检索结果-南通市图书馆

Adaptive and augmented active anomaly detection on dynamic network traffic streams

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2024年第3期25卷 446-460页

作者： Bin li Yijie WANG li CHENG National Key Laboratory of Parallel and Distributed Computing College of ComputerNational University of Defense TechnologyChangsha 410073China College of System Engineering National University of Defense TechnologyChangsha 410073China

Active anomaly detection queries labels of sampled instances and uses them to incrementally update the detection model,and has been widely adopted in detecting network ***,existing methods cannot achieve desirable performance on dynamic network traffic streams because(1)their query strategies cannot sample informative instances to make the detection model adapt to the evolving stream and(2)their model updating relies on limited query instances only and fails to leverage the enormous unlabeled instances on *** address these issues,we propose an active tree based model,adaptive and augmented active prior-knowledge forest(A3PF),for anomaly detection on network trafic streams.A prior-knowledge forest is constructed using prior knowledge of network attacks to find feature subspaces that better distinguish network anomalies from normal *** one hand,to make the model adapt to the evolving stream,a novel adaptive query strategy is designed to sample informative instances from two aspects:the changes in dynamic data distribution and the uncertainty of *** the other hand,based on the similarity of instances in the neighborhood,we devise an augmented update method to generate pseudo labels for the unlabeled neighbors of query instances,which enables usage of the enormous unlabeled instances during model *** experiments on two benchmarks,CIC-IDS2017 and UNSW-NB15,demonstrate that A3PF achieves significant improvements over previous active methods in terms of the area under the receiver operating characteristic curve(AUC-ROC)(20.9%and 21.5%)and the area under the precision-recall curve(AUC-PR)(44.6%and 64.1%).

关键词： Active anomaly detection Network traffic streams Pseudo labels Prior knowledge of network attacks

Guidance strategy of motion camouflage for spacecraft pursuit-evasion game

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第3期37卷 312-319页

作者： Jianqing li Chaoyong li Yonghe ZHANG Space Information Research Institute Hangzhou Dianzi UniversityHangzhou 310018China College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Key Lab of Microsatellites Chinese Academy of SciencesShanghai 201210China

This work is inspired by a stealth pursuit behavior called motion camouflage whereby a pursuer approaches an evader while the pursuer camouflages itself against a predetermined *** formulate the spacecraft pursuit-evasion problem as a stealth pursuit strategy of motion camouflage,in which the pursuer tries to minimize a motion camouflage index defined in this *** Euler-Hill reference frame whose origin is set on the circular reference orbit is used to describe the *** on the rule of motion camouflage,a guidance strategy in open-loop form to achieve motion camouflage index is derived in which the pursuer lies on the camouflage constraint line connecting the central spacecraft and *** order to dispose of the dependence on the evader acceleration in the open-loop guidance strategy,we further consider the motion camouflage pursuit problem within an infinite-horizon nonlinear quadratic differential *** saddle point solution to the game is derived by using the state-dependent Riccati equation method,and the resulting closed-loop guidance strategy is effective in achieving motion *** are performed to demonstrate the capabilities of the proposed guidance strategies for the pursuit–evasion game scenario.

关键词： Pursuit-evasion problem Motion camouflage Differential game Guidance strategy Orbit control

Diffusionmodels for time-series applications: a survey

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2024年第1期25卷 19-41页

作者： Lequan liN Zhengkun li Ruikun li Xuliang li Junbin GAO Discipline of Business Analytics The University of Sydney Business SchoolCamperdownNSW 2006Australia Postdoctoral Programme of Zhongtai Securities Co. Ltd.Jinan 250000China

Diffusion models, a family of generative models based on deep learning, have become increasinglyprominent in cutting-edge machine learning research. With distinguished performance in generating samples thatresemble the observed data, diffusion models are widely used in image, video, and text synthesis nowadays. Inrecent years, the concept of diffusion has been extended to time-series applications, and many powerful models havebeen developed. Considering the deficiency of a methodical summary and discourse on these models, we providethis survey as an elementary resource for new researchers in this area and to provide inspiration to motivate futureresearch. For better understanding, we include an introduction about the basics of diffusion models. Except forthis, we primarily focus on diffusion-based methods for time-series forecasting, imputation, and generation, andpresent them, separately, in three individual sections. We also compare different methods for the same applicationand highlight their connections if applicable. Finally, we conclude with the common limitation of diffusion-basedmethods and highlight potential future research directions.

