Research Communicate | 22-January-2018
the theoretical foundation of the mortality model. Ishikawa (1997b) introduced also the notions of objective and subjective C*-measurement called real and imaginary C*-measurements. In our proposal of the mortality model the function f is treated as an objective C*-measurement and the function g as an subjective C*-measurement, and the membership function μ(z) is represented by means of a complex-valued function f(u) + ig(u), where i is the imaginary unit. We use the Hilbert space of quaternion
Andrzej Szymański,
Agnieszka Rossa
Statistics in Transition New Series, Volume 18 , ISSUE 4, 701–724