DOI QR코드

DOI QR Code

Some properties of equivalent fuzzy norms

  • Published : 2005.06.01

Abstract

In the present paper, we observe a relation between fuzzy norms and induced crisp norms on a linear space. We first prove that if $\rho_1,\;\rho_2$ are equivalent fuzzy norms on a linear space, then for every $\varepsilon\in(0.1)$, the induced crisp norms $P_\varepsilon^1,\;and\;P_\varepsilon^2$, respectively are equivalent. Since the converse does not hold, we prove it under some strict conditions. And consider the following theorem proved in [8]: Let $\rho$ be a lower semicontinuous fuzzy norm on a normed linear space X, and have the bounded support. Then $\rho$ is equivalent to the fuzzy norm $\chi_B$ where B is the closed unit ball of X. The lower semi-continuity of $\rho$ is an essential condition which guarantees the continuity of $P_\varepsilon$, where 0 < e < 1. As the last result, we prove that : if $\rho$ is a fuzzy norm on a finite dimensional vector space, then $\rho$ is equivalent to $\chi_B$ if and only if the support of $\rho$ is bounded.

Keywords

References

  1. A.K. Katsaras, Fuzzy topological vector space I, Fuzzy Sets and Systems 6 (1981) 85-95 https://doi.org/10.1016/0165-0114(81)90082-8
  2. A.K. Katsaras, Fuzzy topological vector space II, Fuzzy Sets and Systems 12 (1984) 143-154 https://doi.org/10.1016/0165-0114(84)90034-4
  3. A.K. Katsaras and D.B. Liu, Fuzzy vector spaces and fuzzy topolpgical vector spaces, J. Math. Anal. Appl. 58 ( 1977) 135-146 https://doi.org/10.1016/0022-247X(77)90233-5
  4. S.V. Krishna and K.K.M. Sarma, Fuzzy topological vector spaces - topolpgical generation and normability, Fuzzy Sets and Systems 41 (1991) 89-99 https://doi.org/10.1016/0165-0114(91)90159-N
  5. S.V.Krishna and K.K.M. Sarma, Fuzzy continuity of linear maps on vector spaces, Fuzzy Sets and systems 45 (1992) 341-354 https://doi.org/10.1016/0165-0114(92)90153-U
  6. S.V.Krishna and K.K.M. Sarma, Separation of fuzzy normed linear spaces, Fuzzy Sets and Systems 63 (1994) 207-217 https://doi.org/10.1016/0165-0114(94)90351-4
  7. R. Larsen, Functional Analysis, Marcel Dekker, New York, 1973
  8. G.S. Rhie, B.M Choi and D.S. Kim, On the completeness of fuzzy normed linear spaces, Math. Japonica 45 (1) (1997) 33-37