关键词： Diffusion models Time-series forecasting Time-series imputation Denoising diffusion probabilistic models Score-based generative models Stochastic differential equations

Phosphorylation Promotes the Accumulation of PERIOD Protein Foci

在线全文

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 59-69页

作者： Mengna li Shujing li Luoying Zhang Key Laboratory of Molecular Biophysics of Ministry of Education College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhanHubei 430074China Department of life Sciences Bengbu Medical CollegeBengbuAnhui 233030China Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration WuhanHubei 430022China

Circadian clock drives the 24-h rhythm in our behavior and *** molecular clock consists of a series of transcriptional/translational feedback loops operated by a number of clock genes.A very recent study reported that the clock protein PERIOD(PER)is organized into discrete foci at the nuclear envelope in fly circadian neurons,which is believed to be important for controlling the subcellular localization of clock *** of inner nuclear membrane protein lamin B receptor(LBR)leads to disruption of these foci,but how they are regulated is yet ***,we found that PER foci are likely phase-separated condensates,the formation of which is mediated by intrinsically disordered region in *** promotes the accumulation of these *** phosphatase 2A,which is known to dephosphorylate PER,hampers the accumulation of the *** the other hand,the circadian kinase DOUBLETIME(DBT)which phosphorylates PER enhances the accumulation of the *** likely facilitates PER foci accumulation by destabilizing the catalytic subunit of protein phosphatase 2A,MICROTUBULE STAR(MTS).In conclusion,here,we demonstrate a key role for phosphorylation in promoting the accumulation of PER foci,while LBR modulates this process by impinging on the circadian phosphatase MTS.

关键词： conclusion separated translational

New insights into the pre-lithiation kinetics of single-crystalline Ni-rich cathodes for long-life li-ion batteries

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第3期9卷 556-564页

作者： Qiang Han Lele Cai Zhaofeng Yang Yanjie Hu Hao Jiang Chunzhong li Shanghai Engineering Research Center of Hierarchical Nanomaterials School of Chemical EngineeringEast China University of Science and TechnologyShanghai200237China Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China

Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of li-ion batteries(liBs).However,the easy-to-loss of li and O in high-temperature lithiation results in unsatisfactory ordered layered structure and ***,we demonstrate the synthesis of highly-ordered and fully-stoichiometric single-crystalline liNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)cathodes by the regulation of pre-lithiation *** well-balanced pre-lithiation kinetics have been proved to greatly improve the proportion of layered phase in the intermediate by inhibiting the formation of metastable spinel phase,which promoted the rapid transformation of the intermediate into highly-ordered layered SC-NCM83 in the subsequent lithiation *** coating a layer of li_(2)O–B_(2)O_(3),the resultant cathodes deliver superior cycling stability with 90.9%capacity retention at 1C after 300 cycles in pouch-type full *** enhancement mechanism has also been *** findings exhibit fundamental insights into the pre-lithiation kinetics process for guiding the synthesis of high-quality singlecrystalline Ni-rich cathodes.

关键词： Single-crystalline cathode Ni-rich oxides Pre-lithiation li-ion batteries Surface modification

农药助剂牛脂胺聚氧乙烯醚的毒性及其分析技术研究进展

在线全文

学校读者我要写书评

暂无评论

农药学学报 2023年第2期25卷 310-318页

作者：李敏洁张琛李晓慧李思蒙陈雪英王琦郑鹭飞金芬中国农业科学院农产品质量与食物安全重点实验室中国农业科学院农业质量标准与检测技术研究所北京100081

牛脂胺聚氧乙烯醚是一类广泛用于草甘膦制剂的农药助剂。大量研究表明,该助剂的毒性大于其活性成分草甘膦,因而引起了国内外研究人员的关注。本文对牛脂胺聚氧乙烯醚的结构、毒性以及其目前在环境中的分布水平和分析方法等内容进行了综... 详细信息

牛脂胺聚氧乙烯醚是一类广泛用于草甘膦制剂的农药助剂。大量研究表明,该助剂的毒性大于其活性成分草甘膦,因而引起了国内外研究人员的关注。本文对牛脂胺聚氧乙烯醚的结构、毒性以及其目前在环境中的分布水平和分析方法等内容进行了综述,旨在为牛脂胺聚氧乙烯醚在我国农药助剂领域的进一步研究、规范使用和管控提供科学依据。

