N Rao Chaganty - Academia.edu (original) (raw)
Papers by N Rao Chaganty
Journal of statistical theory and practice, Nov 26, 2020
Journal of Multivariate Analysis, Dec 1, 1986
Annals of Probability, Apr 1, 1987
Naval Research Logistics Quarterly, Dec 1, 1983
Consider a k-out-of-n system with independent repairable components. Assume that the repair and f... more Consider a k-out-of-n system with independent repairable components. Assume that the repair and failure distributions are exponential with parameters {μ1, ,μn} and {λ1, ,λn}, respectively. In this article we show that if λi – μi = Δ for all i then the life distribution of the system is increasing failure rate (IFR).
S2a. SECURITY CLASSIFICATION AUTHOG 6 ,,~jJJ 3. 01STftlBUTION/AVAILA"ILTY OF REPORT 2b. ECLSSIICA... more S2a. SECURITY CLASSIFICATION AUTHOG 6 ,,~jJJ 3. 01STftlBUTION/AVAILA"ILTY OF REPORT 2b. ECLSSIICA1ONIOWNRAD EA Approved for public release; 2b. ECLASIFA~iO/DOWGRA10W EU Rdistribution unlimited. 4. PERFORMING ORGANtIZATION REPORT NUMB"(5) S. MONITORING ORGANIZATION REPORT NUMBER(S) ARO 24834.2-MA Ga B. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION Old Dominion University (If eppkiablo) U .Am eerhOfc 6_ c. ADDRESS (city. state, aMd ZIP Cods) 7b. ADDRESS (City, State, and ZIP Code) NoflV.25806 P. 0. Box 12211 = Nofolk VA 35080369Research Triangle Park, NC 27709-2211 Ba. NAME OF FUNDING ISPONSORING Bb. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGAIZATON if OP*&b1*)DAAL03-88-C-0076 8c-ADDRESS (City, Stats, and ZIPCo*s) 10. SOURCE OF FUNDING NUMBERSTAKWR UI P0.Bx121PROGRAM PROJECT TKWOKUI ELMN O O. NACCESSION NO.
Journal of Statistical Planning and Inference, Nov 1, 1996
In this paper we obtain some local limit theorems for arbitrary sequences of random vectors. The ... more In this paper we obtain some local limit theorems for arbitrary sequences of random vectors. The local limit theorems give conditions on the characteristic functions of random vectors for their pseudo-density function to converge uniformly on bounded sets. We then use these theorems to obtain strong large deviation results for an arbitrary sequence of random vectors. Thus our paper establishes the connection between the local limit theorems and the strong limit theorems. We apply our results to the multivariate F-distribution.
Journal of the American Statistical Association, 2003
The American Statistician, Nov 1, 1991
Research Methods in Medicine & Health Sciences
Background Meta-analysis is a popular approach for combining results from multiple studies invest... more Background Meta-analysis is a popular approach for combining results from multiple studies investigating the same questions. Meta-analysis has gained wide popularity in genomic analysis due to the availability of large volumes of genomic study results from public databases. In genomic meta-analysis, researchers, often, tend to combine p-values related to significance testing of a gene from multiple studies where thousands of genes are tested simultaneously. The traditional p-value combination approaches aim to find genes which are differentially expressed in at least one of studies. An alternative form of meta-analysis has, recently, gained popularity where the aim is to find genes that are consistently differentially expressed in a large number, possibly a majority, of studies. An approach based on weighted ordered p-values (WOP) has been developed, in the recent past, to perform the latter type of meta-analysis. Methods In this article, we discuss the limitations of the WOP meta-a...
Analytics
In health and social science and other fields where count data analysis is important, zero-inflat... more In health and social science and other fields where count data analysis is important, zero-inflated models have been employed when the frequency of zero count is high (inflated). Due to multiple reasons, there are scenarios in which an additional count value of k > 0 occurs with high frequency. The zero- and k-inflated Poisson distribution model (ZkIP) is more appropriate for such situations. The ZkIP model is a mixture distribution with three components: degenerate distributions at 0 and k count and a Poisson distribution. In this article, we propose an alternative and computationally fast expectation–maximization (EM) algorithm to obtain the parameter estimates for grouped zero and k-inflated count data. The asymptotic standard errors are derived using the complete data approach. We compare the zero- and k-inflated Poisson model with its zero-inflated and non-inflated counterparts. The best model is selected based on commonly used criteria. The theoretical results are supplemen...
ISRN Probability and Statistics, 2012
While univariate instances of binomial data are readily handled with generalized linear models, c... more While univariate instances of binomial data are readily handled with generalized linear models, cases of multivariate or repeated measure binomial data are complicated by the possibility of correlated responses. Likelihood-based estimation can be applied by using mixture distribution models, though this approach can present computational challenges. The logistic transformation can be used to bypass these concerns and allow for alternative estimating procedures. One popular alternative is the generalized estimating equation (GEE) method, though systematic errors can lead to infeasible correlation estimates or nonconvergence problems. Our approach is the coupling of quasileast squares (QLSs) method with a rarely used matrix factorization, which achieves a simplified estimation platform—as compared to the mixture model approach—and does not suffer from the convergence problems in GEE method. A noncontrived example is provided that shows the mechanical breakdown of GEE using several sta...
