Ms. Pac-Man is a challenging video game in which multiple modes of behavior are required: Ms. Pac-Man must escape ghosts when they are threats and catch them when they are edible, in addition to eating all pills in each level. Past approaches to learning behavior in Ms. Pac-Man have treated the game as a single task to be learned using monolithic policy representations. In contrast, this paper ...

A ring is called clean if every element is the sum of a unit and an idempotent. Throughout the last 30 years several characterizations of commutative clean rings have been given. We have compiled a thorough list, including some new equivalences, in hopes that in the future there will be a better understanding of this interesting class of rings. One of the fundamental properties of clean rings i...

Non-exercise activity thermogenesis (NEAT) is the energy expended that is not from sleeping, eating or sports-like exercise. It ranges from the energy expended walking to work, typing, performing yard work, undertaking agricultural tasks and fidgeting. NEAT can be measured by one of two approaches. The first approach is to measure or estimate total NEAT. Here, total daily energy expenditure is ...

In [KSb] we studied the following model for the spread of a rumor or infection: There is a “gas” of so-called A-particles, each of which performs a continuous time simple random walk on Z, with jumprate DA. We assume that “just before the start” the number of A-particles at x, NA(x, 0−), has a mean μA Poisson distribution and that the NA(x, 0−), x ∈ Z , are independent. In addition, there are B...

Commercialised mechanically alloyed yttria dispersion strengthened alloys exhibit unusual recrystallisation behaviour. In spite of their large stored energy content, they tend to recrystallise at temperatures close to melting. The recrystallised microstructure is often very coarse and highly anisotropic, characterised by columnar grains. Such a microstructure is often referred to as being “dire...

A problem that we had encountered in the aggregation process is how to aggregate the elements that have cardinality greater than one. The most common operators used in the aggregation process produce reasonable results, but, at the same time, when the items to aggregate have cardinality greater than one, they may produce distributed problems. The purpose of this article is to present a new neat...