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A GMM approach in coupling internal data and external summary information with heterogeneous data populations

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Science China Mathematics 2024年第5期67卷 1115-1132页

作者： Jun Shao Jinyi Wang lei Wang Key Laboratory of Advanced Theory and Application in Statistics and Data Science(East China Normal University) Ministry of EducationShanghai 200062China School of Statistics East China Normal UniversityShanghai 200062China Department of Statistics University of Wisconsin-MadisonWI 53706USA School of Statistics and Data Science KLMDASRLEBPS and LPMCNankai UniversityTianjin 300071China

Because of advances in data collection and storage,statistical analysis in modern scientific research and practice now has opportunities to utilize external information such as summary statistics from similar studies.A likelihood approach based on a parametric model assumption has been developed in the literature to utilize external summary information when the populations for external and main internal data are assumed to be the *** this article,we instead consider the generalized estimation equation(GEE)approach for statistical inference,which is semiparametric or nonparametric,and show how to utilize external summary information even when internal and external data populations are not the *** approach is coupling the internal data and external summary information to form additional estimation equations and then applying the generalized method of moments(GMM).We show that the proposed GMM estimator is asymptotically normal and,under some conditions,is more efficient than the GEE estimator without using external summary *** of the asymptotic covariance matrix of the GMM estimators are also *** results are obtained to confirm our theory and quantify the improvements by utilizing external *** example is also included for illustration.

关键词： adjustment for heterogeneity constraint data integration generalized method of moments summarystatistic

Collaborative Charging Scheduling in Wireless Charging Sensor Networks

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Computers, Materials & Continua 2024年第4期79卷 1613-1630页

作者： Qiuyang Wang Zhen Xu lei Yang School of Electrical and Electronic Engineering Wuhan Polytechnic UniversityWuhan430048China

Wireless sensor networks (WSNs) have the trouble of limited battery power, and wireless charging provides apromising solution to this problem, which is not easily affected by the external environment. In this paper, we studythe recharging of sensors in wireless rechargeable sensor networks (WRSNs) by scheduling two mobile chargers(MCs) to collaboratively charge sensors. We first formulate a novel sensor charging scheduling problem with theobjective of maximizing the number of surviving sensors, and further propose a collaborative charging schedulingalgorithm(CCSA) for WRSNs. In the scheme, the sensors are divided into important sensors and ordinary *** can adaptively collaboratively charge the sensors based on the energy limit ofMCs and the energy demandof sensors. Finally, we conducted comparative simulations. The simulation results show that the proposed algorithmcan effectively reduce the death rate of the sensor. The proposed algorithm provides a solution to the uncertaintyof node charging tasks and the collaborative challenges posed by multiple MCs in practical scenarios.

关键词： Wireless rechargeable sensor network mobile charger collaborative charging adaptive charging

Improved Double Deep Q Network-Based Task Scheduling Algorithm in Edge Computing for Makespan Optimization

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Tsinghua Science and Technology 2024年第3期29卷 806-817页

作者： lei Zeng Qi Liu Shigen Shen Xiaodong Liu School of Computer Science Nanjing University of Information Science and TechnologyNanjing 210044China School of Software Nanjing University of Information Science and TechnologyNanjing 210044China School of Information Engineering Huzhou UniversityHuzhou 313000China School of Computing Edinburgh Napier UniversityEdinburghEH105DTUK

Edge computing nodes undertake an increasing number of tasks with the rise of business ***,how to efficiently allocate large-scale and dynamic workloads to edge computing resources has become a critical *** study proposes an edge task scheduling approach based on an improved Double Deep Q Network(DQN),which is adopted to separate the calculations of target Q values and the selection of the action in two networks.A new reward function is designed,and a control unit is added to the experience replay unit of the *** management of experience data are also modified to fully utilize its value and improve learning *** learning agents usually learn from an ignorant state,which is *** such,this study proposes a novel particle swarm optimization algorithm with an improved fitness function,which can generate optimal solutions for task *** optimized solutions are provided for the agent to pre-train network parameters to obtain a better cognition *** proposed algorithm is compared with six other methods in simulation *** show that the proposed algorithm outperforms other benchmark methods regarding makespan.

