People are optimistic about problem solving. This paper identifies hallmarks of optimistic human problem solving and how people control for the errors it often engenders. It describes an architecture that permits a controlled version of optimistic problem solving and recounts experiments with it in three very different domains. Results indicate that, controlled for error, optimistic problem sol...

Due to its potential for a high degree of parallelism, optimistic concurrency control is expected to perform better than two-phase locking when integrated with priority-driven CPU scheduling in real-time database systems. In this paper, we examine the overall effects and the impact of the overheads involved in implementing real-time optimistic concurrency control. Using a locking mechanism to e...

This paper introduces a new method for calculating upper bounds on sys_________te~thrQughpuLratcs~multiple-cla.s!Lclosed-queueing--.netwoILmodeIs_when _ any lower bounds are known. The lower (pessimistic) bounds used here are multiple class balanced job bounds. The new technique for calculating upper (optimistic) bounds is independent of the system load. The space-time computational costs are l...

Optimistic replication of data is a widely used tool for mobile environments, but the behavior of concurrent conflicting updates caused by the relaxed consistency model is poorly understood. Through analytical modeling, we derive an exact bound for conflict rates for the common case of two replicas. The shape of the two-replica analytic curve matches well with simulation results at 50 replicas....

Optimistic replication algorithms allow data presented to users to be stale (non-up-to-date) but in a controlled way: they propagate updates in background and allow any replica to be accessed directly most of the time. When the timely propagation of updates to remote distributed replicas is an important issue, it is preferable that a replica gets the same update twice than it does not receive i...

There is an abundant literature in finance on overconfidence, however there exists a different psychological trait well known to financial practitioners and psychologists [see Hilton at al. (2004)] which is optimism. This trait has received little attention. Our paper analyses the consequences of optimism and pessimism on financial markets. We develop a general model of optimism/pessimism where...