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Towards understanding bogus traffic service in online social networks

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Frontiers of Information Technology & Electronic Engineering 2024年第3期25卷 415-431页

作者： ping he Xuhong zhang Changting LIN Ting WANG Shouling JI College of Computer Science and Technology Zhejiang UniversityHangzhou 310027China Binjiang Institute of Zhejiang University Hangzhou 310027China College of Information Sciences and Technology Pennsylvania State UniversityUniversity Park 17057-4846USA

Critical functionality and huge infuence of the hot trend/topic page(HTP)in microblogging sites have driven the creation of a new kind of underground service called the bogus traffic service(BTS).BTS provides a kind of illegal service which hijacks the HTP by pushing the controlled topics into it for malicious customers with the goal of guiding public *** hijack HTP,the agents of BTS maintain an army of black-market accounts called bogus trafic accounts(BTAs)and control BTAs to generate a burst of fake trafic by massively retweeting the tweets containing the customer desired topic(hashtag).Although this service has been extensively exploited by malicious customers,little has been done to understand *** this paper,we conduct a systematic measurement study of the *** first investigate and collect 125 BTS agents from a variety of sources and set up a honey pot account to capture BTAs from these *** then build a BTA detector that detects 162218 BTAs from Weibo,the largest Chinese microblogging site,with a precision of 94.5%.We further use them as a bridge to uncover 296916 topics that might be involved in bogus ***,we uncover the operating mechanism from the perspectives of the attack cycle and the attack *** highlights of our findings include the temporal attack patterns and intelligent evasion tactics of the *** findings bring BTS into the *** work will help in understanding and ultimately eliminating this threat.

关键词： Online social networks Measurement Bogus traffic Black market

Improving Federated Learning through Abnormal Client Detection and Incentive

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 383-403页

作者： Hongle Guo Yingchi Mao Xiaoming he Benteng zhang Tianfu Pang ping ping College of Computer and Information Hohai UniversityNanjing211100China Key Laboratory ofWater Big Data Technology of Ministry ofWater Resources Hohai UniversityNanjing211100China

Data sharing and privacy protection are made possible by federated learning,which allows for continuous model parameter sharing between several clients and a central *** reliable and high-quality clients must participate in practical applications for the federated learning global model to be accurate,but because the clients are independent,the central server cannot fully control their *** central server has no way of knowing the correctness of the model parameters provided by each client in this round,so clients may purposefully or unwittingly submit anomalous data,leading to abnormal behavior,such as becoming malicious attackers or defective *** reduce their negative consequences,it is crucial to quickly detect these abnormalities and incentivize *** this paper,we propose a Federated Learning framework for Detecting and Incentivizing Abnormal Clients(FL-DIAC)to accomplish efficient and security federated *** build a detector that introduces an auto-encoder for anomaly detection and use it to perform anomaly identification and prevent the involvement of abnormal clients,in particular for the anomaly client detection *** them,before the model parameters are input to the detector,we propose a Fourier transform-based anomaly data detectionmethod for dimensionality reduction in order to reduce the computational ***,we create a credit scorebased incentive structure to encourage clients to participate in training in order tomake clients actively *** training models(CNN,MLP,and ResNet-18)and three datasets(MNIST,Fashion MNIST,and CIFAR-10)have been used in *** to theoretical analysis and experimental findings,the FL-DIAC is superior to other federated learning schemes of the same type in terms of effectiveness.