关键词： edge computing task scheduling reinforcement learning makespan Double Deep Q Network(DQN)

Quality assessment of friction-stir-welded aluminum alloy welds via three-dimensional force signals

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Advances in Manufacturing 2024年第1期12卷 61-75页

作者： Ji-Hong Dong Yi-Ming Huang Jia-lei Zhu Wei Guan Xu-Kai Ren Huan-Wei Yu lei Cui Beijing Institute of Petrochemical Technology Beijing102617People’s Republic of China Beijing Academy of Safety Engineering and Technology Beijing102617People’s Republic of China AVIC Manufacturing Technology Institute Beijing100024People’s Republic of China Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin300350People’s Republic of China Shaoxing Special Equipment Testing Institute Shaoxing Key Laboratory of Special Equipment Intelligent Testing and EvaluationShaoxing312071ZhejiangPeople’s Republic of China

An online detection technology must be developed for realizing the real-time control of friction stir *** this study,the three-dimensional force exerted on a material during friction stir welding was collected synchronously and the relationship between the forces and welding quality was *** results indicated that the fluctuation period of the traverse force was equal to that of the lateral force during the stable welding *** phase difference between two horizontal forces wasπ/*** values of the horizontal forces increased with welding speed,whereas their amplitudes remained the *** proposed force model showed that the traverse and lateral forces conformed to an elliptical curve,and this result was consistent with the behavior of the measured *** variational mode decomposition was used to process the plunge *** intrinsic mode function that represented the real fluctuation in the plunge force varied at the same frequency as the spindle rotational *** tunnel defects occurred,the fluctuation period features were consistent with those obtained during normal welding,whereas the ratio parameter defined in this study increased significantly.

关键词： Friction stir welding(FSW) Three-dimensional force model Variational mode decomposition Tunnel defect

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一种位姿解耦的主操作手结构设计与优化方法

哈尔滨工业大学学报 2021年第7期53卷 27-35页

作者：王得晨杜付鑫屈梁成类延强王继来李取浩山东大学机械工程学院济南250061 高效洁净机械制造教育部重点实验室(山东大学) 济南250061 山东大学控制科学与工程学院济南250061 智能无人系统教育部工程研究中心(山东大学) 济南250061

为提高医生对微创手术机器人主操作手进行操作时的一致性和灵活性,设计一种8关节串联型力反馈主操作手。从位姿解耦角度出发,通过一种双平行四边形结构实现位姿解耦,提高了主操作手在不同位姿下操作的一致性。利用改进后的D-H参数法和... 详细信息

为提高医生对微创手术机器人主操作手进行操作时的一致性和灵活性,设计一种8关节串联型力反馈主操作手。从位姿解耦角度出发,通过一种双平行四边形结构实现位姿解耦,提高了主操作手在不同位姿下操作的一致性。利用改进后的D-H参数法和逆变换法,分别建立主操作手的正运动学和逆运动学模型,并从运动学角度验证了该位姿解耦策略的正确性。基于蒙特卡洛法,使用MATLAB编程,分析主操作手的最小工作空间。求解主操作手的雅可比矩阵,基于全域性能指标和全域性能波动指标定义了主操作手的综合运动性能指标,并以最小工作空间作为约束,用遗传算法对主操作手的运动性能和结构尺寸进行了分析与优化。结果表明:相比于优化前的初始设计,优化后主操作手的综合运动性能指标提高了15.32%,尤其是具备良好运动性能的工作空间体积增加到原来的3倍,已基本包含手术要求工作区域。主操作手在保证操作一致性和足够工作空间的基础上,具备了良好且稳定的运动性能。

关键词：主操作手结构设计位姿解耦运动学结构优化

From molecule to cell:the expanding frontiers of plant immunity

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Journal of Genetics and Genomics 2024年第7期51卷 680-690页

作者： lei Li Jing Liu Jian-Min Zhou Key Laboratory of Seed Innovation Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Hainan Yazhou Bay Seed Laboratory SanyaHainan 572025China

In recent years,the field of plant immunity has witnessed remarkable *** the co-evolution between plants and pathogens,plants have developed a wealth of intricate defense mechanisms to safeguard their *** identified immune receptors have added unexpected complexity to the surface and intracellular sensor networks,enriching our understanding of the ongoing plant–pathogen *** the molecular mechanisms of resistosome shapes our understanding of these mysterious molecules in plant ***,technological innovations are expanding the horizon of the plant–pathogen battlefield into spatial and temporal *** the development provides new opportunities for untangling the complex realm of plant immunity,challenges remain in uncovering plant immunity across spatiotemporal dimensions from both molecular and cellular levels.

