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MQTT and blockchain sharding:An approach to user-controlled data access with improved security and efficiency

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Blockchain(Research and Applications) 2023年第4期4卷 86-98页

作者： P.s.Akshatha s.M.Dilip Kumar Department of Computer science and Engineering University of Visvesvaraya College of EngineeringBangalore UniversityBengaluruKarnataka 560056India

The rapid growth of the Internet of Things(IoT)has raised security concerns,including MQTT protocol-based applications that lack built-in security features and rely on resource-intensive Transport Layer security(TLs)*** paper presents an approach that utilizes blockchain technology to enhance the security of MQTT communication while maintaining *** approach involves using blockchain sharding,which enables higher scalability,improved performance,and reduced computational overhead compared to traditional blockchain approaches,making it well-suited for resource-constrained IoT *** approach leverages Ethereum blockchain’s smart contract mechanism to ensure trust,accountability,and user ***,we introduce a shard-based consensus mechanism that enables improved security while minimizing computational *** also provide a user-controlled and secured algorithm using Proof-of-Access implementation to decentralize user access control to data stored in the blockchain *** proposed approach is analyzed for usability,including metrics such as bandwidth consumption,CPU usage,memory usage,delay,access time,storage time,and jitter,which are essential for IoT application *** analysis demonstrated that the approach reduces resource consumption,and the proposed system outperforms TLs and existing blockchain approaches in these metrics,regardless of the choice of the MQTT ***,thoroughly addressing future research directions,including issues and challenges,ensures careful consideration of potential advancements in this domain.

关键词： Blockchain Internet of Things MQTT Publish/subscribe MQTT brokers HiveMQ Mosquitto EMQx Eclipse sharding

Mean-Field Model Beyond Boltzmann-Enskog Picture for Dense Gases

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Communications in Computational Physics 2011年第5期9卷 1106-1116页

作者： s.Ansumali Engineering Mechanics Unit Jawaharlal Nehru Centre for Scientific Research560064 BangaloreIndia

This work proposes an extension to Boltzmann BGK equation for dense *** present model has an H-theorem and it allows choice of the Prandtl number as an independent parameter.I show that similar to Enskog equation this... 详细信息

关键词： Microflows lattice Boltzmann method

Thermo-diffusion impact on immiscible flow characteristics of convectively heated vertical two-layered Baffle saturated porous channels in a suspension of nanoparticles:an analytical study

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Applied Mathematics and Mechanics(English Edition) 2023年第2期44卷 307-324页

作者： s.P.V.ANANTH B.N.HANUMAGOWDA s.V.K.VARMA C.s.K.RAJU I.KHAN P.RANA Department of Mathematics School of Applied SciencesREVA UniversityBangalore 560064India Department of Mathematics GITAM School of ScienceGITAM UniversityBangalore 562163India Department of Mathematics College of Science Al-ZulfiMajmaah UniversityAl-Majmaah 11952Saudi Arabia school of Mathematical sciences College of Science and TechnologyWenzhou-Kean UniversityWenzhou 325060Zhejiang ProvinceChina

The heat and mass transfer of two immiscible fluids in an inclined channel with thermal diffusion,vicious,and Darcy dissipation is *** first region consists of a clear fluid,and the second one is filled with a nanofluid saturated with a porous *** behaviors of Cu-H_(2)O,In-H_(2)O,and Au-H_(2)O nanofluids are *** transport properties are assumed to be *** coupled non-linear equations of the flow model are transformed into the dimensionless form,and the solutions for the velocity,temperature,and concentration are obtained by the regular perturbation *** are carried out on the flow characteristics for various values of the material *** results show that the velocity and temperature of the fluids enhance with the thermal Grashof number,solutal Grashof number,and Brinkman number while decrease with the porosity parameter and solid volume fraction.

关键词： viscous fluid nanofluid heat and mass transfer thermal diffusion

Hydromagnetic unsteady slip stagnation flow of nanofluid with suspension of mixed bio-convection

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Propulsion and Power Research 2019年第4期8卷 362-372页

作者： R.Kumar s.sood C.s.K.Raju s.A.shehzad Department of Mathematics Central University of Himachal PardeshDharamshala176215India Department of Mathematics GITAM UniversityBangalore562163KarnatakaIndia Department of Mathematics COMSATS Institute of Information TechnologySahiwal57000Pakistan

In this paper,stagnation point region(suspended with nanofluid and microorganisms)is examined subjected to velocity and thermal *** flow is assumed to be flowing across an exponentially stretching flat surface under magnetic field *** transport equations(framed under Buongiorno’s model)are converted into self-similar form through suitable unsteady exponential similarity transformations which are then solved by employing implicit finite difference scheme(IFDs)known as Keller-box method(KBM).A parametric analysis is performed along with limited details of *** of pertinent constraints on local skin friction,local Nusselt number,local sherwood number and local density number of micro-organisms are also uncovered through graphs.A significant decrease in skin-friction coefficients has been detected with respect to thermal slip in comparison to velocity slip.

