Showing papers on "Fault model published in 1972"
TL;DR: A deductive method of fault simulation is described, which "deduces" the faults defected by a test at the same time that it simulates explicitly only the good behavior of logic circuit.
Abstract: A deductive method of fault simulation is described, which "deduces" the faults defected by a test at the same time that it simulates explicitly only the good behavior of logic circuit. For large logic circuits (at least several thousand gates) it is expected to be faster than "parallel" fault simulators, but uses much more computer memory than do parallel simulators.
287 citations
TL;DR: The spectrum of the far-field displacement radiation from a conventional fault model has been calculated for comparison with the spectrum calculated from the recent Brune model as mentioned in this paper, which yields an inverse proportionality between the fault dimensions and the corner frequency in the displacement spectrum.
Abstract: The spectrum of the far-field displacement radiation from a conventional fault model has been calculated for comparison with the spectrum calculated from the recent Brune model. The spectrums are generally similar, but some of the details are attributed to different effects in the two models. For example, where the spectrum decays as ω−1 at intermediate frequencies, the effect is attributed to partial stress drop by the Brune theory but to rupture surface shape (width very much less than length) by the conventional theory. Both theories yield an inverse proportionality between the fault dimensions and the corner frequency in the displacement spectrum. The constants of proportionality in the two theories are similar.
226 citations
TL;DR: The source mechanism of the San Fernando earthquake on February 9, 1971, was studied by utilizing seismic body waves, surface waves, and the static displacement and strain fields in this article.
Abstract: The source mechanism of the San Fernando earthquake on February 9, 1971, was studied by utilizing seismic body waves, surface waves, and the static displacement and strain fields. For computing the static fields due to a fault model with arbitrary dip and slip directions, Maruyama's equations are integrated numerically. Very strong asymmetries in displacement fields and complicated surface strain patterns are produced by the dip of the fault plane and inclination of the dislocation vector. The joint interpretation of the body and surface waves, near-field displacement, and far-field strain fields completely define all important source parameters. The mechanism of the San Fernando earthquake is a reverse fault (strike N70°W, dip 52°NE, slip 225°) with dimensions of 14 by 14 km. The average dislocation on the fault plane is 280 cm. The rupture started near the bottom of the fault plane and propagated toward the surface. Stress drop associated with faulting was Δσ = 70 bars, and the seismic moment was M0 = 16.4 × 1025 dyne cm.
53 citations
TL;DR: A model for fault detection of a logic net is outlined from the standpoint of information theory, and the classical ``path sensitizing'' technique is made systematic using the partial Boolean difference.
Abstract: A tool employed in automated fault diagnosis is emphasized: path sensitization by partial Boolean difference analysis. Motivated by the analogy between a test system and a communication system, a model for fault detection of a logic net is outlined from the standpoint of information theory. The classical ``path sensitizing'' technique is made systematic using the partial Boolean difference. This technique is based on a new theorem on the partial Boolean difference. Finally, a programmable fault detection algorithm is presented along with an example.
46 citations
TL;DR: In this paper, the problem of deducing the internal component parameters from external measurements of a large-scale system is studied in the context of the fault isolation problem by assuming an appropriate algebraic connection model matrix.
Abstract: The problem of deducing the internal component parameters from external measurements of a large-scale system is studied in the context of the fault isolation problem. By assuming an appropriate algebraic connection model matrix, algebraic necessary and sufficient conditions for the exact determination of the internal component parameters are obtained for both the single-test frequency and multiple-test frequency cases. In both cases the linear independence of the rows or columns of certain matrices may be used to determine appropriate test points and test frequencies.
42 citations
TL;DR: In this paper, it was shown that surface displacements due to a fault model in a semi-infinite medium can also be obtained by evaluating similar definite integrals in the near field.
Abstract: Surface displacements due to a fault model in a semi-infinite medium are obtained in the near field. Final solution can be found only by evaluating definite integrals. It is shown that displacements due to a moving dislocation can also be obtained by evaluating similar definite integrals.
25 citations
Patent•
01 Mar 1972TL;DR: In this paper, a fault interrupt system is arranged, upon the detection of a fault to cause a processor in which the fault is detected to enter a fault check-out routine. Successive fault conditions detected while performing the fault checkout routine causes re-entry into that routine.