关键词： Federated learning abnormal clients incentive credit score abnormal score detection

Recent advances in bioinspired vision systems with curved imaging structures

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Rare Metals 2024年第4期43卷 1407-1434页

作者： Ze-ping he Xun Han Wen-Qiang Wu zhang-Sheng Xu Cao-Feng Pan CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-Nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing100083China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing100049China ZJU-Hangzhou Global Scientific and Technological Innovation Center School of Micro-Nano ElectronicsZhejiang UniversityHangzhou311200China Institute of Microscale Optoelectronics Shenzhen UniversityShenzhen518060China

Limited by the planar imaging structure,the commercial camera needs to introduce additional optical elements to compensate for the curved focal plane to match the planar image *** results in a complex and bulky *** contrast,biological eyes possess a simple and compact structure due to their curved imaging structure that can directly match with the curved focal *** by the structures and functions of biological eyes,curved vision systems not only improve the image quality,but also offer a variety of advanced ***,we review the recent advances in bioinspired vision systems with curved imaging ***,we focus on their applications in implementing different functions of biological eyes,as well as the emerging curved neuromorphic imaging systems that incorporate bioinspired optical and neuromorphic processing *** addition,the challenges and opportunities of bioinspired curved imaging systems are also discussed.

关键词： Bioinspired Curved vision system Compound eye Chambered eye Neuromorphic

Continuous Forcing Spectra of Even Polygonal Chains

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Acta Mathematicae Applicatae Sinica 2021年第2期37卷 337-347页

作者： he-ping zhang Xiao-yan JIANG School of Mathematics and Statistics Lanzhou UniversityLanzhou 730000China School of Mathematics and Statistics Huizhou UniversityHuizhou 516007China

Let G be a graph that admits a perfect matching M.A forcing set S for a perfect matching M is a subset of M such that it is contained in no other perfect matchings of *** cardinality of a forcing set of M with the smallest size is called the forcing number of M,denoted by f(G,M).The forcing spectrum of G is defined as:Spec(G)={f(G,M)|M is a perfect matching of G}.In this paper,by applying the Ztransformation graph(resonance graph)we show that for any polyomino with perfect matchings and any even polygonal chain,their forcing spectra are integral *** we obtain some sharp bounds on maximum and minimum forcing numbers of hexagonal chains with given number of *** spectra of two extremal chains are determined.

关键词： perfect matching forcing number forcing spectrum polyomino even polygonal chain Z-transformation graph

Preparation of single atom catalysts for high sensitive gas sensing

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International Journal of Extreme Manufacturing 2024年第3期6卷 216-248页

作者： Xinxin he ping Guo Xuyang An Yuyang Li Jiatai Chen Xingyu zhang Lifeng Wang Mingjin Dai Chaoliang Tan Jia zhang Key Laboratory of Microsystems and Microstructure Manufacturing Ministry of EducationHarbin Institute of TechnologyHarbin 150080People’s Republic of China Institute for Frontier Materials Deakin UniversityWaurn Ponds CampusLocked Bag 20000Victoria 3220Australia School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore Department of Electrical and Electronic Engineering The University of Hong KongPokfulam RoadHong Kong Special Administrative Region of China 999077People’s Republic of China Chongqing Research Institute Harbin Institute of TechnologyChongqing 401120People’s Republic of China

Single atom catalysts(SACs)have garnered significant attention in the field of catalysis over the past decade due to their exceptional atom utilization efficiency and distinct physical and chemical *** the semiconductor-based electrical gas sensor,the core is the catalysis process of target gas molecules on the sensitive *** this context,the SACs offer great potential for highly sensitive and selective gas sensing,however,only some of the bubbles come to the *** facilitate practical applications,we present a comprehensive review of the preparation strategies for SACs,with a focus on overcoming the challenges of aggregation and low *** research efforts have been devoted to investigating the gas sensing mechanism,exploring sensitive materials,optimizing device structures,and refining signal post-processing ***,the challenges and future perspectives on the SACs based gas sensing are presented.

