An M/G/1 retrial G-queue for balking, reneging, subject to modified Bernoulli vacation, starting failure

2022 ◽  
Author(s):  
L. Francis Raj ◽  
C. Revathi ◽  
M. C. Saravanarajan
Keyword(s):  
Starting Failure ◽  
Bernoulli Vacation

Analysis of Feedback Retrial Queue with Starting Failure and Server Vacation

2016 ◽  
pp. 71-96
Author(s):  
K. Sathiya Thiyagarajan ◽  
G. Ayyappan
Keyword(s):  
Steady State ◽  
Performance Measures ◽  
Generating Functions ◽  
Retrial Queue ◽  
Laplace Transforms ◽  
Time Dependent ◽  
Steady State Analysis ◽  
Starting Failure ◽  
Dependent Probability ◽  
Bernoulli Vacation

In this chapter we discusses a batch arrival feedback retrial queue with Bernoulli vacation, where the server is subjected to starting failure. Any arriving batch finding the server busy, breakdown or on vacation enters an orbit. Otherwise one customer from the arriving batch enters a service immediately while the rest join the orbit. After the completion of each service, the server either goes for a vacation with probability or may wait for serving the next customer. Repair times, service times and vacation times are assumed to be arbitrarily distributed. The time dependent probability generating functions have been obtained in terms of their Laplace transforms. The steady state analysis and key performance measures of the system are also studied. Finally, some numerical illustrations are presented.

scholarly journals Clinical Impact of COVID-19 Outbreak on Cancer Patients: A Retrospective Study

2021 ◽  
Vol 15 ◽  
pp. 117955492110434
Author(s):  
Sebastiano Buti ◽  
Fabiana Perrone ◽  
Teresa Zielli ◽  
Giulia Mazzaschi ◽  
Chiara Casartelli ◽  
...  
Keyword(s):  
Cancer Therapy ◽  
Cancer Patients ◽  
Clinical Impact ◽  
Treatment Schedule ◽  
Short Term ◽  
Treatment Delays ◽  
Anticancer Treatment ◽  
Starting Failure ◽  
Oncologic Treatment ◽  
The Impact

Background: Coronavirus disease (COVID-19), an acute respiratory syndrome caused by a novel severe acute respiratory syndrome coronavirus (SARS-CoV-2), has rapidly spread worldwide, significantly affecting the outcome of a highly vulnerable group such as cancer patients. The aim of the present study was to evaluate the clinical impact of COVID-19 infection on outcome and oncologic treatment of cancer patients. Patient and methods: We retrospectively enrolled cancer patients with laboratory and/or radiologic confirmed SARS-CoV-2 infection, admitted to our center from February to April 2020. Descriptive statistics were used to summarize the clinical data and univariate analyses were performed to investigate the impact of anticancer treatment modifications due to COVID-19 outbreak on the short-term overall survival (OS). Results: Among 61 patients enrolled, 49 (80%) were undergoing anticancer treatment and 41 (67%) had metastatic disease. Most patients were men; median age was 68 years. Median OS was 46.6 days (40% of deaths occurred within 20 days from COVID-19 diagnosis). Among 59 patients with available data on therapeutic course, 46 experienced consequences on their anticancer treatment schedule. Interruption or a starting failure of the oncologic therapy correlated with significant shorter OS. Anticancer treatment delays did not negatively affect the OS. Lymphocytopenia development after COVID was significantly associated with worst outcome. Conclusions: COVID-19 diagnosis in cancer patients may affect their short-term OS, especially in case of interruption/starting failure of cancer therapy. Maintaining/delaying cancer therapy seems not to influence the outcome in selected patients with recent COVID-19 diagnosis.

Analysis of an M[X]/G/1 unreliable retrial G-queue with orbital search and feedback under Bernoulli vacation schedule

OPSEARCH ◽  
2015 ◽  
Vol 53 (1) ◽  
pp. 197-223 ◽  
Author(s):  
P. Rajadurai ◽  
V. M. Chandrasekaran ◽  
M. C. Saravanarajan
Keyword(s):  
Bernoulli Vacation
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