Journal of statistical theory and practice, Nov 26, 2020
Journal of Multivariate Analysis, Dec 1, 1986
Annals of Probability, Apr 1, 1987
Naval Research Logistics Quarterly, Dec 1, 1983
Consider a k-out-of-n system with independent repairable components. Assume that the repair and f... more Consider a k-out-of-n system with independent repairable components. Assume that the repair and failure distributions are exponential with parameters {μ1, ,μn} and {λ1, ,λn}, respectively. In this article we show that if λi – μi = Δ for all i then the life distribution of the system is increasing failure rate (IFR).
S2a. SECURITY CLASSIFICATION AUTHOG 6 ,,~jJJ 3. 01STftlBUTION/AVAILA"ILTY OF REPORT 2b. ECLSSIICA... more S2a. SECURITY CLASSIFICATION AUTHOG 6 ,,~jJJ 3. 01STftlBUTION/AVAILA"ILTY OF REPORT 2b. ECLSSIICA1ONIOWNRAD EA Approved for public release; 2b. ECLASIFA~iO/DOWGRA10W EU Rdistribution unlimited. 4. PERFORMING ORGANtIZATION REPORT NUMB"(5) S. MONITORING ORGANIZATION REPORT NUMBER(S) ARO 24834.2-MA Ga B. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION Old Dominion University (If eppkiablo) U .Am eerhOfc 6_ c. ADDRESS (city. state, aMd ZIP Cods) 7b. ADDRESS (City, State, and ZIP Code) NoflV.25806 P. 0. Box 12211 = Nofolk VA 35080369Research Triangle Park, NC 27709-2211 Ba. NAME OF FUNDING ISPONSORING Bb. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGAIZATON if OP*&b1*)DAAL03-88-C-0076 8c-ADDRESS (City, Stats, and ZIPCo*s) 10. SOURCE OF FUNDING NUMBERSTAKWR UI P0.Bx121PROGRAM PROJECT TKWOKUI ELMN O O. NACCESSION NO.
Journal of Statistical Planning and Inference, Nov 1, 1996
In this paper we obtain some local limit theorems for arbitrary sequences of random vectors. The ... more In this paper we obtain some local limit theorems for arbitrary sequences of random vectors. The local limit theorems give conditions on the characteristic functions of random vectors for their pseudo-density function to converge uniformly on bounded sets. We then use these theorems to obtain strong large deviation results for an arbitrary sequence of random vectors. Thus our paper establishes the connection between the local limit theorems and the strong limit theorems. We apply our results to the multivariate F-distribution.
Journal of the American Statistical Association, 2003
The American Statistician, Nov 1, 1991
Research Methods in Medicine & Health Sciences
Background Meta-analysis is a popular approach for combining results from multiple studies invest... more Background Meta-analysis is a popular approach for combining results from multiple studies investigating the same questions. Meta-analysis has gained wide popularity in genomic analysis due to the availability of large volumes of genomic study results from public databases. In genomic meta-analysis, researchers, often, tend to combine p-values related to significance testing of a gene from multiple studies where thousands of genes are tested simultaneously. The traditional p-value combination approaches aim to find genes which are differentially expressed in at least one of studies. An alternative form of meta-analysis has, recently, gained popularity where the aim is to find genes that are consistently differentially expressed in a large number, possibly a majority, of studies. An approach based on weighted ordered p-values (WOP) has been developed, in the recent past, to perform the latter type of meta-analysis. Methods In this article, we discuss the limitations of the WOP meta-a...
Analytics
In health and social science and other fields where count data analysis is important, zero-inflat... more In health and social science and other fields where count data analysis is important, zero-inflated models have been employed when the frequency of zero count is high (inflated). Due to multiple reasons, there are scenarios in which an additional count value of k > 0 occurs with high frequency. The zero- and k-inflated Poisson distribution model (ZkIP) is more appropriate for such situations. The ZkIP model is a mixture distribution with three components: degenerate distributions at 0 and k count and a Poisson distribution. In this article, we propose an alternative and computationally fast expectation–maximization (EM) algorithm to obtain the parameter estimates for grouped zero and k-inflated count data. The asymptotic standard errors are derived using the complete data approach. We compare the zero- and k-inflated Poisson model with its zero-inflated and non-inflated counterparts. The best model is selected based on commonly used criteria. The theoretical results are supplemen...
ISRN Probability and Statistics, 2012
While univariate instances of binomial data are readily handled with generalized linear models, c... more While univariate instances of binomial data are readily handled with generalized linear models, cases of multivariate or repeated measure binomial data are complicated by the possibility of correlated responses. Likelihood-based estimation can be applied by using mixture distribution models, though this approach can present computational challenges. The logistic transformation can be used to bypass these concerns and allow for alternative estimating procedures. One popular alternative is the generalized estimating equation (GEE) method, though systematic errors can lead to infeasible correlation estimates or nonconvergence problems. Our approach is the coupling of quasileast squares (QLSs) method with a rarely used matrix factorization, which achieves a simplified estimation platform—as compared to the mixture model approach—and does not suffer from the convergence problems in GEE method. A noncontrived example is provided that shows the mechanical breakdown of GEE using several sta...