检索结果-南通市图书馆

Spectral/hp element methods:Recent developments, applications, and perspectives

在线全文

学校读者我要写书评

暂无评论

journal of Hydrodynamics 2018年第1期30卷 1-22页

作者： Hui Xu Chris D.Cantwell carlos Monteserin Claes Eskilsson Allan P.Engsig-Karup Spencer j.Sherwin Department of Aeronautics Imperial College London Department of Applied Mathematics and Computer Science Technical University of Denmark Department of Civil Engineering Aalborg University Division Safety and Transport Research Institutes of Sweden (RISE) Center for Energy Resources Engineering (CERE) Technical University of Denmark

The spectral/hp element method combines the geometric flexibility of the classical h-type finite element technique with the desirable numerical properties of spectral methods, employing high-degree piecewise polynomial basis functions on coarse finite element-type meshes. The spatial approximation is based upon orthogonal polynomials, such as Legendre or Chebychev polynomials,modified to accommodate a C~0-continuous expansion. Computationally and theoretically, by increasing the polynomial order p,high-precision solutions and fast convergence can be obtained and, in particular, under certain regularity assumptions an exponential reduction in approximation error between numerical and exact solutions can be achieved. This method has now been applied in many simulation studies of both fundamental and practical engineering flows. This paper briefly describes the formulation of the spectral/hp element method and provides an overview of its application to computational fluid dynamics. In particular, it focuses on the use of the spectral/hp element method in transitional flows and ocean engineering. Finally, some of the major challenges to be overcome in order to use the spectral/hp element method in more complex science and engineering applications are discussed.

关键词： High-precision spectral/hp elements continuous Galerkin method discontinuous Galerkin method implicit large eddy simulation

Towards a business model for second-life batteries: Barriers,opportunities, uncertainties, and technologies

在线全文

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2023年第3期78卷 507-525,I0014页

作者： carlos Antônio Rufino júnior Eleonora Riva Sanseverino Pierluigi Gallo Daniel Koch Yash Kotak Hans-Georg Schweiger Hudson Zanin Advanced Energy Storage Division New Energy Innovation CenterUniversity of Campinas(UNICAMP)Campinas 13083-852Brazil Engineering Department University of Palermo(UNIPA)Palermo 90128Italy Consorzio Nazionale Interuniversitario per le Telecomunicazioni(CNIT) Parma 43124Italy Technische Hochschule Ingolstadt Institute for ElectricConnected and Safe Mobility(C-ECOS)Ingolstadt 85049Germany

Electric vehicles(EVs) and the recent pandemic outbreak give cities a new trend to primarily private and shared mobility with low noise and less air *** factors for the widespread of EVs are the electrical charging infrastructure,driving range,and the reduction of the cost of battery *** this reason,there is a massive effort from manufacturers,governments,and the scientific community to reduce battery costs and boost sustainable electrical production and *** reuse is an alternative to reduce batteries’ costs and environmental ***-life batteries can be used in a wide variety of secondary ***-life batteries can be connected with off-grid or on-grid photovoltaic and wind systems,vehicle charging stations,forklifts,and frequency *** present work aims to analyze the main challenges imposed on the reuse of batteries,the leading technologies for their reuse,and the different types of batteries in terms of their feasibility for second-life *** main novelty of this work is the discussion about the barriers,opportunities,uncertainties,and technologies for the second life *** we summarize the present state of the art in reusing lithium-ion batteries discussing technical and economic feasibility,environmental impacts,and *** results show five business models that have been proposed in the literature,three types of markets for trading second-life batteries,and the main opportunities and barriers for each actor in the battery supply chain.

