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Journal of Computational Mathematics 2024年第1期42卷 156-177页

作者： Jingjun zhao Wenjiao zhao Yang xu School of Mathematics Harbin Institute of TechnologyHarbin 150001China

This paper deals with the numerical approximation for the time fractional diffusion problem with fractional dynamic boundary *** well-posedness for the weak solutions is studied.A direct discontinuous Galerkin approach is used in spatial direction under the uniform meshes,together with a second-order Alikhanov scheme is utilized in temporal direction on the graded mesh,and then the fully discrete scheme is ***,the stability and the error estimate for the full scheme are analyzed in *** experiments are also given to illustrate the effectiveness of the proposed method.

关键词： Time fractional diffusion equation Numerical stability Convergence

STRONG CONVERGENCE OF JUMP-ADAPTED IMPLICIT MILSTEIN METHOD FOR A CLASS OF NONLINEAR JUMP-DIFFUSION PROBLEMS

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Journal of Computational Mathematics 2024年第1期42卷 248-270页

作者： xu Yang Weidong zhao School of Mathematics China University of Mining and TechnologyXuzhou 221116China School of Mathematics Shandong UniversityJinan 250100China

In this paper,we study the strong convergence of a jump-adapted implicit Milstein method for a class of jump-diffusion stochastic differential equations with non-globally Lipschitz drift *** with the regular methods,the jump-adapted methods can significantly reduce the complexity of higher order methods,which makes them easily implementable for scenario ***,due to the fact that jump-adapted time discretization is path dependent and the stepsize is not uniform,this makes the numerical analysis of jump-adapted methods much more involved,especially in the non-globally Lipschitz *** provide a rigorous strong convergence analysis of the considered jump-adapted implicit Milstein method by developing some novel analysis techniques and optimal rate with order one is also successfully *** experiments are carried out to verify the theoretical findings.

关键词： Jump-diffusion Jump-adapted implicit Milstein method Poisson jumps Strong convergence rate Non-Lipschitz coefficients

A risk assessment method considering risk attributes and work safety informational needs and its application

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Chinese Journal of Chemical Engineering 2024年第4期68卷 253-262页

作者： Cong Luo Yunsheng zhao Ke xu School of Political Science and Public Administration Shandong UniversityQingdao 266200China Faculty of Engineering China University of GeosciencesWuhan 430074China Department of Emergency Management of Hubei Province Wuhan 430064China

The technological revolution has spawned a new generation of industrial systems,but it has also put forward higher requirements for safety management accuracy,timeliness,and *** assessment needs to evolve to address the existing and future challenges by considering the new demands and advancements in safety *** study aims to propose a systematic and comprehensive risk assessment method to meet the needs of process system safety *** methodology first incorporates possibility,severity,and dynamicity(PSD)to structure the“51X”evaluation indicator system,including the inherent,management,and disturbance risk ***,the four-tier(risk point-unit-enterprise-region)risk assessment(RA)mathematical model has been established to consider supervision *** in conclusion,the application of the PSD-RA method in ammonia refrigeration workshop cases and safety risk monitoring systems is presented to illustrate the feasibility and effectiveness of the proposed PSD-RA method in safety *** findings show that the PSD-RA method can be well integrated with the needs of safety work informatization,which is also helpful for implementing the enterprise's safety work responsibility and the government's safety supervision responsibility.

关键词： Risk assessment Safey “51X”evaluation indicator system Four-tier risk assessment model Risk attributes Process system

Barrier Option Pricing in Regime Switching Models with Rebates

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 849-861页

作者： Yue-xu zhao Jia-yong BAO School of Economics Hangzhou Dianzi UniversityHangzhou 310018China School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China

This paper is concerned with the valuation of single and double barrier knock-out call options in a Markovian regime switching model with specific *** integral formulas of the rebates are derived via matrix Wiener-Hopf factorizations and Fourier transform techniques,also,the integral representations of the option prices are ***,the first-passage time density functions in two-state regime model are *** applications,several numerical algorithms and numerical examples are presented.

