IAPQR Transactions - A UGC-CARE Listed Journal
Published in Association with Indian Association for Productivity, Quality and Reliability
Current Volume: 48 (2023-24 )
ISSN: 0970-0102
Periodicity: Half-Yearly
Month(s) of Publication: September & March
Subject: Quality Management/Statistics
DOI: 10.32381/IAPQRT
Articles in the fields of Quality, Productivity and Reliability are considered for publication in IAPQR Transactions since its initiation in the year 1975. Since then, the journal is being regularly published twice a year. Articles published in this journal are abstracted / reviewed in renowned scientific periodicals like Zentralblatt fur Mathematik, Mathematical Reviews, Statistical Theory and Methods Abstracts, Quality Control and Applied Statistics and some other such publications.The journal has always been a priority to frontline academicians for communicating their research works. To name a few, Jye-Chyi Lu, Benjamin Reiser, David M. Rocke, Unnikrishnan Nair, S. Joseph, Shun-ichi Abe, Barry C. Arnold, J.M.S.E Castillo, Bo Bergman, J. Dahlgaard, W. Kossler and J. H . Sullivan may be cited. The journal also encourages young researchers to publish their research works. University Grants Commission has placed this journal in its approved list of journals.
Articles published in this journal are abstracted / reviewed in renowned scientific periodicals like Zentralblatt fur Mathematik, Mathematical Reviews, Statistical Theory and Methods Abstracts, Quality Control and Applied Statistics and some other such publications.
Founder Editor Former Centenary Professor in Statistics Former Professor, Department of Statistics Department of Statistics, Department of Agricultural Statistics, Pro-Vice Chancellor, Former General Manager, S.Q.C. & O.R. Unit, Indian Statistical Institute, Kolkata, India Department of Mathematics and Statistics, Department of Mathematics and Statistics, Concordia University, Canada Department of Operations Management, S.Q.C. & O.R. Unit, Indian Statistical Institute, Kolkata, India R&D, Uber India, Department of Statistics, Banwarilal Bhalotia College, Asansol, India
Prof. S.P. Mukherjee
University of Calcutta, India
Editor
Prof. Bikas K. Sinha
Indian Statistical Institute, Kolkata, India
Prof. Manisha Pal
University of Calcutta, India
Associate Editor
Prof. Asis Kumar Chattopadhyay
University of Calcutta, India
Prof. Debasish Bhattacharya
Institute of Agriculture,
Visva Bharati University,
Santiniketan, W.B., India
Prof. P.G. Sankaran
Cochin University of Science & Technology, India
Dr. A. Dharmadhikari
Tata Motors, Pune, India
Dr. M. Zafar Anis
Prof. Debasis Kundu
Indian Institute of Technology, Kanpur, India
Prof. Yogendra P. Chaubey
Prof. Arnab Laha
Indian Institute of Management
Ahmedabad, India
Dr. Ashis Kumar Chakraborty
Dr. Sudipto Pal
Bangalore, India
Editorial Secretary
Mr. Kuntal Bakuli
Volume 48 Issue 1-2 , (Apr- to Mar-2024)
Measuring the Reliability, Safety and Sustainability of the Water Supply Utilities in Japan
By: M.L.U.K. Piyasena , T. Oyama
Page No : 1-37
Abstract
Water-supply network systems are an indispensable social infrastructure in modern society. Therefore, water supply utilities require high system robustness towards both accidents and natural disasters. In this study, we define a work performance indicator (WPI) to quantitatively measure the robustness of water supply utilities (WSU) in Japan. The WPI was defined from three perspectives: reliability, safety, and sustainability. Based on actual data expressing the work performance of Japanese WSU from 1980 to 2018, we illustrate the numerical results of WPIs to determine their regional characteristics. We applied statistical data analysis techniques such as multivariate regression analysis, cluster analysis, and principal component analysis to calculate the WPIs and investigate the historical and regional characteristics and trends of WSU in Japan during the investigated period. These approaches can be applied to the design and improvement of natural disaster mitigation policies, such as those focused on earthquakes in Japan.
Authors:
M.L.U.K. Piyasena And T. Oyama
National Graduate Institute for Policy Studies (GRIPS), 7-22-1 Roppongi, Minato-ku, Tokyo, Japan
DOI : https://doi.org/10.32381/IAPQRT.2024.48.01-02.1
Price: 251
By: Pei-Shan Yen , Weihan Zhao , Dulal K. Bhaumik
Page No : 38-64
Abstract
The objective of our study is to discern the aberrant functional and structural brain connectivity in mental disorder patients, ultimately to develop quality therapeutic strategies. We developed a bivariate mixed-effects model to ascertain the differences in brain connectivity between healthy individuals and affected patients. The model accounts for subject-specific variability and heteroscedastic errors, enabling it to handle correlations within and across different connectivity measures. Such comprehensive accounting allowed us to identify notable connectivity differences between groups. To validate the performance of our model, we conducted a simulation study. Then, we applied our method to neuroimaging data for late-life depression patients, assessing biomarker identification compared to univariate mixed-effects models.
Authors:
Pei-Shan Yen : Division of Epidemiology and Biostatistics, University of Illinois at Chicago, USA
Weihan Zhao : Division of Epidemiology and Biostatistics, University of Illinois at Chicago, USA
Dulal K. Bhaumik : Division of Epidemiology and Biostatistics and Department of Psychiatry, University of Illinois at Chicago, USA
DOI : https://doi.org/10.32381/IAPQRT.2024.48.01-02.2
Price: 251
A Note on Analysis of Dynamic Data
By: S.P. Mukherjee , Manisha Pal
Page No : 65-72
Abstract
The current note discusses the analysis of data on a response variable collected at different time points, when the same experimental design is used at each time point. The mean response depends on a number of factors as well as on the time point at which it is measured. The parameters of the model are estimated using the generalized least squares method. A simulation study is conducted and the estimate of the variance-covariance matrix of the parameter estimators is obtained using the Jackknife technique.
Authors :
S.P. Mukherjee : Retd. Centenary Professor, Department of Statistics, University of Calcutta, India
Manisha Pal : Department of Statistics, St. Xavier’s University, Kolkata, India
DOI : https://doi.org/10.32381/IAPQRT.2024.48.01-02.3
Price: 251
Copula based Reliability Measures in Reversed Time
By: P. G. Sankaran , N. Unnikrishnan Nair
Page No : 73-92
Abstract
The reliability measure in reversed time such as reversed hazard rate and mean waiting time are recently employed for modeling and analysis of lifetime data. In the present paper, we introduce these reliability functions in terms of copulas and study their properties. Further, these copula based reliability measures are employed to study the dependence between random variable.
