Papers by Srinivasa Rao Gadde
When the life time of a product follows exponentiated half logistic distribution we can recommend... more When the life time of a product follows exponentiated half logistic distribution we can recommend a two-stage group acceptance sampling plan for truncated life tests. The acceptance of the lot can be done at the first or second stage based on the number of failures in each group. In this paper, we obtained the number of groups essential for each of two stages for the underlying lifetime distribution so as to minimize the average sample number under the constraints of satisfying the producer's and consumer's risks simultaneously. Single-stage group sampling plans are also considered as special cases of the stated plan and compared with the proposed plan in terms of the average sample number and the operating characteristics.
This paper draws inferences about the reliability in a multi-component stress-strength system whe... more This paper draws inferences about the reliability in a multi-component stress-strength system when both stress and strength are independently identically distributed (idd) Burr random variables. We consider both maximum likelihood and Bayes estimators of the system reliability. The two estimators are compared numerically by obtaining empirical efficiencies with respect to the maximum likelihood estimator (MLE) by generating 1000 random samples by a Monte Carlo simulation. It is found that the Bayes estimators are better than the corresponding MLEs for small samples (n~ ~< 7; i = 1, 2). Moreover, the robustness of the Bayes estimators to the change of the prior parameters is also considered.
This research intended to fit the cure model for end-stage chronic kidney disease (CKD) patients ... more This research intended to fit the cure model for end-stage chronic kidney disease (CKD) patients by using statistical computing methods, comparing the survival probabilities of CKD treatments and determining the influence of treatments’ sponsorship on the survival of CKD patients. The study used a dataset from Benjamin Mkapa Hospital (BMH) of end-stage CKD patients treated from 2018 to 2021 for a follow-up time of 172 weeks and an exponentiated half-logistic (EHLD) distribution used as baseline distribution in this cure model. The findings revealed that the cure probability for National health insurance fund (NHIF) sponsored patients were 46% and the cure probability for self-sponsored patients was 5%. Additionally, the median survival for NHIF-sponsored subjects was 48 weeks and for self-sponsored was 36 weeks. The cure fraction for NHIF-sponsored CKD patients was significantly higher than for self-sponsored patients. Therefore, treatment sponsorship was a significant factor in the...
Asia Pacific Journal of Mathematics
A. In every competitive enterprise, there has been a resurgence of interest in increasing the qua... more A. In every competitive enterprise, there has been a resurgence of interest in increasing the quality of products. In this paper, we create new acceptance sampling plans based on truncated life tests for the Marshall-Olkin power Lomax distribution. The minimum sample sizes needed to declare the specified mean life with respect to the newly developed sampling plans are obtained for different values of the model parameters. Besides, the operating characteristic function values, minimum ratios of the true value and the required value of the parameter with a given producer risk are discussed. Moreover, the results are illustrated using numerical examples, and a real data set is considered to illustrate the functioning of the recommended acceptance sampling plans. The result shows that the proposed plan is more adequate compared with other acceptance sampling plans available in the open literature. So, it can be used for industry applications.
International Journal of Computational Intelligence Systems
In this article, an efficient mean chart for symmetric data have been presented for multiple depe... more In this article, an efficient mean chart for symmetric data have been presented for multiple dependent state (MDS) sampling using neutrosophic exponentially weighted moving average (NEWMA) statistics. The existing neutrosophic exponentially weighted moving average charts are not capable of seizure the unusual changes threatened to the manufacturing processes. The control chart coefficients have been estimated using the symmetry property of the Gaussian distribution for the uncertain environment. The neutrosophic Monte Carlo simulation methodology has been developed to check the efficiency and performance of the proposed chart by calculating the neutrosophic average run lengths and neutrosophic standard deviations. The proposed chart has been compared with the counterpart charts for confirmation of the proposed technique and found to be a robust chart.
Statistics in Transition New Series, 2019
In this manuscript, a group acceptance sampling plan (GASP) is developed when the lifetime of the... more In this manuscript, a group acceptance sampling plan (GASP) is developed when the lifetime of the items follows odd generalized exponential log-logistic distribution (OGELLD), the multiple number of items as a group can be tested simultaneously in a tester. The design parameters such as the minimum group size and the acceptance number are derived when the consumer’s risk and the test termination time are specified. The operating characteristic (OC) function values are calculated (intended) according to various quality levels and the minimum ratios of the true average life to the specified average life at the specified producer’s risk are derived. The methodology is illustrated through real data.
