Role based access control (RBAC) is attracting increasing attention as a security mechanism for both commercial and many military systems. Much of RBAC is fundamentally diierent from multi-level security (MLS) systems, and the properties of RBAC systems have not been explored formally to the extent that MLS system properties have. This paper explores some aspects of mutual exclusion of roles as...

taDOM* protocols are designed to provide lock-based approach to handle multiple access to XML databases. The notion of taDOM+ protocol is formalized and generalized and a formal model of taDOM+ lock manager that is parameterized in the number of transactions and in the size of database is represented. An important class of safety properties of taDOM+ lock managers were proven to be checked by e...

We present methods for operating system directed dynamic power management. We model a power-managed system using a continuous-time Markov decision process and solve for the optimal power management policy using a mathematical programming technique. Next we extend the model by using the controllable Generalized Stochastic Petri Nets with cost to handle systems with complex behavioral characteris...

This paper presents two algorithms for mutual exclusion on optical bus architectures including the folded one-dimensional bus, the one-dimensional array with pipeleined buses (1D APPB), and the twodimensional array with pipelined buses (2D APPB). The rst algorithm guarantees mutual exclusion, while the second guarantees both mutual exclusion and fairness. Both algorithms exploit the predictabil...

Mutual Exclusion Bootstrapping (MEB) was designed to overcome the problem of semantic drift suffered by iterative bootstrapping, where the meaning of extracted terms quickly drifts from the original seed terms (Curran et al., 2007). MEB works by extracting mutually exclusive classes in parallel which constrain each other. In this paper we explore the strengths and limitations of MEB by applying...

We present an N -process algorithm for mutual exclusion under read/write atomicity that has O(1) time complexity in the absence of contention and (logN) time complexity under contention, where \time" is measured by counting remote memory references. This is the rst such algorithm to achieve these time complexity bounds. Our algorithm is obtained by combining a new \fast-path" mechanism with an ...

Many token-based, distributed mutual exclusion algorithms can be generalized by a single algorithm. The algorithm’s performance is dependent upon the logical topology imposed on the nodes and the policy used to forward requests. This paper extends the generalized algorithm to support prioritized, real-time requests in a generalized fashion and presents models that can be used to analyze the per...

This paper presents an algorithm for achieving mutual exclusion in Distributed System. The proposed algorithm is a betterment of the already existing Token Ring Algorithm, used to handle mutual exclusion in Distributed system. In the already existing algorithm, there are few problems, which, if occur during process execution, then the distributed system will not be able to ensure mutual exclusi...

We show how the synchronous programming language Esterel can be extended by a new statement to implement mutual exclusive code sections. We also show how the thereby extended Esterel language can be translated back to standard Esterel and we prove the correctness of this transformation. Additionally, we show that the translation fits well into different verification approaches.

The problem of mutual exclusion in distributed systems has attracted considerable attention over the last two decades. The mutual exclusion problem requires that, at a time, only one of the contending processes be allowed to enter its critical section (CS). A number of solutions have been provided to the mutual exclusion problem in distributed systems. Different algorithms have used different t...