–a notion of amenability for topological semigroups is introduced. a topological semigroup s iscalled johnson amenable if for every banach s -bimodule e , every bounded crossed homomorphism froms to e* is principal. in this paper it is shown that a discrete semigroup s is johnson amenable if and only if1(s) is an amenable banach algebra. also, we show that if a topological semigroup s is johns...

In this paper we introduce two symmetric variants of amenability, symmetric module amenability and symmetric Connes amenability. We determine symmetric module amenability and symmetric Connes amenability of some concrete Banach algebras. Indeed, it is shown that $ell^1(S)$ is  a symmetric $ell^1(E)$-module amenable if and only if $S$ is amenable, where $S$ is an inverse semigroup with subsemigr...

Typical man-made locomotive devices use reversible gears, as cranks, for transforming reciprocating motion into directed one. Such gears are holo-nomic and have the transduction efficiency of unity. On the other hand, a typical gear of molecular motors is a ratchet rectifier, which is irreversible. We discuss what properties of rectifier mostly influence the transduction efficiency and show tha...

In view of the recent documented hedging bias attributable to failing to accommodate volatility long memory, we suggest to use the simple, yet superior, realized variancecovariance (RVCOV) in dynamic hedging. For its incremental value from intradaily information, model-free and inherent long memory, RVCOV has been shown to be accurate without misspecification bias and easily generalized to high...

When evaluating computer vision systems, we are often concerned with performance on a task-specific evaluation measure such as the Intersection-Over-Union score used in the PASCAL VOC image segmentation challenge. Ideally, our systems would be tuned specifically to these evaluation measures. However, despite much work on loss-aware structured prediction, top performing systems do not use these ...