Complexity
The proposed sampling plan in this article is referred to as multiple dependent state (MDS) sampl... more The proposed sampling plan in this article is referred to as multiple dependent state (MDS) sampling plans, for rejecting a lot based on properties of the current and preceding lot sampled. The median life of the product for the proposed sampling plan is assured based on a time-truncated life test, when a lifetime of the product follows exponentiated Weibull distribution (EWD). For the proposed plan, optimal parameters such as the number of preceding lots required for deciding whether to accept or reject the current lot, sample size, and rejection and acceptance numbers are obtained by the approach of two points on the operating characteristic curve (OC curve). Tables are constructed for various combinations of consumer and producer’s risks for various shape parameters. The proposed MDS sampling plan for EWD is demonstrated using the coronavirus (COVID-19) outbreak in China. The performance of the proposed sampling plan is compared with the existing single-sampling plan (SSP) when t...
Brazilian Journal of Probability and Statistics, 2013
ABSTRACT In this article, acceptance sampling plans are developed for the Marshall–Olkin extended... more ABSTRACT In this article, acceptance sampling plans are developed for the Marshall–Olkin extended exponential distribution percentiles when the life test is truncated at a pre-specified time. The minimum sample size necessary to ensure the specified life percentile is obtained under a given customer’s risk. The operating characteristic values (and curves) of the sampling plans as well as the producer’s risk are presented. Two examples with real data sets are also given as illustration.
In this study, the main aim is to analyze the dependence structure of a financial time series whi... more In this study, the main aim is to analyze the dependence structure of a financial time series which is generally consisting of speculative prices of assets such as stocks or foreign currencies using the extreme value copulas. The attention is put on extreme value copula analysis for financial data. It is possible to analyze extreme values in bivariate or multivariate case by using the copula approach. We present an inference procedure which is based on the maximum pseudo-likelihood estimate for the copula parameter. Some numerical techniques are used for selecting an appropriate extreme value copula model and for checking its goodness-of-fit. The presented method is illustrated by examples coming from Turkish financial market as a developing market, and also world’s leading financial markets;USA and Germany.
Quality and Reliability Engineering International
International Journal of Mathematics in Operational Research
Journal of Industrial Engineering International
This paper deals with construction of confidence intervals for process capability index using boo... more This paper deals with construction of confidence intervals for process capability index using bootstrap method (proposed by Chen and Pearn in Qual Reliab Eng Int 13(6):355-360, 1997) by applying simulation technique. It is assumed that the quality characteristic follows type-II generalized log-logistic distribution introduced by Rosaiah et al. in Int J Agric Stat Sci 4(2):283-292, (2008). Discussed different bootstrap confidence intervals for process capability index. Maximum likelihood method is considered for obtaining the estimators of the parameter. Monte Carlo simulation technique is applied to find out the coverage probabilities and average widths of the bootstrap confidence intervals. The results are illustrated with real data sets.
We propose a new lifetime model, called the odd generalized exponential log logistic distribution... more We propose a new lifetime model, called the odd generalized exponential log logistic distribution (OGELLD).We obtain some of its mathematical properties. Some structural properties of the new distribution are studied. The maximum likelihood method is used for estimating the model parameters and the Fisher's information matrix is derived. We illustrate the usefulness of the proposed model by applications to real lifetime data.
The sequential probability ratio procedures of Statistical Inference are made use of in construct... more The sequential probability ratio procedures of Statistical Inference are made use of in construction of a Cumulative Sum Control Chart for a variable process characteristic. The distribution of process variate is log-logistic distribution. The construction of mask and values of average run length are also presented. Such a chart is useful in early detection of shifts in the process average.
Life Cycle Reliability and Safety Engineering
International Journal of Quality & Reliability Management
International Journal of Quality & Reliability Management
Purpose The purpose of this paper is to develop a new control chart using two EWMA statistics cal... more Purpose The purpose of this paper is to develop a new control chart using two EWMA statistics called the hybrid exponentially weighted moving average (HEWMA) chart to improve the sensitivity of EWMA chart proposed by Zhang et al. (2014). When mean and variance of process are not constants, the use of control chart using coefficient of variation (CV) is a successful approach. Design/methodology/approach The control chart using EWMA statistics has ability to detect moderate and small shifts in the process. The authors present the designing of the proposed HEWMA statistics control chart called the HEWMACV chart based on two hybrid EWMA (HEWMA) statistics. The proposed control chart utilizes the current information and previous information to make decision about the state of control chart. Findings In this paper, the authors will present the designing of HEWMA statistics control chart called the HEWMACV chart. The efficiency of the proposed control chart is shown using the simulated dat...
Life Cycle Reliability and Safety Engineering
International Journal of Quality & Reliability Management
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Papers by Srinivasa Rao Gadde