关键词： Unsteady flow stagnation point region Mixed convection Microorganisms Nanoparticles slip regime Keller-box scheme

Wind energy conversion system using perturb&observe-based maximum power point approach interfaced with T-type three-level inverter connected to grid

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Clean Energy 2022年第4期6卷 534-549页

作者： Pranupa s A.T.sriram s.Nagaraja Rao M s Ramaiah University of Applied sciences BangaloreIndia

In this paper,the performance of a permanent magnet synchronous generator(PMsG)-based wind energy conversion system(WECs)supplied to an uncontrolled rectifier-fed boost converter(BC)interfaced with a three-phase T-type three-level inverter(TLI)has been *** proposed WECs involves three converters,namely an uncontrolled rectifier that is used for conversion from AC to DC;a BC supplied by a PMsG-fed rectifier used to enhance the voltage gain;and a grid-connected three-phase T-type TLI is proposed to eliminate power-quality issues with synchronization of grid voltage and *** main goal of this research is to model and control the grid-connected T-type TLI using a d-q synchronous frame for wind energy for regulating the DC-link voltage and transferring the generated wind power from the BC to the ***,the perturb&observe(P&O)-based maximum power point(MPP)approach is recommended to keep track of the MPP for a BC that is supplied from a PMsG-based WECs under constant and variable wind *** proposed PMsG-based WECs interfaced with grid-connected T-type TLI using d-q control has been computationally modelled,simulated and validated with constant and variable speeds using MATLAB®and simulink®.It is confirmed that the P&O-based MPP approach ensures maximum power for varying wind speeds,and the total harmonic distortion of the T-type TLI grid current value is 3.18%,which is within IEEE-519 ***,with grid synchronization,the power factor of the T-type TLI is maintained at unity to avoid power-quality issues.

关键词： boost converter grid synchronization perturb&observe T-type three-level inverter wind turbine

Cloud-Based software Development Lifecycle:A simplified Algorithm for Cloud service Provider Evaluation with Metric Analysis

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Big Data Mining and Analytics 2023年第2期6卷 127-138页

作者： santhosh s Narayana swamy Ramaiah Computer science&Engineering Jain(Deemed-to-be University)Bangalore 562112India

At present,hundreds of cloud vendors in the global market provide various services based on a customer’s *** cloud vendors are not the same in terms of the number of services,infrastructure availability,security strategies,cost per customer,and reputation in the ***,software developers and organizations face a dilemma when choosing a suitable cloud vendor for their developmental ***,there is a need to evaluate various cloud service providers(CsPs)and platforms before choosing a suitable *** existing solutions are either based on simulation tools as per the requirements or evaluated concerning the quality of service ***,they require more time to collect data,simulate and evaluate the *** proposed work compares various CsPs in terms of major metrics,such as establishment,services,infrastructure,tools,pricing models,market share,etc.,based on the comparison,parameter ranking,and weightage ***,the parameters are categorized depending on the priority *** weighted average is calculated for each CsP,after which the values are sorted in descending *** experimental results show the unbiased selection of CsPs based on the chosen *** proposed parameter-ranking priority level weightage(PRPLW)algorithm simplifies the selection of the best-suited cloud vendor in accordance with the requirements of software development.