Authors :
P. G. Sankaran And N. Unnikrishnan Nair
Department of Statistics, Cochin University of Science and Technology, Kerala, India
DOI : https://doi.org/10.32381/IAPQRT.2024.48.01-02.4
Price: 251
By: Habbiburr Rehman , Navin Chandra , Aquil Ahmed , Anupam Kumar
Page No : 93-107
Abstract
In this article, we considered the problem of survival analysis with competing causes of failure. For analysing competing risks survival data, we used parametric cause specific hazard regression model by assuming Rayleigh distribution as baseline model. The estimates of unknown parameters and cumulative cause specific hazard function are obtained through maximum likelihood as well as Bayesian methods of estimation. The Bayes estimates are obtained based on non-informative prior under two types of loss functions such as squared error loss function and LINEX loss function. For the comprehensive comparison of methods of estimation, we conduct a Monte Carlo simulation study. For the validation of proposed model, a bone marrow transplant real data is considered.
Authors :
Habbiburr Rehman : Department of Statistics, Ramanujan School of Mathematical Sciences, Pondicherry University, Puducherry, India
Navin Chandra : Department of Statistics, Ramanujan School of Mathematical Sciences, Pondicherry University, Puducherry, India
Aquil Ahmed : Department of Statistics & Operations Research, Aligarh Muslim University, India
Anupam Kumar : Department of Statistics, PUC, Mizoram University, Aizawl, India
DOI : https://doi.org/10.32381/IAPQRT.2024.48.01-02.5
Price: 251
Binomial Type Exponential Class Software Reliability Growth Model and Estimation of Parameters
By: Rajesh Singh , Kailash R. Kale , Pritee Singh
Page No : 108-122
Abstract
The total number of failures and the failure rate are the parameters to be estimated for assessing the performance of the Software. The Binomial type and exponential class software reliability growth model is considered and the Bayes estimators of the parameters are derived in this research paper. A non-informative prior for the total number of failures and gamma prior for Failure rate are assumed to obtain the Bayes estimator for the parameters. Using the Monte Carlo simulation technique, the performance of the derived Bayes estimators is studied by comparing with the corresponding maximum likelihood estimators. The proposed Bayes estimators are recommended for use with appropriate selection of prior constants.
Authors :
Rajesh Singh : Department of Statistics, Sant Gadge Baba Amravati University, Amravati
Kailash R. Kale : Department of Statistics, Ghulam Nabi Azad Arts, Commerce, and Science College, Barshitakli, Dist-Akola
Pritee Singh : Department of Statistics, Institute of Science, Nagpur
DOI : https://doi.org/10.32381/IAPQRT.2024.48.01-02.6
Price: 251
Apr- to Mar-2023
Obituary
Prof. Hemshankar Ray by Subrata Ghosh
By: No author
Page No : (i-ii)
Price: 251
By: S. P. Mukherjee
Page No : 1-15
Abstract
The present article reflects on a few issues regarding the on-going trend in theory and applications of Statistics. The aspect of applications and the problems with sample surveys in several domains have been emphasized.
Author :
S. P. Mukherjee
Mentor, Indian Association for Productivity, Quality and Reliability.
DOI : https://doi.org/10.32381/IAPQRT.2023.47.01-02.1
Price: 251
By: N.K. Sajeev Kumar , Sumi A.R.
Page No : 16-42
Abstract
In this article we have derived the best linear unbiased estimator (BLUE) of the parameters ?2 and ?2 involved in the Morgenstern type bivariate exponential distribution by ranked set sampling (RSS). Also we have evaluated the BLUE's of ?2 and ?2 involved in the Morgenstern type bivariate exponential distribution by concomitants of ranked set sampling for some specific values of the sample size n. The efficiency comparison of the proposed estimators with that of the estimators using concomitants of order statistics and modified ranked set sampling is also made.
Authors :
N.K. Sajeev Kumar : Department of Statistics, University College, Trivandrum, Kerala, India.
Sumi A.R. : Department of Statistics, University College, Trivandrum, Kerala, India.
DOI : https://doi.org/10.32381, IAPQRT.2023.47.01-02.2
Price: 251
Weighted Alternated Charting Statistic Control Chart to Monitor the Mean Vector
By: M.P. Gadre
Page No : 43-60
Abstract
In this article, modification of the ‘Alternated Charting Statistic’ (ACS) scheme with the traditional Hotelling c 2 chart to control the mean vector of a bivariate normal process is proposed. With the bivariate ACS scheme in use, the two quality characteristics (X, Y) are controlled in an alternating fashion. The proposed control chart is called as ‘Weighed Alternated Charting Statistic’ (WACS) control chart to monitor the mean vector by using variable inspection. In WACS chart, which one of the two quality characteristic is to be inspected, is explained in detail. While defining the rule of the status of the process, the weights of each of the two quality characteristics are considered. It is numerically illustrated that the WACS chart performs better as compared to the c 2chart and ACS chart.
Author :
M.P. Gadre
Shriram Institute of Information Technology, Solapur, India.
DOI : https://doi.org/10.32381/IAPQRT.2023.47.01-02.3
Price: 251
Reliability and Availability Improvement of Raw Material Charging Station in A Steel Industry
By: Subrata Rath , Ashis Kumar Chakraborty , Subhashis Chatterjee
Page No : 61-85
Abstract
Raw Material Charging Station (RMCS) is one of the most important infrastructures in steel industry and is used to load and carry crushed iron ore to furnace. Breakdown behaviour of the RMCS was observed for a certain period, and its future behaviour was predicted using a reliability model. For improvement of availability however, a Six sigma approach was used. Initial focus was to reduce the repair time per month in order to make RMCS more available for use and save the financial loss due to unavailability of the furnaces to produce steel. This study discovers a way to simultaneously improve reliability, reduce repair time and thereby improve availability of the RMCS. The study also generalises an approach for improving reliability and availability for any mechanised repairable system using six sigma methodologies.
Authors :
Subrata Rath : SQC & OR Unit, Indian Statistical Institute, Pune, India.
Ashis Kumar Chakraborty : SQC & OR Unit, Indian Statistical Institute, Kolkata, India.
Subhashis Chatterjee : Mathematics Department, IIT(ISM) Dhanbad, India.
DOI : https://doi.org/10.32381/IAPQRT.2023.47.01-02.4
Price: 251
Inference and Prediction of Order Statistics Based On K-Record Values from A Weibull Distribution
By: Laji Muraleedharan , Manoj Chacko
Page No : 86-102
Abstract
In this paper, the problem of estimation of parameters and prediction of order statistics from a future sample based on upper k-record values arising from a two parameter Weibull distribution is considered. The maximum likelihood estimators and the Bayes estimators are obtained based on observed upper k-record values. Bayesian point predictors of the order statistics from a future sample and its two-sided equi-tailed prediction intervals are also derived. Finally, a numerical illustration is considered for exemplifying the proposed inferential procedures developed in this paper.
Authors :
Laji Muraleedharan and Manoj Chacko
Department of Statistics, University of Kerala, Trivandrum, India.
DOI : https://doi.org/10.32381/IAPQRT.2023.47.01-02.5
Price: 251
News Corner : Golden Jubilee Celebration Conference of IAPQR
By: ..
