... tincậy của hệthống không thể nhỏ hơn độtincậy của phần tử có độ tin cậy thấp nhất min)(tPi . Trong sơ đồ nối tiếp, muốn nâng cao độtincậy của hệ thống, phải nâng cao độtin cậy của ... hệthống ≥ độtincậy của phần tử. trong các phần tử song song, số phần tử song song càng tăng thì độtincậy của hệ thống càng tăng. → độtincậy của hệthống ≥ độtincậy của phần tử. ... 1) Độtincậy của sơ đồ nối tiếp: Giả sử có n phần tử, mà mỗi p tử có độtincậy là )(tPi. Độ tincậy của hệthống được xác định: 1)()()(1≤→=∏=tPtPtPiniiht Ta thấy rằng: độ tin...
... developments in operating system software werethe UNIX operating system (1969–70), the CM operating system for the8086Microprocessor (1980), and the MS-DOS operating system (1981). ... York,1988.Echte, K. Dependable Computing—EDCC-1. Proceedings of the First EuropeanDependable Computing Conference, Berlin, Germany,1994.Fault-Tolerant Computing Symposium,25th Anniversary ... appendices of this book interrelate.1.1WHAT IS FAULT-TOLERANT COMPUTING?Literally, fault-tolerant computing means computing correctly despite the exis-tence of errors in a system. Basically,...
... error detecting; single error correcting320Double error detecting; zero error correcting430Triple error detecting; zero error correcting421Double error detecting; single error correcting540Quadruple ... detecting; zero error correcting531Triple error detecting; single error correcting522Double error detecting; double error correcting650Quintuple error detecting; zero error correcting641Quadruple ... codes that wediscuss in this chapter are error-detecting and -correcting codes. The principlethat underlies error-detecting and -correcting codes is the addition of speciallycomputed redundant...
... will provide an error-detecting but not an error-correcting code; however, the availability of parity checks for more than onegroup of strips provides error-correcting ability. Consider the ... the expendi-tures.2. Parallel redundancy, where one or more extra components are operatingand waiting to take over in case of a failure of the primary system. Inthe case of two computers ... Eq. (3.33) by approximating e−lctand e−ltbythe first two terms in the expansion—cf. Eq. (3.17)—yielding (1− e−lt) ≈ lt,e−lct≈1− lct. Substituting these approximations...
... pairwise voting is slightly worse than it is for TMR.There are various other combinations of advanced voting techniques de-TABLE4.12Comparison of Reliabilities for Various Voting SystemsPairwise-out-of-Single ... Level VotingAssume that a digital system is composed of m series subsystems, each havinga constant-failure rate l, and that voting is to be applied at the subsystem level.The majority voting ... a5-level voter system.Higher-Level Voting. One could extend the above analysis to cover higher-level voting systems; for example,7-level and9-level voting. Even though itis easy to replicate...
... constructing the prototype, an initial control struc-ture (the main program coordinating all the parts) is written and tested along withthe interfaces to the various components (subroutines and ... errors[Shooman,1983, pp.332–335].dEd(t)dtaEr(t)(5.25a)Substituting for Er(t), from Eq. (5.20) and letting Ed(t)Ec(t) yieldsdEc(t)dta[ET− Ec(t)] (5.25b)Rearranging ... by5k100and9k100. Taking logarithms and solving the resulting equations yields2.09≤ k ≤2.86. Thus, starting with the top-level0, we will have about2or3successorlevels....