102,492 Hits in 6.9 sec

An optimal control approach to a posteriori error estimation in finite element methods

Roland Becker, Rolf Rannacher
2001 Acta Numerica  
These include problems from viscous fluid flow, chemically reactive flow, elasto-plasticity, radiative transfer, and optimal control.  ...  This article surveys a general approach to error control and adaptive mesh design in Galerkin finite element methods that is based on duality principles as used in optimal control.  ...  Acknowledgements The authors wish to thank several members of the Numerical Analysis Group at their institute for important contributions to this survey article, particularly W. Bangerth, M.  ... 
doi:10.1017/s0962492901000010 fatcat:jnz3v3b3sjbnpkpk5kccbv2iae

Planet Formation: An Optimized Population-synthesis Approach

John Chambers
2018 Astrophysical Journal  
The physics of planet formation is investigated using a population synthesis approach.  ...  Although the study was designed to match the extrasolar planet distribution, analogs of the Solar System form in 1-2% of systems that contain at least 4 protoplanets.  ...  In this paper, we adopt a population synthesis approach to examine the physics of planet formation.  ... 
doi:10.3847/1538-4357/aada09 fatcat:bzryk27qsjct3bef3ob6xo2564

An optimization-based approach to calculating neutrino flavor evolution

Eve Armstrong, Amol V. Patwardhan, Lucas Johns, Chad T. Kishimoto, Henry D. I. Abarbanel, George M. Fuller
2017 Physical Review D  
D.A. uses measurements obtained from a physical system to estimate the state variable evolution and parameter values of the associated model.  ...  Formulated as an optimization procedure, D.A. can offer an integration-blind approach to predicting model evolution, which offers an advantage for models that thwart solution via traditional numerical  ...  OPTIMIZATION-BASED APPROACH TO NEUTRINO … PHYSICAL REVIEW D 96, 083008 (2017) 083008 -13 in P y that is common to many of the results reflects the slight deviation from perfect adiabaticity: the polarization  ... 
doi:10.1103/physrevd.96.083008 fatcat:pr6jgmwi7nborf6ms7r6adqdny

Speciality oils supply chain optimization: From a decoupled to an integrated planning approach

Mario Guajardo, Martin Kylinger, Mikael Rönnqvist
2013 European Journal of Operational Research  
We present numerical examples to illustrate potential effects of integration and coordination and discuss the advantages and disadvantages of the integrated over the decoupled approach.  ...  We study a problem of tactical planning in a divergent supply chain. It involves decisions regarding production, inventory, internal transportation, sales and distribution to customers.  ...  They would also like to thank Vivienne Knowles for her help in bringing this article to fruition.  ... 
doi:10.1016/j.ejor.2013.03.007 fatcat:syuvfajiqbdb3npsgfcdojgqcu

An Optimal Multiple Stopping Approach to Infrastructure Investment Decisions [article]

Eric Dahlgren, Tim Leung
2015 arXiv   pre-print
In order to value the underlying real option, we introduce an optimal multiple stopping approach that accounts for operational flexibility, delay induced by lead time, and multiple (finite/infinite) future  ...  We provide an analytical characterization of the firm's value function and optimal stopping rule.  ...  Acknowledgements The authors are grateful to Klaus Lackner, Garrett van Ryzin and Caner Göçmen for their useful suggestions and conversations.  ... 
arXiv:1502.00861v1 fatcat:dfginh2w6resrijjnkswyrftse

An Optimization Approach for Deriving Upper and Lower Bounds of Transportation Network Vulnerability under Simultaneous Disruptions of Multiple Links

Xiangdong Xu, Anthony Chen, Chao Yang
2017 Transportation Research Procedia  
This paper aims to develop an optimization approach for deriving the upper and lower bounds of transportation network vulnerability under simultaneous disruptions of multiple links without the need to  ...  Abstract This paper aims to develop an optimization approach for deriving the upper and lower bounds of transportation network vulnerability under simultaneous disruptions of multiple links without the  ...  Acknowledgements The authors are grateful to three anonymous referees for their constructive comments and suggestions to improve the quality and clarity of the paper.  ... 
doi:10.1016/j.trpro.2017.05.036 fatcat:t27i2jrzpfhvvfydspfqvy7zca

Case Study for an Operation-based Topology Optimization Using the Digital Twin Approach

Fahmi Bellalouna
2021 Procedia CIRP  
Based on Datum Flow Chain, the physical structure of the products is analyzed. Functional subassemblies are identified, and a functional analysis is performed.  ...  An industrial case study on two product families of steering columns of thyssenkrupp Presta France is then carried out to give a first industrial evaluation of the proposed approach.  ...  The case study addressed the product topology optimization for an arbor press based on collected operational product load data in place of estimated or experience data, in order to reduce the use of materials  ... 
doi:10.1016/j.procir.2021.01.114 fatcat:xgv7ftzlbzbuvpasbu6wgw3ane

Station Importance Evaluation in Dynamic Bike-Sharing Rebalancing Optimization Using an Entropy-Based TOPSIS Approach

