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APSO-CNN-SE: An Adaptive Convolutional Neural Network Approach for IoT Intrusion Detection

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Computers, Materials and Continua 2024年第1期81卷 567-601页

作者： Ban y. Zhang D. He q. Shen q. College of Big Data and Information Engineering Guizhou University Guizhou 550025 China

The surge in connected devices and massive data aggregation has expanded the scale of the Internet of Things (IoT) networks. The proliferation of unknown attacks and related risks, such as zero-day attacks and Distributed Denial of Service (DDoS) attacks triggered by botnets, have resulted in information leakage and property damage. Therefore, developing an efficient and realistic intrusion detection system (IDS) is critical for ensuring IoT network security. In recent years, traditional machine learning techniques have struggled to learn the complex associations between multidimensional features in network traffic, and the excellent performance of deep learning techniques, as an advanced version of machine learning, has led to their widespread application in intrusion detection. In this paper, we propose an Adaptive Particle Swarm Optimization Convolutional Neural Network Squeeze-and-Excitation (APSO-CNN-SE) model for implementing IoT network intrusion detection. A 2D CNN backbone is initially constructed to extract spatial features from network traffic. Subsequently, a squeeze-and-excitation channel attention mechanism is introduced and embedded into the CNN to focus on critical feature channels. Lastly, the weights and biases in the CNN-SE are extracted to initialize the population individuals of the APSO. As the number of iterations increases, the population’s position vector is continuously updated, and the cross-entropy loss function value is minimized to produce the ideal network architecture. We evaluated the models experimentally using binary and multiclassification on the UNSW-NB15 and NSL-KDD datasets, comparing and analyzing the evaluation metrics derived from each model. Compared to the base CNN model, the results demonstrate that APSO-CNN-SE enhances the binary classification detection accuracy by 1.84% and 3.53% and the multiclassification detection accuracy by 1.56% and 2.73% on the two datasets, respectively. Additionally, the model outperforms the

关键词： adaptive particle swarm optimization channel attention mechanism convolutional neural network internet of things Intrusion detection system

Digital Image Steganographer Identification: A Comprehensive Survey

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Computers, Materials and Continua 2024年第1期81卷 105-131页

作者： Zhang q. Zhang y. Ma y. Liu y. Luo X. Information Engineering University Zhengzhou 450001 China Key Laboratory of Cyberspace Situation Awareness of Henan Province Zhengzhou 450001 China College of Computer and Information Engineering Henan Normal University Xinxiang 453007 China

The rapid development of the internet and digital media has provided convenience while also posing a potential risk of steganography abuse. Identifying steganographer is essential in tracing secret information origins and preventing illicit covert communication online. Accurately discerning a steganographer from many normal users is challenging due to various factors, such as the complexity in obtaining the steganography algorithm, extracting highly separability features, and modeling the cover data. After extensive exploration, several methods have been proposed for steganographer identification. This paper presents a survey of existing studies. Firstly, we provide a concise introduction to the research background and outline the issue of steganographer identification. Secondly, we present fundamental concepts and techniques that establish a general framework for identifying steganographers. Within this framework, state-of-the-art methods are summarized from five key aspects: data acquisition, feature extraction, feature optimization, identification paradigm, and performance evaluation. Furthermore, theoretical and experimental analyses examine the advantages and limitations of these existing methods. Finally, the survey highlights outstanding issues in image steganographer identification that deserve further research. © 2024 The Authors. Published by Tech Science Press.

关键词： covert communication Information hiding steganalysis steganographer identification steganography survey

Rational design of AggaS/ZnS/ZnS quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

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Journal of Materials Science & Technology 2024年第2期169卷 235-242页

作者： H.X.Lu H.Liu Z.Z.Fu y.y.Chen H.q.Dai Z.Hu W.L.Zhang R.q.guo Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of Future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China yiwu Research Institute of Fudan University YiwuZhejiang 322000China Zhongshan-Fudan Joint Innovation Center Zhongshan 528437China

