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Multivariate Time Series Anomaly Detection Based on Spatial-Temporal Network and Transformer in Industrial Internet of Things

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Computers, Materials & Continua 2024年第8期80卷 2815-2837页

作者： Mengmeng Zhao Haipeng Peng Lixiang Li Yeqing Ren Information Security Center State Key Laboratory ofNetworking and Switching TechnologyBeijing University of Posts and TelecommunicationsBeijing100876China National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and TelecommunicationsBeijing100876China Department of Information Science and Engineering Zaozhuang UniversityZaozhuang277160China

In the Industrial Internet of Things(IIoT),sensors generate time series data to reflect the working *** the systems are attacked,timely identification of outliers in time series is critical to ensure *** many anomaly detection methods have been proposed,the temporal correlation of the time series over the same sensor and the state(spatial)correlation between different sensors are rarely considered simultaneously in these *** to the superior capability of Transformer in learning time series *** paper proposes a time series anomaly detection method based on a spatial-temporal network and an improved ***,the methods based on graph neural networks typically include a graph structure learning module and an anomaly detection module,which are ***,in the initial phase of training,since neither of the modules has reached an optimal state,their performance may influence each *** scenario makes the end-to-end training approach hard to effectively direct the learning trajectory of each *** interdependence between the modules,coupled with the initial instability,may cause the model to find it hard to find the optimal solution during the training process,resulting in unsatisfactory *** introduce an adaptive graph structure learning method to obtain the optimal model parameters and graph *** on two publicly available datasets demonstrate that the proposed method attains higher anomaly detection results than other methods.

关键词： Multivariate time series anomaly detection spatial-temporal network Transformer

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Bearing capacity and failure behavior of disconnectable coupling joint with double row wedges(DCJD)used in the prestressed internal bracing

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Underground Space 2022年第4期7卷 498-513页

作者： Mingju Zhang Zhitian Xie Pengfei Li Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing 100124China

A disconnectable coupling joint with double row wedges(DCJD)is a crucial component of the prestressed internal bracing in subway foundation ***,only a few studies have been conducted on the bearing capacity of the joints;moreover,the yield load and compression stiffness of DCJDs are typically determined from *** aim of this study was to quantitatively determine the bearing capacity and propose accurate formulas for calculating the yield load and compression stiffness of ***,a DCJD was selected from a foundation pit in beijing,China,and loading experiments were conducted under axial ***–displacement and load–strain curves were obtained,and the failure modes of the joint were *** experimental results were verified through several finite element ***,parametric analyses were performed to investigate the effects of the dimensions of the key position on the DCJD’s bearing ***,regression analysis was used to obtain the formulae for estimating the initial compression stiffness and yield load of the ***,the fitting formulae results were compared with the numerical and experimental *** comparisons showed that the fitting formulae were highly accurate in estimating the bearing capacity of the DCJD.

关键词： Deep foundation pit Disconnectable coupling joints Loading experiments Parametric study Formulae fitting

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Three-dimensional theoretical analysis of seepage field in front of shield tunnel face

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Underground Space 2022年第4期7卷 528-542页

作者： Qiguang Di Pengfei Li Mingju Zhang Caixia Guo Fan Wang Jie Wu Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing 100124China

To evaluate hydraulic head distribution in front of a shield tunnel in a saturated soil layer,theoretical analysis and numerical simulations are carried out in this *** on the partial differential equilibrium equation of seepage flow,a three-dimensional(3D)theoretical analytical model of the shield tunnel face and the seepage field in front of it is established using the eigenfunction and the Fourier series expansion methods,and the hydraulic head calculation formula is *** with engineering cases,the theoretical analysis results and the 3D numerical simulation results are compared and *** effect of the water pressure of the tunnel face on the hydraulic head distribution is also *** results of the proposed analytical solution are in agreement with those of the numerical simulation solutions;moreover,the proposed analytical solution requires less time to calculate the seepage hydraulic head than the numerical *** ratio of the initial water table to the diameter(D)of tunnel face has a more significant impact on the hydraulic head distribution at a position 0.5D above the tunnel *** the water pressure on the tunnel face is not considered,the values of the hydraulic head are significantly underestimated.

关键词： Seepage flow Hydraulic head distribution Shield tunnel Numerical simulation Water pressure

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Mechanical response and fault-resistant design of urban shallow subway tunnel under normal fault

Mechanical response and fault-resistant design of urban shal...