Page No : 103-107
Price: 251
Apr- to Mar-2022
By: Yehenew G Kifle , Tshepo F. Maja , Ramon A. Tamayo
Page No : 1-16
Abstract
Peritoneal Dialysis (PD) is a process of replacing kidney function that cleans waste product from the blood and removes extra fluid from the body. In most cases, PD process is slowed down by a peritoneal membrane infection called peritonitis, which is the leading cause of morbidity and dialysis failure among PD patients in developing countries. Early prevention of this infection is very crucial for the success of PD in resource-poor countries. Using a prospective study from Pietersburg provincial hospital in South Africa, we have investigated potential social, demographic, and biological risk factors that contribute to the first episode of peritonitis. Both semiparametric Cox proportional hazards and two parametric Accelerated Failure Time (AFT) survival models were fitted to the data and compared for their performance. Weibull AFT model fits better to the peritonitis longitudinal dataset followed by exponential AFT and Cox PH models. Among PD cohort of patients, 60.38% of peritonitis infections were recorded over the follow-up period with the majority of peritonitis infections are recorded among females (65.4%) and rural dwellers (65.7%) with (62.6%) of black Africans which shows a higher risk of developing peritonitis. Patients with no running water and electricity in the house who are living in rural areas with a low level of hemoglobin and shorter duration on PD are associated with a higher risk (hazard) of developing the first episode of peritonitis infections in the study area.
Authors :
Yehenew G Kifle
Department of Mathematics and Statistics, University of Maryland Baltimore County, USA
Tshepo F. Maja
Department of Statistics and Operations Research, University of Limpopo, South Africa
Ramon A. Tamayo
Pietersburg Limpopo Provincial Hospital, South Africa
DOI : DOI-https://doi.org/10.32381/IAPQRT.2022.46.01-02.1
Price: 251
By: Avinash Dharmadhikari , Bikas K Sinha
Page No : 17-29
Abstract
The first author was involved in a study with the goal of enhancing the quality and productivity of pregnancy/birth of children under “Suprajanan Scheme”, developed and initiated by Manashakti Research Centre (MRC) at Lonavla, near Mumbai, India in 2010. After implementation of the said scheme and collection of relevant data, the author had access to the data and accordingly, he analysed the same for statistical analysis. In order to derive and apply exact inference theory for meaningful elaborate analysis and valid conclusions, he collaborated with the second author and together, they developed the necessary results. It amounted to the formulation of inference problems involving four parameters p, a, b, c; 0 < p < 1 involved in four independent Bernoulli/Binomial experiments having P(H) = (p, ap, bp, cp); 0 < p, ap, bp, cp < 1 respectively. The applications and conclusions are explained with reference to the contexts.
Authors :
Avinash Dharmadhikari
Pune. India.
Bikas K Sinha
Koltata, India
DOI : DOI-https://doi.org/10.32381/IAPQRT.2022.46.01-02.2
Price: 251
Proportional Cause-Specific Hazards Model for Recurrent Events
By: P. G. Sankaran , Sisuma M.S.
Page No : 30-52
Abstract
The present paper discusses the modelling and analysis of recurrent event data with competing risks in the presence of covariates. We propose an extension of the proportional cause-specific hazards model based on averaged counting process and averaged at-risk set process of recurrent events. The regression parameters are estimated using a partial likelihood approach. Asymptotic properties of the proposed estimators are established. Simulation procedures are carried out to assess the finite sample properties of the proposed estimators. The proposed method is applied to reallife data.
Authors :
P. G. Sankaran
Department of Statistics, Cochin University of Science and Technology Kerala
Sisuma M.S.
Department of Statistics, Cochin University of Science and Technology Kerala
DOI : DOI-https://doi.org/10.32381/IAPQRT.2022.46.01-02.3
Price: 251
By: R. N. Rattihalli , M. P. Gadre , R. A. Patel
Page No : 53-74
Abstract:
In this article, for univariate processes, we propose improved control charts useful to detect shift in the process mean and to identify increases in the fraction nonconforming. These modified control charts are intended to reduce the out-of-control ‘Average Time to Signal’ (ATS). When the charting statistic is inside the control limits, but close to control limits (between the warning and the control limits), the process may not be operating properly. In such situations, to have substantial/additional information about quality of the process, in this article, we propose ‘Modified Control Chart with Warning Limits’ (MCCWL) to detect shifts in the process mean, increases in fraction nonconforming and to monitor shifts in the mean vector. It is modified in the sense that a rule is defined to stop the sampling and to declare the process as out of control. The corresponding expression for Average Run Length (ARL) is obtained. The design parameters are obtained under ‘Average Time to Signal’ (ATS) criterion. The proposed charts namely, ????? ? ??, ????? ? ??,????? ? ??? are shown to perform better than their competitors considered. Abstract: In this article, for univariate processes, we propose improved control charts useful to detect shift in the process mean and to identify increases in the fraction nonconforming. These modified control charts are intended to reduce the out-of-control ‘Average Time to Signal’ (ATS). When the charting statistic is inside the control limits, but close to control limits (between the warning and the control limits), the process may not be operating properly. In such situations, to have substantial/additional information about quality of the process, in this article, we propose ‘Modified Control Chart with Warning Limits’ (MCCWL) to detect shifts in the process mean, increases in fraction nonconforming and to monitor shifts in the mean vector. It is modified in the sense that a rule is defined to stop the sampling and to declare the process as out of control. The corresponding expression for Average Run Length (ARL) is obtained. The design parameters are obtained under ‘Average Time to Signal’ (ATS) criterion. The proposed charts namely, ????? ? ??, ????? ? ??,????? ? ??? are shown to perform better than their competitors considered.
Authors :
R. N. Rattihalli
Retd. Professor, Shivaji University, Kolhapur
M. P. Gadre
Shriram Institute of Information Technology, Paniv, District Solapur
R. A. Patel
Karnatak University, Dharwad
DOI : DOI-https://doi.org/10.32381/IAPQRT.2022.46.01-02.4
Price: 251
Mining and Matching of Profiles in a Social Network – A Static Measure of Friendship
By: Puspendu Biswas , Aditya Bagchi
Page No : 75-98
Abstract
In the process of preventing possible cyber-crimes through social media, a new research paradigm named Proactive Forensics has evolved. As a part of such research effort, this paper attempts to match profiles of two members in a social network as a measure of compatibility between two persons. Profile matching efforts made so far include; matching job profile with candidate profile to choose “right man for the right job”, matching profiles of same person from two different social nets like Facebook and LinkedIn and to ascertain that they belong to the same person and even matching of two different Genome profiles. However, this paper tries to identify whether a friendship request on a social net can be accepted on the basis of a matching value generated by comparing the features of two profiles. For the purpose of matching, this paper provides two measures of closeness between two profiles; first a measure of the degree of exact match of feature values and secondly a composite distance measure of different feature wise distances. This composite measure has been termed as a static measure of friendship. A modified Jacardian similarity and standard Cosine similarity have been used for final measure of closeness between two profiles. In addition, it has been found that many features, used for matching, give rise to different types of hierarchies. New distance measures have been developed for matching such hierarchic structures. It has also been proved that such new measures are valid distance measures.