关键词： cloud-based software development life cycle(sDLC) cloud evaluation parameter-ranking priority level weightage(PRPLW)algorithm cloud service providers software engineering

synthesis of β-cyclodextrin functionalized gold nanoparticles for the selective detection of Pb2＋ ions from aqueous solution

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Frontiers of Materials science 2012年第2期6卷 168-175页

作者： B.AsWATHY G.s.AVADHANI s.sUJI G.sONY Department of Chemistry University of KeralaKariavattom CampusThiruvananthapuramKerala 691021India Department of Materials Engineering Indian Institute of ScienceBangaloreIndia

In the present study we carried out the synthesis of β-cyclodextrin （β-CD） functionalized gold nanoparticles （AuNPs） using a microwave assisted heating method in alkaline media. stable dispersion of β-CD stabilized AuNPs was obtained at an optimized pH of 10,5. At this pH value the deprotonated secondary hydroxyl group of β-CD shows the highest chelating affinity toward Pb2＋ ions thereby inducing AuNP aggregation. The Pb2＋ induced aggregation in β-CD-AuNP solution is monitored by both colorimetric response and UV-Vis spectroscopy. TEM, DLs and FTIR analyses were carried out to confirm the Pb2＋ ion induced aggregation behaviour of β-CD-AuNPs under alkaline conditions. Furthermore at the experimental pH the response of the β-CD-AuNP system towards Pb2＋ ions is selective when compared with other interfering metal cations.

关键词： gold nanoparticle (AuNP) β-cyclodextrin (β-CD) colorimetric detection,metal ion

Optimization of cloud load balancing using fitness function and duopoly theory

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International Journal of Intelligent Computing and Cybernetics 2021年第2期14卷 198-217页

作者： Resma K.s. sharvani G.s. Ramasubbareddy somula Computer science and Engineering Research Center Affiliated to VTU BelagaviRV College of EngineeringBangaloreIndia Computer science and Engineering RV College of EngineeringBangaloreIndiaand Information Technology VNRVJIETHyderabadIndia

Purpose-Current industrial scenario is largely dependent on cloud computing ***-demand services provided by cloud data centre are paid as per ***,it is very important to make use of the allocated resources to the *** resource utilization is highly dependent on the allocation of resources to the incoming *** allocation of requests is done with respect to the physical machines present in the *** allocating the tasks to these physical machines,it needs to be allocated in such a way that no physical machine is underutilized or over *** make sure of this,optimal load balancing is very ***/methodology/approach-The paper proposes an algorithm which makes use of the fitness functions and duopoly game theory to allocate the tasks to the physical machines which can handle the resource requirement of the incoming *** major focus of the proposed work is to optimize the load balancing in a *** optimization happens,none of the physical machine is neither overloaded nor under-utilized,hence resulting in efficient utilization of the ***-The performance of the proposed algorithm is compared with different existing load balancing algorithms such as round-robin load(RR)ant colony optimization(ACO),artificial bee colony(ABC)with respect to the selected parameters response time,virtual machine migrations,host shut down and energy *** the four parameters gave a positive result when the algorithm is ***/value-The contribution of this paper is towards the domain of cloud load *** paper is proposing a novel approach to optimize the cloud load balancing *** results obtained show that response time,virtual machine migrations,host shut down and energy consumption are reduced in comparison to few of the existing algorithms selected for the *** proposed algorithm based on the duopoly function and fitness function brings in an optimized performance

关键词： Cloud computing Load balancer Load balancing algorithms Duopoly game theory Fitness functions Response time Virtual machine migrations Host shut down Energy consumption

Adaptive Cloud Refinement(ACR)-Adaptation in Meshless Framework

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Communications in Computational Physics 2012年第4期11卷 1372-1385页

作者： M.somasekhar s.Vivek Keshav.s.Malagi V.Ramesh s.M.Deshpande CTFD CSIR–National Aerospace LaboratoriesBangaloreIndia Dept.of Mechanical Engineering Indian Institute of Technology MadrasChennaiIndia Engineering Mechanics Unit JNCASRBangaloreIndia

In the present work adaptation in meshless framework is *** grid adaptation or mesh adaptation is quite well developed area in case of conventional grid based solvers and is popularly known asAdaptivemesh refinement(AMR).In such cases the adaptation is done by subdividing the cells or elements into finer cells or *** case ofmeshlessmethods there are no cells or elements but only a cloud of *** this work we propose to achieve the meshless adaptation by locally refining the point density in the regions demanding higher *** results into an adaptive enriched cloud of *** call this method as Adaptive Cloud Refinement(ACR).Themeshless solvers need connectivity information,which is a set of neighboring *** is crucial part of meshless *** because of refining point density,the connectivity of nodes in such regions gets modified and hence has to be *** efficient connectivity update must exploit the fact that the node distribution would be largely unaffected except the region of *** connectivity updating needs to be done locally,only in these *** this paper we also present an extremely fast algorithm to update connectivity over adapted cloud called as ACU(Automatic Connectivity Update).

关键词： KFVs LsKUM meshless methods adaptation ACR ACU