检索结果-南通市图书馆

stochastic Models to Mitigate sparse sensor Attacks in Continuous-Time non-Linear Cyber-Physical systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第9期76卷 3189-3218页

作者： Borja Bordel sánchez Ramón Alcarria Tomás Robles Information Technologies Department Universidad Politécnica de MadridMadrid28031Spain Geospatial Information Department Universidad Politécnica de MadridMadrid28031Spain

Cyber-Physical systems are very vulnerable to sparse sensor *** current protection mechanisms employ linear and deterministic models which cannot detect attacks ***,in this paper,we propose a new non-linear generalized model to describe Cyber-Physical *** model includes unknown multivariable discrete and continuous-time functions and different multiplicative noises to represent the evolution of physical processes and randomeffects in the physical and ***,the digitalization stage in hardware devices is represented *** and most critical sparse sensor attacks are described through a stochastic *** reconstruction and protectionmechanisms are based on aweighted *** probability in data samples is estimated through different indicators commonly employed in non-linear dynamics(such as the Fourier transform,first-return maps,or the probability density function).A decision algorithm calculates the final reconstructed value considering the previous error *** experimental validation based on simulation tools and real deployments is also carried ***,the new technology performance and scalability are *** prove that the proposed solution protects Cyber-Physical systems against up to 92%of attacks and perturbations,with a computational delay below 2.5 *** proposed model shows a linear complexity,as recursive or iterative structures are not employed,just algebraic and probabilistic *** conclusion,the new model and reconstructionmechanism can protect successfully Cyber-Physical systems against sparse sensor attacks,even in dense or pervasive deployments and scenarios.

关键词： Cyber-physical systems sparse sensor attack non-linear models stochastic models security

A Probabilistic Trust Model and Control Algorithm to Protect 6G networks against Malicious Data Injection Attacks in Edge Computing Environments

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & sciences 2024年第10期141卷 631-654页

作者： Borja Bordel sánchez Ramón Alcarria Tomás Robles Department of Computer systems Universidad Politécnica de MadridMadrid28031Spain Department of Geospatial Engineering Universidad Politécnica de MadridMadrid28031Spain

Future 6G communications are envisioned to enable a large catalogue of pioneering *** will range from networked Cyber-Physical systems to edge computing devices,establishing real-time feedback control loops critical for managing Industry 5.0 deployments,digital agriculture systems,and essential *** provision of extensive machine-type communications through 6G will render many of these innovative systems autonomous and *** full automation will enhance industrial efficiency significantly,it concurrently introduces new cyber risks and *** particular,unattended systems are highly susceptible to trust issues:malicious nodes and false information can be easily introduced into control ***,Denialof-service attacks can be executed by inundating the network with valueless *** anomaly detection schemes require the entire transformation of the control software to integrate new steps and can only mitigate anomalies that conform to predefined mathematical *** based on an exhaustive data collection to detect anomalies are precise but extremely *** models,with their limited understanding of mobile networks,can achieve precision rates no higher than 75%.Therefore,more general and transversal protection mechanisms are needed to detect malicious behaviors *** paper introduces a probabilistic trust model and control algorithm designed to address this *** model determines the probability of any node to be *** channels are pruned for those nodes whose probability is below a given *** trust control algorithmcomprises three primary phases,which feed themodel with three different probabilities,which are weighted and ***,anomalous nodes are identified using Gaussian mixture models and clustering ***,traffic patterns are studied using digital Bessel functions and the functional scalar ***,the in

关键词： 6G networks noise injection attacks Gaussian mixture model Bessel function traffic filter Volterra filter

Micro-phytoplankton distribution and biomass in and around a channel-based fish farm: implications for sustainable aquaculture

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Oceanologica sinica 2014年第12期33卷 180-191页

作者： sADALLY s. B nAZURALLY n TALEB-HOssEnKHAn n BHAGOOLI R Department of Biosciences Faculty of Science University of Mauritius Department of Marine and Ocean science Fisheries and Mariculture Faculty of Ocean Studies

Micro-phytoplankton density, genera composition, chlorophyllaconcentration, and physico-chemical pa-rameters were investigated at five stations （s1-near the coast; s2 and s4-at the edges of the aquaculture set-up; s3-in the center of the set-up; and s5-nearby patch of corals） in and around a coastal channel-based fish farm. The highest total micro-phytoplankton density （TPD）, including diatoms, dinoflagellates and cyanobacteria, was recorded at s3 （（6.28±2.00）×10^6 cells/L） followed by s4 （（5.87±2.81）×10^5 cells/L）, s1 （（4.92×10^5±8.70×10^4） cells/L）, s5 （（3.54×10^5±5.33×10^4） cells/L） and s2 （（2.60±1.14）×10^5cells/L）. Chlorophyll a and nutrient concentrations were highest at s3 and were positively correlated with TPD. Among the 35 genera documented in this study,Chaetoceros spp. was the dominant diatom whilePeridinium spp. was the most dominant dinoflagellate. Very low densities of toxic bloom-forming dinoflagellates were encountered during this study. These results suggest that occurrence of non-bloom densities of micro-phytoplankton, possibly due to the natural flushing of the existing lagoonal channel at the aquaculture site, yielded in little environmental impact and can represent an appropriate sustainable approach for future aquaculture de-velopment.