关键词： Business models Batteries Sustainability Electric vehicles Challenges Opportunities Lithium-ion batteries Reuse

Co-Simulation of an SRG Wind Turbine Control and GPRS/EGPRS Wireless Standards in Smart Grids

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA journal of Automatica Sinica 2021年第3期8卷 656-663页

作者： Andre Luiz de Oliveira carlos Eduardo Capovilla Ivan Roberto Santana Casella joséLuis Azcue-Puma Alfeu j.Sguarezi Filho University of Sao Paulo Sao Paulo 05508-010Brazil Federal University of ABC Santo Andre 09210-580Brazil

Wind energy can be considered a push-driver factor in the integration of renewable energy sources within the concept of smart *** its full deployment,it requires a modern telecommunication infrastructure for transmitting control signals around the distributed generation,in which,the wireless communication standards stand out for employing modern digital modulation and coding schemes for error correction,in order to guarantee the power plant *** some developing countries,such as Brazil,the high penetration of commercial mobile wireless standards GPRS and EGPRS(based on GSM technology)have captivated the interests of the energy sector,and they now seek to perform remote monitoring and control *** this context,this article presents a comparative performance analysis of a wireless control system for a wind SRG,when a GPRS or EGPRS data service is *** system performance is analyzed by co-simulations,including the wind generator dynamics and the wireless channel *** satisfactory results endorse the viability and robustness of the proposed system.

关键词： General packet radio service(GPRS)/enhanced GPRS(EGPRS) smart grids switched reluctance generator(SRG) wind energy wireless communications

Single droplet drying of detergents:Experimentation and modelling

在线全文

学校读者我要写书评

暂无评论

Particuology 2021年第5期19卷 35-47页

作者： Borja Hernandez Rosa Mondragon Mark A.Pintoa Leonor Hernandez j.Enrique julia juan carlos jarque Sergio Chiva Mariano Martin Newcastle Innovation Centre Procter&Gamble R&DNewcastle upon TyneUK Departamento de Ingenieria Quimica y Textil.Universidad de Salamanca SalamancaSpain Departamento de Ingenieria Mecanica y Construccion Universitat Jaume ICastellon de la PlanaSpain Instituto de Tecnologia Ceramica Universitat Jaume ICastellon de la PlanaSpain

This study evaluates the single droplet drying(SDD)of *** data are used to validate a theoretical multistage *** experiments are carried out in an acoustic levitator analysing six different detergent formulations at 393 *** work is completed by developing a model based on conservation *** model is composed of the three stages observed in the drying *** the first stage,an external surface drying stage occurs until the surface is saturated and the crust is *** the next stage,the drying rate is governed by diffusion through the *** the same time,the particle heats up until boiling conditions are achieved in the core of the *** this point,the third stage *** the final stage,the droplet core is in boiling conditions which are governed by the pressure drop through the crust and the concentration of *** model has been evaluated for the different formulations being flexible to predict the drying of different mixtures with good accuracy.

关键词： Drying Single droplet Acoustic levitator Detergents

Price distortions and municipal bonds premiums:evidence from Switzerland

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Financial Innovation 2021年第1期7卷 1359-1379页

作者： Darko B.Vukovic carlos j.Rincon Moinak Maiti Department for Finance St.Petersburg School of Economics and ManagementNational Research University Higher School of EconomicsKantemirovskaya 3AOffice 331Sankt Petersburg 194100Russia

This study examines the pricing of municipal bonds before and after a currency shock in *** approaches are used to decompose the municipal to treasuries bond spreads into liquidity,maturity,and default risk *** first approach is the model of the cross-sectional instrumental variables,and the second approach is the model of the instrumental variables with panel *** study examines the composition of spreads for both approaches,in three scenarios:before,throughout,and after the currency *** study performed Durbin-Wu-Hausman tests for each decisive model to verify endogeneity issues,including the Lagrangian Multiplier test,the Cragg-Donald Wald F statistic to confirm the relationship of instrumental and endogenous variables,and the structural break test(Bai-Perron test)to determine the existence of structural breaks in bond *** study finds that the currency price distortions of the Swiss franc in january 2015 made long-run changes in the composition of the municipal bond *** research contributes to the understanding of municipal bond pricing by showing that default risk accounts for a large portion of the municipal bond spread,while maturity risk plays a lesser *** to our empirical findings,unexpected large currency price shocks may have long-term implications on the municipal bond spreads.

