Reliability Measures Analysis of a Computer System Incorporating Two Types of Repair Under Copula Approach

The use of semi-Markov process and regenerative point has been made for determining reliability measures of a computer system. The stochastic model is developed by considering the ideas of unit wise redundancy and failure of service facility. The treatment to the failed service facility is given in order to resume the jobs with full efficiency. The system is analyzed at different time points in the steady state. The profit of the system model has been obtained under the following two policies: In first policy, the profit is evaluated by taking cost per unit time for busy period of the service facility and cost per unit time treatment of the service facility. In second policy, the profit is evaluated by taking cost per unit hardware repair, per unit time software up-gradation and cost per unit time treatment of the service facility. The behavior of some reliability measures, such as MTSF, availability and profit function, has been shown graphically for arbitrary values of the parameters.

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Reliability Measures of a Computer System with Priority for Repair and Hardware Redundancy

International Journal of Computer Applications ◽

10.5120/ijca2015906125 ◽

2015 ◽

Vol 125 (8) ◽

pp. 32-37

Author(s):

V.J. Munday ◽

S.C. Malik

Keyword(s):

Computer System ◽

Reliability Measures ◽

Hardware Redundancy

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Some Recent Results in Quiescent Prominence Spectrometry

International Astronomical Union Colloquium ◽

10.1017/s0252921100065179 ◽

1979 ◽

Vol 44 ◽

pp. 41-47

Author(s):

Donald A. Landman

Keyword(s):

Real Time ◽

Computer System ◽

Spectral Response ◽

Absolute Intensity ◽

Solar Observatory ◽

Target Size ◽

Small Target ◽

Signal Averaging ◽

Quiescent Prominence

This paper describes some recent results of our quiescent prominence spectrometry program at the Mees Solar Observatory on Haleakala. The observations were made with the 25 cm coronagraph/coudé spectrograph system using a silicon vidicon detector. This detector consists of 500 contiguous channels covering approximately 6 or 80 Å, depending on the grating used. The instrument is interfaced to the Observatory’s PDP 11/45 computer system, and has the important advantages of wide spectral response, linearity and signal-averaging with real-time display. Its principal drawback is the relatively small target size. For the present work, the aperture was about 3″ × 5″. Absolute intensity calibrations were made by measuring quiet regions near sun center.

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