Several properties of the products of finite maximal prefix, maximal biprefix, semaphore, synchronous, maximal infix and maximal outfix codes are discussed respectively. We show that, for two nonempty subsets X and Y of A such that the product XY being thin, if XY is a maximal biprefix code, then X and Y are maximal biprefix codes. Also, it is shown that, for two finite nonempty subsets X and Y...

The starting point of this note is the article On the synchronizing properties of certain prefix codes published by Schützenberger in 1964 [2]. This article presents a family of maximal prefix codes called J -codes, that we call semaphore codes. The main result is that a semaphore code is always of the form X where X is a synchronized semaphore code and n ≥ 1. Two proofs are presented of this r...

In object-oriented programming, updates to the state variables of objects (by the methods of the object) have to be protected through semaphores to ensure mutual exclusion. Semaphore operations are invoked each time an object is accessed, and this represents signiicant run-time overhead. This is of special concern in cost-conscious, small-size embedded systems | such as those used in automotive...

Semaphore, a way of communicating remotely, usually practiced in scouting activities. Information is delivered by gestures or movements using specific tools such as flags, paddles or rods. Teacher and instructors are needed for learning semaphore in conventional way as they will give examples and make correction when such an error occured. Based on the practical need to provide an alternative w...

We address a problem arising in debugging parallel programs, detecting race conditions in programs using a single semaphore for synchronization. It is NP-complete to detect races in programs that use many semaphores. For the case of a single semaphore, we give an algorithm that takesO(n1:5p) time, where p is the number of processors and n is the total number of semaphore operations executed. Ou...