关键词： Municipal bonds Risk premiums Bond spreads Price distortions

Parameter identification for a damage phase field model using a physics-informed neural network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2023年第3期13卷 229-246页

作者： carlos j.G.Rojas jos L.Boldrini Marco L.Bittencourt Department of Integrated System School of Mechanical EngineeringUniversity of CampinasRua Mendeleyev 200CampinasSPZip Code 13083-860Brazil

This work applies concepts of artificial neural networks to identify the parameters of a mathematical model based on phase fields for damage and *** mechanics is the part of the continuum mechanics that models the effects of micro-defect formation using state variables at the macroscopic *** equations that define the model are derived from fundamental laws of physics and provide important relationships among state *** using the model considered in this work produce good qualitative and quantitative results,but many parameters must be adjusted to reproduce certain material *** identification of model parameters is considered by solving an inverse problem that uses pseudo-experimental data to find the best values that fit the *** apply physics informed neural network and combine some classical estimation methods to identify the material parameters that appear in the damage equation of the *** strategy consists of a neural network that acts as an approximating function of the damage evolution with output regularized using the residue of the differential *** stages of optimization seek the best possible values for the neural network and the material *** training alternates between the fitting of only the pseudo-experimental data or the total loss that includes the regularizing *** test the robustness of the method to noisy data and its generalization capabilities using a simple physical case for the damage *** procedure deals better with noisy data in comparison with a more standard PDE-constrained optimization method,and it also provides good approximations of the material parameters and the evolution of damage.

关键词： Deep learning Damage Phase field Parameter fitting Inverse analysis

Effect of Noisy Fitness in Real-Time Strategy Games Player Behaviour Optimisation Using Evolutionary Algorithms

在线全文

学校读者我要写书评

暂无评论

journal of Computer Science & Technology 2012年第5期27卷 1007-1023页

作者： Antonio M. Mora Antonio Fernndez-Ares juan j. Merelo Pablo García-Snchez carlos M. Fernandes Computer Architecture and Technology Department University of Granada Institute for Systems and Robotics Technical University of Lisbon

This paper investigates the performance and the results of an evolutionary algorithm （EA） specifically designed for evolving the decision engine of a program （which, in this context, is called bot） that plays Planet Wars. This game, which was chosen for the Google Artificial Intelligence Challenge in 2010, requires the bot to deal with multiple target planets, while achieving a certain degree of adaptability in order to defeat different opponents in different scenarios. The decision engine of the bot is initially based on a set of rules that have been defined after an empirical study, and a genetic algorithm （GA） is used for tuning the set of constants, weights and probabilities that those rules include, and therefore, the general behaviour of the bot. Then, the bot is supplied with the evolved decision engine and the results obtained when competing with other bots （a bot offered by Google as a sparring partner, and a scripted bot with a pre-established behaviour） are thoroughly analysed. The evaluation of the candidate solutions is based on the result of non-deterministic battles （and environmental interactions） against other bots, whose outcome depends on random draws as well as on the opponents＇ actions. Therefore, the proposed GA is dealing with a noisy fitness function. After analysing the effects of the noisy fitness, we conclude that tackling randomness via repeated combats and reevaluations reduces this effect and makes the GA a highly valuable approach for solving this problem.

关键词： real-time strategy game genetic algorithm noisy fitness player behaviour optimisation parameter adaptation

Strategy for reliable identification of ischaemic stroke, thrombolytics and thrombectomy in large administrative databases

在线全文

学校读者我要写书评

暂无评论

Stroke & Vascular Neurology 2021年第2期6卷 194-200页

作者： Kori S Zachrison Sijia Li Mathew j Reeves Opeolu Adeoye carlos A Camargo Lee H Schwamm Renee Y Hsia Department of Emergency Medicine Massachusetts General HospitalBostonMassachusettsUSA Department of Emergency Medicine Harvard Medical SchoolBostonMassachusettsUSA Department of Epidemiology and Biostatistics Michigan State UniversityEast LansingMichiganUSA University of Cincinnati CincinnatiOhioUSA Massachusetts General Hospital BostonMassachusettsUSA Department of Emergency Medicine University of California San FranciscoSan FranciscoCaliforniaUSA

