检索结果-南通市图书馆

CToMP: a cycle-task-oriented memory protection scheme for unmanned systems

Science China(information Sciences) 2024年第6期67卷 399-417页

作者： Chengyan ma Ning Xi Di LU Yebo FENG Jianfeng ma School of Cyber Engineering Xidian University School of Computer Science and Technology Xidian University Department of Computer and information Science University of Oregon

Memory corruption attacks(MCAs) refer to malicious behaviors of system intruders that modify the contents of a memory location to disrupt the normal operation of computing systems, causing leakage of sensitive data or perturbations to ongoing processes. Unlike general-purpose systems, unmanned systems cannot deploy complete security protection schemes, due to their limitations in size, cost and *** in unmanned systems are particularly difficult to defend against. Furthermore, MCAs have diverse and unpredictable attack interfaces in unmanned systems, severely impacting digital and physical sectors. in this paper, we first generalize, model and taxonomize MCAs found in unmanned systems currently, laying the foundation for designing a portable and general defense approach. According to different attack mechanisms,we found that MCAs are mainly categorized into two types — return2libc and return2shellcode. To tackle return2libc attacks, we model the erratic operation of unmanned systems with cycles and then propose a cycle-task-oriented memory protection(CToMP) approach to protect control flows from tampering. To defend against return2shellcode attacks, we introduce a secure process stack with a randomized memory address by leveraging the memory pool to prevent Shellcode from being executed. Moreover, we discuss the mechanism by which CTo MP resists the return-oriented programming(ROP) attack, a novel variant of return2libc attacks. Finally, we implement CTo MP on CUAV V5+ with Ardupilot and Crazyflie. The evaluation and security analysis results demonstrate that the proposed approach CTo MP is resilient to various MCAs in unmanned systems with low footprints and system overhead.

关键词： unmanned system memory corruption attack memory protection system security randomized memory address

来源：

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Unconfined compressive strength and failure behaviour of completely weathered granite from a fault zone

引用

Journal of Mountain Science 2024年第6期21卷 2140-2158页

作者： DU Shaohua ma Jinyin ma Liyao ZHAO Yaqian School of Civil Engineering and Architecture Henan University of Science and TechnologyLuoyang 471023China School of Resources and safety Engineering Central South UniversityChangsha 410083China China Railway 18th Bureau Group Co. LtdTianjin 300222 China China General Nuclear Power Corporation Shenzhen 518031China

Understanding the strength characteristics and deformation behaviour of the tunnel surrounding rock in a fault zone is significant for tunnel stability *** this study,a series of unconfined compression tests were conducted to investigate the mechanical characteristics and failure behaviour of completely weathered granite(CWG)from a fault zone,considering with height-diameter(h/d)ratio,dry densities(ρd)and moisture contents(ω).Based on the experimental results,a regression mathematical model of unconfined compressive strength(UCS)for CWG was developed using the Multiple Nonlinear Regression method(MNLR).The research results indicated that the UCS of the specimen with a h/d ratio of 0.6 decreased with the increase ofω.When the h/d ratio increased to 1.0,the UCS increasedωwith up to 10.5%and then ***ρd is conducive to the improvement of the UCS at anyω.The deformation and rupture process as well as final failure modes of the specimen are controlled by h/d ratio,ρd andω,and the h/d ratio is the dominant factor affecting the final failure mode,followed byωandρ*** specimens with different h/d ratio exhibited completely different fracture mode,i.e.,typical splitting failure(h/d=0.6)and shear failure(h/d=1.0).By comparing the experimental results,this regression model for predicting UCS is accurate and reliable,and the h/d ratio is the dominant factor affecting the UCS of CWG,followed byρd and thenω.These findings provide important references for maintenance of the tunnel crossing other fault fractured zones,especially at low confining pressure or unconfined condition.