关键词： option pricing Markovian regime switching Wiener-Hopf factorization Fourier transform

A linkable signature scheme supporting batch verification for privacy protection in crowd-sensing

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Digital Communications and Networks 2024年第3期10卷 645-654页

作者： xu Li Gwanggil Jeon Wenshuo Wang Jindong zhao School of Computer and Control Engineering Yantai UniversityYantai264005China Department of Embedded Systems Engineering Incheon National UniversityAcademyro-119Incheon22012Republic of Korea

The maturity of 5G technology has enabled crowd-sensing services to collect multimedia data over wireless network,so it has promoted the applications of crowd-sensing services in different fields,but also brings more privacy security challenges,the most commom which is privacy *** a privacy protection technology combining data integrity check and identity anonymity,ring signature is widely used in the field of privacy ***,introducing signature technology leads to additional signature verification *** the scenario of crowd-sensing,the existing signature schemes have low efficiency in multi-signature ***,it is necessary to design an efficient multi-signature verification scheme while ensuring *** this paper,a batch-verifiable signature scheme is proposed based on the crowd-sensing background,which supports the sensing platform to verify the uploaded multiple signature data efficiently,so as to overcoming the defects of the traditional signature scheme in multi-signature *** our proposal,a method for linking homologous data was presented,which was valuable for incentive mechanism and data *** results showed that the proposed scheme has good performance in terms of security and efficiency in crowd-sensing applications with a large number of users and data.

关键词： 5G network Crowd-sensing Privacy protection Ring signature Batch verification

DCEL:classifier fusion model for Android malware detection

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Journal of Systems Engineering and Electronics 2024年第1期35卷 163-177页

作者： xu Xiaolong JIANG Shuai zhao Jinbo WANG Xinheng Jiangsu Key Laboratory of Big Data Security&Intelligent Processing Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Computer Science Nanjing University of Posts and TelecommunicationsNanjing 210023China School of Computing and Engineering University of West LondonLondon W55RFUK

The rapid growth of mobile applications,the popularity of the Android system and its openness have attracted many hackers and even criminals,who are creating lots of Android ***,the current methods of Android malware detection need a lot of time in the feature engineering ***,these models have the defects of low detection rate,high complexity,and poor practicability,*** analyze the Android malware samples,and the distribution of malware and benign software in application programming interface(API)calls,permissions,and other *** classify the software’s threat levels based on the correlation of ***,we propose deep neural networks and convolutional neural networks with ensemble learning(DCEL),a new classifier fusion model for Android malware ***,DCEL preprocesses the malware data to remove redundant data,and converts the one-dimensional data into a two-dimensional gray ***,the ensemble learning approach is used to combine the deep neural network with the convolutional neural network,and the final classification results are obtained by voting on the prediction of each single *** based on the Drebin and Malgenome datasets show that compared with current state-of-art models,the proposed DCEL has a higher detection rate,higher recall rate,and lower computational cost.

关键词： Android malware detection deep learning ensemble learning model fusion

Evolution of inner wall wrinkle defects in the sinking zone of a thick-walled steel tube during radial forging

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Advances in Manufacturing 2024年第2期12卷 396-408页

作者： Yu-zhao Yang Cheng xu Li-Xia Fan School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094People’s Republic of China

An axial wrinkle defect was observed in the inner wall of the sinking zone of a thick-wall steel tube processed by cold radial *** can evolve into *** present study focuses on the evolution of wrinkles and the effects of process parameters on them using a three-dimensional radial forging process finite element model,radial forging experiments,and surface morphology *** results indicated that the vertical section angle of the hammer die and the size of the tube blank significantly affect the evolution of *** height-to-width ratioλwas introduced to describe the morphology of *** had an approximately linear relationship with the radius reduction in the sinking *** was a linear correlation between the growth slope ofλand the axial to circumferential strain ratio|εr/εθ|,which can predict theλunder few process *** the 30SiMn2MoVA steel,at the junction of the forging and sinking zones,the threshold ofλof the wrinkle that can evolve into a fissure is approximately 1.123.

