The issue of executing concurrent transactions reliably in a multidatabase system is addressed. Our formalization assumes the most pessimistic scenario where individual database managers that make up the multidatabase...
We here discuss an invariant semantics of concurrent systems which is a generalisation of the causal partial order (CPO) semantics. The new semantics is consistent with the full operational behaviour of inhibitor and ...
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We introduce a new invariant semantics of concurrent systems which is a direct generalisation of the causal partial order semantics. Our new semantics overcomes some of the problems encountered when one uses causal pa...
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The consequences of bridging, transition, and stuck-open faults in self-testing checkers designed only for single stuck-at faults are examined. A methodology for design that guarantees that the checkers will be self-t...
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The consequences of bridging, transition, and stuck-open faults in self-testing checkers designed only for single stuck-at faults are examined. A methodology for design that guarantees that the checkers will be self-testing in the presence of bridging, transition and stuck-open faults is established. This methodology is applied to several implementations of self-testing checkers. Simulations confirm that these checkers are self-testing in the presence of bridging, transition, and stuck-open faults. The problems associated with testing the checkers in the presence of non-stuck-at faults and the problems that result from reducing the number of checker outputs from two to one are discussed. It is shown that self-testing checkers designed for stuck-at faults will remain self-testing in the presence of nonclassical faults.< >
作者：
L. AvraCenter for Reliable Computing
Computer Systems Laboratory Departments of Electrical Engineering Computer Science University of Stanford Stanford CA USA
Simple bounds on the aliasing probability for serial signature analysis are presented. To motivate the study, it is shown that calculation of exact aliasing is NP-hard and that coding theory does not necessarily help....
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Simple bounds on the aliasing probability for serial signature analysis are presented. To motivate the study, it is shown that calculation of exact aliasing is NP-hard and that coding theory does not necessarily help. It is shown that the aliasing probability is bounded above by 2/(L+2) for test lengths L less than the period, L/sub c/, of the signature polynomials; for test lengths L that are multiples of L/sub c/, the aliasing probability is bounded above by 1; and, for test lengths L greater than L/sub c/ and not a multiple of L/sub c/, the aliasing probability is bounded above by 2/(L/sub c/+1). These simple bounds avoid any exponential complexity associated with the exact computation of the aliasing probability. Simple bounds also apply to signature analysis based on any linear finite state machine (including linear cellular automata).< >
We here discuss an approach which uses the optimal simulation - a kind of reachability relation - to enable reasoning about important dynamic properties of a concurrent system. The optimal simulation usually involves ...
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The issue of executing concurrent transactions reliably in a multidatabase system is addressed. The authors' formalization assumes the most pessimistic scenario where individual database managers that make up the ...
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The issue of executing concurrent transactions reliably in a multidatabase system is addressed. The authors' formalization assumes the most pessimistic scenario where individual database managers that make up the multidatabase system are totally autonomous. The authors present algorithms that ensure transaction atomicity and crash recovery. The atomicity algorithms are based on the emulation of the well-known two-phase commit protocol. It is applied among autonomous participants that neither know of each other's existence nor how to communicate.< >
Algorithms based on grid files as the underlying spatial index are presented for spatial joins in databases which store images, pictures, maps and drawings. For typical data distributions, it is shown that the size of...
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Algorithms based on grid files as the underlying spatial index are presented for spatial joins in databases which store images, pictures, maps and drawings. For typical data distributions, it is shown that the size of the index and its maintenance cost are relatively small. The effect of diagonal distributions and different densities of the two grid files on the size of the index is also studied. It is expected that similar algorithms can be employed with other types of multidimensional data structures.< >
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