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Enhancing Log Anomaly Detection with Semantic Embedding and Integrated Neural Network Innovations

Computers, Materials and Continua 2024年第3期80卷 3991-4015页

作者： Xu z. Wang z. Xu j. Shi H. z.ao H. School of Computer and Software Nanjing University of Information Science and Technology Nanjing 210044 China

System logs, serving as a pivotal data source for performance monitoring and anomaly detection, play an indispensable role in assuring service stability and reliability. Despite this, the maj.rity of existing log-based anomaly detection methodologies predominantly depend on the sequence or quantity attributes of logs, utiliz.ng solely a single Recurrent Neural Network (RNN) and its variant sequence models for detection. These approaches have not thoroughly exploited the semantic information embedded in logs, exhibit limited adaptability to novel logs, and a single model struggles to fully unearth the potential features within the log sequence. Addressing these challenges, this article proposes a hybrid architecture based on a multiscale convolutional neural network, efficient channel attention and mogrifier gated recurrent unit networks (LogCEM), which amalgamates multiple neural network technologies. Capitaliz.ng on the superior performance of robustly optimiz.d BERT approach (RoBERTa) in the realm of natural language processing, we employ RoBERTa to extract the original word vectors from each word in the log template. In conj.nction with the enhanced Smooth Inverse Frequency (SIF) algorithm, we generate more precise log sentence vectors, thereby achieving an in-depth representation of log semantics. Subsequently, these log vector sequences are fed into a hybrid neural network, which fuses 1D Multi-Scale Convolutional Neural Network (MSCNN), Efficient Channel Attention Mechanism (ECA), and Mogrifier Gated Recurrent Unit (GRU). This amalgamation enables the model to concurrently capture the local and global dependencies of the log sequence and autonomously learn the significance of different log sequences, thereby markedly enhancing the efficacy of log anomaly detection. To validate the effectiveness of the LogCEM model, we conducted evaluations on two authoritative open-source datasets. The experimental results demonstrate that LogCEM not only exhibits excellent ac

关键词： anomaly detection Deep learning log analysis natural language processing

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A New Method for Deriving High-Vertical-Resolution Wind Vector Data from the L-Band Radar Sounding System in China

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Advances in Atmospheric Sciences 2024年第11期41卷 2192-2202页

作者： Yuan F. z.ou z. Liao j. National Meteorological Information Center China Meteorological Administration Beijing 100081 China

High-vertical-resolution radiosonde wind data are highly valuable for describing the dynamics of the meso- and microscale atmosphere. However, the current algorithm used in China’s L-band radar sounding system for calculating high-vertical-resolution wind vectors excessively smooths the data, resulting in significant underestimation of the calculated kinetic energy of gravity waves compared to similar products from other countries, which greatly limits the effective utiliz.tion of the data. To address this issue, this study proposes a novel method to calculate high-vertical-resolution wind vectors that utiliz.s the elevation angle, az.muth angle, and slant range from L-band radar. In order to obtain wind data with a stable quality, a two-step automatic quality control procedure, including the RMSE-F (root-mean-square error F) test and elemental consistency test are first applied to the slant range data, to eliminate continuous erroneous data caused by unstable signals or radar malfunctions. Then, a wind calculation scheme based on a sliding second-order polynomial fitting is utiliz.d to derive the high-vertical-resolution radiosonde wind vectors. The evaluation results demonstrate that the wind data obtained through the proposed method show a high level of consistency with the high-resolution wind data observed using the Vaisala Global Positioning System and the data observed by the new Beidou Navigation Sounding System. The calculation of the kinetic energy of gravity waves in the recalculated wind data also reaches a level comparable to the Vaisala observations. © Institute of Atmospheric Physics/Chinese Academy of Sciences, and Science Press 2024.

关键词： high-vertical-resolution radiosonde wind vectors L-band radar sounding system polynomial fitting quality control upper air

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Quantitative Identification of Delamination Damage in Composite Structure Based on Distributed Optical Fiber Sensors and Model Updating

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SDHM Structural Durability and Health Monitoring 2024年第6期18卷 785-803页

作者： Xu H. Wang j. z.u R. Strauss A. Cao M. Wu z. School of Materials Science and Engineering Dalian University of Technology Dalian 116000 China School of Mechanics and Aerospace Engineering Dalian University of Technology Dalian 116000 China Department of Civil Engineering and Natural Haz.rds University of Natural Resources and Life Sciences Vienna 1180 Austria Department of Engineering Mechanics Hohai University Nanjing China

Delamination is a prevalent type of damage in composite laminate structures. Its accumulation degrades structural performance and threatens the safety and integrity of aircraft. This study presents a method for the quantitative identification of delamination identification in composite materials, leveraging distributed optical fiber sensors and a model updating approach. Initially, a numerical analysis is performed to establish a parameteriz.d finite element model of the composite plate. Then, this model subsequently generates a database of strain responses corresponding to damage of varying siz.s and locations. The radial basis function neural network surrogate model is then constructed based on the numerical simulation results and strain responses captured from the distributed fiber optic sensors. Finally, a multi-island genetic algorithm is employed for global optimiz.tion to identify the siz. and location of the damage. The efficacy of the proposed method is validated through numerical examples and experiment studies, examining the correlations between damage location, damage siz., and strain responses. The findings confirm that the model updating technique, in conj.nction with distributed fiber optic sensors, can precisely identify delamination in composite structures. © 2024 The Authors. Published by Tech Science Press.