关键词： Radial forging Inner wall Wrinkle defects Evolution Sinking zone

Effects of Bionic Leading Edge on the Aerodynamic Performance of a Compressor Cascade at a Low Reynolds Number

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Journal of Thermal Science 2024年第4期33卷 1272-1285页

作者： xu Huafeng zhao Shengfeng WANG Mingyang YANG Chengwu Laboratory of Light-Duty Gas-Turbine Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing100049China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Beijing100190China

To achieve high-performance compressor cascades at low Reynolds number(Re),it is important to organize the boundary layer transition and separation processes efficiently and *** this study,the airfoil is focused on at a 5%blade height at the root of the orthogonal blade in the downflow passage of the high-load booster *** bionics modeling design is carried out for the leading edge of the original blade cascade;the response characteristics of laminar transition and separation to blades with different leading edge shapes at low Reynolds numbers are studied by using large eddy simulations combined with Omega vortex *** findings of this study demonstrate that bionic leading edge modeling can significantly improve the aerodynamic performance of blades at low Reynolds *** blades effectively suppress the formation of separation bubbles at low Reynolds numbers and weaken or even eliminate large-scale flow separation at the trailing *** addition,the blades can weaken the vortex intensity on the blade surface,reduce the areas of high-velocity fluctuations,and minimize aerodynamic losses caused by turbulence *** results should serve as a valuable reference for the aerodynamic design and flow control of the high-load booster stage blade at low Re.

关键词： low Reynolds number booster stage bionic leading edge large eddy simulation

Broadband intelligent programmable metasurface with polarization-modulated self-adaptive electromagnetic functionality switching

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Photonics Research 2024年第7期12卷 1395-1409页

作者： XIMING LI RUI xu XIAOFENG SUN YUAN zhao zhao YANG GUOHONG DU College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China

Programmable metasurfaces have received a great deal of attention due to their ability to dynamically manipulate electromagnetic(EM) waves. Despite the rapid growth, most of the existing metasurfaces require manual control to switch among different functionalities, which poses severe limitations on practical applications. Here, we put forth an intelligent metasurface that has self-adaptive EM functionality switching in broadband without human participation. It is equipped with polarization discrimination antennas(PDAs) and feedback components to automatically adjust functionalities for the different incident polarization information.

关键词： equipped adjust polarization

Singularity analysis and avoidance for an SSRMS-type reconfigurable space manipulator with a non-spherical wrist and two lockable passive telescopic links

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Chinese Journal of Aeronautics 2024年第8期37卷 435-459页

作者： Zhiyuan zhao Xiaohang YANG Yuntao LI Zichun xu Jingdong zhao Hong LIU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

This study focuses on addressing kinematic singularity analysis and avoidance issues for a space station remote manipulator system(SSRMS)-type reconfigurable space *** manipulator is equipped with a non-spherical wrist and two lockable passive telescopic links(LPTLs),which enable it to have both active revolute and passive prismatic joints and operate in two distinct *** begin with the kinematic singularity analysis,the study derives the differential kinematic equations for the manipulator and identifies the dominant Jacobian matrix that causes ***,an in-depth analysis of singularities from multiple perspectives is ***,a kinematic singularity map method is proposed to capture the distribution of singularities within the reachable ***,the influence of the two LPTLs on singularities is thoroughly ***,a new method based on the matrix rank equivalence principle is introduced to determine singularity conditions,enabling the identification of all the singular configurations for the SSRMS-type reconfigurable ***,this method significantly reduces computational complexity,and the singularity conditions obtained have more concise *** the singularity avoidance problem,a novel method is developed,which simultaneously addresses the requirements of real-time performance,high precision,and the avoidance of both kinematic singularities and joint limit *** from these excellent properties,the proposed method can effectively resolve the singularity issues encountered separately by the SSRMS-type reconfigurable manipulator in its two operational *** typical simulations validate the utility of all the proposed methods.

关键词： Reconfigurable space manipulator Redundant manipulator Kinematics Singularity analysis Singularity avoidance