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ITA-AITES World Tunnel Congress, WTC 2024

作者： Tao, Lianjin Liu, Jiangong Wang, Zhigang Shi, Ming The Key Laboratory of Urban Security and Disaster Engineering Ministry of Education Beijing University of Technology Beijing China Beijing University of Technology Beijing China

ISBN: (纸本)9781032800424

Based on the Taiyuan subway tunnel project crossing through an active fault zone, this paper utilizes ABAQUS software to construct a three-dimensional refined model. The model aims to investigate the mechanical behaviour and fault-resistant design methods of urban shallow subway tunnels that cross normal faults. Using numerical simulation and mathematical induction, the study explores the impact of two primary factors, namely fault dip angle and fault displacement, on the mechanical response and damage degree of the subway tunnel structure. In addition, ellipticity is employed to unveil the spatial deformation characteristics of the tunnel cross-section. The findings indicate that due to normal fault dislocation, the lining structure deflects at a specific angle to adjust to the fault’s forced displacement. This results in local segments of the structure becoming de-hollowed and out of sync with the soil layer’s movement. Secondly, the hanging wall’s damage area and stress-strain exceed that of the footwall by several times. Thirdly, the tunnel deformation’s maximum position depends on the fault dislocation’s location. The implementation of segmental lining mitigation measures notably diminishes the detrimental impact of fault displacement, ultimately leading to a reduction in both the magnitude of destruction and the affected area of the tunnel structure. © 2024 The Author(s).

关键词： Soils

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A Fixed End Composed of Long Bolts and Mold Bag Concrete for Prefabricated Inner Support in Foundation Pit and Experimental Investigation on its Bearing Capacity 18th

A Fixed End Composed of Long Bolts and Mold Bag Concrete for...

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18th Conference of the Associated Research Centers for the Urban Underground Space, ACUUS 2023

作者： Shan, Yuhan Zhang, Mingju Guo, Caixia Li, Pengfei Liu, Wenjie Key Laboratory of Urban Security and Disaster Engineering Ministry of Education Beijing University of Technology Beijing100124 China

ISBN: (纸本)9789819712564

In the internal support system of foundation pit engineering, reinforced concrete support is widely used in foundation pit due to high load-bearing capacity, unrestricted arrangement, cast-in-place end nodes, and good integrity. However, the disadvantages of reinforced concrete support in design and construction are also significant, including oversized design sections, long construction periods, strong pollution, high costs, and severe waste. Considering the advantages and disadvantages of concrete supports in foundation pit engineering and combining with the characteristics of deep foundation pits in subway cut-and-cover stations, a new type of prefabricated composite steel tube concrete internal support is designed. From the perspectives of improving the stiffness and strength of the end nodes and achieving fixed connections at the ends, a matching new type of end node is proposed, called the "A fixed end composed of long bolts and mold bag concrete." By elucidating the design scheme, structural characteristics, and working principles of the fixed end composed of special components such as embedded steel plates, hollow flanges, mold bag concrete, and long bolts, it is demonstrated the fixed end functions as a fixed support in the support system. Through the analysis of the mechanical characteristics, failure modes, and evolution laws of the fixed end, the analytical methods for compressive and flexural load-bearing capacities of the fixed support end are obtained. To verify the constructability and construction effect of the prefabricated internal support system, the field technique test of the prefabricated internal support system was conducted. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Tubular steel structures

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Meso-Scale Study on Dynamic Shear Property and Size Effect of RC Beams Reinforced with CFRP 2nd

Meso-Scale Study on Dynamic Shear Property and Size Effect o...

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2nd International Conference on Green Building, Civil engineering and Smart City, GBCESC 2023

作者： Li, Dong Yang, Bo Zhang, Jiangxing Jin, Liu Du, Xiuli Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of Technology Beijing100124 China

ISBN: (纸本)9789819999460

A three-dimensional mesoscale numerical analytical model for studying CFRP reinforced RC beams was developed using the ABAQUS finite element numerical calculation platform. The heterogeneity of concrete material and the interaction between rebar/CFRP and concrete was considered. Different strain rates were studied to explore the size effect behaviors and shear failure. The conclusions show that: 1) with the increase of the strain rate, the shear bearing capacity increases, and with the increase of the beam height, the nominal shear strength decreases;2) increased strain rate can result in RC beams reinforced with CFRP having greater nominal shear strength, while it can also result in diminished size effect behaviors;3) the nominal shear strength was predicted, a formula that considers both the size effect and the strain rate effect was proposed. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2024.

关键词： Strain rate

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A Comprehensive Review on Deep Learning System Testing 24th

A Comprehensive Review on Deep Learning System Testing

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24th International Conference on Algorithms and Architectures for Parallel Processing, ICA3PP 2024

作者： Li, Ying Shan, Chun Liu, Zhen Liao, Shuyan Beijing Key Laboratory of Software Security Engineering Technology Beijing Institute of Technology Beijing China School of Computer Science and Technology Beijing Institute of Technology Beijing China Computer School Beijing Information Science and Technology University Beijing China School of Cyberspace Science and Technology Beijing Institute of Technology Beijing China