关键词： Composite structures damage identification fiber optic sensor model updating surrogate model

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Observability Analysis of Integrated Electricity and Heating Systems with Thermal Quasi-dynamics in Pipelines

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CSEE j.urnal of Power and Energy Systems 2024年第3期10卷 1145-1158页

作者： z.igang Li Wenj.an zheng j.nbo z.ao j.H.zheng Q.H.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China Fuz.ou Changle District Power Supply Company of State Grid Fuj.an Electric Power Co. Ltd.Fuzhou 350000China Department of Electrical and Computer Engineering University of ConnecticutStorrsCT 06269USA CSEE IEEE

Observability analysis(OA)is vital to obtaining the available input measurements of state estimation(SE)in an integrated electricity and heating system(IEHS).Considering the thermal quasi-dynamics in pipelines,the measurement equations in heating systems are dependent on the estimated results,leading to an interdependency between OA and *** OA methods require measurement equations be known exactly before SE is performed,and they are not applicable to *** bridge this gap,a scenario-based OA scheme for IEHSs is devised that yields reliable analysis results for a predefined set of time-delay scenarios to cope with this *** its core procedure,the observable state identification and observability restoration are formulated in terms of integer linear *** tests are conducted to demonstrate the validity and superiority of the proposed formulation.

关键词： Integrated electricity and heating system measurement observability analysis state estimation thermal quasi-dynamics

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Convexification of Hybrid AC-DC Optimal Power Flow with Line-Commutated Converters

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CSEE j.urnal of Power and Energy Systems 2024年第2期10卷 617-628页

作者： Hongyuan Liang z.igang Li j.H.zheng Q.H.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

Line-commutated converter (LCC)-based high-voltage DC (HVDC) systems have been integrated with bulk AC power grids for interregional transmission of renewable power. The nonlinear LCC model brings additional nonconvexity to optimal power flow (OPF) of hybrid AC-DC power grids. A convexification method for the LCC station model could address such nonconvexity but has rarely been discussed. We devise an equivalent reformulation for classical LCC station models that facilitates second-order cone convex relaxation for the OPF of LCC-based AC-DC power grids. We also propose sufficient conditions for exactness of convex relaxation with its proof. Equivalence of the proposed LCC station models and properties, exactness, and effectiveness of convex relaxation are verified using four numerical simulations. Simulation results demonstrate a globally optimal solution of the original OPF can be efficiently obtained from relaxed model.

关键词： AC-DC power system convex relaxation linecommutated converter optimal power flow second-order cone programming

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In situ digital testing method for quality assessment of soft soil improvement with polyurethane

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j.urnal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1732-1748页

作者： X.F.Wang C.j.Wang W.V.Yue z.j.z.ang z.Q.Yue Department of Civil Engineering China University of Geosciences (Beijing)BeijingChina Department of Water Science and Engineering Zhengzhou UniversityZhengzhouChina Department of Geotechnical Engineering Tongji UniversityShanghaiChina Department of Civil Engineering The University of Hong KongChina

This study purposes an in situ testing method on quality assessment of soil *** drilling data includes the spatial distribution and in situ strength of untreated and treated soil along three different drillholes measured by on-site drilling monitoring *** factual drilling data can characteriz. the degree of soil improvement by penetration inj.ction with permeable *** from on-site drilling monitoring shows that the linear z.nes represent constant drilling speeds shown in the plot of drill bit advancement *** drilling time,which indicates the spatial distributions of soil *** soil profile at the study site is composed of four layers,which includes fill,untreated silty clay,treated silty clay,and mucky *** results of soil profile are verified by the parallel site *** constant drilling speeds profile the coring-resistant strength of drilled *** comparing with the untreated silty clay,the constant drilling speeds of the treated silty clay have been decreased by 13.0-62.8%.Two drilling-speed-based indices of 61.2%and 65.6%are proposed to assess the decreased average drilling speed and the increased in situ strength of treated silty *** tests,*** compressive strength(UCS)test,have been performed with core sample to investigate and characteriz. in situ strength by comparing that with drilling *** show that the average predicted strengths of treated silty clay are 2.4-6.9 times higher than the average measured strength of untreated silty *** UCS-based indices of 374.5%and 344.2%verified the quality assessment(QA)results by this new in situ *** method provides a cost-effective tool for quality assessment of soil improvement by utiliz.ng the digital drilling data.

