Sachidanand Gupta

Reliability analysis of a two-unit cold standby redundant system with administrative delay and no priority in repair

Abstract This paper discusses the stochastic behaviour of a two-unit cold standby redundant system in which each unit works in three different modes—normal, partial failure and total failure, with administrative delay and no priority in repair. The administrative time distribution is assumed to be exponential and the repair and failure time distributions are exponential and arbitrary. Various reliability parameters for system designers have been evaluated.

Maternal and fetal outcome in patients of heart failure at a tertiary care centre

Background: To study maternal and fetal outcome in antenatal patients with heart failure. Methods: The present study was conducted on pregnant female with heart failure admitted to hospital UISEMH, Kanpur from January 2012 to August, 2013. We attended 6800 pregnant female admitted to hospital out of which 48 pregnant female had heart failure during pregnancy or in labour. This was descriptive observational study. Results: Percentage of pregnant female with heart failure in our study was 0.7%. The mean of age distribution in pregnant patients with heart failure is 22.66 ± 2.82 years. Primigravida and primipara contributed to major group with 77.09% (37/48). Delivery was conducted in 33.3%, while 60.4% were expired. 4% of cases lost follow-up. None of patient belonged to AHA class A or B of heart failure. 37.5% were in AHA class C while 62.5% were in class D. Early diagnosis was made in only 16.58% of cases. 75% of early diagnosed case survived in comparison to 32% of late diagnosis. 31.25% cases delivered term healthy babies, 37.5% were dead born and pre-term and small for gestation babies are 12.5% and 18.75% respectively. Of dead born 66.6% were macerated and 33.3% were fresh still-births. Among survivals 57% had ventilator support. Conclusion: Early diagnosis and prompt management improves outcome. Maternal and fetal outcome is dependent on time of diagnosis, severity of heart failure and ventilator support.

Reliability analysis of two-unit warm standby system with partial failure mode and inspection time

Abstract A two-unit warm standby system is discussed, in which units are identical. Partial failure and complete failure of a unit can be detected by inspection from time to time. The inspection time follows an exponential distribution, whereas the repair and failure time follows an exponential and arbitrary distribution. Several reliability characteristics of interest to system designers and operation managers have been evaluated.