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Maximizing Submodular+Supermodular Functions Subject to a Fairness Constraint

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Tsinghua Science and Technology 2024年第1期29卷 46-55页

作者： Zhenning Zhang Kaiqiao meng Donglei Du yang Zhou Beijing institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing 100124China Faculty of Management University of New BrunswickFredericton E3B 5A3Canada School of Mathematics and Statistics Shandong Normal UniversityJinan 250014China

We investigate the problem of maximizing the sum of submodular and supermodular functions under a fairness *** sum function is non-submodular in *** an offline model,we introduce two approximation algorithms:A greedy algorithm and a threshold greedy *** a streaming model,we propose a one-pass streaming *** also analyze the approximation ratios of these algorithms,which all depend on the total curvature of the supermodular *** total curvature is computable in polynomial time and widely utilized in the literature.

关键词： submodular function supermodular function fairness constraint greedy algorithm threshold greedy algorithm streaming algorithm

Atomic-level coupled Ruo_(2)/BaRuo_(3) heterostructure for efficient alkaline hydrogen evolution reaction

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Journal of Energy Chemistry 2024年第1期88卷 356-362,I0009页

作者： Yueying Yan Tian meng Yuting Chen yang yang Dewen Wang Zhicai Xing Xiurong yang State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026AnhuiChina

The slow water dissociation is the rate-determining step that slows down the reaction rate in alkaline hydrogen evolution reaction(HER).optimizing the surface electronic structure of the catalyst to lower the energy barrier of water dissociation and regulating the binding strength of adsorption intermediates are crucial strategy for boosting the catalytic performance of *** this study,Ruo_(2)/BaRuo_(3)(RBRo)heterostructures with abundant oxygen vacancies and lattice distortion were in-situ constructed under a low temperature via the thermal decomposition of *** RBRo heterostructures obtained at 550℃ exhibited the highest HER activity in 1 M KoH,showing an ultra-low overpotential of 16 mV at 10 mA cm^(-2)and a Tafel slope of 33.37 m V dec^(-1).Additionally,the material demonstrated remarkable durability,with only 25 mV of degradation in overpotential after 200 h of stability testing at 10 mA cm^(-2).Density functional theory calculations revealed that the redistribution of charges at the heterojunction interface can optimize the binding energies of H*and oH*and effectively lower the energy barrier of water *** research offers novel perspectives on surpassing the water dissociation threshold of alkaline HER catalysts by means of a systematic design of heterogeneous interfaces.

关键词： Heterostructure Hydrogen evolution reaction interfacial electron transfer oxygen vacancies

Double Moving Extremes Ranked Set Sampling Design

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 75-90页

作者： meng Chen Wang-xue Chen Rui yang Department of Mathematics and Statistics Jishou UniversityJishou416000China

The traditional simple random sampling(SRS)design method is inefficient in many *** proposed some new designs to increase *** this paper,as a variation of moving extremes ranked set sampling(MERSS),double MERSS(DMERSS)is proposed and its properties for estimating the population mean are *** turns out that,when the underlying distribution is symmetric,DMERSS gives unbiased estimators of the population ***,it is found that DMERSS is more efficient than the SRS and MERSS methods for usual symmetric distributions(normal and uniform).For asymmetric distributions considered in this study,the DMERSS has a small bias and it is more efficient than SRS for usual asymmetric distribution(exponential)for small sample sizes.

关键词： double moving extremes ranked set sampling symmetric distribution efficiency

A digital twins enabled underwater intelligent internet vehicle path planning system via reinforcement learning and edge computing

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Digital Communications and Networks 2024年第2期10卷 282-291页

作者： Jiachen yang meng Xi Jiabao Wen yang Li Houbing Herbert Song School of Electrical and information Engineering Tianjin UniversityTianjin300072China Security and optimization for Networked g.obe Laboratory(SoNg Lab) Embry-Riddle Aeronautical UniversityDaytona BeachFL32114USA