关键词： chlorophyll a micro-phytoplankton physico-chemical parameters sustainable aquaculture

A Robust Image Watermarking scheme Using Z-Transform, Discrete Wavelet Transform and Bidiagonal singular Value Decomposition

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2019年第1期58卷 263-285页

作者： n.Jayashree R.s.Bhuvaneswaran Ramanujan Computing Centre Anna UniversityChennai600025India

Watermarking is a widely used solution to the problems of authentication and copyright protection of digital media especially for images,videos,and audio *** is one of the emerging techniques adopted in image watermarking schemes due to its intrinsic cryptographic *** paper proposes a new chaotic hybrid watermarking method combining Discrete Wavelet Transform(DWT),Z-transform(ZT)and Bidiagonal singular Value Decomposition(BsVD).The original image is decomposed into 3-level DWT,and then,ZT is applied on the HH3 and HL3 *** watermark image is encrypted using Arnold Cat *** for the watermark and transformed original image were computed,and the watermark was embedded by modifying singular values of the host image with the singular values of the watermark *** of the proposed scheme was examined using standard test images and assessed against common signal processing and geometric *** indicated that the proposed method is transparent and highly robust.

关键词： Digital watermarking chaotic mapping z-transform arnold cat map discrete wavelet transform(DWT) bidiagonal singular value decomposition(BsVD)

Dispersion effect of nano-structure pyrolytic carbon on mechanical,electrical,and microstructural characteristics of cement mortar composite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of smart and nano Materials 2024年第3期15卷 534-578页

作者： n.K.Karthikeyan s.Elavenil school of Civil Engineering Vellore Institute of TechnologyChennaiIndia

In material science,converting waste into nanomaterials by green technologies highlights the interest in producing sus-tainable carbon nanomaterial(sCn).This study first-ever uti-lized tyre-char as a nano-structure Pyrolytic Carbon(nsPC)to develop electrically conductive *** other car-bon nanomaterials,the efficiency of nsPC particle as an sCn in developing electrically conductive composites was investi-gated in terms of dispersion,mechanical,water absorption,electrical resistivity,and *** results of sedi-mentation and zeta potential(-19 mV)showed the excellent dispersion of nsPC particle in water with the combined effect of superplasticizer and *** compressive(40.37%)and flexural strength(10.76%)than that of plain cement mortar composite(CMC)is achieved with 2 wt.%and 1.5 wt.%of nsPC particle,*** water absorption rate and volume of permeable voids were reduced,exhibiting less *** percolation zone of AC and DC resis-tivity of nsPC composite ranges between 1 and 2 wt.%,and the established percolation threshold is at 2 wt.%.XRD analysis showed C-s-H formation consistently increased with curing age,and HR-sEM with EDAX analysis exhibits the dense micro-structure and well-distributed nsPC particle at the *** experimental outcomes significantly enhanced the relia-bility and provided a framework for tailoring nsPC particle as sCn for developing electrically conductive composite.

关键词： sustainable nanomaterial dispersion mechanical properties electrical resistivity microstructure analysis

Comparison of mantle lithosphere beneath early Triassic kimberlite fields in siberian craton reconstructed from deep-seated xenocrysts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2016年第4期7卷 639-662页

作者： I.V.Ashchepkov s.s.Kuligin n.V.Vladykin H.Downes M.A.Vavilov E.n.nigmatulina s.A.Babushkina n.s.Tychkov O.s.Khmelnikova lnstitute of Geology and Mineralogy sD RAs Koptyug ave 3NovosibirskRussia Institute of Geochemistry sD RAs Favorskky str laIrkutskRussia Department of Earth and Planetary sciences Birkbeck University of LondonLondonUK Institute of Geology of Diamonds and noble metals sD RAs Lenina ave 39YakutskRussia

