There are several ways to create an exact recognizer for the language defined by a context free grammar. The recursive backup technique, proposed by [Kos75], is capable of handling (locally) ambiguous grammars. Due to its structure, it is not limited to context free grammars, but applicable for affix grammars in general. This paper shows that ‘tactful’ recursive backup parsing can be efficient,...

Primary/Backup has been well studied as an effective fault-tolerance technique. In this paper, with the objectives of tolerating a single permanent fault and maintaining system reliability with respect to transient faults, we study dynamic-priority based energy-efficient fault-tolerance scheduling algorithms for periodic real-time tasks running on multiprocessor systems by exploiting the primar...

With the negative effects of the popular Dynamic Voltage and Frequency Scaling (DVFS) technique on transient faults being considered, the Primary/Backup approach has recently been exploited to save energy while preserving system reliability. In this paper, with the objectives of tolerating a single permanent fault and maintaining system reliability with respect to transient faults, we study ene...

UNLABELLED The purpose of this study was to assess normal hearing listeners' performance in detecting a stationary backup alarm signal and to quantify the linear distance at detection point. METHOD Detection distances for 12 participants with normal hearing were measured while they were fitted with 7 hearing protectors and while they were unoccluded (open ear). A standard (narrowband) backup ...

Abstract Fault-tolerant scheduling is an important issue for optimal heterogeneous distributed systems because of a wide range of resource failures. Primary-backup approach is a common methodology used for fault tolerance wherein each task has a primary copy and a backup copy on two different processors. For independent tasks, the backup copy can overload with other backup copies on the same pr...

Data Management Systems in enterprises constitute a significant portion of the total cost of management of data in enterprise systems. Maintaining data with a high degree of availability and reliability is typically done by having a centralized backup system that to maintain backup copies of data present on the workstations of enterprises. Maintaining a large dedicated backup server for data ma...

Peer-to-peer (P2P) backup systems are an attractive alternative to server-based systems because the immense costs of large data centers can be saved by using idle resources on millions of private computers instead. This paper presents the design and theoretical analysis of a market for a P2P backup system. While our long-term goal is an open resource exchange market using real money, here we co...

A swarm of robots is composed of several small and simple robots that can communicate to perform complex tasks. Those robots are subject to failures: battery outage, hardware destruction, or hardware failure. When a robot fails, its whole state is lost. The task realized by this robot needs to be restarted then the swarm might need some data from the failed robot. Even when this data is not nee...

We address the problem of routing and wavelength assignment (RWA) considering differentiated reliability (DiR) in WDM mesh networks. The backup resource can be shared by the primary lightpaths. However, both the primary-backup sharing and the different levels of fault tolerance requirement have never been considered together in the literature. In the paper, we consider the dynamic character of ...

In an effort to combine research in peer-to-peer systems with techniques for incremental backup systems, we propose pStore: a secure distributed backup system based on an adaptive peer-to-peer network. pStore exploits unused personal hard drive space attached to the Internet to provide the distributed redundancy needed for reliable and effective data backup. Experiments on a 30 node network sho...