Abstract
The paper proposes a new formal approach to vagueness and vague sets taking inspirations from Pawlak’s rough set theory. Following a brief introduction to the problem of vagueness, an approach to conceptualization and representation of vague knowledge is presented from a number of different perspectives: those of logic, set theory, algebra, and computer science. The central notion of the vague set, in relation to the rough set, is defined as a family of sets approximated by the so called lower and upper limits. The family is simultaneously considered as a family of all denotations of sharp terms representing a suitable vague term, from the agent’s point of view. Some algebraic operations on vague sets and their properties are defined. Some important conditions concerning the membership relation for vague sets, in connection to Blizard’s multisets and Zadeh’s fuzzy sets, are established as well. A classical outlook on a logic of vague sentences (vague logic) based on vague sets is also discussed.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Blizard, W.D.: Multiset Theory. Notre Dame J. Formal Logic 30(1), 36–66 (1989)
Bonikowski, Z.: A Certain Conception of the Calculus of Rough Sets. Notre Dame J. Formal Logic 33, 412–421 (1992)
Bonikowski, Z.: Sets Approximated by Representations (in Polish, the doctoral dissertation prepared under the supervision of Prof. U.Wybraniec-Skardowska), Warszawa (1996)
Bonikowski, Z., Wybraniec-Skardowska, U.: Rough Sets and Vague Sets. In: Kryszkiewicz, M., Peters, J.F., Rybinski, H., Skowron, A. (eds.) RSEISP 2007. LNCS, vol. 4585, pp. 122–132. Springer, Heidelberg (2007)
Bonissone, P., Tong, R.: Editorial: reasoning with uncertainty in expert systems. Int. J. Man–Machine Studies 22, 241–250 (1985)
Codd, E.F.: A Relational Model of Data for Large Shared Data Banks. Comm. ACM 13, 377–387 (1970)
Cresswell, M.J.: Logics and Languages. Methuen, London (1973)
Demri, S., Orłowska, E.: Incomplete Information: Structure, Inference, Complexity. Springer, Heidelberg (2002)
Fine, K.: Vagueness, Truth and Logic. Synthese 30, 265–300 (1975)
Iwiński, T.: Algebraic Approach to Rough Sets. Bull. Pol. Acad. Sci. Math. 35, 673–683 (1987)
Malinowski, G.: Many-Valued Logics. Oxford University Press, Oxford (1993)
Marcus, S.: A Typology of Imprecision. In: Brainstorming Workshop on Uncertainty in Membrane Computing Proceedings, Palma de Mallorca, pp. 169–191 (2004)
Marek, W., Pawlak, Z.: Rough Sets and Information Systems, ICS PAS Report 441 (1981)
Pagliani, P.: Rough Set Theory and Logic-Algebraic Structures. In: Orłowska, E. (ed.) Incomplete Information: Rough Set Analysis, pp. 109–190. Physica Verlag, Heidelberg (1998)
Parsons, S.: Current approaches to handling imperfect information in data and knowledge bases. IEEE Trans. Knowl. Data Eng. 8(3), 353–372 (1996)
Pawlak, Z.: Information Systems, ICS PAS Report 338 (1979)
Pawlak, Z.: Information Systems – Theoretical Foundations (in Polish). PWN – Polish Scientific Publishers, Warsaw (1981)
Pawlak, Z.: Information Systems – Theoretical Foundations. Information Systems 6, 205–218 (1981)
Pawlak, Z.: Rough Sets. Intern. J. Comp. Inform. Sci. 11, 341–356 (1982)
Pawlak, Z.: Rough Sets. Theoretical Aspects of Reasoning about Data. Kluwer Academic Publishers, Dordrecht (1991)
Pawlak, Z.: Vagueness and uncertainty: A rough set perspective. Computat. Intelligence 11(2), 227–232 (1995)
Pawlak, Z.: Orthodox and Non-orthodox Sets - some Philosophical Remarks. Found. Comput. Decision Sci. 30(2), 133–140 (2005)
Pomykała, J., Pomykała, J.A.: The Stone Algebra of Rough Sets. Bull. Pol. Acad. Sci. Math. 36, 495–508 (1988)
Shafer, G.: A Mathematical Theory of Evidence. Princeton University Press, Princeton (1976)
Skowron, A., Komorowski, J., Pawlak, Z., Polkowski, L.: Rough Sets Perspective on Data and Knowledge. In: Klösgen, W., Żytkow, J.M. (eds.) Handbook of Data Mining and Knowlewdge Discovery, pp. 134–149. Oxford University Press, Oxford (2002)
Słowiński, R., Stefanowski, J.: Rough-Set Reasoning about Uncertain Data. Fund. Inform. 23(2–3), 229–244 (1996)
Wybraniec-Skardowska, U.: Knowledge, Vagueness and Logic. Int. J. Appl. Math. Comput. Sci. 11, 719–737 (2001)
Zadeh, L.A.: Fuzzy Sets. Information and Control 8, 338–353 (1965)
Zadeh, L.A.: PRUF: A meaning representation language for natural languages. Int. J. Man–Machine Studies 10, 395–460 (1978)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2008 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Bonikowski, Z., Wybraniec-Skardowska, U. (2008). Vagueness and Roughness. In: Peters, J.F., Skowron, A., Rybiński, H. (eds) Transactions on Rough Sets IX. Lecture Notes in Computer Science, vol 5390. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-89876-4_1
Download citation
DOI: https://doi.org/10.1007/978-3-540-89876-4_1
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-89875-7
Online ISBN: 978-3-540-89876-4
eBook Packages: Computer ScienceComputer Science (R0)