关键词： Fault fracture zone Completely weathered granite(CWG) Unconfined compression strength(UCS) Multiple nonlinear regression model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deterministic and Robust Volt-var Control Methods of Power System Based on Convex Deep Learning

引用

Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 719-729页

作者： Qing ma Changhong Deng the School of Electrical Engineering and Automation Wuhan UniversityWuhanChina

Volt-var control(VVC)is essentially a non-convex optimization problem due to the non-convexity of power flow(PF)constraints,resulting in the difficulty in obtaining the optimum without convexity *** existing second-order cone method for the convexity conversion often leads to a sharp increase in PF constraints and optimization variables,which in turn increases the optimization difficulty or even leads to optimization *** paper first proposes a deterministic VVC method based on convex deep learning power flow(DLPF).This method uses the input convex neural network(iCNN)to establish a single convex mapping between state parameters and node voltage to complete the convexity conversion while the optimization variables only correspond to reactive power equipment,which can ensure the global optimum with extremely fast computation *** cope with the impact brought by the uncertainty of distributed energy and omit the additional worst scenario search of traditional robust VVC,this paper proposes robust VVC method based on convex deep learning interval power flow(DLiPF),which continues to adopt iCNN to establish another convex mapping between state parameters and node voltage *** DLiPF with DLPF,this method decreases the modeling and optimization difficulty of robust VVC *** results on 30-bus,118-bus,and 200-bus systems prove the correctness and rapidity of the proposed methods.

关键词： Volt-var control convexity conversion convex deep learning power flow

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhancing capacitive deionization performance and cyclic stability of nitrogen-doped activated carbon by the electro-oxidation of anode materials

引用

Chinese Journal of Chemical Engineering 2024年第5期69卷 23-33页

作者： Xiaona Liu Baohua Zhao Yanyun Hu Luyue Huang Jingxiang ma Shuqiao Xu Zhonglin Xia Xiaoying ma Shuangchen ma School of Environmental Science and Engineering North China Electric Power UniversityBaoding 071003China Huadian Zhengzhou machinery Design and Research institute Co. LtdZhengzhou 450002China Huadian inner Mongolia Energy Co. Ltd.Baotou Power Generation BranchBaotou 014013China

Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDi) community. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon(NAC) was prepared by pyrolyzing the blend of activated carbon powder(ACP) and melamine for the positive electrode of asymmetric CDi. By comparing the indicators changes such as conductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDi cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDi performance were revealed. it was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential(E_(pzc)) shift positively,which results in the uneven distribution of potential windows of CDi units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N.

关键词： Anodic oxidation Capacitive deionization Cyclic stability N-doping

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Triple-path feature transform network for ring-array photoacoustic tomography image reconstruction

引用

Journal of innovative Optical Health Sciences 2024年第3期17卷 23-40页

作者： Lingyu ma Zezheng Qin Yiming ma Mingjian Sun School of Astronautics Harbin Institute of Technology HarbinHeilongjiang 150000P.R.China

Photoacoustic imaging(PAi)is a noninvasive emerging imaging method based on the photoacoustic effect,which provides necessary assistance for medical *** has the characteristics of large imaging depth and high ***,limited by the equipment cost and reconstruction time requirements,the existing PAi systems distributed with annular array transducers are difficult to take into account both the image quality and the imaging *** this paper,a triple-path feature transform network(TFT-Net)for ring-array photoacoustic tomography is proposed to enhance the imaging quality from limited-view and sparse measurement ***,the network combines the raw photoacoustic pressure signals and conventional linear reconstruction images as input data,and takes the photoacoustic physical model as a prior information to guide the reconstruction *** addition,to enhance the ability of extracting signal features,the residual block and squeeze and excitation block are introduced into the *** further efficient reconstruction,the final output of photoacoustic signals uses‘filter-then-upsample’operation with a pixel-shuffle multiplexer and a max out *** results on simulated and in-vivo data demonstrate that the constructed TFT-Net can restore the target boundary clearly,reduce background noise,and realize fast and high-quality photoacoustic image reconstruction of limited view with sparse sampling.

