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An air combat maneuver pattern extraction based on time series segmentation and clustering analysis

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Defence Technology（防务技术） 2024年第6期36卷 149-162页

作者： Zhifei xi Yingxin Kou Zhanwu li Yue Lv You li Air Force Engineering University No.1 Baling RoadBaqiao DistrictXi'anShaanxi ProvinceChina

Target maneuver recognition is a prerequisite for air combat situation awareness,trajectory prediction,threat assessment and maneuver *** get rid of the dependence of the current target maneuver recognition method on empirical criteria and sample data,and automatically and adaptively complete the task of extracting the target maneuver pattern,in this paper,an air combat maneuver pattern extraction based on time series segmentation and clustering analysis is proposed by combining autoencoder,G-G clustering algorithm and the selective ensemble clustering analysis ***,the autoencoder is used to extract key features of maneuvering trajectory to remove the impacts of redundant variables and reduce the data dimension;Then,taking the time information into account,the segmentation of Maneuver characteristic time series is realized with the improved FSTS-AEGG algorithm,and a large number of maneuver primitives are extracted;Finally,the maneuver primitives are grouped into some categories by using the selective ensemble multiple time series clustering algorithm,which can prove that each class represents a maneuver *** maneuver pattern extraction method is applied to small scale air combat trajectory and can recognize and correctly partition at least 71.3%of maneuver actions,indicating that the method is effective and satisfies the requirements for engineering *** addition,this method can provide data support for various target maneuvering recognition methods proposed in the literature,greatly reduce the workload and improve the recognition accuracy.

关键词： Maneuver pattern extraction Data mining Fuzzy segmentation Selective ensemble clustering

A Cooperated Imperialist Competitive Algorithm for Unrelated Parallel Batch Machine Scheduling Problem

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Computers, Materials & Continua 2024年第5期79卷 1855-1874页

作者： Deming lei Heen li College of Automation Wuhan University of TechnologyWuhan430070China

This study focuses on the scheduling problem of unrelated parallel batch processing machines(BPM)with release times,a scenario derived from the moulding process in a *** this process,a batch is initially formed,placed in a sandbox,and then the sandbox is positioned on a BPM *** complexity of the scheduling problem increases due to the consideration of BPM capacity and sandbox *** minimize the makespan,a new cooperated imperialist competitive algorithm(CICA)is *** CICA,the number of empires is not a parameter,and four empires aremaintained throughout the search *** types of assimilations are achieved:The strongest and weakest empires cooperate in their assimilation,while the remaining two empires,having a close normalization total cost,combine in their assimilation.A new form of imperialist competition is proposed to prevent insufficient competition,and the unique features of the problem are effectively *** experiments are conducted across several instances,and a significant amount of experimental results show that the newstrategies of CICAare effective,indicating promising advantages for the considered BPMscheduling problems.

关键词： Release time assimilation imperialist competitive algorithm batch processing machines scheduling

Corrosion behavior of Gd_(2)Zr_(2)O_(7)thermal barrier coatings under Fe-containing environmental sediment attack

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Journal of Advanced Ceramics 2024年第4期13卷 447-462页

作者： lei Guo Yanyan li Kai Yan School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin 300072China Key Laboratory of Special Equipment Safety and Energy-saving for State Market Regulation China Special Equipment Inspection&Research InstituteBeijing 100029China

