Reliability analysis of the triple modular redundancy system under step-partially accelerated life tests using Lomax distribution

Abstract Triple modular redundancy (TMR) is a robust technique utilized in safety-critical applications to enhance fault-tolerance and reliability. This article focuses on estimating the distribution parameters of a TMR system under step-stress partially accelerated life tests, where each component included in the system follows a Lomax distribution. The study aims to analyze the system’s reliability and mean residual lifetime based on the estimated parameters. Various estimation techniques, including maximum likelihood, percentile, least squares, and maximum product of spacings, are explored. Additionally, the optimal stress change time is determined using two criteria. An illustrative example supported by two actual data sets is presented to showcase the methodology’s application. By conducting Monte Carlo simulations, the assessment of the estimation methods’ effectiveness reveals that the maximum likelihood method outperforms the other three methods in terms of both accuracy and performance, as indicated by the numerical outcomes. This research contributes to the understanding and practical implementation of TMR systems in safety-critical industries, potentially saving lives and preventing catastrophic events

31. Differential effects of intravenous bolus furosemide and continuous furosemide infusion on in-hospital management and outcomes among patients admitted with acute decompensated heart failure

Loop diuretics are a cornerstone in the management of Acute Decompensated Heart Failure (ADHF). However, the best therapeutic strategy in terms of intermittent boluses versus continuous infusion is still unclear.We set to examine the differences in hospital management and short-term and long-term mortality of patient receiving furosemide bolus or infusion treatment for ADHF.This is a retrospective cohort study of 207 patients admitted to KKUH with ADHF. Clinical data, labs, in-hospital outcomes and long-term mortality data were collected through review of medical records and HEARTS registry database. We stratified our cohort into two groups; furosemide infusion and bolus groups.The Mean age was 61.5 ± 13.87 years, and 66.2% were males. Approximately 42% had left ventricular ejection fraction LVEF <40%. Use of intravenous infusions furosemide and boluses during admission was 42.86% and 57.14%, respectively. Compared to patient received bolus therapy, patients on infusion therapy had more renal impairment at presentation (26.4% vs. 12.5%, p = 0.033) and anemia (18.1% vs. 4.25, P = 0.006). They had less diabetes (30.6% vs. 38.5%, p = 0.006) and prior MI (18.1% vs. 32.3%, p = 0.006). Infusion group received higher total daily diuretic dose (p < 0.001), more Metolazone (19.4% vs. 3.1%, p = 0.002) and mechanical ventilation (11.1% vs. 3.1, p = 0.038). There was no difference in total urine output and renal outcomes between the two groups. The infusion group had longer hospital stay (15.40 ± 12.14 vs. 10.26 ± 6.74 days, p < 0.001). The long-term mortality up to 3 years was significantly higher among patient who received infusion therapy (27.78% vs. 9.38%, p = 0.002). ADHF patients who received furosemide infusion needed higher diuretic dose, had significantly longer hospital stay and higher long-term mortality