关键词： Deep learning feature transformation image reconstruction limited-view measurement photoacoustic tomography.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A combined Liouville integrable hierarchy associated with a fourth-order matrix spectral problem

引用

Communications in Theoretical Physics 2024年第7期76卷 3-10页

作者： Wen-Xiu ma Department of mathematics Zhejiang Normal University Department of mathematics King Abdulaziz University Department of mathematics and Statistics University of South Florida Tampa material Science innovation and Modelling Department of Mathematical Sciences North-West University Mafikeng Campus

This paper aims to propose a fourth-order matrix spectral problem involving four potentials and generate an associated Liouville integrable hierarchy via the zero curvature formulation. A bi-Hamiltonian formulation is furnished by applying the trace identity and a recursion operator is explicitly worked out, which exhibits the Liouville integrability of each model in the resulting hierarchy. Two specific examples, consisting of novel generalized combined nonlinear Schr?dinger equations and modified Korteweg–de Vries equations, are given.

关键词： Hamiltonian structure integrable hierarchy Lax pair matrix spectral problem zero curvature equation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Bio-Based waterborne Poly(Vanillin-Butyl Acrylate)/MXene Coatings for Leather with Desired warmth Retention and Antibacterial Properties

引用

Engineering 2024年第5期36卷 250-263页

作者： Jianzhong ma Li ma Lei Zhang Wenbo Zhang Qianqian Fan Buxing Han College of Bioresources Chemical and materials Engineering Shaanxi University of Science and TechnologyXi’an 710021China Xi’an Key Laboratory of Green Chemicals and Functional materials Xi’an 710021China College of Chemistry and Chemical Engineering Shaanxi University of Science and TechnologyXi’an 710021China Shaanxi Collaborative innovation Center of industrial Auxiliary Chemistry and Technology Shaanxi University of Science and TechnologyXi’an 710021China institute of Chemistry Chinese Academy of SciencesBeijing 100190China

This study presents a solvent-free,facile synthesis of a bio-based green antibacterial agent and aromatic monomer methacrylated vanillin(MV)using *** resulting MV not only imparted antibacterial properties to coatings layered on leather,but could also be employed as a green alternative to petroleum-based carcinogen styrene(St).Herein,MV was copolymerized with butyl acrylate(BA)to obtain waterborne bio-based P(MV-BA)miniemulsion via miniemulsion ***,MXene nanosheets with excellent photothermal conversion performance and antibacterial properties,were introduced into the P(MV-BA)miniemulsion by ultrasonic *** the gradual solidification of P(MV-BA)/MXene nanocomposite miniemulsion on the leather surface,MXene gradually migrated to the surface of leather coatings due to the cavitation effect of ultrasonication and amphiphilicity of MXene,which prompted its full exposure to light and bacteria,exerting the maximum photothermal conversion efficiency and significant antibacterial *** particular,when the dosage of MXene nanosheets was 1.4 wt%,the surface temperature of P(MV-BA)/MXene nanocomposite miniemulsioncoated leather(PML)increased by about 15℃ in an outdoor environment during winter,and the antibacterial rate against Escherichia coli and Staphylococcus aureus was nearly 100%under the simulated sunlight treatment for 30 ***,the introduction of MXene nanosheets increased the air permeability,water vapor permeability,and thermal stability of these *** study provides a new insight into the preparation of novel,green,and waterborne bio-based nanocomposite coatings for leather,with desired warmth retention and antibacterial *** can not only realize zerocarbon heating based on sunlight in winter,reducing the use of fossil fuels and greenhouse gas emissions,but also improve ability to fight off invasion by harmful bacteria,viruses,and other microorganisms.