关键词：牛脂胺聚氧乙烯醚草甘膦助剂毒性分析方法

Development of EPDM composites reinforced by CNTs@SiO_(2)for thermal protection systems of aerospace propulsion:Significant improvement in oxidation and ablation resistance properties

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 471-481页

作者： li WANG Jiang li Kang li Yiwei WANG Chenyang MA Science and Technology on Combustion Internal Flow and Thermal-Structure LaboratoryNorthwestern Polytechnical UniversityXi’an 710072China

Carbon Nanotubes(CNTs)reinforced Polymer-Matrix Composites(PMCs)is widely used as insulation materials in thermal protection system of aerospace ***,CNTs are prone to oxidation and have high thermal conductivities,which makes it difficult to improve the ablation resistance of insulation materials that contain ***_(2)was encapsulated onto the surface of CNTs(CNTs@SiO_(2)),which were then added to Ethylene Propylene Diene Monomer(EPDM)rubber to prepare the insulation *** analysis and ablation test were used to evaluate the resistance of the insulation materials to thermal oxidation and ***,scanning electron microscopy was performed to analyze their *** revealed that the addition of CNTs@SiO_(2)could visibly reduce the effects of hot corrosion and ablation on insulation *** C-CNTs@SiO_(2)-1 formulation had the best ablative ***,compared with the unencapsulated formulation(C-CNTs-10),the C-CNTs@SiO_(2)-1 formulation reduced the line ablation rate by 51%to 0.0130 mm/s after oxygen-acetylene ***,the ablation mechanism was investigated based on the effects of the CNTs@SiO_(2)additive on their ***,the improvement in ablation performance may be attributed to CNTs@SiO_(2)-induced decreases in thermal conductivity,improvement in the hot corrosion resistance in the char layer,and changes in the microstructure.

关键词： Polymer-Matrix Composites(PMCs) Carbon Nanotubes(CNTs) Thermal properties Ablation Oxidation

Additives strategies to improving cycling stability of li metal batteries by modifying electrode electrolyte interphases

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2024年第2期 338-344页

作者： Yuan li Pengfei Huang Chunyu Cui Xiaoyuan Ma li Chen Zekun li linhai li Yuhong Tian School of Biological and Chemical Engineering Guangxi University of Science and Technology School of College of Chemistry and Chemical Engineering Hunan University Isky Future Energy Institute

li metal batteries（LMBs） have attracted much attention due to the ultra-high theoretical capacity of the li metal anode（LMA）.However,the uncontrollable dendrites growth and low coulombic efficiency hinder their practical ***,we explore 3,5-difluoropyridine（2F-BD） as a novel electrolyte additive to enable highperformance *** 2F-BD additive participates in and modifies the solvation structure of li ions by reducing the coordinated number of PF6-at the electrode surface,leading to the formation of a liF and li3N-rich solid electrolyte interphase（SEI）.The liF component increases the robustness of SEI and suppresses the formation of li dendrites,while the li3N component facilitates the transportation and reaction kinetics of li *** a result,the li‖li symmetric cell presents a stable cycling performance of up to 500 h at a current density of 1 mA *** coupling with liFePO4cathode,the obtained full cell achieves high specific capacities of 106.06 mA h g-1and 84.98 mA h g-1at 2.55 mA cm-2and 5.10 mA cm-2,respectively,and maintains a high capacity retention of84.0% after 1000 cycles at 0.13 mA cm-2,with an average cycling CE of 99.58%.

关键词：

APF-GAN:Exploring asymmetric pre-training and fine-tuning strategy for conditional generative adversarial network

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computational Visual Media 2024年第1期10卷 187-192页

作者： Yuxuan li lingfeng Yang Xiang li College of Computer Science Nankai UniversityTianjinChina School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjingChina

The use of generative adversarial network(GAN)-based models for the conditional generation of image semantic segmentation has shown promising results in recent ***,there are still some limitations,including limited diversity of image style,distortion of detailed texture,unbalanced color tone,and lengthy training *** address these issues,we propose an asymmetric pre-training and fine-tuning(APF)-GAN model.

关键词： tuning network asymmetric