关键词： single atom catalysts preparation sensing mechanism gas sensing

Crystallinity-defect matching relationship of g-C_(3)N_(4): Experimental and theoretical perspectives

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Green Energy & Environment 2024年第4期9卷 623-658页

作者： Yuhan Li Ziteng Ren Zhengjiang he ping Ouyang Youyu Duan Wendong zhang Kangle Lv Fan Dong Engineering Research Center for Waste Oil Recovery Technology and Equipment Ministry of EducationChongqing Key Laboratory of Catalysis and New Environmental MaterialsChongqing Technology and Business UniversityChongqing400067China Nanchang Institute of Technology Nanchang33044China Key Laboratory of Resources Conversion and Pollution Control of the State Ethnic Affairs Commission College of Resources and Environmental ScienceSouth-Central Minzu UniversityWuhan430074China College of Physics and Center of Quantum Materials and Devices Chongqing UniversityChongqing401331China Chongqing Key Laboratory of Green Synthesis and Application Chongqing Normal UniversityChongqing401331China

Good crystallinity can reduce the charge recombination centers caused by defects,whilst structures with strong polycondensation have high charge mobility,leading to more charge transfer to the material surface for *** effort has been put into the preparation of a highly efficient g-C_(3)N_(4) with defects to improve its application potential under the premise in high ***,this review paper emphasizes the importance to balance the defect and crystallinity of g-C_(3)N_(4).In addition,detailed discussion on the relationship between defects and activity of g-C_(3)N_(4) was carried out based on its applications in environmental purification(e.g.,VOCs oxidation,NO_(x) oxidation,H_(2)O_(2) evolution,sterilization,pesticide oxidation)and energy conversion(H_(2) evolution,N_(2) fixation and CO_(2) reduction).Lastly,the challenge in developing more efficient defective g-C_(3)N_(4) photocatalytic materials is summarized.

关键词： Photocatalysis Defect G-C_(3)N_(4) Crystallinity Application

Halogenated Thienoacene Derivatives with Improved Emission Properties

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Chemical Research in Chinese Universities 2024年第4期40卷 699-703页

作者： zhang Jingmei MENG Zhihao ZheN Yonggang he ping YU Panpan HU Wenping Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic-Inorganic CompositesBeijing University of Chemical TechnologyBeijing100029P.R.China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074P.R.China State Key Laboratory of Fine Chemicals Dalian University of TechnologyDalian116024P.R.China Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province China West Normal UniversityNanchong637000P.R.China Key Laboratory of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education Jiangxi Normal UniversityNanchang330022P.R.China MOE Key Laboratory of Organic Integrated Circuits&Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of SciencesTianjin UniversityTianjin300072P.R.China

Thienoacenes is one of most important groups of semiconducting materials due to the high stability and superior ***,there are scarce studies on the emission properties of thienoacenes to ***,we synthesized fluorinated and chlorinated dibenzo[d,d’]thieno[3,2-b;4,5-b’]dithiophenes(DBTDTs)derivatives F6-DBTDT and Cl6-DBTDT by sulfoxide cyclization,significantly lowering the energy levels relative to the parent compound *** to single crystal structure analysis,F6-DBTDT molecules adopt one-dimensional slipped stacking with closeπ-πinteractions of 3.43Å(1Å=0.1 nm),which is different from the parent compound DBTDT with herringbone stacking ***,the halogenated DBTDT derivatives exhibit enhanced emission properties both in solution and in the solid state,opening up possiblities to improve photoluminescence of thienoacences by halogenation.

关键词： Thienoacene Halogenation Photoluminescence Aggregation structure

ATAT1 deficiency enhances microglia/macrophage-mediated erythrophagocytosis and hematoma absorption following intracerebral hemorrhage

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Neural Regeneration Research 2024年第5期19卷 1072-1077页

作者： Yihua zhang ping Huang Min Cao Yi Chen Xinhu Zhao Xuzhi he Lunshan Xu Department of Neurosurgery Daping HospitalArmy Medical UniversityChongqingChina

