Despite the ubiquity of XML, research in metrics for XML documents is scarce. This paper proposes and discusses eleven metrics to measure the quality and complexity of XML Schema and conforming XML documents. To provide an easy view of these metrics, two composite indices have been defined to measure quality and complexity. An open source metric analyzer… (More)
Codd proposed the use of two interpretations of nulls to handle missing information in relational databases that may lead to a 4-valued logic [Codd86, Codd87]. In a more general model, three interpretations of nulls are necessary [Roth, Zani]. Without simplification, this may lead to a 7-valued logic, which is too complicated to be adopted in relational… (More)
The priority ceiling protocol (PCP) is an effective protocol for minimizing priority inversions in real-time scheduling. Priority inversion occw-s when a high priority task is blocked by a low priority task, such as at a shared semaphore or a protected operation. PCP guarantees the absence of chained priority inversion or deadlock. The ceiling locking (CL)… (More)
Several articles have appeared in SIGART Newsletter on the game of Mastermind during the recent three to four years (1 - 8). In particular, P. Norvig described a heuristic for obtaining an approximation to the optimal solution(1). In this article, several simple heuristics to play Mastermind are analyzed.