Authors :
Puspendu Biswas
Software Development Department, IGT Solutions Pvt. Ltd., Gurgaon
Aditya Bagchi
Computer Science Department, Ramakrishna Mission Vivekananda Educational & Research Institute, Belur Math, Howrah
DOI : DOI-https://doi.org/10.32381/IAPQRT.2022.46.01-02.5
Price: 251
A Hidden Projection Property of the 24-Run Plackett-Burman Design
By: Renu Kaul , Sanjoy Roy Chowdhury
Page No : 99-121
Abstract
In the class of two-level non-regular designs, Plackett-Burman ([14], 1946) designs have a special place. These designs have been widely used as screening designs because of their relative simplicity of use. Wang and Wu ([16],1995) observed that these designs possess certain hidden projection properties which are bestowed by the complexity of their partial aliasing relationships. They attributed the success of Hamada and Wu’s ([9],1992) strategy for entertaining and estimating twofactor interactions from Plackett-Burman (PB) type designs to the hidden projection property.
In this paper, we have used the hidden projection property of the 24-run PB design to propose an alternative to the design suggested by Mclean and Anderson ([13],1984). The proposed design performs better in terms of increased degrees of freedom efficiency and reduced run size. We have also drawn non-isomorphic interaction graphs making D and Ds efficiency as the underlying criterion.
Authors :
Renu Kaul
Department of Statistics, Lady Shri Ram College for Women (University of Delhi), New Delhi
Sanjoy Roy Chowdhury
Department of Statistics, Lady Shri Ram College for Women (University of Delhi), New Delhi
DOI : DOI-https://doi.org/10.32381/IAPQRT.2022.46.01-02.6
Price: 251
Page No : 125-126
Price: 251
Apr-2020 to Mar-2021
Multivariate Process Capability Indices for Non-Normal Processes
By: Kailas Govinda Khadse , Ramkrishna Lahu Shinde
Page No : 1-24
Abstract
In this paper by using fraction conforming probabilities p1 and p2, we introduce Multivariate Process Capability Indices (MPCIs) ( 1) ( 2 ) and p p pk p MC MC which measures potential capability and actual capability respectively for multivariate non-normal processes. Computing aspects of p( p1) MC and pk ( p2 ) MC are discussed in detail considering hyper rectangular specification region. Two cases of multivariate non-normal processes are considered. While constructing MPCIs, in the first case it is assumed that process variables are independent and in the second case it is assumed that process variables are linearly related. In the second case Principal Component Analysis is used to compute point estimate and interval estimate of proposed MPCIs. Real life problems are given for illustration of proposed MPCIs with their interpretations.
Authors :
Kailas Govinda Khadse
School of Mathematical Sciences, M. J. College (Autonomous), Jalgaon
Ramkrishna Lahu Shinde
School of Mathematical Sciences, Kavayitri Bahinabai Chaudhari North Maharashtra University, Jalgaon
DOI : DOI-https://doi.org/10.32381/IAPQRT.2021.45.01-02.1
Price: 251
Combined Array Approach for the 12 Run Plackett-Burman Design
By: Renu Kaul , Sanjoy Roy Chowdhury
Page No : 25-35
Abstract
Taguchi’s ([8], 1987) robust parameter design, is a very useful technique for reducing variation and improving product’s quality. However, in some applications, his approach leads to unnecessary expensive experiments. Alternatively, one can use combined arrays by modelling the response itself rather than the expected loss for Orthogonal Fractional Factorial Designs.
In this paper, we have exploited the non-orthogonal column structure of the 12 run Plackett-Burman (PB) design to generate non-orthogonal combined arrays.
Authors :
Renu Kaul
Department of Statistics, Lady Shri Ram College for Women (University of Delhi), New Delhi
Sanjoy Roy Chowdhury
Department of Statistics, Lady Shri Ram College for Women (University of Delhi), New Delhi
DOI : DOI-https://doi.org/10.32381/IAPQRT.2021.45.01-02.2
Price: 251
Estimation of Parameters for Distribution of Timber Pole Failures Due to in-Ground Decay
By: Anisur Rahman , Gopinath Chattapadhyay
Page No : 36-48
Abstract
Timber components are very popular due to its flexibility in use and therefore, widely used in bridges and building constructions, rail tracks and supply electricity throughout the world and in Australia. The main reason of this choice is for their high strength per unit weight, low cost and excellent durability. Reliability of these components is extremely important because a failure of these components may cause loss of money, loss of properties, injuries or even loss of lives. Reliability depends on various factors such as species of the timber, structural dimensions in design, environmental condition, human factors in installation, operations and maintenance. In general, the timber structure failures are due to the loss of load bearing capacity from the decrease in peripheral dimensions at or below ground level and loss of strength of timber fibre affecting bending resistance. Soil factors and related decays reduce the diameter and the strength of timber component affecting the safety in operation and service. Rotting of fibre can be from centre to outward or outward to centre by accelerating fungal and insect (termite) attack affecting reliability, availability, maintainability and safety of infrastructure assets. This paper is on investigating soil factors for modelling in ground decay and estimating parameters for failure distribution of timber poles. Real life data from electricity supply company in Australia have been used for modelling and validation. Results from this investigation can be used in optimal decision in maintenance and replacements for reducing the life cycle costs and risks of in-service failure of timber poles and infrastructure assets in similar environment.
Authors :
Anisur Rahman
Griffith University, Gold Coast campus, Southport, Australia
Gopinath Chattapadhyay
Federation University, Victoria, Australia
DOI : DOI-https://doi.org/10.32381/IAPQRT.2021.45.01-02.3
Price: 251
By: Sobita Sapam , Nripes Kumar Mandal , Bikas K Sinha
Page No : 49-62
Abstract
We contemplate an experimental situation which deals with a 2-factor quadratic response involving, in its model expectation, the mean term, both the linear effects parameters, and both the quadratic effects parameters as well as the product term parameter. We assume the errors to be homoscedastic and uncorrelated. Our intention is to conduct a saturated design [SD] - using a subset of six distinct but suitably chosen design points in an appropriately defined factor space. Further to this, we wish to achieve maximum precision in joint estimation of the last three [quadratic effects] parameters. It is known beforehand that these three effect(s)/interaction(s) are likely to be non-negligible. We examine the flexibility to the extent that an experimenter can make a choice of an SD, retaining information on the three remaining effects/interactions as well. We use the D-optimality criterion and deal with a continuous design set-up. At the end, we also discuss about A-optimality criterion.
Authors :
Bikas K Sinha
Indian Statistical Institute, Kolkata.
Sobita Sapam
Manipur University, Canchipur [Imphal], Manipur.
Nripes Kumar Mandal
Calcutta University, Kolkata.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2021.45.01-02.4
Price: 251
Regional Variation in Female Employment Within the Tertiary Sector – A State wise Analysis
By: Dyuti Chatterjee
Page No : 63-75
Abstract
The growth of the tertiary sector helped India to move on a higher growth pedestal. The present paper tries to explore the regional variation in female employment in the tertiary sector post liberalization. For the sake of the analysis, the states were classified under six zones. The percentage of female main and female marginal workers in the tertiary sector across the states were first analyzed to understand the level of interregional and intraregional variation in female employment in the tertiary sector across the states. The Modified Lilien Index was then used to understand the pace of change in female employment post liberalization across the zones. Lastly a multivariate regression was run to identify the factors behind such regional variation in female employment in the tertiary sector. The paper concluded that the regional variation in female employment could not be captured properly through some macroeconomic aggregates. Introduction of vocational training for women along with a change in state policies are required for the reduction of such regional variation.
