检索结果-南通市图书馆

Journal of Materials Science and Chemical Engineering 2022年第12期10卷 1-9页

作者： Sunday Boladale Alabi Abasiyake Uku Ekpenyong Department of Chemical and Petroleum Engineering University of Uyo Uyo Nigeria

Research reports show that the accuracies of many explicit friction factor models, having different levels of accuracies and complexities, have been improved using genetic algorithm (GA), a global optimization approach. However, the computational cost associated with the use of GA has yet to be discussed. In this study, the parameters of sixteen explicit models for the estimation of friction factor in the turbulent flow regime were optimized using two popular global search methods namely genetic algorithm (GA) and simulated annealing (SA). Based on 1000 interval values of Reynolds number (Re) in the range of and 100 interval values of relative roughness () in the range of , corresponding friction factor (f) data were obtained by solving Colebrook-White equation using Microsoft Excel spreadsheet. These data were then used to modify the parameters of the selected explicit models. Although both GA and SA led to either moderate or significant improvements in the accuracies of the existing friction factor models, SA outperforms the GA. Moreover, the SA requires far less computational time than the GA to complete the corresponding optimization process. It can therefore be concluded that SA is a better global optimizer than GA in the process of finding an improved explicit friction factor model as an alternative to the implicit Colebrook-White equation in the turbulent flow regime.

关键词： Genetic Algorithm Simulated Annealing Global Optimization Explicit Friction Factor computational cost

Feasibility study of symmetric solution of molecular argon flow inside microscale nozzles

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

Applied Mathematics and Mechanics(English Edition) 2018年第4期39卷 489-500页

作者： S.M.H.KARIMIAN A.AMANI M.SEYEDNIA Department of Aerospace Engineering Amirkabir University of Technology Faculty of New Sciences and Technologies University of Tehran

The computational cost of numerical methods in microscopic-scales such as molecular dynamics(MD) is a deterrent factor that limits simulations with a large number of particles. Hence, it is desirable to decrease the computational cost and run time of simulations, especially for problems with a symmetrical domain. However, in microscopic-scales, implementation of symmetric boundary conditions is not straightforward. Previously, the present authors have successfully used a symmetry boundary condition to solve molecular flows in constant-area channels. The results obtained with this approach agree well with the benchmark cases. Therefore, it has provided us with a sound ground to further explore feasibility of applying symmetric solutions of micro-fluid flows in other geometries such as variable-area ducts. Molecular flows are solved for the whole domain with and without the symmetric boundary condition. Good agreement has been reached between the results of the symmetric solution and the whole domain solution. To investigate robustness of the proposed method, simulations are conducted for different values of affecting parameters including an external force, a flow density, and a domain length. The results indicate that the symmetric solution is also applicable to variable-area ducts such as micro-nozzles.

关键词： molecular dynamics(MD) symmetric boundary condition computational cost nozzle argon flow

维普期刊数据库

Secure Localization Based Authentication (SLA) Strategy for Data Integrity in WNS

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第6期67卷 4005-4018页

作者： V.Manikandan M.Sivaram Amin Salih Mohammed V.Porkodi K.Shankar Assistant Professor Research Research CenterLebanese French UniversityErbil44001Iraq Vice President Lebanese French UniversityErbil44001Iraq Department of Information Technology College of Engineering and Computer ScienceLebanese French UniversityErbil44001Iraq Department of Computer Applications Alagappa UniversityKaraikudi630003India

Wireless Sensor Networks(WSN)has been extensively utilized as a communication model in Internet of Things(IoT).As well,to offer service,numerous IoT based applications need effective transmission over unstable *** ensure reliability,prevailing investigations exploit multiple candidate forwarders over geographic opportunistic routing in ***,these models are affected by crucial denial of service(DoS)attacks,where huge amount of invalid data are delivered intentionally to the receivers to disturb the functionality of ***,secure localization based authentication(SLA)is presented to fight against DoS attack,and to fulfil the need of reliability and *** examining state information,SLA projects a trust model to enhance efficacy of data ***,of the prevailing opportunistic protocols,SLA guarantees data integrity by modelling a trust based authentication,providing protection against DoS attackers and diminishing computational ***,this model acts as a verification strategy to accelerate?attackers and to handle *** strategy helps SLA in eliminating duplicate transmission and by continuous verification that results from conventional opportunistic *** is performed in a MATLAB environment that offers authentic and reliable delivery by consuming approximately 50%of the cost in contrast to other *** anticipated model shows better trade off in comparison to the prevailing ones.