In this study,a two-step method was used to synthesize highly luminescent AggaS/ZnS/ZnS quantum dots(qDs).In the first step,an inner ZnS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AggaS core and the outer ZnS shell,thereby facilitating the formation of a thick outer *** the two-step shelling process,the synthesized AggaS/ZnS/ZnS qDs showed an excellent photoluminescence quantum yield(PLqy)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLqy reported thus far for AggaS ***,the effect of halogen ions in Zn precursors on the shelling process was *** was proposed that the capacity of halogen ions to coordinate with the qDs influenced the balance between Zn cation diffusion and ZnS shelling ***,the ZnS shelling reaction was dominant when ZnCl_(2)was employed,while Zn cation diffusion was the dominant process under the I^(−)-rich *** work provides insights into the interfacial restructuring during the ZnS shelling and offers a clear map for the tailored synthesis of core/shell qDs.

关键词： AggaS quantum dots Photoluminescence Core/shell Alloyed core/shell interface

Effect of Al_(2)O_(3)on the Mechanical Properties of(B_(4)C+Al_(2)O_(3))/Al Neutron Absorbing Materials

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： J.X.Cai B.M.Shi N.Li y.Liu Z.g.Zhang y.N.Zan q.Z.Wang B.L.Xiao Z.y.Ma Shi‑Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China Department of Materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

B_(4)C/Al composites are widely utilized as neutron absorbing materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of B_(4)C/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adjusted by utilizing spheroid Al powder with varying diameters,thereby investigating the impact of Al_(2)O_(3)content on the tensile properties of(B_(4)C+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain boundaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhibited a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional B_(4)C/Al composites.

关键词： Al matrix composites Neutron absorbing materials (B_(4)C+Al_(2)O_(3))/Al composites High-temperature strength

Screening for metabolic dysfunction-associated fatty liver disease:Time to discard the emperor’s clothes of normal liver enzymes?

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World Journal of gastroenterology 2024年第22期30卷 2839-2842页

作者： Chen-Xiao huang Xiao-Dong Zhou Calvin q Pan Ming-hua Zheng Metabolic Dysfunction-Associated Fatty Liver Disease Research Center Department of HepatologyThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhou 325000Zhejiang ProvinceChina Department of Cardiovascular Medicine The Key Laboratory of Cardiovascular Diseases of WenzhouThe First Affiliated Hospital of Wenzhou Medical UniversityWenzhou 325000Zhejiang ProvinceChina Division of gastroenterology and Hepatology Department of MedicineNew York University Langone HealthNew York University Grossman School of MedicineNew YorkNY 11355United States Institute of Hepatology Wenzhou Medical UniversityKey Laboratory of Diagnosis and Treatment for the Development of Chronic Liver Disease in Zhejiang ProvinceWenzhou 325000Zhejiang ProvinceChina

Metabolic dysfunction-associated fatty liver disease(MAFLD)is the most prevalent chronic liver condition *** liver enzyme-based screening methods have limitations that may missed diagnoses and treatment *** Chen et al,the risk of developing MAFLD remains elevated even when alanine aminotransferase levels fall within the normal ***,there is an urgent need for advanced diagnostic techniques and updated algorithms to enhance the accuracy of MAFLD diagnosis and enable early *** paper proposes two potential screening methods for identifying individuals who may be at risk of developing MAFLD:Lowering these thresholds and promoting the use of noninvasive liver fibrosis scores.

关键词： Metabolic dysfunction-associated fatty liver disease Non-alcoholic fatty liver disease Alanine aminotransferase Liver enzymes Screening Noninvasive liver fibrosis scores

Creep-induced redistribution of alloying elements in CZ1 zirconium alloys

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Journal of Materials Science & Technology 2024年第6期173卷 31-44页

作者： W.T.Lin q.y.Lv D.Jiao L.B.Zhang J.Tan g.Sha J.Hu China Nuclear Power Technology Research Institute Shenzhen 518026China School of Material Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China

