Download or read book A Verified Design of a Fault Tolerant Clock Synchronization Circuit written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Schneider demonstrates that many fault tolerant clock synchronization algorithms can be represented as refinements of a single proven correct paradigm. Shankar provides mechanical proof that Schneider's schema achieves Byzantine fault tolerant clock synchronization provided that 11 constraints are satisfied. Some of the constraints are assumptions about physical properties of the system and cannot be established formally. Proofs are given that the fault tolerant midpoint convergence function satisfies three of the constraints. A hardware design is presented, implementing the fault tolerant midpoint function, which is shown to satisfy the remaining constraints. The synchronization circuit will recover completely from transient faults provided the maximum fault assumption is not violated. The initialization protocol for the circuit also provides a recovery mechanism from total system failure caused by correlated transient faults. Miner, Paul S. Langley Research Center ALGORITHMS; CIRCUITS; CLOCKS; FAULT TOLERANCE; SYNCHRONISM; CONVERGENCE; PROTOCOL (COMPUTERS); PROVING; SYSTEM FAILURES...
Download or read book A Verified Design of a Fault tolerant Clock Synchronization Circuit Preliminary Investigations written by and published by . This book was released on 1992 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Hardware Implementation of a Probably Correct Design of a Fault tolerant Clock Synchronization Circuit written by Wilfredo Torres-Pomales and published by . This book was released on 1993 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Hardware Implementation of a Provably Correct Design of a Fault tolerant Clock Synchronization Circuit written by and published by . This book was released on 1993 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Hardware Implementation of a Provably Correct Design of a Fault Tolerant Clock Synchronization Circuit written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-09 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fault-tolerant clock synchronization system was designed to a proven correct formal specification. Formal methods were used in the development of this specification. A description of the system and an analysis of the tests performed are presented. Plots of typical experimental results are included. Torres-Pomales, Wilfredo Langley Research Center NASA-TM-109001, NAS 1.15:109001 RTOP 505-64-10-10...
Download or read book Validation of a Fault Tolerant Clock Synchronization System written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-06 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A validation method for the synchronization subsystem of a fault tolerant computer system is investigated. The method combines formal design verification with experimental testing. The design proof reduces the correctness of the clock synchronization system to the correctness of a set of axioms which are experimentally validated. Since the reliability requirements are often extreme, requiring the estimation of extremely large quantiles, an asymptotic approach to estimation in the tail of a distribution is employed. Butler, R. W. and Johnson, S. C. Langley Research Center NASA-TP-2346, L-15799, NAS 1.60:2346 RTOP 505-34-13
Download or read book Verification of Fault tolerant Clock Synchronization Systems written by Paul S. Miner and published by . This book was released on 1993 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Extension to Schneider s General Paradigm for Fault tolerant Clock Synchronization written by Paul S. Miner and published by . This book was released on 1992 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Formal Verification of a Fault Tolerant Clock Synchronization Algorithm written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-24 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: A formal specification and mechanically assisted verification of the interactive convergence clock synchronization algorithm of Lamport and Melliar-Smith is described. Several technical flaws in the analysis given by Lamport and Melliar-Smith were discovered, even though their presentation is unusally precise and detailed. It seems that these flaws were not detected by informal peer scrutiny. The flaws are discussed and a revised presentation of the analysis is given that not only corrects the flaws but is also more precise and easier to follow. Some of the corrections to the flaws require slight modifications to the original assumptions underlying the algorithm and to the constraints on its parameters, and thus change the external specifications of the algorithm. The formal analysis of the interactive convergence clock synchronization algorithm was performed using the Enhanced Hierarchical Development Methodology (EHDM) formal specification and verification environment. This application of EHDM provides a demonstration of some of the capabilities of the system. Rushby, John and Vonhenke, Frieder Unspecified Center NASA-CR-4239, NAS 1.26:4239 NAS1-17067; RTOP 505-66-21-01...
Download or read book An Optimized Implementation of a Fault Tolerant Clock Synchronization Circuit written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-30 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fault-tolerant clock synchronization circuit was designed and tested. A comparison to a previous design and the procedure followed to achieve the current optimization are included. The report also includes a description of the system and the results of tests performed to study the synchronization and fault-tolerant characteristics of the implementation. Torres-Pomales, Wilfredo Langley Research Center RTOP 505-64-10-13...
Download or read book Formal Verification of a Fault Tolerant Clock Synchronization Algorithm written by John Rushby and published by . This book was released on 1989 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Validation of a Fault tolerant Clock Synchronization System written by Ricky W. Butler and published by . This book was released on 1984 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Validation of Clock Synchronization Algorithms written by Daniel L. Palumbo and published by . This book was released on 1992 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Second NASA Formal Methods Workshop 1992 written by and published by . This book was released on 1992 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Optimized Implementation of a Fault tolerant Clock Synchronization Circuit written by and published by . This book was released on 1995 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Extension to Schneider s General Paradigm for Fault Tolerant Clock Synchronization written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1987, Schneider presented a general paradigm that provides a single proof of a number of fault tolerant clock synchronization algorithms. His proof was subsequently subjected to the rigor of mechanical verification by Shankar. However, both Schneider and Shankar assumed a condition Shankar refers to as a bounded delay. This condition states that the elapsed time between synchronization events (i.e., the time that the local process applies an adjustment to its logical clock) is bounded. This property is really a result of the algorithm and should not be assumed in a proof of correctness. This paper remedies this by providing a proof of this property in the context of the general paradigm proposed by Schneider. The argument given is a generalization of Welch and Lynch's proof of a related property for their algorithm. Miner, Paul S. Langley Research Center...