Mantle xenocrysts from early Triassic kimberlite pipes from Kharamai, Ary-Mastakh and Kuranakh fields in the Anabar shield of siberia revealing similar compositional trends were studied to estimate the superplume influence on the subcratonic lithosphere mantle （sCLM）. Pressure-temperature （PT） reconstructions using monomineral thermobarometry for 5 phases show division of the sCLM beneath the Kharamai field into 6 units： pyroxenitic Fe-rich （1-2 GPa） and Mg-rich （2-3 GPa） layers; middle with two levels of Gar-sp pyroxenites at - 3 and 4-5 GPa; Gar-dunite-harzburgites - 4.5-6.5 GPa subjected to llm-Px vein metasomatism; and a Mg-rich dunite lower part. In the Anabar shield （Ary-Mastakh, Dyuken and Kuranakh fields） mantle lithosphere is composed of three large units divided into two parts： upper part with amphiboles and phlogopite; two levels of pyroxenites and eclogites at 3 and 4 GPa, and a lower part composed of refertilized dunites. Diagrams showing P-Fe#Gar clusters for garnets and omphacites illustrate the differences between sCLM of these localities. Differences of Triassic sCLM from Devonian sCLM are in simple layering; abundance of na-Cr-amphiboles and metasomatism in the upper sCLM part, thick pyroxenite-eclogite layer and lower part depletion, heated from sCLM base to 5.0 GPa. Kharamai mantle clinopyroxenes represent three geochemical types：（1） harzburgitic with inclined linear REE, HFsE troughs and elevated Th, U; （2） lherzolitic or pyroxenitic with round TRE patterns and decreasing incompatible elements; （3） eclogitic with Eu troughs, Pb peak and high LILE content. Calculated parental melts for garnets with humped REE patterns suggest dissolution of former Cpx and depression means Cpx and garnets extraction. Clinopyroxenes from Ary-Mastakh fields show less in- dined REE patterns with HMREE troughs and an increase of incompatible elements. Clinopyroxenes from Kuranakh field show flatter spoon-like REE patterns and peaks in Ba, U, Pb and st, similar to th

关键词： Mantle lithosphere Monomineral thermobarometry Mineral geochemistry Triassic kimberlite Layering

The Mathematical Analysis for Peristaltic Flow of Hyperbolic Tangent Fluid in a Curved Channel

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2013年第6期59卷 729-736页

作者： s.nadeem E.n.Maraj Department of Mathematics Quaid-i-Azam University

In the present paper, we have investigated the peristaltic flow of hyperbolic tangent fluid in a curved channel. The governing equations of hyperbolic tangent fluid model for curved channel are derived including the effects of curvature. The highly nonlinear partial differential equations are simplified by using the wave frame transformation,long wave length and low Reynolds number assumptions. The reduced nonlinear partial differential equation is solved analytically with the help of homotopy perturbation method (HPM). The physical features of pertinent parameters have been discussed by plotting the graphs of pressure rise and stream functions.

关键词： tangent hyperbolic fluid curved channel peristaltic flow HPM

Phytochemistry and biological activities of Heracleum persicum: a review

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2018年第4期16卷 223-235页

作者： Zahra Majidi s.n.sadati Lamardi Department of Traditional Pharmacy School of Traditional Medicine Tehran University of Medical Sciences

Heracleum persicum Desf. ex Fisch is used in Iranian traditional medicines, for the treatment of various diseases including neurological, gastrointestinal, respiratory, rheumatological and urinary tract diseases. In phytochemical analysis of H. persicum, several classes of natural chemicals including volatile （aliphatic esters, carbonyls, phenyl propenes and terpenes） and nonvolatile （flavonoids, furanocoumarins, tannins and alkaloids） constituents as well as different minerals have been identified. scientific studies on H. persicum proved that it has a wide range of biological and pharmacological activities. This article has provided comprehensive information on Iranian traditional uses, phytochemistry and pharmacolog- ical activities of H. persicum.

关键词： Colpar heracleum persicum Pharmacology phytochemistry

Efficient Energy Optimized Faithful Adder with Parallel Carry Generation

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第2期70卷 2543-2561页

作者： K.n.Vijeyakumar s.Maragatharaj Dr.Mahalingam College of Engineering and Technology PollachiTamilnaduIndia Dhirajlal Gandhi College of Technology SalemTamilnaduIndia

Abstract:Approximate computing has received significant attention in the design of portable CMOs hardware for error-tolerant *** work proposes an approximate adder that to optimize area delay and achieve energy efficiency using Parallel Carry(PC)generation ***‘n’bits in input,the proposed algorithm use approximate addition for least n/2 significant bits and exact addition for most n/2 significant bits.A simple OR logic with no carry propagation is used to implement the approximate *** the exact part,addition is performed using 4-bit adder blocks that implement PC at block level to reduce node capacitance in the critical *** reveal that the maximum error of the proposed adder confines not more than 2n/*** an enhancement of the proposed algorithm,we use the Error Recovery(ER)module to reduce the average *** results of Proposed-PC(P-PC)and Proposed-PCER(P-PCER)adders with n-16 in 180nm Application specific Integrated Circuit(AsIC)PDK technology revealed 44.2%&41.7%PDP reductions and 43.4%&40.7%ADP reductions,respectively compared to the latest best approximate design *** functional and driving effectiveness of proposed adders are examined through digital image processing applications.

关键词： Application-specific integrated circuit approximate computing power dissipation energy dissipation image processing