Environmental sediments mainly consisting of CaO–MgO–Al_(2)O_(3)–SiO_(2)(CMAS)corrosion are a serious threat to thermal barrier coatings(TBCs),in which Fe element is usually ***_(2)Zr_(2)O_(7)TBCs are famous for their excellent CMAS *** this study,the characteristics of Fe-containing environmental sediments(CMAS-Fe)and their corrosiveness to Gd_(2)Zr_(2)O_(7)coatings were *** types of CMAS-Fe glass with different Fe contents were *** melting points were measured to be 1322–1344℃,and the high-temperature viscosity showed a decreasing trend with increasing Fe *** corrosion behavior of four types of CMAS-Fe to Gd_(2)Zr_(2)O_(7)coatings at 1350℃was *** the initial corrosion stage(0.1 h),anorthite was precipitated in CMAS-Fe with a high Ca:Si ratio,while Fe-garnet was formed in the melt with the highest Fe *** the corrosion time resulted in the formation of a reaction layer,which exhibited an interpenetrating network composed of Gd-oxyapatite,ZrO_(2),and residual *** spinel was precipitated within the reaction *** 1 h or even longer time,the reaction layers tended to be stable and compact,which had comparable hardness and fracture toughness to those of Gd_(2)Zr_(2)O_(7)*** the cyclic CMAS-Fe attack,the residual CMAS-Fe in the interpenetrating network provided a pathway for the redeposited CMAS-Fe infiltration,resulting in the continuous growth of the reaction *** a result,the Gd_(2)Zr_(2)O_(7)coatings had a large consumption in the thickness,degrading the coating ***,the Gd_(2)Zr_(2)O_(7)coatings exhibit unsatisfactory corrosion resistance to CMAS-Fe attack.

关键词： thermal barrier coatings(TBCs) Gd_(2)Zr_(2)O_(7) Fe-containing CaO-MgO-Al2O3-SiO_(2)(CMAS) corrosion resistance reaction layer

A comprehensive comparison of different regression techniques and nature-inspired optimization algorithms to predict carbonation depth of recycled aggregate concrete

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 30-50页

作者： Bin xi Ning ZHANG Enming li Jiabin li Jian ZHOU Pablo SEGARRA Department of Civil and Environmental Engineering Politecnico Di MilanoMilano 20133Italy leibniz Institute of Ecological Urban and Regional Development(IOER) Dresden 01217Germany Universidad Politécnica de Madrid-ETSI Minas y Energía Madrid 28003Spain Department of Civil Engineering KU Leuven CampusBrugge 8200Belgium School of Resources and Safety Engineering Central South UniversityChangsha 410083China

The utilization of recycled aggregates(RA)for concrete production has the potential to offer substantial environmental and economic ***,RA concrete is plagued with considerable durability concerns,particularly *** advance the application of RA concrete,the establishment of a reliable model for predicting the carbonation is *** the one hand,concrete carbonation is a long and slow process and thus consumes a lot of time and energy to *** the other hand,carbonation is influenced by many factors and is hard to *** this,this paper proposes the use of machine learning techniques to establish accurate prediction models for the carbonation depth(CD)of RA *** types of regression techniques and meta-heuristic algorithms were employed to provide more alternative predictive *** was found that the best prediction performance was obtained from extreme gradient boosting-multi-universe optimizer(XGB-MVO)with R^(2) value of 0.9949 and 0.9398 for training and testing sets,***-MVO was used for evaluating physical laws of carbonation and it was found that the developed XGB-MVO model could provide reasonable predictions when new data were *** also showed better generalization capabilities when compared with different models in the ***,this paper emphasizes the need for sustainable solutions in the construction industry to reduce its environmental impact and contribute to sustainable and low-carbon economies.

关键词： recycled aggregate concrete carbonation depth nature-inspired optimization algorithms extreme gradient boosting technique parametric analysis

TIGAR mediates the inhibitory role of hypoxia on ROS production and apoptosis in rat nucleus pulposus cells

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TIGAR mediates the inhibitory role of hypoxia on ROS product...

Boosting Hydrogen Storage Performance of MgH_(2) by Oxygen Vacancy-Rich H-V_(2)O_(5) Nanosheet as an Excited H-Pump

第二十四届中国中西医结合骨伤科学术年会

作者： li-Bo Jiang Hui-Ren Wang xi-lei li Jian Dong Department of Orthopedic Surgery Zhongshan Hospital Fudan University

