Research

Research Interests:

• Sequential Analysis, Statistical Inference, Statistical Reliability Theory, Statistical Quality Control

Ongoing Research Projects:

• Project Title: Improved Estimation of Regression Parameters Using Adaptive Sampling Strategies with Applications

Funding Agency: Planning Unit, Indian Institute of Technology Delhi

Grant Name: New Faculty Seed Grant (NFSG)

Sanctioned Budget: INR 20,00,000

Duration: Feb 12, 2024 - Feb 11, 2027

Refereed Journal Articles:

2025

1. Chaturvedi, A., Joshi, N., Bapat, S.R., and Nadarajah, S. (2025). 

Control Charts for the Percentiles of an Inverse Pareto Distribution Under Complete and Middle-Censored Data.

Quality and Reliability Engineering International, 41(5): 1971-1984.

2. Chaturvedi, A., Bhatti, M.I., Bapat, S.R., and Joshi, N. (2025). 

Modeling wind speed data using the generalized positive exponential family of distributions.

Modeling Earth Systems and Environment, 11(2): 98.

2024

3. Joshi, N., Bapat, S.R., and Sengupta, R.N. (2024). 

Two-stage and purely sequential minimum risk point estimation of the scale parameter of a family of distributions under modified LINEX loss plus sampling cost.

Metrika, Ahead of Print.

4. Bapat, S.R., and Joshi, N. (2024). 

Optimal Estimation of the Length-Biased Inverse Gaussian Mean with a Case Study on Eastern Tropical Pacific Dolphins. 

Environmental and Ecological Statistics, 31(3): 675-689.

5. Joshi, N., Bapat, S.R., and Sengupta, R.N. (2024). 

Optimal Estimation of Reliability Parameter for Inverse Pareto Distribution with Application to Insurance Data.

International Journal of Quality & Reliability Management, 41(7): 1811-1837.

6. Sengupta, R.N., Bapat, S.R., and Joshi, N. (2024). 

Sequential Estimation for the Multiple Linear Regression Models with Balanced Loss Functions.

Sequential Analysis, 43(2): 211-232.

7. Joshi, N., Bapat, S.R., and Sengupta, R.N. (2024). 

Estimation of fixed-accuracy confidence interval of the stress-strength reliability for inverse Pareto distribution using two-stage sampling technique. 

Sequential Analysis, 43(1): 79-102.

2023

8. Bapat, S.R., Joshi, N., and Shukla, A.K. (2023). 

On Fixed-Accuracy Confidence Intervals for the Parameters of Lindley Distribution and Its Extensions. 

Austrian Journal of Statistics, 52(2): 104-115. 

2022

9. Joshi, N., Bapat, S.R., and Shukla, A.K. (2022). 

Multi-Stage Estimation Methodologies for an Inverse Gaussian Mean with Known Coefficient of Variation. 

American Journal of Mathematical and Management Sciences, 41(4): 334-349.

10. Joshi, N. and Bapat, S.R. (2022). 

On improved accelerated sequential estimation of the mean of an inverse Gaussian distribution. 

Communications in Statistics - Theory and Methods, 51(17): 6127-6143. 

11. Chaturvedi, A., Bapat, S.R., and Joshi, N. (2022). 

Sequential Estimation of an Inverse Gaussian Mean with Known Coefficient of Variation. 

Sankhya B, 84(1): 402-420. 

2021

12. Joshi, N. and Bapat, S.R. (2021). 

On a class of purely sequential procedures with applications to estimation and ranking and selection problems. 

Sequential Analysis, 40(4): 482-500. 

13. Joshi, N., Bapat, S.R., and Shukla, A.K. (2021). 

A class of accelerated sequential procedures with applications to estimation problems for some distributions useful in reliability theory. 

Communications for Statistical Applications and Methods, 28(5): 563-582. 

14. Chaturvedi, A., Chattopadhyay, S., Bapat, S.R., and Joshi, N. (2021). 

Sequential point estimation procedures for the parameter of a family of distributions. 

Communications in Statistics - Simulation and Computation, 50(9): 2678-2704.  

15. Chaturvedi, A., Bapat, S.R., and Joshi, N. (2021). 

Two-stage and sequential procedures for estimation of powers of parameter of a family of distributions. 

Sequential Analysis, 40(2): 170-197.  

2020

16. Chaturvedi, A., Bapat, S.R., and Joshi, N. (2020). 

Purely Sequential and k-Stage Procedures for Estimating the Mean of an Inverse Gaussian Distribution. 

Methodology and Computing in Applied Probability, 22(3): 1193-1219. 

17. Chaturvedi, A., Bapat, S.R., and Joshi, N. (2020). 

Second-order approximations for a multivariate analog of Behrens-Fisher problem through three-stage procedure. 

Communications in Statistics - Theory and Methods, 49(14): 3466-3480. 

18. Chaturvedi, A., Bapat, S.R., and Joshi, N. (2020). 

Sequential Minimum Risk Point Estimation of the Parameters of an Inverse Gaussian Distribution. 

American Journal of Mathematical and Management Sciences, 39(1): 20-40. 

2019

19. Chaturvedi, A., Bapat, S.R., and Joshi, N. (2019). 

A k-stage procedure for estimating the mean vector of a multivariate normal population. 

Sequential Analysis, 38(3): 369-384.

20. Chaturvedi, A., Bapat, S.R., and Joshi, N. (2019). 

Multi-stage procedures for the minimum risk and bounded risk point estimation of the location of negative exponential distribution under the modified LINEX loss function. 

Sequential Analysis, 38(2): 135-162. 

21. Chaturvedi, A., Bapat, S.R., and Joshi, N. (2019). 

Multi-stage point estimation of the mean of an inverse Gaussian distribution. 

Sequential Analysis, 38(1): 1-25. 

Refereed Book Chapters in Edited Books:

2024

1. Bapat, S.R. and Joshi, N. (2024). 

Understanding Censoring Techniques in Business Analytics and Decision Making.

In: R.N. Sengupta, B. Basu, J.K. Jha, and I. Mukherjee (Eds.), Data Science and Statistical Modeling in Business: Towards Operational and Business Excellence (Volume four of the Book Series titled “Decision Sciences and Data Analytics for Operations and Business Excellence”), Springer,  Accepted for Publication. 

Submitted Papers:

1. Joshi, N., Bapat, S.R., Chaturvedi, A., and Nadarajah, S. (2024+). 

Optimal estimation of the length-biased Pareto mean with case studies on Indian billionaires and Olympic marathon runners. Second round of major  revision under preparation. 

2. Joshi, N. (2025+). 

Optimal estimation of the scale parameter of an inverse Maxwell distribution: illustrations with tax revenues and car brake lifetimes. Communicated.

3. Rajput, A. and Joshi, N. (2025+). 

On testing the ratio of scale parameters of two Pareto distributions using a novel accelerated sequential sampling technique with applications. Major revision submitted.

 Working Papers:

1. Adaptive estimation using records data under asymmetric loss with applications (Jointly with S. Chattopadhyay and R.N. Sengupta).

2. Statistical Inference for Weibull Accelerated Lifetimes with Censored Observations: A Comparative Analysis Using Optimization and Neural Network Algorithms (Jointly with R. Jat and R.N. Sengupta).

3. Statistical Inference for Log-Logistic Accelerated Lifetimes with Censored Observations: A Comparative Analysis Using Optimization and Neural Network Algorithms (Jointly with R. Jat and R.N. Sengupta).