Abstract: A fault interrupt system is arranged, upon the detection of a fault to cause a processor in which the fault is detected to enter a fault check-out routine. Successive fault conditions detected while performing the fault check-out routine causes re-entry into that routine. A faulty processor is therefore, trapped within the fault check-out routine. Additionally the detection of a fault causes the master capability register of the fault detecting processor to be overwritten with a capability defining a special capability table which is only relevant to the fault check-out programs. By this mechanism the faulty processor cannot, even under fault conditions, gain access to any storage areas outside those of the fault check-out programs. In the multi-processor/multi-storage module system of the PP250 a number of copies of the fault check-out programs and related workspace areas on a one copy per store module basis are provided together with a special capability pointer for each processor of the system and each entry into the check-out program is performed using a different store and therefore entry mechanism into the check-out programs copy so that intermittent processor faults or particular storage module faults will not maintain the processor indefinitely in the check-out program.
23 citations
TL;DR: The concept of error vectors that indicate how the effect of a fault propagates through a network are introduced that allow one to identify redundancies in the network as well as calculate the output of the network given a fault and an input.
Abstract: In this note we study the problem of fault detection in linear logic networks. We introduce the concept of error vectors that indicate how the effect of a fault propagates through a network. These vectors allow one to identify redundancies in the network as well as calculate the output of the network given a fault and an input. Problems related to fault diagnosis and the detection of multiple faults are also considered.
20 citations
05 Dec 1972
TL;DR: This paper focuses on the behavioral simulation of the behavior of a digital logic net which contains a physical defect, or fault, and is known as digital fault simulation.
Abstract: During the past few years it has become increasingly apparent that in order to design and develop highly reliable and maintainable digital logic systems it is necessary to be able to accurately simulate those systems. Not only is it necessary to be able to simulate a logic net as it was intended to behave, but it is also necessary to be able to model or simulate the behavior of the logic net when it contains a physical defect. (The representation of a physical defect is known as a fault.) The behavioral simulation of a digital logic net which contains a physical defect, or fault, is known as digital fault simulation.
9 citations
TL;DR: In this article, the sensitivity of the directivity function for P waves to the kinematic parameters and to the orientation of the fault plane is demonstrated, showing that the S wave directivity functions appear to be relatively insensitive to the change in the KNN parameters.
Abstract: The earthquake focus is represented by a bilateral bidirectional fault model in which the final fault area is rectangular. The transfer functions for body waves for this fault model have been derived. The directivity functions for body waves are defined by taking the ratio of the transfer functions corresponding to two observation stations. The sensitivity of the directivity function for P waves to the kinematic parameters and to the orientation of the fault plane is demonstrated. The S wave directivity function appears to be relatively insensitive to the change in the kinematic parameters. A deep focus earthquake (H = 600 km, mb = 7.0) has been investigated and the kinematic parameters have been successfully recovered using the modulus of the P wave directivity function. The kinematic parameters are as follows: The fault plane is the y-z nodal plane of the focal mechanism solution, the faulting is of the bilateral bidirectional type with total rupture along the y axis of 75 km and total rupture along the z axis of 29.5 km; the rupture speed along the y axis is 3.97 km/sec and along the z axis is 2.98 km/sec. The fault area is 2212 km2 and the dislocation is estimated to be 26 cm.
9 citations
TL;DR: A new procedure is developed for finding first- and second-order diagnostic resolutions in a generalized fault table employing more than one fault q cube per fault pattern.
Abstract: The definition of the generalized fault table [1] is expanded to cover a representation employing more than one fault q cube per fault pattern. On the basis of this expanded definition and simple concepts from a cover algebra, a new procedure is developed for finding first- and second-order diagnostic resolutions.
01 May 1972
TL;DR: The authors present several techniques to design asynchronous sequential networks, assuming that the asynchronous sequential machines to be realized are described by normal mode flow tables and that only single input variables changes occur and the state variables are delayed appropriately such that essential hazards need not be considered.
Abstract: : In this paper the authors present several techniques to design asynchronous sequential networks. It is assumed that the asynchronous sequential machines to be realized are described by normal mode flow tables; also, that only single input variables changes occur and that the state variables (feedback variables) are delayed appropriately such that essential hazards need not be considered. The fault model for the design techniques and necessary and sufficient conditions on the state assignments for m-fault-tolerant asynchronous sequential networks are given. Three design techniques for the fault-tolerant networks are given.