There are two fundamental obstructions to representing noncommutative rings via sheaves. First, there is no subcanonical coverage on the opposite of the category of rings that includes all covering families in the big Zariski site. Second, there is no contravariant functor F from the category of rings to the category of ringed categories whose composite with the global sections functor is natur...

We present a new approach to implement an object bitempo-ral database where both valid-time and transaction-time are represented. It is based on the DataBase Version model, which allows an eecient management of object versions. This facilitates the manipulation of past events and allows a straightforward representation of branching evolution in valid-time.

Reinforcement learning algorithms need to deal with the exponential growth of states and actions when exploring optimal control in high-dimensional spaces. This is known as the curse of dimensionality. By projecting the agent’s state onto a low-dimensional manifold, we can represent the state space in a smaller and more efficient representation. By using this representation during learning, the...

The author draws on an Australian study using multiple qualitative methods to investigate truth telling in aged care. Thematic analysis of data from five nursing homes involving 23 personal care assistants revealed participants' role understanding as influencing their perceptions about truth telling in practice. Five themes emerged: role as the happy comfort carer, division of labor, division o...

In this paper we conduct a laboratory experiment to test the extent to which Moore and Repullo’s subgame perfect implementation mechanism induces truth-telling in practice, both in a setting with perfect information and in a setting where buyers and sellers face a small amount of uncertainty regarding the good’s value. We find that Moore-Repullo mechanisms fail to implement truth-telling in a s...

Weconsider full-truthfulNash implementation, which requires that truth telling by each agent should be a Nash equilibrium of a direct revelation mechanism, and that the set of Nash equilibrium outcomes of the mechanism should coincide with the f -optimal outcome. We show that restricted monotonicity together with an auxiliary condition called boundedness is both necessary and sufficient for ful...

In this paper, we compare three heuristic methods for choosing which of a set of features to use to represent a domain of stimuli when we know the categories to which those stimuli belong. Our methods are based on three measures of category differentiation: cue validity, category validity, and their product, collocation. In a comparison of their ability to predict human similarity ratings in th...

This paper presents a new metamodel based on partially ordered hypersets. The metamodel is minimalist, its only primitives being atoms, potentially infinite hypersets and partial order. The type system is very loose and supports concurrent extensional and intensional definition of types. Every element of the metamodel can be directly referenced, thanks to a powerful automated reification facili...