Author :
Dyuti Chatterjee
The Bhawanipur Education Society College, Kolkata
DOI : DOI-https://doi.org/10.32381/IAPQRT.2021.45.01-02.5
Price: 251
By: Manisha Pal , N. K. Mandal
Page No : 76-92
Abstract
Scheffé ([12],1958) introduced models of different degrees to represent the response function in a mixture experiment. He also introduced designs for the estimation of the model parameters. Later, several authors discussed the problem of finding optimum designs, especially for quadratic and cubic models. In this paper, we consider the problem of designing an optimal experiment for the purpose of performing one or more hypothesis tests in a quadratic mixture model with three components. We use the Bayesian decision theoretic approach for the purpose.
Authors :
N. K. Mandal
Former Professor, Department of Statistics, University of Calcutta
Manisha Pal
Department of Statistics, University of Calcutta
DOI : DOI-https://doi.org/10.32381/IAPQRT.2021.45.01-02.6
Price: 251
Development of a Model to Integrate Six Sigma Approaches
By: Subrata Rath , Ashis Kumar Chakraborty , Subhashis Chatterjee
Page No : 93-115
Abstract
Six Sigma was born with a disciplined problem-solving approach called D M A I C (Define, Measure, Analyse, Improve and Control) way back in 1979. The approach is data-intensive requiring statistical orientation and is used for defect reduction. Effect of such defect reduction is visible in the increased profit margin. This approach was a little silent on the waste accumulation in as-is complicated processes. Accumulated waste has direct impact on the cash flow of an organization and usually lean approach is adopted to optimise process flow to reduce, if not eliminate waste in any process. Hence, a new approach was initiated to adapt lean methodology to create better flow in the processes while continuing delivering Six Sigma results. Such approach is known as Lean Six Sigma (LSS). LSS is process flow intensive, requiring more of Industrial Engineering, Operations Research and lean orientation. Results derived from Six Sigma and Lean Six Sigma are well appreciated worldwide across the type and scale of the organizations. However, question started brewing on why the defects and waste are available in any organization in the first instance. This question designated both the Six Sigma and Lean Six Sigma approaches as reactive problem solving initiatives and gave birth of another very important initiative, named Design for Six Sigma (DFSS), to prevent defects and waste in any product and process, in its launch itself. This process is more domain discipline intensive, requiring discovery, invention and innovation. All these approaches together make more sense in business and unfortunately literature is little silent where these approaches are synchronised to leverage the business results for an organization. This paper is an attempt to create a model to integrate all these three approaches with adequate flexibility of interconnectivity within the approach elements for the overall sustainable, predictable and desirable business results. A case is also used to demonstrate the implementation of the mode.
Authors :
Subrata Pal
Shriram Institute for Industrial Research, 19, University Road, Delhi-110007, India
Ashis Kumar Chakraborty
Statistical Quality Control and Operations Research unit, Indian Statistical Institute
Subhashis Chatterjee
Department of Mathematics and Computing, IIT (ISM), Dhanbad
DOI : DOI-https://doi.org/10.32381/IAPQRT.2021.45.01-02.7
Price: 251
On Model Robustness in Discrete Design(s) Set Up: A Teacher’s Manual
By: Madhura Mandal
Page No : 116-123
Abstract
The problem studied here involves choice of optimum designs for estimation of a full set of treatment effects contrasts in a block design (BD) setup, when positional effects may also be present, besides treatment and block effects. The experimenter is not sure about which of the two models, viz. a block design model or a row-column design model is appropriate. Using weights on the optimality criteria in the two set-ups based on prior knowledge, robust designs are investigated.
Author :
Madhura Mandal
Vivekananda Mahavidyalaya, Burdwan, West Bengal
DOI : DOI-https://doi.org/10.32381/IAPQRT.2021.45.01-02.8
Price: 251
By: Shruti Kanga
Page No : 127-129
Price: 251
Apr-2019 to Sep-2019
By: G. C. Manna
Page No : 1-19
Abstract
This article analyzes the level of precision of estimates of gross value added as per Annual Survey of Industries by examining the relative standard errors associated with the estimates. Annual trend in the estimates of gross value added at the level of state and industrial category is also studied to see if there exist any apparent fluctuations. Further, the article cross-validates the annual growth rates of production of manufacturing sector as assessed by the Index of Industrial Production by comparing the same with the growth rates based on Annual Survey of Industries.
Author :
G. C. Manna
Former Director General Central Statistics Office and National Sample Survey Office, Government of India Currently, Professor, Institute for Human Development & Senior Adviser, NCAER.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.44.01.1
Price: 251
Harris Extended Log-Kumaraswamy Distribution and its Applications
By: K. K. Jose , Jisha Virghese
Page No : 20-37
Abstract
Harris Extended Log-Kumaraswamy Distribution and its specialized form namely, the Marshall-Olkin Log-Kumaraswamy Distribution (MOLKw) is introduced and studied in this paper. We have given explicit form for the probability density function and the hazard rate function is derived and its shape properties are studied. Expressions for cumulative distribution function, quantiles and survival function are obtained. Method of maximum likelihood estimation is used for estimation of unknown parameters of the new distribution. The new model is applied on two real data sets on survival times of cancer patients and another data set on carbon fibre strength in the context of reliability studies. The stress strength analysis is carried out with respect to the new model and a simulation study is conducted to estimate the average bias, mean square error, coverage probability etc. for different parameter values.
Authors :
K. K. Jose
Department of Statistics, St.Thomas College, Palai, Arunapuram.
Jisha Varghese
Mahatma Gandhi University, Kottayam, Kerala, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.44.01.2
Price: 251
Multivariate Unit and Group Runs Control Chart to Detect Shifts in the Mean Vector
By: M. P. Gadre , V. C. Kakade
Page No : 38-51
Abstract
In some production processes, observations related to the quality characteristics of the process are independent. Under this set up, we propose the ‘Multivariate Unit and Group Runs control chart for mean vector’ (MV-UGR-M). It is verified that, the MV-UGR-M gives a significant reduction in the out-of-control ‘Average Time to Signal’ (ATS) in the zero state, as well in the steady state as compared to the ‘Multivariate Synthetic control chart for Mean vector’ (MV-Syn-M) chart, the ‘Multivariate Group Runs control chart for Mean vector’ (MV-GR-M) and the ‘Multivariate Modified Group Runs control chart for Mean vector’ (MV-MGR-M) charts.
Authors :
M.P. Gadre
Department of Statistics, Savitribai Phule Pune University, Pune.
