In a distributed system where scalability is an issue, the problem of enforcing mutual exclusion often arises in a soft form: the infrequent failure of the mutual exclusion predicate is tolerated, without compromising the consistent operation of the overall system. For instance this occurs when the operation subject to mutual exclusion requires massive use of a shared resource. We introduce a s...

In a distributed system, mutual exclusion is a condition which ensures that a shared resource in the system can be accessed by one and only one process at a time. Mutual exclusion ensures that only one process can be in its critical section at a time. Many distributed mutual exclusion algorithms have been proposed and verified [1][2][3][4][5]. In this paper, we have modeled and verified the dyn...

We deal with the search process of the GraphPlan algorithm in this paper. We concentrate on the problem of finding supports for a sub-goal which arises during the search. We model the problem of finding supports as a constraint satisfaction problem in which arcconsistency or singleton arc-consistency is maintained. Contrary to other works on the similar topic, we do not model the whole planning...

In this paper, we present a dynamic information-structure mutual exclusion algorithm for distributed systems whose informationstructure evolves with time as sites learn about the state of the system through messages. An interesting feature of the algorithm is that it adapts itself to heterogeneous or fluctuating traffic conditions to optimize the performance (the number of messages exchanged). ...

Coteries may be used to construct permission based distributed mutual exclusion algorithms. One such algorithm is Maekawa's p N algorithm in which the co-terie is constructed based on nite projective planes. This paper presents a token based mutual exclusion algorithm which uses data structures similar to coter-ies, called quorum agreements. The performance of the algorithm depends upon the quo...

Eliminating interference between concurrently executing activities through mutual exclusion is one of the most fundamental problems in computer systems. The problem of mutual exclusion in a distributed system is especially interesting owing to the lack of global knowledge in the presence of variable communication delays. In this paper, a new token-based distributed mutual exclusion algorithm is...

The paper presents a token based distributed mutual exclusion algorithm. The algorithm assumes a fully connected, reliable physical network and a directed acyclic graph (dag) structured logical network. The number of messages required to provide mutual exclusion is dependent upon the logical topology imposed on the nodes. Using the best topology, the algorithm attains comparable performance to ...

In stomach, Helicobacter pylori (Hp) adheres to gastric mucous epithelial cells (GMEC) and initiates several different signal transduction events. Alteration of intracellular Ca2+ concentration ([Ca2+]i) is an important signaling mechanism in numerous bacteria-host model systems. Changes in [Ca2+]i induced by Hp in normal human GMEC have not yet been described; therefore, we examined effects of...

One of the most recent techniques for propagating resource constraints in Constraint Based scheduling is Energy Constraint. This technique focuses in precedence based scheduling, where precedence relations are taken into account rather than the absolute position of activities. Although, this particular technique proved to be efficient on discrete unary resources, it provides only loose bounds f...

Many planning domains require a richer notion of time in which actions can overlap and have di erent durations. The key to fast performance in classical planners (e.g., Graphplan, ipp, and Blackbox) has been the use of a disjunctive representation with powerful mutual exclusion reasoning. This paper presents tgp, a new algorithm for temporal planning. tgp operates by incrementally expanding a c...