Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River Hohhot 010018China Department of Geography National University of Singapore117570Singapore

Greenhouse gases(GHGs)emitted or absorbed by lakes are an important component of the global carbon ***,few studies have focused on the GHG dynamics of eutrophic saline lakes,thus preventing a comprehensive understanding of the carbon ***,we conducted four sampling analyses using a floating chamber in Daihai Lake,a eutrophication saline lake in Inner Mongolia Autonomous Region,China,to explore its carbon dioxide(CO_(2))and methane(CH_(4))*** mean CO_(2)emission flux(FCO_(2))and CH_(4)emission flux(FCH_(4))were 17.54±14.54 mmol/m^(2)/day and 0.50±0.50 mmol/m^(2)/day,*** results indicated that Daihai Lake was a source of CO_(2)and CH_(4),and GHG emissions exhibited temporal *** mean CO_(2)partial pressure(p CO_(2))and CH_(4)partial pressure(p CH_(4))were 561.35±109.59μatm and 17.02±13.45μatm,which were supersaturated relative to the *** regression and correlation analysis showed that the main influencing factors of p CO_(2)were wind speed,dissolved oxygen(DO),total nitrogen(TN)and Chlorophyll a(Chl.a),whereas the main influencing factors of p CH_(4)were water temperature(WT),Chl.a,nitrate nitrogen(NO_(3)^(-)-N),TN,dissolved organic carbon(DOC)and water *** regulated carbon mineralization and organic matter decomposition,and it was an important influencing factor of p CO_(2)and p CH_(4).Additionally,the trophic level index(TLI)significantly increased p CH_(4).Our study elucidated that salinity and eutrophication play an important role in the dynamic changes of GHG ***,research on eutrophic saline lakes needs to be strengthened.

关键词： Eutrophication Salinity Greenhouse gas emissions Inland lake Inner Mongolia Autonomous Region

感知与突围:教育场域中农村家庭的阶层代际流动——基于CGSS数据的实证分析

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教育发展研究 2020年第6期40卷 1-8页

作者：周向伟张天雪浙江师范大学教育改革与发展研究院金华321004

人民的幸福感、获得感、安全感是新时代的民生重点,仅关注以经济资本为代表的客观阶层,忽视个体主观的阶层感知,将无助于从根本上促进社会阶层的有序流动。本文基于有正规学校教育经历的农村家庭子代,着眼教育与家庭背景因素,通过对其... 详细信息

人民的幸福感、获得感、安全感是新时代的民生重点,仅关注以经济资本为代表的客观阶层,忽视个体主观的阶层感知,将无助于从根本上促进社会阶层的有序流动。本文基于有正规学校教育经历的农村家庭子代,着眼教育与家庭背景因素,通过对其与阶层流动感知关系的研究发现:子代的主观阶层水平依然较低,仅有小幅度的代际正向流动,突围藩篱依然存在。教育、家庭背景对农村子代的主观阶层流动具有直接与间接双重解释效应。不同于客观阶层流动,在对子代阶层流动感知的影响中,子代及其母亲的教育程度具有显著的负向效应,家庭经济水平有显著的正向效应,父母的职级和父亲的教育经历不具有显著效应。子代及其母亲的教育经历、家庭经济水平、客观阶层水平均通过子代的阶层期望对其阶层流动感知产生显著影响。基于此,在提升人力资本的同时,应注重在政府及家校合作的基础上,对农村子代阶层认知进行积极引导,助其更有效地实现主观阶层突围。

关键词：教育社会阶层代际流动农村家庭