V.C. Kakade
Department of Statistics, Tuljaram Chaturchand College, Baramati.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.44.01.3
Price: 251
By: Manoj Kumar
Page No : 52-84
Abstract
In this paper we use firms’ data to study the effects of financial development on total factor productivity of India’s manufacturing sector between 1990 and 2018. We find evidence that financial development has significantly enhanced firm-level TFP in the sector. The evidence is stronger when micro indicators of financial development are used. The firms in Indian private sector need better access to the banking system, while the firms in the government sector and the foreign sector reveal the need for accessing the capital market. We find a significant relationship between financial development and industry-level TFP growth when controlling for time, and industry-time fixed effects. Our results are both statistically and economically significant. Our results are robust to different samples and specifications. Our results suggest that policies favoring financial development in India should be pursued further in order for the largest democracy in the world to advance its economic growth.
Author :
Manoj Kumar
SP Jain School of Global Management, Singapore.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.44.01.4
Price: 251
Literature Review on Methods of Classification in Pattern Recognition
By: Khimya S. Tinani , Deepa H. Kandpal
Page No : 85-102
Abstract
The objective of this review paper is to summarize some of the well-known methods used in various stages of a pattern recognition system. Pattern recognition has become more and more popular and important to us and it induces attractive attention coming from wider areas. The general processing steps of pattern recognition are discussed, starting with the pre-processing, then the feature extraction, and classification. In this paper we have reviewed methods used in pattern recognition. This review paper introduces the basic concepts of pattern recognition, different methods used for pattern recognition like statistical and structural techniques, template matching, neural network and provides the understanding of various methods and related algorithms for classification.
Authors :
Khimys S. Tinani
Department of Statistics, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, India.
Deepa H. Kandpal
Department of Statistics, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.44.01.5
Price: 251
By: Sucheta Mukherjee
Page No : 103-105
Price: 251
Oct-2019 to Mar-2020
Balancing Cost, Performance and risk in Maintenance and Capital Expenditure
By: Gopinath Chattapadhyay
Page No : 107-126
Abstract
Asset Management is focused on realisation of value from assets through managing risk and opportunity. ISO standard for asset management ISO55000, 2014 stipulates effective control and governance of assets for desired balancing act of cost, performance and risk. This paper aims to study the maintenance and capital expenditure problems. It proposes how to balance cost, performance and risk for asset management. Decisions need to be based on performance and risk in addition to costs based on whole of life are supported by international standards for asset management. Option analysis and informed decision-making are proposed considering life cycle costs. Recent trend with industries is to align with latest international standards for asset management. Asset management in heavy haul rail network focuses on this by realisation of value from assets through managing risk and opportunity. Model for total cost of maintenance was developed covering risk costs associated with undetected surface/ subsurface cracks causing rail breaks and derailments and wear loss due to gauge face lubrication problems and intervention costs in inspections and interventions using progressive rail grinding and solar powered electric lubricators with remote performance monitoring. Illustrative examples are used to show how actions in inspection and subsequent rail grinding for controlling rolling contact fatigue (RCF) along with gauge face lubrication for controlling wear can be achieved in heavy haul railway. This maintenance and capital investment policy and decisions based on life cycle cost models can be used as reference for capital expenditure (capex) and operational expenditure (opex) balancing in any industry in general and heavy haul in particular.
Author :
Gopinath Chattopadhyay
School of Science Engineering and Information Technology, Federation University Northways Road, Churchill, PO Box 3191, Gippsland Mail Centre, Vic 3841.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2020.44.02.1
Price: 251
By: Manoj Chacko , Rakhi Mohan
Page No : 127-156
Abstract
In reliability studies, the failure of individuals or items may be due to more than one causes or factors. These risk factors in some sense compete for the failure of the experimental units. Analysis of data in these circumstances is called competing risks analysis. In this paper, we consider the analysis of competing risk data under progressive type-II censoring by assuming the number of units removed at each stage is being random and follows a binomial distribution. Bayes estimators are obtained by assuming the population under consideration follows an exponential distribution. A simulation study is carried out to study the performance of different estimators derived in this paper. A real data set is also used for illustration.
Authors :
Manoj Chacko
Department of Statistics, University of Kerala Trivandrum 695 581, India.
Rakhi Mohan
Department of Statistics, University of Kerala Trivandrum 695 581, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2020.44.02.2
Price: 251
Sampling Inspection Plan For Exponentially Distributed Quality Characteristic And Beyond
By: Harsh Tripathi , Sudhansu S. Maiti , Shovan Biswas , Mahendra Saha
Page No : 157-173
Abstract
In this article, an acceptance sampling inspection plan for variable is discussed when the quality characteristic follows some non-normal distributions, viz., the exponential, Lindley, xgamma or Akash distribution. In this plan, the lot quality is to be measured by the lot mean (). The plan parameters have been obtained by the two point approaches: the acceptable quality level (AQL) and the limiting quality level (LQL) or the rejectable quality level (RQL). For the given producer’s risk () and consumer’s risk (), the plan parameters: sample size () and acceptance number () are determined for different choices of AQL and LQL. A comparison study has been made in terms of the sample size () and an example is provided to illustrate the performance of the proposed plan
Authors :
Harsh Tripathi
Department of Statistics, Central University of Rajasthan, Rajasthan, India.
Sudhansu S. Maiti
Department of Statistics, Visva-Bharati University, Santiniketan, India.
Shovan Biswas
Department of Statistics, Visva-Bharati University, Santiniketan, India.
Mahendra Saha
Department of Statistics, Central University of Rajasthan, Rajasthan, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2020.44.02.3
Price: 251
A Generalization of Exponentiated Rectangular Distribution
By: E.S. Sindhu , Sophia P. Thomas , Jiju Gillariose
Page No : 174-200
Abstract
This paper introduces a new generalization of the exponentiated rectangular distribution namely, Marshall-Olkin exponentiated rectangular distribution and studied its various properties. Also we illustrated empirically the potentiality of the new family by applying to real data sets. Applications in autoregressive time series modeling and stress-strength analysis are also considered. A simulation study is carried out to study the behaviour of estimates. Sample path properties of the newly developed time series models are also discussed.
Author :
E.S. Sindhu
Department of Statistics, Kuriakose Elias College, Mannanam, Kerala, India.
Sophia P. Thomas
Department of Statistics, St,Thomas College, Pala, Kerala, India.
Jiju Gillariose
Department of Statistics, St,Thomas College, Pala, Kerala, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2020.44.02.4
Price: 251
By: Deepa H. Kandpal
Page No : 201-203
Price: 251
Apr-2018 to Sep-2018
Marshall Olkin Exponential Power Distribution and its Generalization : Theory and Applications
By: K. K. Jose , Albin Paul
Page No : 1-29
Abstract
In this paper we introduce a new family of distributions namely Marshall Olkin Exponential Power (MOEP) distribution and its extensions. The advantage of studying this new family of distributions is the wide use of the model with respect to various data sets obtained from different areas. Some statistical and reliability properties of the new family of distributions are discussed. The method of maximum likelihood estimation is used to estimate the unknown parameters. The obtained results are validated using some real data set and it is shown that the new family provides a better fit than its base distributions. The stress strength reliability analysis is also carried out. Average mean square error, average confidence length, coverage probability etc. are computed using simulated data. Using the proposed model we develop autoregressive process with minification structure. We further extend the new distribution to obtain the Harris generalized exponential power distribution and some of its properties are studied.
