Abstract
Rough sets was first studied by Pawlak to describe the approximation of a set X by using its lower bound L(X) and upper bound U(X). λ-connectedness was originally proposed as a technique to search layers in 2D or 3D digital seismic data. This note introduces λ-connected components to represent lower and upper approximations for rough sets. According to Pawlak’s definition of the boundary of X, BN(X) = U(X)-L(X), U(X) contains two “layers:” L(X) and BN(X). Representing the “layer” of BN(X) is one of the key problems in rough set theory. This note shows when the boundary of X contains the property of gradual variations, BN(X) can be represented by a partition of λ-connectedness which is a generalization of α-cut representation.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Adjei, O., Chen, L., Cheng, H.D., Cooley, D., Cheng, R., Twombly, X.: A fuzzy search method for rough sets and data mining. Proceedings of IFSA/NAFIPS Conference (2001) 980–985
Chen, L.: Three-dimensional fuzzy digital topology and its applications (I). Geophysical Prospecting for Petroleum 24 (1985) 86–89
Chen, L.: The necessary and sufficient condition and the efficient algorithms for gradually varied fill. Chinese Science Bulletin 35(1990) 870–873 (Its Chinese version was published in 1989.)
Chen, L, Adjei, O., Cooley, D.H.: λ-connectedness: method and application. Proceedings of IEEE Conference on System, Man, and Cybernetics (2000) 1157–1562
Chen, L., Cheng, H.D., Zhang, J.: Fuzzy subfiber and its application to seismic lithology classification. Information Science: Applications 1 (1994) 77–95
Cormen, T.H., Leiserson, C.E., Rivest, R.L.: Introduction to Algorithms. MIT Press (1993)
Gonzalez, R.C., Wood, R.: Digital Image Processing. Addison-Wesley, Reading, MA (1993)
Pal, S., Skowron, A. (eds): Rough Fuzzy Hybridization. Springer-Verlag (1999)
Pawlak, Z.: Rough set theory. In: Wang, P. P.(ed): Advances in Machine Intelligence and Soft-computing. Duke University (1997) 34–54
Pawlak, Z.: Rough sets, rough functions and rough calculus. In: Pal, S., Skowron, A. (eds): Rough Fuzzy Hybridization. Springer-Verlag (1999) 99–109
Polkowski, L., Skowron, A. (eds): Rough Sets in Knowledge Discovery, Physica Verlag, Heidelberg (1998)
Rosenfeld, A.: “Continuous” functions on digital pictures. Pattern Recognition Letters 4(1986) 177–184
Skowron, A., Stepaniuk, J.: Tolerance approximation spaces, Fundamenta Informaticae 27(1996) 245–253
Ziarko, W.: Variable precision rough set model. Journal of Computer and System Sciences 46(1993) 39–59
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2002 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Chen, L. (2002). λ-Connected Approximations for Rough Sets. In: Alpigini, J.J., Peters, J.F., Skowron, A., Zhong, N. (eds) Rough Sets and Current Trends in Computing. RSCTC 2002. Lecture Notes in Computer Science(), vol 2475. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-45813-1_76
Download citation
DOI: https://doi.org/10.1007/3-540-45813-1_76
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-44274-5
Online ISBN: 978-3-540-45813-5
eBook Packages: Springer Book Archive