Mingjia He, Xinwei Ma, Yuchuan Jin
2021 IEEE Access  
An entropy-based Technique for Order of Preference by Similarity to the Ideal Solution (TOPSIS) approach is proposed to weigh different criteria and evaluate station importance.  ...  As an eco-friendly travel mode, bike-sharing has prevailed around the world. However, the systems are imbalanced due to the asymmetric spatial and temporal distribution of user demand.  ...  [18] put forward an improved ARIMA model, considering signals from neighboring stations and seasonal trends to estimate available bicycles at each station.  ... 
doi:10.1109/access.2021.3063881 fatcat:qtwqjnijubfoxhjhbkquvw6bwu

Machine layout: an optimization and knowledge-based approach

1990 International Journal of Production Research  
of material from plant i to plant k of transporting a unit material from location j to location I following were defined: total number of plants/locations net revenue from operating plant i at location  ...  Flow doninance can be defined as the coefficient of variation of the flow data, computed from the flow matrix elements as (Herroelen and Gils, 1985) : 1 0'1 MSTA appears to provide optimal results when  ...  Four patterns of layou! were identified. The motion characteristic of an AGV was also anal.yzed. À neri approach lo modelling the layout problem was presented. The nain inten!  ... 
doi:10.1080/00207549008942744 fatcat:du3nk7vhjzfpnmglypwbgx2cse

Optimizing Public Transportation Networks Using Space Syntax as an Evidence-Based Approach: The Case Study of Mansoura City. (Dept. A)

Sara Elgamal, Sherief Sheta, Mohand Foda
2020 MEJ. Mansoura Engineering Journal  
This research applies Space Syntax configurational analysis with the aim to present an evidence approach to optimize its transportation network.  ...  Transport network planning in Egypt suffers from insufficient planning that should be done prior to execution.  ...  The predominant question this research attempts to answer is what are the potentials and limitations of Space Syntax as an approach in the process of optimizing public transportation networks?  ... 
doi:10.21608/bfemu.2020.118212 fatcat:bv4r6byo2vhcxbo3gpuhqze4v4

An Integer Optimization Approach to Large-Scale Air Traffic Flow Management

Dimitris Bertsimas, Guglielmo Lulli, Amedeo Odoni
2011 Operations Research  
The model covers all the phases of each flight-i.e., takeoff, en route cruising, and landing-and solves for an optimal combination of flow management actions, including ground-holding, rerouting, speed  ...  Moreover, three classes of valid inequalities are incorporated into the model to strengthen the polyhedral structure of the underlying relaxation.  ...  Guglielmo Lulli's research has benefited from a six-month Fulbright Scholarship (May-November 2007).  ... 
doi:10.1287/opre.1100.0899 fatcat:yh5upktw6ndpfkm2oi5va7fjlq

An Integrated Modeling Approach to Evaluate and Optimize Data Center Sustainability, Dependability and Cost

Gustavo Callou, João Ferreira, Paulo Maciel, Dietmar Tutsch, Rafael Souza
2014 Energies  
Our work aims to propose an integrated approach to estimate and optimize these issues with the support of the developed environment, Mercury.  ...  The approaches that evaluate and optimize these requirements are essential to support designers of data center architectures.  ...  Acknowledgments The authors would like to thank the reviewers for their valuable comments and suggestions to improve the quality of this work.  ... 
doi:10.3390/en7010238 fatcat:nvg6rc3zgrfmxbtakv2ad5lwnq

Carbon and Phosphorus Allocation in Annual Plants: An Optimal Functioning Approach

Marko Kvakić, George Tzagkarakis, Sylvain Pellerin, Philippe Ciais, Daniel Goll, Alain Mollier, Bruno Ringeval
2020 Frontiers in Plant Science  
We develop a dynamic plant model based on the principle of optimal carbon (C) and P allocation to investigate growth and functional response to contrasting levels of soil P availability.  ...  modelling plant response to environmental change that can be used in more physically driven vegetation models.  ...  We would like to thank Sanna Sevanto, Assad Mrad and Chonggang Xu for their valuable input.  ... 
doi:10.3389/fpls.2020.00149 pmid:32174939 pmcid:PMC7056904 fatcat:pj7m5itiezhbpnaowzawtxbc6a

An Optimization-Based Impedance Approach for Robot Force Regulation with Prescribed Force Limits

R. de J. Portillo-Vélez, A. Rodriguez-Angeles, C. A. Cruz-Villar
2015 Mathematical Problems in Engineering  
An optimization based approach for the regulation of excessive or insufficient forces at the end-effector level is introduced.  ...  Penalty functions are considered in the DOP to handle the constraints on the interaction force. The optimization problem is online solved through the gradient flow approach.  ...  Acknowledgments All authors acknowledge support from CONACyT Mexico via Projects 133527 and 84060. The first author acknowledges support from CONACyT Mexico through Scholarship 28753.  ... 
doi:10.1155/2015/918301 fatcat:xjoykscwszdb3fdiuwi3i6w4jy

Multivariate Optimization in Large-Scale Building Problems: An Architectural and Urban Design Approach for Balancing Social, Environmental, and Economic Sustainability

Grant Mosey, Brian Deal
2020 Sustainability  
This paper explores the promise of genetic algorithms as a tool for optimization of buildings at a neighborhood scale across the conflicting demands of social, environmental, and economic sustainability  ...  A large urban site in Chicago, Illinois, is selected to test the viability of using a multi criteria genetic algorithm to optimize the potential building mix in a newly planned development.  ...  Conflicts of Interest: The authors declare no conflict of interest.  ... 
doi:10.3390/su122310052 fatcat:ycgmxxyrhrebnpnbgo7xonjsey
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