In this paper we introduce a new family of distributions namely Marshall Olkin Exponential Power (MOEP) distribution and its extensions. The advantage of studying this new family of distributions is the wide use of the model with respect to various data sets obtained from different areas. Some statistical and reliability properties of the new family of distributions are discussed. The method of maximum likelihood estimation is used to estimate the unknown parameters. The obtained results are validated using some real data set and it is shown that the new family provides a better fit than its base distributions. The stress strength reliability analysis is also carried out. Average mean square error, average confidence length, coverage probability etc. are computed using simulated data. Using the proposed model we develop autoregressive process with minification structure. We further extend the new distribution to obtain the Harris generalized exponential power distribution and some of its properties are studied.
Authors :
K.K. Jose
Department of Statistics and Biostatistics, St. Thomas College Pala, Arunapuram.
Albin Paul
Mahatma Gandhi University, Kottayam, Kerala, India.
DOI : DOI- https://doi.org/10.32381/IAPQRT.2018.43.01.1
Price: 251
By: Showkat Ahmad Lone , A. Islam , Ahmdur Hrahman
Page No : 31-45
Abstract
The Mukherjee-Islam model is commonly used as a simple life time distribution to assess system reliability. We have introduced a location parameter ? (i.e. a time before which failure can’t occur) which makes it a more useful failure distribution than the existing ones. It has been shown to represent appropriate lower tail of the distribution of random variables having fixed lower bound. This study presents reliability computations and probability weighted moment estimation for this model. A comparative analysis is carried out between three-parameter finite range model and some existing bathtub shaped curve fitting models. Maximum likelihood estimation method has also been applied. Key words and Phrases: Reliability, Location parameter, Finite range failure model, Probability weighted moment, Comparative analysis.
Authors :
Showkat Ahmad Lone
Department of Statistics & Operations Research, Aligarh Muslim University, India.
A. Islam
Department of Statistics & Operations Research, Aligarh Muslim University, India.
Ahmdur Hrahman
Department of Statistics & Operations Research, Aligarh Muslim University, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2018.43.01.2
Price: 251
Inferential Aspects of a Three Unit Hot Standby System with Dependent Structure
By: V. S. Vaidyanathan , P. Chandrasekhar
Page No : 47-59
Abstract
Statistical analysis of standby systems with more than two units has received little attention because of mathematical intricacies involved in analyzing them. Also, such systems have been studied assuming the lifetime and repair time of the units to be independent. The present article is an attempt to study certain inferential aspects of a three unit hot standby system with dependent structure, assuming quadrivariate exponential distribution for the lifetimes of online unit, standby units and the repair time of a failed unit.
Authors :
V.S. Vaidyanathan
Department of Statistics, Pondicherry University, India.
P. Chandrasekhar
Department of Statistics, Loyola College, Chennai, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2018.43.01.3
Price: 251
By: Sagar Sikder , Indrajit Mukerjee , Subhash Chandra Panja
Page No : 61-71
Abstract
In manufacturing process, quality of an end product or component is often assessed by multiple critical output characteristics (or responses). These responses are often correlated or interacting. Change in process setting condition, with an intension to improve a particular response characteristic, may adversely affect another response. In this context, researchers had proposed various parametric and nonparametric Multivariate Statistical Process Control (MSPC) charts for monitoring of correlated responses and detecting out-of-control signal. However, there is little evidence of nonparametric MSPC research to identify influential response(s) for any out-of-control situation in a manufacturing process. In this paper, Mahalanobis-Taguchi System (MTS), based on Mahalanobis Distance (MD) scale and Taguchi’s Orthogonal Array (OA) design, is explored for detecting out-ofcontrol state and identify influential response(s) for an out-of-control state. Suitability of the approach is verified using a manufacturing process case study.
Authors :
Sagar Sikder
SQC & OR Unit, Indian Statistical Institute, Mumbai, India.
Iindrajit Mukerjee
Shailesh J. Mehta School of Management, IIT Bombay, India.
Subhash Chandra Panja
Department of Mechanical Engineering, Jadavpur University, Kolkata, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2018.43.01.4
Price: 251
Finite Range Life Distributions of Coherent Dependent Systemsby
By: Subhradev Sen , Ahmed Z. Afify
Page No : 73-88
Abstract
Opposed to the general theory of infinite upper limit for lifetime distributions, Mukherjee and Islam ([4], 1983) proposed and studied a finite range distribution considering the fact that designed lifetime of equipment is actually finite. It is quite rational to consider interdependency of multi-component systems in analyzing reliability characteristics. In this article, we consider two-component coherent dependent systems by developing bivariate finite range distribution following the method of Farlie-Gumbel-Morgenstern copula. We investigate and study different reliability characteristics, such as mean time to system failure, system reliability and failure rate functions for finite range coherent dependent systems. We also compare the dependent finite range systems with independent finite range systems for mentioned reliability characteristics.
Authors :
Subhradev Sen
Alliance School of Business, Alliance University, Bangalore, India.
Ahmed Z. Afify
Department of Statistics, Mathematics and Insurance, Benha University, Egypt.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2018.43.01.5
Price: 251
Reliability Test Plans based on Exponentiated Rayleigh Distribution
By: B. Sriram , R.R.L. Kantam
Page No : 89-100
Abstract
Sampling plans in which items are put to test, to collect the life of the items in order to decide upon accepting or rejecting a submitted lot, are called reliability test plans. The basic probability model of the life of the product is specified as exponentiated Rayleigh distribution. For a given producer’s risk sample size, termination number, the waiting time to terminate the test plan and the operating characteristics are presented. The preference of the test plan over similar plans existing in the literature is established with respect to cost and time of the experiment.
Authors :
B. Sriram
Acharya Nagarjuna University Nagarjuna Nagar, India.
R.R.L. Kantam
Acharya Nagarjuna University Nagarjuna Nagar, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2018.43.01.6
Price: 251
Oct- to Mar-2019
By: Nabanita Mukherjee , Rita Lala , Indrajit Mukerjee
Page No : 101-116
Abstract
An antihyperlipidemic drug like Atorvastatin calcium (ATC) suffers from poor oral bioavailability due to low solubility and first-pass metabolism by the liver. Combination of cholesterol synthesis inhibitor (ATC) and cholesterol absorption inhibitor (Ezetimibe) lowers the cholesterol level more than ATC alone. The combined drug can also reduce the risk of Type II diabetes mellitus due to use of a lower dose of atorvastatin calcium, particularly for geriatric patients. The objective of this work is to screen critical factors for developing a novel combined antihyperlipidemic drug delivery system in nanostructured lipid carrier (NLC) considering percent drug loading, and particle size(nm), as responses. Taguchi’s L8 orthogonal array design with replicates was used to screen factors. TEM study and zeta potential study of the optimal formulation was done which shows formulation within nanometric size range with high stability. Results indicate all four factors are critical to determining optimal formulation.
