Determination of pulse locations by a multipulse coder is formulated as the minimisation of an error function in P-dimensional discrete space. A suboptimum solution is presented which offers better performance than co...
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Determination of pulse locations by a multipulse coder is formulated as the minimisation of an error function in P-dimensional discrete space. A suboptimum solution is presented which offers better performance than conventional designs.
A large number of computing systems require very high levels of reliability, availability, or safety. A fault-avoidance approach is not practical in many eases, and is costly and difficult for software, if not impossi...
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A large number of computing systems require very high levels of reliability, availability, or safety. A fault-avoidance approach is not practical in many eases, and is costly and difficult for software, if not impossible. One way of reducing tiie effects of an error introduced during the design of a program is to use multiple versions of the program, independently designed from a common specification. If these versions are designed by independent programming teams, it is to be expected that a fault in one version will not have the same behavior as any fault in the other versions. Since the errors in the output of the versions will be different and uncorrclated, it is pos-sible to run the versions concurrently, cross-check their results at prespecified points, and mask errors. A Design Diversity experiments (DEDIX) testbed has been implemented at UCLA to study the influence of common mode errors which can result in a failure of the entire system. The layered design of DEDDC and its decision algorithm are described. The usage of the system and its application in an ongoing experiment are explained.
A simple in-service method for monitoring errors in the DMI code is proposed, and its principle is explained. A DMI decoder with an error detection circuit can be realised using digital components exclusively. In a tr...
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A simple in-service method for monitoring errors in the DMI code is proposed, and its principle is explained. A DMI decoder with an error detection circuit can be realised using digital components exclusively. In a transmission experiment, good accuracy was obtained for a wide error rate range, irrespective of mark occurrence in the signal sequence.
errors within an assembler program for limiting the local power density in a reactor vessel are to be identified and corrected during two test phases. According to the special features for error detection of the testi...
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errors within an assembler program for limiting the local power density in a reactor vessel are to be identified and corrected during two test phases. According to the special features for error detection of the testing facilities, the errors are classified, and an appropriate software reliability model is applied to each error class. These models allow prediction of certain reliability parameters from the observation of the test. Depending on the model employed these parameters can be e.g. the number of remaining errors, the probability for the occurance of an error within a given time interval, the meantime between successive errors. In this contribution references are only made to the number of remaining errors.
Using a finite-field transform, a simplified algorithm for decoding Reed-Solomon codes is developed to correct erasures as well as errors over the finite-fieldGF(qm), whereqis a prime andmis an integer. If the finite-...
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Using a finite-field transform, a simplified algorithm for decoding Reed-Solomon codes is developed to correct erasures as well as errors over the finite-fieldGF(qm), whereqis a prime andmis an integer. If the finite-field transform is a fast transform, this decoder can be faster and simpler than a decoder that uses more conventional methods.
A technique for reducing the visibility of transmission errors in television signals which have been digitally encoded using differential pulse-code modulation(d.p.c.m.) is to weight the predicted value of the signal ...
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A technique for reducing the visibility of transmission errors in television signals which have been digitally encoded using differential pulse-code modulation(d.p.c.m.) is to weight the predicted value of the signal by a factor less than unity. This prediction ‘leak’ has the effect of reducing the extent of the propagation, and hence the visibility, of transmission errors, but it may also increase the quantising distortion. A closely controlled subjective investigation of this error visibility against quantising distortion trade-off is described. Details of both the equipment and procedure followed are given and a mathematical model is derived to allow the plotting of curves of constant impairment for varying leak factor and error rate. The investigation indicated that for moderate channel error rates, a leak factor of 15/16 is a good compromise between error visibility and quantisation distoration.
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