Objective Hypoxia has been shown to inhibit reactive oxygen species(ROS)production in nucleus pulposus(NP)*** TP53-induced glycolysis and apoptosis regulator(TIGAR)has been reported to suppress oxidative *** sought to explore the role of TIGAR in the effect of hypoxia on ROS production and *** An intervertebral disc degeneration(IDD)model of Sprague-Dawley(SD)rat caudal spine was established by stabbing their intervertebral *** expression was detected by immunohistochemistry in human and SD rat NP tissues of degenerated *** primary NP cells treated with hypoxia and cobalt chloride(CoCl)were analyzed by western blotting for TIGAR *** TIGAR inhibition with TIGAR siRNA transfection,apoptosis percentage,mitochondrial and total intracellular ROS levels were *** was used to further check the effects of TIGAR on oxidative ***,NADPH/NADPand GSH/GSSH ratio were examined after TIGAR silencing under hypoxic conditions and after HO *** degree-dependent increase in TIGAR expression was observed in human and rat degenerated NP *** and hypoxia-inducer CoClenhanced TIGAR and P53 expressions in rat NP *** inhibition reversed the inhibitory effects of hypoxia on intracellular and mitochondrial ROS production,as well as apoptosis ***,TIGAR inhibition aggravated HO-induced ROS *** addition,TIGAR increased NADPH/NADPand GSH/GSSH ratio in NP *** hese results suggested that TIGAR appears to mediate the protective role of hypoxia on ROS production and apoptosis percentage by enhancing NADPH/NADP+and GSH/GSSH ratio.

关键词： ntervertebral disc degeneration Nucleus pulposus Hypoxia Reactive oxygen species TP53-induced glycolysis and apoptosis regulator

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Nano-Micro Letters 2024年第8期16卷 398-416页

作者： li Ren Yinghui li Zi li xi lin Chong Lu Wenjiang Ding Jianxin Zou National Engineering Research Center of light Alloys Net Forming&State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Shanghai Engineering Research Center of Mg Materials and Applications&School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Center of Hydrogen Science Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Instrumental Analysis Center of SJTU Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

MgH_(2) is a promising high-capacity solid-state hydrogen storage material,while its application is greatly hindered by the high desorption temperature and sluggish ***,intertwined 2D oxygen vacancy-rich V_(2)O_(5) nanosheets(H-V_(2)O_(5))are specifically designed and used as catalysts to improve the hydrogen storage properties of MgH_(2).The as-prepared MgH_(2)-H-V_(2)O_(5) composites exhibit low desorption temperatures(Tonset=185℃)with a hydrogen capacity of 6.54 wt%,fast kinetics(Ea=84.55±1.37 kJ mol^(-1) H_(2) for desorption),and long cycling ***,hydrogen absorption can be achieved at a temperature as low as 30℃ with a capacity of 2.38 wt%within 60 ***,the composites maintain a capacity retention rate of~99%after 100 cycles at 275℃.Experimental studies and theoretical calculations demonstrate that the in-situ formed VH_(2)/V catalysts,unique 2D structure of H-V_(2)O_(5) nanosheets,and abundant oxygen vacancies positively contribute to the improved hydrogen sorption ***,the existence of oxygen vacancies plays a double role,which could not only directly accelerate the hydrogen ab/de-sorption rate of MgH_(2),but also indirectly affect the activity of the catalytic phase VH_(2)/V,thereby further boosting the hydrogen storage performance of MgH_(2).This work highlights an oxygen vacancy excited“hydrogen pump”effect of VH_(2)/V on the hydrogen sorption of Mg/MgH_(2).The strategy developed here may pave a new way toward the development of oxygen vacancy-rich transition metal oxides catalyzed hydride systems.

