Abstract
The set of interval Hausdorff continuous functions constitutes the largest space preserving basic algebraic and topological structural properties of continuous functions, such as linearity, ring structure, Dedekind order completeness, etc. Spaces of interval functions have important applications not only in the construction of numerical methods and algorithms, but to problems in abstract areas such as real analysis, set-valued analysis, approximation theory and the analysis of PDEs. In this work, we summarize some basic results about the family of interval Hausdorff continuous functions that make interval analysis a bridge between numerical and real analysis. We focus on some approximation issues formulating a new result on the Hausdorff approximation of Hausdorff continuous functions by interval step functions. The Hausdorff approximation of the Heaviside interval step function by sigmoid functions arising from biological applications is also considered, and an estimate for the Hausdorff distance is obtained.
Notes
- 1.
For brevity we shall further write “interval function” instead of “interval-valued function”.
- 2.
In topology, a meagre set, also called a set of first Baire category, is a set that, considered as a subset of a (usually larger) topological space, is small or negligible.
References
Anguelov, R.: Dedekind order completion of \(C(X)\) by Hausdorff continuous functions. Quaestiones Mathematicae 27, 153–170 (2004)
Anguelov, R., Markov, S.: Extended segment analysis, Freiburger Intervall-Berichte, Inst. Angew. Math, U. Freiburg i. Br. 10, pp. 1–63 (1981)
Anguelov, R., Markov, S., Sendov, B.: On the normed linear space of Hausdorff continuous functions. In: Lirkov, I., Margenov, S., Waśniewski, J. (eds.) LSSC 2005. LNCS, vol. 3743, pp. 281–288. Springer, Heidelberg (2006)
Anguelov, R., Markov, S., Sendov, B.: Algebraic operations on the space of Hausdorff continuous interval functions. In: Bojanov, B. (ed.) Constructive Theory of Functions, pp. 35–44. Marin Drinov Academic Publishing House, Sofia (2006)
Anguelov, R., Markov, S., Sendov, B.: The set of Hausdorff continuous functions–the largest linear space of interval functions. Reliable Comput. 12, 337–363 (2006). http://dx.doi.org/10.1007/s11155-006-9006-5
Anguelov, R., Rosinger, E.E.: Hausdorff continuous solutions of nonlinear PDEs through the order completion method. Quaest. Math. 28, 271–285 (2005)
Anguelov, R., Rosinger, E.E.: Solving large classes of nonlinear systems of PDEs. Comput. Math. Appl. 53, 491–507 (2007)
Anguelov, R., Markov, S., Minani, F.: Hausdorff continuous viscosity solutions of Hamilton-Jacobi equations. In: Lirkov, I., Margenov, S., Waśniewski, J. (eds.) LSSC 2009. LNCS, vol. 5910, pp. 231–238. Springer, Heidelberg (2010)
Anguelov, R., van der Walt, J.H.: Order Convergence on \(C (X)\). Quaestiones Mathematicae 28(4), 425–457 (2005)
Anguelov, R., Kalenda, O.F.K.: The convergence space of minimal USCO mappings. CZECHOSLOVAK MATH. J. 59(1), 101–128 (2009)
Anguelov, R.: Rational extensions of \(C(X)\) via Hausdorff continuous functions. Thai J. Math. 5(2), 261–272 (2007)
Anguelov, R., van der Walt, J.H.: Algebraic and topological structure of some spaces of set-valued maps. Comput. Math. Appl. 66, 1643–1654 (2013)
Baire, R.: Lecons sur les Fonctions Discontinues. Collection Borel, Paris (1905)
Costarelli, D., Spigler, R.: Approximation results for neural network operators activated by sigmoidal functions. Neural Netw. 44, 101–106 (2013)
Dilworth, R.P.: The normal completion of the lattice of continuous functions. Trans. Amer. Math. Soc. 68, 427–438 (1950)
Dimitrov, S., Markov, S.: Metabolic Rate Constants: some Computational Aspects, Mathematics and Computers in Simulation (2015). doi:10.1016/j.matcom.2015.11.003
Hausdorff, F.: Set theory, 2nd edn. Chelsea Publ., New York (1962) [1957], ISBN 978-0821838358 (Republished by AMS-Chelsea 2005)
Kraemer, W., Gudenberg, J.W.v (eds.): Scientific Computing, Validated Numerics, Interval Methods, Proc. SCAN-2000/Interval-2000, Kluwer/Plenum (2001)
Markov, S.: Biomathematics and interval analysis: A prosperous marriage. In: Christov, C., Todorov, M.D. (eds.) Proceedings of the 2nd International Conference on Application of Mathematics in Technical and Natural Sciences (AMiTaNS’10), AIP Conference Proceedings 1301, 26–36 (2010)
Markov, S.: Cell Growth Models Using Reaction Schemes: Batch Cultivation, Biomath 2/2, 1312301 (2013). http://dx.doi.org/10.11145/j.biomath.2013.12.301
Sendov, B.: Hausdorff Approximations. Kluwer, Boston (1990)
van der Walt, J. H.: The Linear Space of Hausdorff Continuous Interval Functions. Biomath 2, 1311261 (2013). http://dx.doi.org/10.11145/j.biomath.2013.11.261
Mathematics Subject Classification (MSC2010), AMS (2010). http://www.ams.org/mathscinet/msc/msc2010.html
Acknowledgments
RA acknowledges partial support of the National Research Foundation of South Africa. RA and SM acknowledge partial support by the Institute of Mathematics and Informatics at the Bulgarian Academy of Sciences. The authors thank Prof. Kamen Ivanov for the analysis and derivation of formula (9). They are grateful to the anonimous reviewer for his careful reading and many remarks.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 2.5 International License (http://creativecommons.org/licenses/by-nc/2.5/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.
The images or other third party material in this chapter are included in the chapter's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the chapter's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.
Copyright information
© 2016 Springer International Publishing Switzerland
About this paper
Cite this paper
Anguelov, R., Markov, S. (2016). Hausdorff Continuous Interval Functions and Approximations. In: Nehmeier, M., Wolff von Gudenberg, J., Tucker, W. (eds) Scientific Computing, Computer Arithmetic, and Validated Numerics. SCAN 2015. Lecture Notes in Computer Science(), vol 9553. Springer, Cham. https://doi.org/10.1007/978-3-319-31769-4_1
Download citation
DOI: https://doi.org/10.1007/978-3-319-31769-4_1
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-31768-7
Online ISBN: 978-3-319-31769-4
eBook Packages: Computer ScienceComputer Science (R0)