关键词： Wireless sensor networks opportunistic routing secure localization based authentication denial of service computational cost

A fuzzy-logic-based approach to accurate modeling of a double gate MOSFET for nanoelectronic circuit design

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

Journal of Semiconductors 2012年第9期33卷 43-49页

作者： F.Djeffal A.Ferdi M.Chahdi LEA Department of ElectronicsUniversity of Batna05000 BatnaAlgeria LEPCM Department of ElectronicsUniversity of Batna05000 BatnaAlgeria

The double gate （DG） silicon MOSFET with an extremely short-channel length has the appropriate fea- tures to constitute the devices for nanoscale circuit design. To develop a physical model for extremely scaled DG MOSFETs, the drain current in the channel must be accurately determined under the application of drain and gate voltages. However, modeling the transport mechanism for the nanoscale structures requires the use of overkill meth- ods and models in terms of their complexity and computation time （self-consistent, quantum computations ）. Therefore, new methods and techniques are required to overcome these constraints. In this paper, a new approach based on the fuzzy logic computation is proposed to investigate nanoscale DG MOSFETs. The proposed approach has been implemented in a device simulator to show the impact of the proposed approach on the nanoelectronic cir- cuit design. The approach is general and thus is suitable for any type ofnanoscale structure investigation problems in the nanotechnology industry.

关键词： nanoscale circuit DG MOSFET fuzzy modelling computational cost circuit design

维普期刊数据库

Efficient identity-based signature scheme with batch authentication for delay tolerant mobile sensor network

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2013年第4期20卷 80-86页

作者： LI Wen-ji ZHENG Kang-feng ZHANG Dong-mei YE-Qing YANG Yi-xian Information Security Center Beijing University of Posts and Telecommunications National Engineering Laboratory for Disaster Backup and Recovery Beijing University of Posts and Telecommunications

Identity-based cryptography （IBC） has drawn a lot of attentions in delay tolerant environment. However, the high computational cost of IBC becomes the most critical issue in delay tolerant mobile sensor network （DTMSN） because of the limited processing power. In this paper, an efficient identify-based signature scheme with batch authentication （ISBA） is proposed for DTMSN. ISBA designs an online/offline signature with batch authentication to reduce the computational cost, and improves data delivery mechanism to increase the number of messages for each batch authentication. Simulation results show that ISBA not only realizes a lower computational cost than existed schemes, but also does not induce negative impact on the delivery performance.

关键词： IBC DTMSN signature batch authentication computational cost

维普期刊数据库

由算法分析引出的一类差分方程的解及其相应的求和公式——悼念游兆永教授

在线全文

学校读者我要写书评

暂无评论

高等学校计算数学学报 1998年第4期 289-298页

作者：王兴华杭州大学数学与信息科学系杭州310028

感谢会议对我的邀请并提供发言的机会，此时此地，此会此际，本来游兆永教授当应居东道的首席，不幸不久前逝世了，令人不胜悲痛和惆怅。

关键词： constructive recursive technique difference equation computational cost summation formula with geometric series factor.

Block Iterative STMV Algorithm and Its Application in Multi-Targets Detection

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2020年第7期8卷 1346-1361页

作者： Daizhu Zhu Haoquan Guo Yuanao Wei Kaiju Wang Shanghai Marine Electronic Equipment Research Institute Shanghai China

STMV beamforming algorithm needs inversion operation of matrix, and its engineering application is limited due to its huge computational cost. This paper proposed block iterative STMV algorithm based on one-phase regressive filter, matrix inversion lemma and inversion of block matrix. The computational cost is reduced approximately as 1/4 M times as original algorithm when array number is M. The simulation results show that this algorithm maintains high azimuth resolution and good performance of detecting multi-targets. Within 1 - 2 dB directional index and higher azimuth discrimination of block iterative STMV algorithm are achieved than STMV algorithm for sea trial data processing. And its good robustness lays the foundation of its engineering application.

关键词： Beamforming Steered Minimum Variance (STMV) Block Iterative computational cost Multi-Targets Detection

Block Iterative STMV Algorithm and Its Application in Multi-Targets Detection

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

Block Iterative STMV Algorithm and Its Application in Multi-...