We examine the evolutionary foundations of intertemporal preferences. When all the risk affecting survival and reproduction is idiosyncratic, evolution selects for agents who maximize the discounted sum of expected utility, discounting at the sum of the population growth rate and the mortality rate. Aggregate uncertainty concerning survival rates leads to discount rates that exceed the sum of p...

We study the development of conjunctive keyword searchable scheme which enables one to search encrypted documents by using more than one keyword. The notion of conjunctive keyword searching was presented by Golle et al. in 2004. However, their security model was constructed in a symmetric-key setting which is not applicable for the overall applications in the reality. So Park et al. extended Go...

In this paper we present several proofs on the extension of M. Riesz fractional integration and di¤erentiation to the contexts of spaces of homogeneous type and measure metric spaces with non-doubling measures. 1. Introduction, some de…nitions, and a basic lemma Professor M. Ash asked me to write a survey article on some of the results that Stephen Vági and I obtained in the nineties on fractio...

Computing the output of fuzzy systems usually passes through three stages i.e. fuzzification, inference, and defuzzification. The computation of the output requires too many operations and considerable time. This apparently discourages the use of fuzzy systems in time-critical applications. In this paper, a new two-stage representation of fuzzy systems, which reduces the operations needed to co...

Many aggregation operators like fuzzy integrals and similar require a preference relation as input. If the number of decision alternatives increases it becomes almost impossible to provide the exponentially increasing number of preference statements which are needed because a preference relation is defined upon the power set of the set of decision alternatives. If, as in many real world applica...