关键词： MXene nanosheets Vanillin Styrene substitute Leather coating Photothermal conversion warmth retention Antibacterial properties

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear phylogenomics of angiosperms and insights into their relationships and evolution

引用

Journal of integrative Plant Biology 2024年第3期66卷 546-578页

作者： Guojin Zhang Hong ma College of Life Sciences Hunan Normal UniversityChangsha 410081China Department of Biology 510 Mueller LaboratoryHuck Institutes of the Life SciencesThe Pennsylvania State UniversityUniversity ParkPA 16802USA

Angiosperms(flowering plants) are by far the most diverse land plant group with over 300,000 species. The sudden appearance of diverse angiosperms in the fossil record was referred to by Darwin as the “abominable mystery,”hence contributing to the heightened interest in angiosperm evolution. Angiosperms display wide ranges of morphological, physiological,and ecological characters, some of which have probably influenced their species richness. The evolutionary analyses of these characteristics help to address questions of angiosperm diversification and require well resolved phylogeny. Following the great successes of phylogenetic analyses using plastid sequences,dozens to thousands of nuclear genes from next-generation sequencing have been used in angiosperm phylogenomic analyses, providing well resolved phylogenies and new insights into the evolution of angiosperms. in this review we focus on recent nuclear phylogenomic analyses of large angiosperm clades, orders, families,and subdivisions of some families and provide a summarized Nuclear Phylogenetic Tree of Angiosperm Families. The newly established nuclear phylogenetic relationships are highlighted and compared with previous phylogenetic results. The sequenced genomes of Amborella,Nymphaea, Chloranthus, Ceratophyllum, and species of monocots, magnoliids, and basal eudicots, have facilitated the phylogenomics of relationships among five major angiosperms clades. All but one of the 64 angiosperm orders were included in nuclear phylogenomics with well resolved relationships except the placements of several orders. Most families have been included with robust and highly supported placements, especially for relationships within several large and important orders and ***, we examine the divergence time estimation and biogeographic analyses of angiosperm on the basis of the nuclear phylogenomic frameworks and discuss the differences compared with previous analyses. Furthermore,we discuss the implicatio

关键词： angiosperms evolution flowering plants nuclear gene phylogenomics phylogeny

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

in silico optimization of actuation performance in dielectric elastomercomposites via integrated finite element modeling and deep learning

引用

Theoretical & Applied Mechanics Letters 2024年第1期14卷 48-56页

作者： Jiaxuan ma Sheng Sun materials Genome institute Shanghai UniversityShanghai 200444China Zhejiang Laboratory Hangzhou 311100China Shanghai Frontier Science Center of Mechanoinformatics Shanghai UniversityShanghai 200444China

Dielectric elastomers(DEs)require balanced electric actuation performance and mechanical integrity under applied *** high dielectric particles as fillers provides extensive design space to optimize concentration,morphology,and distribution for improved actuation performance and material *** study presents an integrated framework combining finite element modeling(FEM)and deep learning to optimize the microstructure of DE *** first calculates actuation performance and the effective modulus across varied filler combinations,with these data used to train a convolutional neural network(CNN).integrating the CNN into a multi-objective genetic algorithm generates designs with enhanced actuation performance and material modulus compared to the conventional optimization approach based on FEM approach within the same *** framework harnesses artificial intelligence to navigate vast design possibilities,enabling optimized microstructures for high-performance DE composites.

关键词： Dielectric elastomer composites Multi-objective optimization Finite element modeling Convolutional neural network

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CoDetect: cooperative anomaly detection with privacy protection towards UAV swarm

引用

Science China(information Sciences) 2024年第5期67卷 325-326页

作者： Teng Li Weiguo LiN Ruichen ma Zhuo ma Yulong SHEN Jianfeng ma School of Cyber Engineering Xidian University School of Computer Science and Technology Xidian University

As mission scenarios grow more complex, the role of a single unmanned aerial vehicle(UAV) is limited. The UAV swarm,surpassing the single UAV, dynamically establishes temporary communication networks, ensuring high transmission rates and expansive communication coverage [1]. Unlike a single UAV, a swarm faces increased security risks, requiring specific capabilities.(1) Anomalies detection.

关键词： Unmanned aerial vehicles (UAV)

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：