M. Varalakshmi

Bio: M. Varalakshmi is an academic researcher from VIT University. The author has contributed to research in topics: Queue & Retrial queue. The author has an hindex of 3, co-authored 4 publications receiving 23 citations.

Analysis of M[X]/G/1 retrial queue with two phase service under Bernoulli vacation schedule and random breakdown

Abstract: This paper investigates the steady state behaviour of an M[x]/G/1 retrial queue with two phases of service under Bernoulli vacation schedule and breakdown. Any arriving batch finding the server busy, breakdown or on vacation enters an orbit. Otherwise one customer from the arriving batch enters the service immediately while the rest join the orbit. After completion of each two phases of service, the server either goes for a vacation with probability p or may wait for serving the next customer with probability (1-p). While the server is working with any phase of service, it may breakdown at any instant and the service channel will fail for a short interval of time. We construct the mathematical model and derive the probability generating functions of number of customers in the system when it is idle, busy, on vacation and under repair. Some system performances are obtained.

An M/G/1 retrial queueing system with two phases of service, immediate Bernoulli feedbacks, single vacation and starting failures

Abstract: This paper analyses an M/G/1 retrial queueing system with second multi-optional services and immediate Bernoulli feedbacks, where the server is subject to starting failure and repair. An arriving customer, who finds the server busy, breakdown or on vacation enters an orbit; otherwise the arriving customer enters into service area. Upon completion of both phases of service in the first round if the customer desires to make a feedback, the customer immediately proceeds for a second round of service. The customer is allowed to make a finite number of such feedbacks before departing from the system. After the completion of both phases of service, if the orbit becomes empty, the server goes for a single vacation. We derive the probability generating functions of number of customers in the orbit for different server states. Important system performance measures are obtained. The effect of various parameters on the system performance are analysed numerically.

An Unreliable Optional Stage M X ∕ G ∕1 Retrial Queue with Immediate Feedbacks and at most J Vacations

Abstract: A repeated attempt queue with multistages of service and almost J vacations is investigated. Balking (or reneging) is applicable for customers. If the orbit is empty at service accomplishment time, the server takes at most J vacations. Busy server may fail for a short interval of time. Using supplementary variable technique, the steady results are deduced.

Enhanced Dengue Outbreak Prediction in Tamilnadu using Meteorological and Entomological data

Abstract: This paper focuses on studying the impact of climate data and vector larval indices on dengue outbreak. After a comparative study of the various LSTM models, Bidirectional Stacked LSTM network is selected to analyze the time series climate data and health data collected for the state of Tamil Nadu (India), for the period 2014 to 2020. Prediction accuracy of the model is significantly improved by including the mosquito larval index, an indication of VBD control measure.

A study on M/G/1 feedback retrial queue with subject to server breakdown and repair under multiple working vacation policy

Abstract: In this paper, we consider a single server feedback retrial queueing system with multiple working vacations and vacation interruption. An arriving customer may balk the system at some particular times. As soon as orbit becomes empty at regular service completion instant, the server goes for a working vacation. The server works at a lower service rate during working vacation (WV) period. After completion of regular service, the unsatisfied customer may rejoin into the orbit to get another service as feedback customer. The normal busy server may get to breakdown and the service channel will fail for a short interval of time. The steady state probability generating function for the system size is obtained by using the supplementary variable method. Some important system performance measures are obtained. Finally, some numerical examples and cost optimization analysis are presented.

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

Abstract: In this paper, we consider a batch arrival retrial queue with feedback under Bernoulli vacation schedule, where the busy server is subjected to breakdown due to the arrival of negative customers. Any arriving batch of positive customers finds the server free, one of the customers from the batch enters into the service area and the rest of them join into the orbit. Arriving positive customers may balk (or renege) the system at particular times. After completion of service the unsatisfied positive customer may rejoin into the orbit to get another regular service as feedback customer. The server takes Bernoulli vacation after service completion of positive customers. After completion of service (if the server is not taking vacation), repair or vacation the server searches for the customers in the orbit or remains idle. The steady state probability generating function for the system size is obtained by using the supplementary variable method. Some system performance measures, reliability measures and stochastic decomposition law are discussed. Finally, some numerical examples and cost optimization analysis are presented.

Supplementary variable technique (SVT) for non-Markovian single server queue with service interruption (QSI)

Abstract: In most of the queueing models, service is considered to be complete without any interruption. But in reality, queueing systems are subject to interruptions due to failure of server or any other cause. In the present article, we present an overview and literature survey on the performance modeling and analysis of single server, general service queueing system with service interruption using supplementary variable technique. The factors causing service interruption such as unreliable server and server vacation are elaborated. The brief of supplementary variable technique to establish the queue size distribution is explained for single server non-Markovian queueing models by incorporating the features of service interruption. The basic concepts and review of literature on the queues with server breakdown and/or vacationing server are described. The research works done during last 10 years (2010–2019) on queues with service interruption involving many other key concepts namely Bernoulli vacation, multiple vacation, bulk arrival, discouragement, etc. and queueing scenarios of service interruption are reported. Some specific applications are also highlighted.