Introducing minor alloying elements is an effective strategy to improve the corrosion and mechanical properties of zirconium alloys for nuclear *** in-reactor service,external environment and stress can affect the distribution of alloying elements,substantially changing the degradation process of zirconium *** date,there is a lack of in-depth understanding of the interaction between creep and microchemistry ***,we conducted systematic transmission electron microscopy(TEM)and atom probe tomography(APT)investigations to address creep-induced redistribution of alloying elements in CZ1(Zr-Sn-Nb-Fe-Cr-Cu)zirconium alloy with different initial ***,Fe,Sn,and Cu are found to co-segregate at grain *** higher the intermediate annealing temperature,the larger the gibbsian interfacial excesses of solute elements *** further demonstrate that creep can reduce the excess value of Fe at grain boundaries due to the coarsening of Zr-Fe-Cr second phase particles via grain boundary and dislocation pipe *** the same time,the excess value of Sn is increased by diffusing from the matrix to grain ***,Cu as a minor element in the concentration range of 0.05-0.3 wt.%is found to segregate at dislocations to form the Cottrell atmosphere and develop Cu-rich nanoclusters for suppressing dislocation *** new understanding of the segregation and clustering of minor alloying elements provides guidance for developing zirconium alloys with enhanced creep resistance.

关键词： Zirconium alloy Thermal creep grain boundary segregation Dislocation segregation Cu-rich nanoclusters

In situ TEM investigation of electron irradiation and aging-induced high-density nanoprecipitates in an Mg-10gd-3y-1Zn-0.5Zr alloy

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Journal of Magnesium and Alloys 2024年第5期12卷 1841-1853页

作者： M.Lv H.L.ge q.q.Jin X.H.Shao y.T.Zhou B.Zhang X.L.Ma Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences72 Wenhua RoadShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Materials Science and Engineering Research Center Guangxi University of Science and TechnologyLiuzhou 545006China

In-situ electron irradiation and aging are applied to introduce high-density precipitates in an Mg-10gd-3y-1Zn-0.5Zr(gWZ1031K,wt.%)alloy to improve the *** results show that the hardness of the Mg alloy after irradiation for 10 h and aging for 9 h at 250℃ is 1.64 gPa,which is approximately 64% higher than that of the samples before being *** is mainly attributed to γ'precipitates on the basal plane after irradiation and the high-density nanoscale β'precipitates on the prismatic plane after aging,which should be closely related to the irradiation-induced homogenous *** latter plays a key role in precipitation *** result paves a way to improve the mechanical properties of metallic materials by tailoring the precipitation through irradiation and aging.

关键词： Mg alloy Electron beam irradiation Hardening Precipitates In-situ TEM

Improved Harris Hawks Algorithm and Its Application in Feature Selection

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Computers, Materials and Continua 2024年第1期81卷 1251-1273页

作者： Zhang q. Li y. Zhan J. Chen S. School of Computer Science and Information Engineering Harbin Normal University Harbin 150025 China College of Systems Engineering National University of Defense Technology Changsha 410073 China

This research focuses on improving the Harris' Hawks Optimization algorithm (HHO) by tackling several of its shortcomings, including insufficient population diversity, an imbalance in exploration vs. exploitation, and a lack of thorough exploitation depth. To tackle these shortcomings, it proposes enhancements from three distinct perspectives: an initialization technique for populations grounded in opposition-based learning, a strategy for updating escape energy factors to improve the equilibrium between exploitation and exploration, and a comprehensive exploitation approach that utilizes variable neighborhood search along with mutation operators. The effectiveness of the Improved Harris Hawks Optimization algorithm (IHHO) is assessed by comparing it to five leading algorithms across 23 benchmark test functions. Experimental findings indicate that the IHHO surpasses several contemporary algorithms its problem-solving capabilities. Additionally, this paper introduces a feature selection method leveraging the IHHOalgorithm(IHHO-FS) to address challenges such as lowefficiency in feature selection and high computational costs (time to find the optimal feature combination and model response time) associated with high-dimensional datasets. Comparative analyses between IHHO-FS and six other advanced feature selection methods are conducted across eight datasets. The results demonstrate that IHHO-FS significantly reduces the computational costs associated with classification models by lowering data dimensionality, while also enhancing the efficiency of feature selection. Furthermore, IHHO-FS shows strong competitiveness relative to numerous algorithms. © 2024 The Authors. Published by Tech Science Press.

关键词： deep exploitation strategy energy factor update strategy feature selection HHO IHHO population diversity

Microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials Science & Technology 2024年第4期171卷 80-93页

作者： y.H.Zhang H.Li Z.W.yang X.Liu q.F.gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning