Jump to content

In situ adaptive tabulation: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
Nacopt (talk | contribs)
No edit summary
m top: disambiguation no longer needed; target is no longer a disambiguation page, removed: {{disambiguation needed|date=April 2024}}
 
(29 intermediate revisions by 19 users not shown)
Line 1: Line 1:
{{Short description|Algorithm for approximating nonlinear relationships}}
'''In Situ Adaptive Tabulation''' (ISAT) is an algorithm for the approximation of nonlinear relationships. ISAT is based on multiple linear regressions that are dynamically added as additional information is discovered. The technique is adaptive as it adds new linear regressions dynamically to a store of possible retrieval points. ISAT maintains error control by defining finer granularity in regions of increased nonlinearity. A binary tree search transverses cutting hyper-planes to locate a local linear approximation.
'''''In situ''''' '''adaptive tabulation''' ('''ISAT''') is an [[algorithm]] for the approximation of [[nonlinear]] relationships. ISAT is based on [[multiple linear regression]]s that are dynamically added as additional information is discovered. The technique is adaptive as it adds new linear regressions dynamically to a store of possible retrieval points. ISAT maintains error control by defining finer granularity in regions of increased nonlinearity. A binary tree search transverses cutting hyper-planes to locate a local linear approximation. ISAT is an alternative to [[artificial neural network]]s that is receiving increased attention for desirable characteristics, namely:


* scales [[quadratic function|quadratically]] with increased dimension
ISAT is an alternative to artificial neural networks that is recieving increased attention for desireable characteristics, namely:
* approximates functions with [[discontinuity (mathematics)|discontinuities]]
* maintains explicit bounds on [[approximation error]]
* controls local [[derivative]]s of the approximating function
* delivers new data training without re-[[optimization]]


ISAT was first proposed by [[Stephen B. Pope]] for computational reduction of [[turbulent]] [[combustion]] [[simulation]]<ref>{{cite journal | last=Pope | first=S. B. | title=Computationally efficient implementation of combustion chemistry using ''in situ'' adaptive tabulation | journal=Combustion Theory and Modelling | year=1997 | url=http://tcg.mae.cornell.edu/pubs/Pope_CTM_97.pdf | volume=1 | issue=1 | pages=44–63| doi=10.1080/713665229 | bibcode=1997CTM.....1...41P }}</ref> and later extended to model predictive control.<ref>{{cite journal | last=Hedengren | first=J. D. | title=Approximate Nonlinear Model Predictive Control with In Situ Adaptive Tabulation | journal=Computers and Chemical Engineering | year=2008 | url=http://hedengren.net/research/Publications/CACE/hedengren_cace_2006.pdf | volume=32 | issue=4–5 | pages=706–714| doi=10.1016/j.compchemeng.2007.02.010 }}</ref> It has been generalized to an [http://hedengren.net/research/isat.htm ISAT framework] that operates based on any input and output data regardless of the application. An improved version of the algorithm<ref>{{cite journal | last=Lu | first=L. | title=An improved algorithm for in situ adaptive tabulation | journal=Journal of Computational Physics | year=2009 | url=https://tcg.mae.cornell.edu/pubs/Lu_LRP_JCP_09.pdf | volume=228 | issue=2 | pages=361–386| doi=10.1016/j.jcp.2008.09.015 | bibcode=2009JCoPh.228..361L }}</ref> was proposed just over a decade later of the original publication, including new features that allow you to improve the efficiency of the search for tabulated data, as well as error control.
* quadratic scaling with increasing dimensionality
* approximates functions with discontinuities
* maintains explicit bounds on approximation error and approximation derivatives
* delivers new data training without re-optimization


==See also==
ISAT was first proposed by Stephen Pope for computational reduction of turbulent combustion simulation<ref>{{cite journal | last=Pope | first=S. | title=Computationally efficient implementation of combustion chemistry using in situ adaptive tabulation | journal=Combustion Theory and Modelling | year=1997 | url=http://eccentric.mae.cornell.edu/~tcg/pubs/Pope_CTM_97.pdf | volume=1 | pages=44-63}}</ref>. It has been extended to a general framework that accepts general input and output data.


== See also ==
*[[Artificial neural network]]
*[[Predictive analytics]]
*[[Predictive analytics]]
*[[Radial basis function network]]
*[[Radial basis function network]]
Line 19: Line 19:


==References==
==References==

{{reflist}}
{{Reflist}}


==External links==
==External links==
*[http://eccentric.mae.cornell.edu/~tcg/isat.html In Situ Adaptive Tabulation (ISAT) in Turbulent Combustion]
*[http://tcg.mae.cornell.edu/isat.html In Situ Adaptive Tabulation (ISAT) in Turbulent Combustion]
*[http://www.hedengren.net/research/isat.htm Tutorial Overview of ISAT]
*[http://www.hedengren.net/research/isat.htm Tutorial Overview of ISAT]
*[https://tcg.mae.cornell.edu/ISATCK7/ ISAT-CK7: an implementation in Fortran 90 developed by Turbulence and Combustion Group at Cornell]
*[http://www.fluent.com/software/fluent/focus/reacting.htm ISAT in Fluent]
*[https://github.com/nogenmyr/ISAT-CK7-Cantera ISAT-CK7-Cantera: an adaptation of Cornell code to use with Cantera library]
*[https://github.com/americocunhajr/CRFlowLib CRFlowLib: alternative implementation in C language]

[[Category:Computer networking]]

Latest revision as of 15:49, 18 June 2024

In situ adaptive tabulation (ISAT) is an algorithm for the approximation of nonlinear relationships. ISAT is based on multiple linear regressions that are dynamically added as additional information is discovered. The technique is adaptive as it adds new linear regressions dynamically to a store of possible retrieval points. ISAT maintains error control by defining finer granularity in regions of increased nonlinearity. A binary tree search transverses cutting hyper-planes to locate a local linear approximation. ISAT is an alternative to artificial neural networks that is receiving increased attention for desirable characteristics, namely:

ISAT was first proposed by Stephen B. Pope for computational reduction of turbulent combustion simulation[1] and later extended to model predictive control.[2] It has been generalized to an ISAT framework that operates based on any input and output data regardless of the application. An improved version of the algorithm[3] was proposed just over a decade later of the original publication, including new features that allow you to improve the efficiency of the search for tabulated data, as well as error control.

See also

[edit]

References

[edit]
  1. ^ Pope, S. B. (1997). "Computationally efficient implementation of combustion chemistry using in situ adaptive tabulation" (PDF). Combustion Theory and Modelling. 1 (1): 44–63. Bibcode:1997CTM.....1...41P. doi:10.1080/713665229.
  2. ^ Hedengren, J. D. (2008). "Approximate Nonlinear Model Predictive Control with In Situ Adaptive Tabulation" (PDF). Computers and Chemical Engineering. 32 (4–5): 706–714. doi:10.1016/j.compchemeng.2007.02.010.
  3. ^ Lu, L. (2009). "An improved algorithm for in situ adaptive tabulation" (PDF). Journal of Computational Physics. 228 (2): 361–386. Bibcode:2009JCoPh.228..361L. doi:10.1016/j.jcp.2008.09.015.
[edit]