Background Administrative data are frequently used in stroke *** accurate identification of patients who had an ischaemic stroke,and those receiving thrombolysis and endovascular thrombectomy(EVT)is critical to ensure representativeness and *** examined differences in patient samples based on mode of identification,and propose a strategy for future patient and procedure identification in large administrative *** We used non-public administrative data from the state of California to identify all patients who had an ischaemic stroke discharged from an emergency department(ED)or inpatient hospitalisation from 2010 to 2017 based on International Classification of Disease(ICD-9)(2010-2015),ICD-10(2015-2017)and Medicare Severity-Diagnosis-related Group(MS-DRG)discharge *** identified patients with interhospital transfers,patients receiving thrombolytics and patients treated with EVT based on ICD,Current Procedural Terminology(CPT)and MS-DRG *** determined what proportion of these transfers and procedures would have been identified with ICD versus MS-DRG discharge *** Of 365099 ischaemic stroke encounters,most(87.70%)had both a stroke-related ICD-9 or ICD-10 code and stroke-related MS-DRG code;12.28% had only an ICD-9 or ICD-10 code and 0.02% had only an MS-DRG *** all transfers(99.99%)were identified using ICD *** identified 32433 thrombolytic-treated patients(8.9% of total)using ICD,CPT and MS-DRG codes;the combination of ICD and CPT codes identified nearly all(98%).We identified 7691 patients treated with EVT(2.1%of total)using ICD and MS-DRG codes;both MS-DRG and ICD-9/ICD-10 codes were necessary because ICD codes alone missed 13.2%of *** codes only pertain to outpatient/ED patients and are not useful for EVT *** ICD-9/ICD-10 diagnosis codes capture nearly all ischaemic stroke encounters and transfers,while the combination of ICD-9/ICD-10 and CPT codes are adequate

关键词： thrombolytic diagnosis administrative

Robust hybrid bismuth perovskites as potential photocatalysts for overall water splitting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 4593-4601页

作者： Antonio j.Chacón-García Herme G.Baldovi Artem A.Babaryk Antonio Rodríguez-Diéguez Sergio Navalón Yolanda Pérez Hermenegildo García Patricia Horcajada Advanced Porous Materials Unit IMDEA Energy InstituteAvda.Ramón y Cajal 328935 MóstolesMadridSpain Departamento de Química Universitat Politècnica de València46022 ValènciaSpain Departamento Química Inorgánica Universidad de Granada1807GranadaSpain Departamento de Biología y Geología Física y Química Inorgánica.ESCET.Universidad Rey Juan Carlos28933 MóstolesMadridSpain Instituto de tecnología química CSIC-UPV Universitat Politècnica de València(UPV)46022Spain

Organic-inorganic hybrid perovskites have gained great attention as promising photocatalysts for hydrogen ***,due to their poor stability in water,the use of aqueous hydrohalic acid solutions is specifically required for an efficient hydrogen ***,three novel photoactive lead-free hybrid perovskites based on bismuth and triazolium cations(denoted as IEF-15,IEF-16,and IEF-17(IEF stands for IMDEA energy frameworks))were synthesized and fully characterized(structural,compositional,optical,etc.).Further,these solids were proposed as photocatalysts for the challenging gas phase overall water splitting(OWS)***,IEF-16 thin films exhibited a remarkable photocatalytic activity in both H_(2) and O_(2) evolution,as a consequence of its appropriate bandgap and energy-band alignment,achieving hydrogen evolution rates ofμmol·g_(H_(2))^(-)1846 and 360 after 24 h under ultraviolet-visible(UV-vis)irradiation or simulated solar irradiation,*** study additionally highlights the remarkable structural and photochemical stability of IEF-16 under different operational conditions(*** volume,irradiation and temperature),paving the way for green hydrogen production from OWS using perovskite-based photocatalysts.

关键词： bismuth-based hybrid perovskites thin films photocatalysis overall water splitting green hydrogen