ISBN: (纸本)9789819615476

Deep learning(DL) systems exhibit multiple behavioral characteristics such as correctness, robustness, and fairness. Ensuring that these behavioral characteristics function properly is crucial for maintaining the accuracy of DL systems’ outputs. As a specialized form of software, DL systems’ security testing techniques have increasingly become a focus of research in quality assurance. We analyze and organize the testing techniques for DL systems based on an investigation of the current state of the art both domestically and internationally. This paper categorizes existing approaches as component-oriented and attribute-oriented methods, providing a detailed review based on this classification. Additionally, we forecast the future development of testing techniques for DL systems. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Adversarial machine learning

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Analytical algorithms of compressive bending capacity of bolted circumferential joint in metro shield tunnels

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Frontiers of Structural and Civil engineering 2023年第6期17卷 901-914页

作者： Xiaojing GAO Pengfei LI Mingju ZHANG Haifeng WANG Zenghui LIU Ziqi JIA Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing100124China Nantong Railway Construction Component Co. Ltd.Nantong226000China

The integrity and bearing capacity of segment joints in shield tunnels are associated closely with the mechanical properties of the *** study focuses on the mechanical characteristics and mechanism of a bolted circumferential joint during the entire bearing *** analytical algorithms for four stress stages are established to describe the bearing behaviors of the joint under a compressive bending load.A height adjustment coefficient,α,for the outer concrete compression zone is introduced into a simplified analytical *** affectingαare determined,and the degree of influence of these factors is investigated via orthogonal numerical *** numerical results show thatαcan be specified as approximately 0.2 for most metro shield tunnels in ***,a case study is performed to verify the rationality of the simplified theoretical analysis for the segment joint via numerical simulations and *** the proposed simplified analytical algorithms,a parametric investigation is conducted to discuss the factors affecting the ultimate compressive bending capacity of the *** method for optimizing the joint flexural stiffness is *** results of this study can provide a theoretical basis for optimizing the design and prediciting the damage of bolted segment joints in shield tunnels.

关键词： shield tunnel segment joint joint structural model failure mechanism

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Aggregation-based dual heterogeneous task allocation in spatial crowdsourcing

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Frontiers of Computer Science 2024年第6期18卷 215-227页

作者： Xiaochuan LIN Kaimin WEI Zhetao LI Jinpeng CHEN Tingrui PEI College of Information Science and Technology&Cyberspace Security Jinan UniversityGuangzhou 510632China National&Local Joint Engineering Research Center of Network Security Detection and Protection Technology Guangzhou 510632China Guangdong Provincial Key Laboratory of Data Security and Privacy Protection Guangzhou 510632China School of Computer Science Beijing University of Posts and TelecommunicationsBeijing 100876China

Spatial crowdsourcing(SC)is a popular data collection paradigm for numerous *** the increment of tasks and workers in SC,heterogeneity becomes an unavoidable difficulty in task *** researches only focus on the single-heterogeneous task ***,a variety of heterogeneous objects coexist in real-world SC *** dramatically expands the space for searching the optimal task allocation solution,affecting the quality and efficiency of data *** this paper,an aggregation-based dual heterogeneous task allocation algorithm is put *** investigates the impact of dual heterogeneous on the task allocation problem and seeks to maximize the quality of task completion and minimize the average travel *** problem is first proved to be ***,a task aggregation method based on locations and requirements is built to reduce task ***,a time-constrained shortest path planning is also developed to shorten the travel distance in a *** that,two evolutionary task allocation schemes are ***,extensive experiments are conducted based on real-world datasets in various *** with baseline algorithms,our proposed schemes enhance the quality of task completion by up to 25% and utilize 34% less average travel distance.

关键词： task allocation aggregation shortest path dual heterogeneous spatial crowdsourcing

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Bending failure performance of a shield tunnel segment based on full-scale test and numerical analysis

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Frontiers of Structural and Civil engineering 2023年第7期17卷 1033-1046页

作者： Pengfei LI Ziqi JIA Mingju ZHANG Xiaojing GAO Haifeng WANG Wu FENG Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China Nantong Railway Construction Component Co. Ltd.Nantong 226000China

This study focuses on the bending failure performance of a shield tunnel segment.A full-scale test was conducted to investigate deformation and failure *** the loading,the bending failure process can be divided into four stages:the elastic stage,working stage with cracks,failure stage,and ultimate *** characteristic loads between contiguous stages are the cracking,failure,and ultimate loads.A numerical model corresponding to the test was established using the elastoplastic damage constitutive model of *** a comparative analysis of the simulation and test results,parametric studies were performed to discuss the influence of the reinforcement ratio and proportion of tensile longitudinal reinforcement on the bearing *** results indicated that the change in the reinforcement ratio and the proportion of tensile longitudinal reinforcement had little effect on the cracking load but significantly influenced the failure and ultimate loads of the *** is suggested that in the reinforcement design of the subway segment,the reinforcement ratio and the proportion of tensile longitudinal reinforcement can be chosen in the range of 0.7%–1.2%and 49%–55%,respectively,allowing the segment to effectively use the reinforcement and exert the design strength,thereby improving the bearing capacity of the segment.

关键词： shield tunnel bearing capacity failure mechanism segment reinforcement

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