The Autonomous Underwater glider(AUg)is a kind of prevailing underwater intelligent internet vehicle and occupies a dominant position in industrial applications,in which path planning is an essential *** to the complexity and variability of the ocean,accurate environment modeling and flexible path planning algorithms are pivotal *** traditional models mainly utilize mathematical functions,which are not complete and *** existing path planning algorithms depend on the environment and lack *** overcome these challenges,we propose a path planning system for underwater intelligent internet *** applies digital twins and sensor data to map the real ocean environment to a virtual digital space,which provides a comprehensive and reliable environment for path *** design a value-based reinforcement learning path planning algorithm and explore the optimal network structure *** path simulation is controlled by a closed-loop model integrated into the terminal vehicle through edge *** integration of state input enriches the learning.of neural networks and helps to improve generalization and *** task-related reward function promotes the rapid convergence of the *** experimental results prove that our reinforcement learning based path planning algorithm has great flexibility and can effectively adapt to a variety of different ocean conditions.

关键词： Digital twins Reinforcement learning Edge computing Underwater intelligent internet vehicle Path planning

Advances and challenges in artificial intelligence text generation

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Frontiers of information Technology & Electronic Engineering 2024年第1期25卷 64-83页

作者： Bing Li Peng yang Yuankang SUN Zhongjian HU meng Yi School of Computer Science and Engineering Southeast UniversityNanjing 210000China Key Laboratory of Computer Network and information integration Ministry of EducationSoutheast UniversityNanjing 210000China

Text generation is an essential research area in artificial intelligence(Ai)technology and natural language processing and provides key technical support for the rapid development of Ai-generated content(AigC).it is based on technologies such as natural language processing,machine learning,and deep learning,which enable learning language rules through training models to automatically generate text that meets grammatical and semantic *** this paper,we sort and systematically summarize the main research progress in text generation and review recent text generation papers,focusing.on presenting a detailed understanding.of the technical *** addition,several typical text generation application systems are ***,we address some challenges and future directions in Ai text *** conclude that improving the quality,quantity,interactivity,and adaptability of generated text can help fundamentally advance Ai text generation development.

关键词： Ai text generation Natural language processing Machine learning Deep learning

Natural marmatite photocatalyst for treatment of mineral processing wastewater to help zero wastewater discharge

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Journal of Environmental Sciences 2024年第8期142卷 83-91页

作者： Meirong Wu Wei Sun Xiang.ong meng Jianhua Kang Yue yang School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China

Mineral processing wastewater(MPW)with large discharge and high toxicity affects environmental safety,and the realizing zero discharge of MPW is of great significance for reducing environmental pollution,saving water resources,and promoting the sustainable development of the mining *** this study,we reported natural marmatite(NM)as a low-cost and efficient photocatalyst for the treatment of MPW to help zero wastewater *** photocatalytic activity of NM was evaluated by the removal of total organic carbon(ToC)from MPW under visible-light illumination,and the optimal degradation conditions were *** showed that superoxide free radicals(^(·)o_(2)^(-))were the dominant active species responsible for organic pollutants degradation,and 74.25%ToC removal was obtained after 120 min reaction under the optimum treatment ***,the wastewater treated by NM photocatalysis can be reused in the flotation system without adverse impact on the product *** on these findings,a model of zero wastewater discharge for flotation with the help of photocatalytic treatment was established,it indicated that the water of the whole system can be balanced without affecting the ore dressing index,which showed that visible light-driven photocatalyst has a promising application prospect in the treatment and recycling.of industrial wastewater.

关键词： Natural mineral Photocatalysis industrial wastewater Wastewater recycling Water balance

Key processes of carbon cycle and sink enhancement paths in natural wetland ecosystems in China

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Science China Earth Sciences 2024年第8期67卷 2444-2459页