MIcroglia/macrophage-mediated erythrophagocytosis plays a crucial role in hematoma clearance after intracerebral *** cytoskeletal changes accompany ***,whether and how these changes are associated with microglia/macrophage-mediated erythrophagocytosis remain *** this study,we investigated the function of acetylatedα-tubulin,a stabilized microtubule form,in microglia/macrophage erythrophagocytosis after intracerebral hemorrhage both in vitro and in *** first assessed the function of acetylatedα-tubulin in erythrophagocytosis using primary DiO GFP-labeled red blood cells co-cultured with the BV2 microglia or RAW264.7 macrophage cell ***α-tubulin expression was significantly decreased in BV2 and RAW264.7 cells during ***,silencingα-tubulin acetyltransferase 1(ATAT1),a newly discoveredα-tubulin acetyltransferase,decreased Ac-α-tub levels and enhanced the erythrophagocytosis by BV2 and RAW264.7 *** with these findings,in ATAT1-/-mice,we observed increased ionized calcium binding adapter molecule 1(Iba1)and Perls-positive microglia/macrophage phagocytes of red blood cells in peri-hematoma and reduced hematoma volume in mice with intracerebral ***,knocking out ATAT1 alleviated neuronal apoptosis and pro-inflammatory cytokines and increased anti-inflammatory cytokines around the hematoma,ultimately improving neurological recovery of mice after intracerebral *** findings suggest that ATAT1 deficiency accelerates erythrophagocytosis by microglia/macrophages and hematoma absorption after intracerebral *** results provide novel insights into the mechanisms of hematoma clearance and suggest ATAT1 as a potential target for the treatment of intracerebral hemorrhage.

关键词： acetylatedα-tubulin α-tubulin acetyltransferase 1(ATAT1) erythrophagocytosis hematoma absorption intracerebral hemorrhage macrophage microglia

Attribution analysis of groundwater level fluctuation in the Xinxiang section of the Lower Yellow River's suspended river after the construction of the Xiaolangdi Reservoir

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Journal of Geographical Sciences 2024年第7期34卷 1348-1370页

作者： LI he ping Jianhua LENG Wei MEI Xuemei zhang Min LIU Jiaqi School of Water Conservancy and Transportation Zhengzhou UniversityZhengzhou450001China College of Ecology and Environment Zhengzhou UniversityZhengzhou450001China Geothermal and Ecological Geology Research Center Zhengzhou UniversityZhengzhou450001China Institute of Geology and Geophysics CASBeijing100101China

The clear identification and quantification of the factors affecting groundwater systems is crucial for protecting groundwater resources and ensuring safety in agricultural *** Lower Yellow River(LYR)is a suspended river that replenishes groundwater continuously due to clear differences in the water head,especially in the Xinxiang *** its construction,the Xiaolangdi Reservoir has reversed the LYR’s *** accurately determine the factors influencing the groundwater level(GWL),the study area was divided into five subzones based on hydrogeology.A dynamic factor model(DFM),variational mode decomposition(VMD),and a multiple linear regression model were used to identify and quantify the factors influencing the *** impact of the suspended river on the groundwater before and after the construction of the Xiaolangdi Reservoir was *** results show that:(1)The rate of decrease in the GWL was 8.53×10^(–4)m/month,and the rate of decrease in the Yellow River water level(RWL)was 4.63×10^(–4)m/month.(2)Mountain front recharge(MFR)(scale=3 months)and precipitation(scale=9 months)were the dominant factors in subzones I and II,accounting for more than 40%of the fluctuation in the *** III was dominated by exploitation(scale=7 months)and precipitation(scale=12months),accounting for 28.43%,and 23.44%of changes in the GWL,*** subzone IV,agricultural irrigation(scale=12 months)was the major factor,accounting for32.47%of GWL changes,while in subzone V,the RWL(scale=12 months)accounted for52.52%of these changes.(3)The Xiaolangdi Reservoir has increased the lateral seepage of the suspended river and altered the inter-annual *** results of this study can provide a valuable reference for controlling groundwater overexploitation and ensuring water supply security.

关键词： groundwater level influencing factor dynamic factor analysis Xiaolangdi Reservoir Lower Yellow River lateral seepage of the Yellow River