关键词： Drilling process monitoring system Hydraulic rotary drilling process Constant drilling speed Soil improvement Quality assessment

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Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/CdS heteroj.nction with photothermal effect for efficient photocatalytic hydrogen production

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j.urnal of Materials Science & Technology 2024年第4期171卷 1-9页

作者： T.Y.Huang z.Yang S.Y.Yang z.H.Dai Y.j.Liu j.H.Liao G.Y.z.ong z.j.Xie Y.P.Fang S.S.z.ang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China School of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utiliz.tion of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/CdS heteroj.nction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)CdS nanosheets on 2D MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous *** unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of *** irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of CdS *** study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure Heterostructure Photothermal effect Photocatalyst Hydrogen evolution

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Compressive property and energy absorption characteristic of interconnected porous Mg-z.-Y alloys with adj.sting Y addition

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j.urnal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： j.A.Liu S.j.Liu B.Wang W.B.Sun X.j.Liu z.W.Han College of Materials Science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of Bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China Weihai Institute for Bionics-j.lin University Weihai 264205PR China

In this study,interconnected porous Mg-2z.-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adj.st the compressive properties and energy absorption *** characteriz.tion methods were then applied to identify the microstructure of the porous Mg-z.-Y and describe the details of the second *** tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-z.-Y ternary phases appear:I-phase(Mg_(3)z._(6)Y),W-phase(Mg_(3)z._(3)Y_(2)),and LPSO phase(Mg_(12)z.Y).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 Mj.m^(3)to 10.97 Mj.m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-z.-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-z.-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

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An Improved Image Steganography Security and Capacity Using Ant Colony Algorithm Optimiz.tion

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Computers, Materials and Continua 2024年第3期80卷 4643-4662页

作者： j.sim z.K.j. Kurnaz.S. Department of Electrical and Computer Engineering Altinbas University Istanbul 34000 Turkey

This advanced paper presents a new approach to improving image steganography using the Ant Colony Optimiz.tion (ACO) algorithm. Image steganography, a technique of embedding hidden information in digital photographs, should ideally achieve the dual purposes of maximum data hiding and maintenance of the integrity of the cover media so that it is least suspect. The contemporary methods of steganography are at best a compromise between these two. In this paper, we present our approach, entitled Ant Colony Optimiz.tion (ACO)-Least Significant Bit (LSB), which attempts to optimiz. the capacity in steganographic embedding. The approach makes use of a grayscale cover image to hide the confidential data with an additional bit pair per byte, both for integrity verification and the file checksum of the secret data. This approach encodes confidential information into four pairs of bits and embeds it within uncompressed grayscale images. The ACO algorithm uses adaptive exploration to select some pixels, maximiz.ng the capacity of data embedding while minimiz.ng the degradation of visual quality. Pheromone evaporation is introduced through iterations to avoid stagnation in solution refinement. The levels of pheromone are modified to reinforce successful pixel choices. Experimental results obtained through the ACO-LSB method reveal that it clearly improves image steganography capabilities by providing an increase of up to 30% in the embedding capacity compared with traditional approaches; the average Peak Signal to Noise Ratio (PSNR) is 40.5 dB with a Structural Index Similarity (SSIM) of 0.98. The approach also demonstrates very high resistance to detection, cutting down the rate by 20%. Implemented in MATLAB R2023a, the model was tested against one thousand publicly available grayscale images, thus providing robust evidence of its effectiveness. Copyright © 2024 The Authors. Published by Tech Science Press.

关键词： ant colony algorithm capacity optimiz.tion steganalysis Steganography

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Four Late-type Galaxies with Double Radio Lobes and Properties of Such Galaxies

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Research in Astronomy and Astrophysics 2024年第4期24卷 84-90页

作者： z.S.Yuan X.Y.Gao z.L.Wen j.L.Han National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China

The triggering mechanism for radio lobes from late-type galaxies is not fully *** samples are desired for a thorough investigation and *** utiliz.ng the optical data from the newly released Dark Energy Spectroscopic Instrument imaging surveys and the radio sources from the NRAO VLA Sky Survey and the Faint Images of the Radio Sky at Twenty-centimeter,we identify four Late-type Galaxies with double Radio Lobes(La GRLs):j.217-3645,j.947+6220,j.412+3723 and j.736+*** previously known La GRLs,we confirm the correlation between radio power P_(1.4GHz.and stellar mass M_(*)of host ***(25/35)La GRLs belong to the blue cloud galaxies,while the newly identified cases in this work are located within the region of the red *** find a clear correlation between the differential radio power,i.e.,the offset from the P_(1.4GHz.-M_(*)relation,and the galaxy color,indicating that bluer galaxies at a fixed M_(*)tend to host more powerful radio ***,the maj.rity(31/36)of La GRLs are either located in a galaxy group or displaying a disturbed *** suggest that all of the galaxy mass,color and surrounding environment could play important roles in triggering radio lobes in late-type galaxies.

关键词： galaxies:active galaxies:j.ts galaxies:spiral radio continuum:galaxies

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