作者： Jinshuai Li Tianxiang HAo meng yang guirui YU Key Laboratory of Ecosystem Network observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Wetland ecosystems have become one of the long-term solutions for mitigating g.obal climate change due to their strong carbon sequestration ***,the key carbon cycle processes in wetland ecosystems still lack a systematic *** the context of wetland protection and restoration,there is still a lack of consensus on the technical pathways to realize carbon sink multiplication in wetland *** this paper,the key processes of carbon cycle,such as photosynthetic carbon uptake,microbial carbon decomposition and carbon deposition and burial,are sorted out and summarized in four major wetland types,namely,swamp and peat wetlands,river and riparian wetlands,lake and lakeshore wetlands,and estuarine and coastal *** on the key processes of carbon cycle,three technological pathways for carbon sink multiplication are proposed,including,vegetation carbon sequestration and sink enhancement technology,soil carbon emission reduction technology and carbon deposition and burial *** key technologies under each pathway are further *** the carbon sink effects of the carbon sink technologies in different wetland types are qualitatively ***,wetland protection and restoration methods in corresponding reg.ons are given in the light of the reg.onal characteristics of wetlands in *** will provide a scientific basis for the strategy of doubling the carbon sinks of China′s wetland ecosystems.

关键词： Wetlands Carbon cycle Carbon sinks Technology pathways Conservation and restoration

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Seamless indoor-outdoor Switching Localization Algorithm based on CKF

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Journal of Communications and information Networks 2024年第1期9卷 88-98页

作者： gang yang g.odong Hou Ningning Feng Weida meng School of Communication and information Engineering Xi’an University of Posts and TelecommunicationsXi’an 710121China

To solve the problem of large positioning error and discontinuous positioning.of special forces members when moving in cross-reg.on indoors and outdoors, and to compensate for the linearization error and local convergence problem that may exist in the extended Kalman filter(EKF)in nonlinear systems, that is,the iterative results may be trapped in a local optimum situation, a seamless indoor-outdoor switching localization algorithm based on cubature Kalman filter (CKF) is proposed. CKF does not require the computation of Jacobian matrices, which can improve computational efficiency and filtering accuracy to a certain extent. in the system, an inertial measurement unit (iMU) is employed to correct the positioning errors of ultra-wideband (UWB)and BeiDou navigation satellite system(BDS).The positioning data from UWB and BeiDou in cross-reg.on are weighted fused and then fused with the data from the iMU using CKF to obtain the final accurate positioning information. This study designs a scene-switching mechanism to achieve seamless switching between indoor and outdoor positioning scenes. By jointly analyzing the positioning accuracy of UWB and BeiDou,the positioning scene is determined, and appropriate counting thresholds are set to avoid frequent erroneous scene switches. Experimental results show that the proposed algorithm achieves a positioning accuracy of approximately 21.7 cm in cross-reg.on,which can enable seamless integration of indoor and outdoor positioning,avoid positioning jumps, and enhance positioning accuracy.

关键词： cubature Kalman filtering ultra-wideband inertial measurement unit fusion positioning seamless switching

A Fast insertion Tabu Search with Conflict-Avoidance Heuristic for the Multisatellite Multimode Crosslink Scheduling Problem

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Tsinghua Science and Technology 2024年第3期29卷 843-862页

作者： Weiyi yang Lei He Xiaolu Liu Weican meng Yingwu Chen College of Systems Engineering National University of Defense TechnologyChangsha 410000China Beijing institude of Tranking and Telecommunication Technology Beijing 100000China

An agile earth-observing satellite equipped with multimode cameras capable of transmitting.observation data to other satellites is developed to rapidly respond to requests with multiple observation *** gives rise to the Multisatellite Multimode Crosslink Scheduling(MMCS)problem,which involves allocating.observation requests to agile satellites,selecting appropriate timing and observation modes for the requests,and transmitting the data to the g.ound station via the satellite communication ***,a mixed integer programming model is introduced to include all complex time and operation *** solve the MMCS problem,a two-stage heuristic method,called Fast insertion Tabu Search with Conflict-avoidance(FTS-C)heuristic,is *** the first stage,a conflict-avoidance insertion algorithm is designed to generate a high-quality initial solution by considering the requests transmission and ***,the tabu search-based second stage optimizes the initial ***,an extensive empirical study based on a real-world situation demonstrates that FTS-C can generate a solution with higher quality in less time than other state-of-the-art algorithms and the CPLEX solver.

关键词： earth observation satellites scheduling tabu search heuristic data transmission and download mixedinteger programming model