Authors :
Nabanita Mukherjee
Principal K M Kundnani College of Pharmacy, Mumba.
Rita Lala
Principal K M Kundnani College of Pharmacy, Mumba.
Indrajit Mukherjee
Shailesh J. Mehta School of Management, IIT Bombay.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.43.02.1
Price: 251
Improving Reliability of HTDC Compressor in a Petrochemical Industry using Six Sigma Methodologies
By: Subrata Rath , Ashis Kumar Chakraborty
Page No : 117-134
Abstract
Low reliability problem due to high temperature direct chlorination (HTDC) vent gas compressor on Vinyl Chloride Monomer (VCM) plant of a petrochemical industry was solved. The study uses the conventional Six Sigma:Define, Measure, Analysis, Improvement and Control (DMAIC) phases to improve reliability of the HTDC compressor in terms of mean time between failure (MTBF). In many cases the Total Preventive Maintenance method or the classical reliability improvement method are adopted to solve such reliability problems. However, Authors found that the DMAIC approach of Six Sigma could solve this problem.
Authors :
Subrata Rath
Statistical Quality Control and Operations Research unit, Indian Statistical Institute, Pune.
Ashis Kumar Chakraborty
Statistical Quality Control and Operations Research unit, Indian Statistical Institute, Kolkata.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.43.02.2
Price: 251
Odds Xgamma – G Family of Distributions
By: Sudhanshu S. Maiti , Sukanta Pramanik
Page No : 135-163
Abstract
A new class of distributions, called Odds xgamma-G family of distributions is proposed for modelling lifetime data. An account of the structural and reliability properties of the new class is presented. Maximum likelihood estimation of parameters of the class of distributions has been described. Two data sets have been analyzed to illustrate its applicability.
Authors :
Sudhansu S. Maiti
Department of Statistics, Visva-Bharati University, Santiniketan, India.
Sukanta Pramanik
Department of Statistics, Siliguri College, North Bengal University, Siliguri, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.43.02.3
Price: 251
A two Non-Identical Unit Cold Standby System with Two Phase Repair of a Failed Unit
By: Rakesh Gupta , Vaishali
Page No : 165-177
Abstract
The paper deals with the two non-identical unit cold standby system with two phase repair (Phase-1 and Phase-2) of a failed unit. Unit-1 gets priority in operation over the unit-2. A failed unit first attended by the skilled repairman in phase-1 to inspect and identify the faults and then attended by an ordinary repairman in phase-2 who completes the process of repair. After phase-2 repair the unit becomes as good as new. The failure time distributions of both the units and repair time distributions of Phase-1 for both the units are taken as exponential with different parameters, whereas the repair time distributions of phase-2 for both the units are taken as general. The various measures of system effectiveness are obtained by using regenerative point technique.
Authors :
Rakesh Gupta
Department of Statistics Ch. Charan Singh University, Meerut, India.
Vaishali
Department of Statistics Ch. Charan Singh University, Meerut, India.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.43.02.4
Price: 251
Variance Function Estimation using Signal-to-Noise Ratio
By: Soham Chakraborty , Pathik Mandal
Page No : 178-211
Abstract
A new methodology is developed for estimating the variance function in a heteroscedastic regression set up with a focus on small sample regression based estimation. The three main features of the proposed methodology are as follows: (i) Signal-to-noise ratio is used as the response for the purpose of regression instead of a function of only the residuals of the fitted mean function, (ii) Before fitting the variance function, the data are trimmed following an optimal trimming procedure and (iii) The estimates of the parameters of the variance function obtained from the trimmed data are adjusted to minimize the mean square error of the estimates of variances. The effectiveness of the proposed methods of trimming and adjustments are demonstrated through extensive simulation. It is shown that the variances can be estimated more accurately as above compared to those obtained directly from an estimate of the corresponding variance function. Four sets of real life data are also analyzed for the purpose of illustration.
Authors :
Soham Chakraborty
SQC & OR Unit, Indian Statistical Institute, Kolkata.
Pathik Mandal
SQC & OR Unit, Indian Statistical Institute, Kolkata.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.43.02.5
Price: 251
On Suitable Model Selection Approach for Analysis of Mental Health Service use Data
By: Dulal K. Bhaumik , Subhash Aryal , Scott Hur
Page No : 212-223
Abstract
Various methods are available in the literature for analysis of multi-level longitudinal service utilization and expenditure data. We discuss implementation of several methods to analyze service utilization and cost data. Hierarchical longitudinal service utilization data was analyzed using a log-gamma model. Mixed-effects models with random intercept and trend are the most appropriate method for analyzing data from hierarchical longitudinal studies and they provide the best fitting models. But these models also suffer from non-convergence problem, especially in the presence of random-effects at multiple levels. Researchers generally perform log transformation and use normal-based method to analyze service utilization data due to ease of use. Even though they are difficult to implement, generalized linear models is a more appropriate choice for analyzing service utilization data.
Authors :
Dulal K. Bhaumik
Department of Psychiatry, University of Illinois at Chicago, USA.
Subhash Aryal
Department of Biostatistics and Epidemiology UNT Health Science Center Fort Worth, TX, USA.
Scott Hur
Department of Psychiatry, University of Illinois at Chicago, USA.
DOI : DOI-https://doi.org/10.32381/IAPQRT.2019.43.02.6
Price: 251
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1. Saaty, T.L. (1961): Elements of Queueing Theory and Applications. McGraw-Hill Company, Inc. 2. Mudholkar, G. S., Srivastva, D.K. and Freimer, M. (1995): The exponentiated Weibull family: a reanalysis of the bus- motor-failure data, Technometrics, 37(4), 436-445.
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The Editors and EB Members take every precaution to guard against any violation of publication ethics by the contributors to the journal. Mostly the manuscripts deal with ‘secondary’ data sets for illustrative purposes of the theories/methodologies proposed therein and suggestive possible application areas. When there are theoretical issues dealt with by the authors, the Editors aim at choosing Reviewers who are subject-area experts and competent enough to judge the merits and the technical details in the submission. Generally there are cases of 2-3 revisions before a manuscript is eventually accepted for publication. There are submissions leading to rejection as well.
Any submitted manuscript is first read by one of the Editors for ‘screening purpose’. Once satisfied, it is assigned to one EB Member for further reading and processing. Otherwise, the Editor suggests the names of Reviewers who are known to be a subject-area experts.
The contributors are generally aware of the implications of following any malpractice while preparing a manuscript for journal publication. Every precaution should be exercised by the contributors of manuscripts [for publication in the journal] to stay completely away from following any malpractice whatsoever. All necessary references must be included in the list of references and due acknowledgement should be made in the manuscript for use of any published material. Any explicit/implicit implication of malpractice will immediately force towards outright rejection of the manuscript and no further correspondence/submission by the concerned author will be entertained by the Editors.
All the above considerations are equally applicable to the Editors and EB Members in case they wish to submit manuscript(s) for publication in the journal.