关键词： Plant immunity Calcium Spatiotemporal Biomolecular condensate Immune receptor Resistosome

Tannic acid and silicate-functionalized polyvinyl alcohol-hyaluronic acid hydrogel for infected diabetic wound healing

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Regenerative Biomaterials 2024年第4期3卷 125-137页

作者： Zhentian Diao Longkang Li Huan Zhou lei Yang School of Materials Science and Engineering Hebei University of TechnologyTianjin 300131China Center for Health Science and Engineering Hebei Key Laboratory of Biomaterials and Smart TheranosticsSchool of Health Sciences and Biomedical EngineeringHebei University of TechnologyTianjin 300131China

Healing of chronic diabetic wounds is challenging due to complications of severe inflammatory microenvironment,bacterial infection and poor vascular ***,a novel injectable polyvinyl alcohol-hyaluronic acid-based composite hydrogel was developed,with tannic acid(TA)and silicate functionalization to fabricate an‘all-in-one’hydrogel *** one hand,after being locally injected into the wound site,the hydrogel underwent a gradual sol-gel transition in situ,forming an adhesive and protective dressing for the *** of rheological characteristics,mechanical properties and swelling ability of PTKH could be performed via regulating TA and silicate content in *** the other hand,PTKH was capable of eliminating reactive oxygen species overexpression,combating infection and generating a cell-favored microenvironment for wound healing acceleration in *** animal studies demonstrated that PTKH could greatly stimulate angiogenesis and epithelization,accompanied with inflammation and infection risk ***,in consideration of its impressive in vitro and in vivo outcomes,this‘all-in-one’multifunctional hydrogel may hold promise for chronic diabetic wound treatment.

关键词： diabetic wound healing ROS overexpression combating infection stimulate angiogenesis

Research progress in performance improvement strategies and sulfur conversion mechanisms of Li-S batteries based on Fe series nanomaterials

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Nano Research 2024年第9期17卷 8045-8067页

作者： Ziyang Huang Zhenghua Wang lei Zhou Jun Pu Key Laboratory of Functional Molecular Solids(Ministry of Education) College of Chemistry and Materials ScienceAnhui Provincial Engineering Laboratory for New-Energy Vehicle Battery Energy-Storage MaterialsAnhui Normal UniversityWuhu 241000China School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013China Department of Electrical Engineering Eindhoven University of TechnologyEindhoven MB 5600The Netherlands

Lithium-sulfur(Li-S)batteries hold the potential to revolutionize energy storage due to the high theoretical capacity and energy ***,the commercialization process is seriously hindered by the rapid capacity decay and low utilization of sulfur,caused by the inevitable slow dynamics and the“shuttle effect”.The incorporation of metal-based electrocatalysts into sulfur cathodes shows promise in promoting the conversion of lithium polysulfides(LiPSs),reducing the“shuttle effect”,and enhancing cell kinetics and cycle *** these,Fe-based materials,characterized by environmental friendliness,low cost,abundant reserves,and high activity,are extensively used in sulfur cathode *** article reviews the advancements of Fe-based materials in enhancing Li-S batteries in recent *** from single/multi-component Fe-based metal compounds and single/bimetallic atoms,the influence of different Fe coordination environments on the conversion mechanism of LiPSs is *** is hoped that this review and the proposed prospects can further stimulate the development and application of the Fe element in Li-S batteries in the future.

关键词： Li-S batteries Fe-based nanomaterials shuttle effect reaction kinetics

Transient features of graphitization and nitrogen-vacancy color centers in a diamond fabricated by localization femtosecond laser direct writing

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Science China(Technological Sciences) 2024年第8期67卷 2530-2536页

作者： CUI Lin YIN SiYu HU ZiFan WANG lei State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China

Femtosecond laser direct writing provides an efficient approach to fabricating single nitrogen vacancy(NV) color centers with a relatively high yield. Different from previously reported NV color centers with a random distribution in a bulk diamond or nanocrystals, this gives an opportunity to study the photophysical properties of single NV color centers with precise numbers and positions. However, ultrafast studies on single NV color centers prepared by localization femtosecond laser direct writing are still rare, especially for the graphitization inside a diamond and its relationship with single NV color centers. Here, we report the broadband transient absorption(TA) spectroscopic features of the graphitization and NV color centers in a diamond fabricated by localization femtosecond laser direct writing at room temperature under 400 nm excitation. In comparison with the graphene oxide film, the bleaching features of the graphitization point array in a diamond are similar to reduced graphene oxide,accompanied by excited state absorption signals from local carbon atom vacancy defects in graphene-like structures induced by laser writing. On the other hand, transient features of laser processing array containing single NV color centers with a yield of~50% are different from those of the graphitization point array. Our findings suggest that for ultrashort pulse processing of diamonds, broadband TA spectral signals are sensitive to the surrounding atomic environment of processing sites, which could be applied to laser writing point defects in other materials used as solid-state single photon sources.

关键词： nitrogen-vacancy color center graphitization diamond femtosecond laser direct writing ultrafast spectroscopy