关键词： Hydrogen storage MgH_(2) V_(2)O_(5)nanosheets Oxygen vacancies VH_(2)

Prompt learning in computer vision: a survey

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Frontiers of Information Technology & Electronic Engineering 2024年第1期25卷 42-63页

作者： Yiming lei Jingqi li Zilong li Yuan CAO Hongming SHAN Shanghai Key Laboratory of Intelligent Information Processing School of Computer ScienceFudan UniversityShanghai 200438China Institute of Science and Technology for Brain-Inspired Intelligence Fudan UniversityShanghai 200433China MOE Frontiers Center for Brain Science Fudan UniversityShanghai 200433China Shanghai Center for Brain Science and Brain-Inspired Technology Shanghai 201210China

Prompt learning has attracted broad attention in computer vision since the large pre-trained visionlanguagemodels (VLMs) exploded. Based on the close relationship between vision and language information builtby VLM, prompt learning becomes a crucial technique in many important applications such as artificial intelligencegenerated content (AIGC). In this survey, we provide a progressive and comprehensive review of visual promptlearning as related to AIGC. We begin by introducing VLM, the foundation of visual prompt learning. Then, wereview the vision prompt learning methods and prompt-guided generative models, and discuss how to improve theefficiency of adapting AIGC models to specific downstream tasks. Finally, we provide some promising researchdirections concerning prompt learning.

关键词： Prompt learning Visual prompt tuning(VPT) Image generation Image classification Artificial intelligence generated content(AIGC)

Application of multi-algorithm ensemble methods in high-dimensional and small-sample data of geotechnical engineering:A case study of swelling pressure of expansive soils

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1896-1917页

作者： Chao li lei Wang Jie li Yang Chen School of Urban Railway Transportation Shanghai University of Engineering ScienceShanghai201620China Discipline of Civil and Infrastructure Engineering RMIT UniversityMelbourne3001Australia School of Naval Architecture and Civil Engineering Shanghai Jiao Tong UniversityShanghai200240China

Geotechnical engineering data are usually small-sample and high-dimensional,which brings a lot of challenges in predictive *** paper uses a typical high-dimensional and small-sample swell pressure(P_(s))dataset to explore the possibility of using multi-algorithm hybrid ensemble and dimensionality reduction methods to mitigate the uncertainty of soil parameter *** on six machine learning(ML)algorithms,the base learner pool is constructed,and four ensemble methods,Stacking(SG),Blending(BG),Voting regression(VR),and Feature weight linear stacking(FWL),are used for the multi-algorithm ***,the importance of permutation is used for feature dimensionality reduction to mitigate the impact of weakly correlated variables on predictive *** results show that the proposed methods are superior to traditional prediction models and base ML models,where FWL is more suitable for modeling with small-sample datasets,and dimensionality reduction can simplify the data structure and reduce the adverse impact of the small-sample effect,which points the way to feature selection for predictive *** on the ensemble methods,the feature importance of the five primary factors affecting P_(s) is the maximum dry density(31.145%),clay fraction(15.876%),swell percent(15.289%),plasticity index(14%),and optimum moisture content(13.69%),the influence of input parameters on P_(s) is also investigated,in line with the findings of the existing literature.

关键词： Expansive soils Swelling pressure Machine learning(ML) Multi-algorithm ensemble Sensitivity analysis

Fatigue-resistant Hydrogels

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Chemical Research in Chinese Universities 2024年第1期40卷 64-77页

作者： li Luofei lei Hai CAO Yi Collaborative Innovation Center of Advanced Microstructures National Laboratory of Solid State MicrostructureDepartment of PhysicsNanjing UniversityNanjing 210093P.R.China Department of Physics Zhejiang UniversityHangzhou 310027P.R.China

Hydrogels have been extensively studied for applications in various fields, such as tissue engineering and soft robotics, as determined by their mechanical properties. The mechanical design of hydrogels typically focuses on the modulus, toughness, and deformability. These characteristics play important roles and make great achievements for hydrogel use. In recent years, a growing body of research has concentrated on the fatigue property of hydrogels, which determines their resistance to crack propagation in the networks during cyclic mechanical loads for applications. However, knowledge of hydrogel fatigue behavior remains notably deficient. Here, we present a brief overview of the fatigue behavior of hydrogels, encompassing the general experimental methods to measure the fatigue property and fundamental theoretical calculation models. Then, we highlight multiple strategies to enhance the fatigue resistance of hydrogels. Finally, we present our perspectives on fatigue-resistant hydrogels, outstanding challenges and potential directions for future research.

关键词： Hydrogel Fatigue-resistant Fracture