Okechukwu Jeremiah Obulezi

Dr. Okechukwu Jeremiah Obulezi

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 June 2025 in Innovation in Statistics and Probability
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Journal Article
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GOGabriel O. Orji
Gabriel O. Orji
HEHarrison O. Etaga
Harrison O. Etaga
EAEhab M. Almetwally
Ehab M. Almetwally
CIChinyere P. Igbokwe
Chinyere P. Igbokwe
OAObioma Chukwudi Aguwa
Obioma Chukwudi Aguwa
Okechukwu Jeremiah ObuleziOkechukwu Jeremiah Obulezi
Okechukwu Jeremiah Obulezi
In this study, we designed a new family of distributions called new odd reparameterized exponential transformed-X family of distributions. This was achieved by utilizing an exponential distribution with a constant scale parameter as the transformer and then the odd function of the baseline distribution as the generalizer. The new family was used to extend the classical Weibull distribution. We further studied the characteristics of the new extended Weibull distribution which include the quantile function, moment, moment generating function, mean residual life function, order statistic, entropy and extropy. Again, the parameters were estimated using both non-Bayesian and Bayesian approaches. A comprehensive Monte Carlo simulation was conducted under four different scenarios. The proposed distribution was fitted to HIV/AIDS and COVID-19 data and then compared with the baseline distribution (Weibull) and other related models. The new distribution commands superior fit with a probability value of 0.9959 and 0.7086 in the two datasets respectively.

26 June 2025 in Innovation in Statistics and Probability
Verified
Journal Article
Open access
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COChrisogonus Kelechi Onyekwere
Chrisogonus Kelechi Onyekwere
OAObioma Chukwudi Aguwa
Obioma Chukwudi Aguwa
Okechukwu Jeremiah ObuleziOkechukwu Jeremiah Obulezi
Okechukwu Jeremiah Obulezi
This paper introduces the updated Lindley (UL) distribution, an innovative mixture of exponential and gamma distributions designed to model lifetime data with various failure rate patterns. The statistical properties of the UL distribution, including moments, skewness, kurtosis, and tail behavior, are thoroughly examined to highlight its flexibility and applicability. Parameter estimation methods using non-Bayesian are evaluated for their accuracy using bias and mean squared error metrics across various scenarios. The paper further explores applications of the UL distribution in acceptance sampling plans, actuarial risk assessment, and reliability analysis. Comprehensive simulation studies and graphical visualizations underscore the robustness and versatility of the distribution in addressing real-world problems, making it a valuable tool in statistical modeling and decision-making processes.

6 October 2023 in Symmetry
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ECEbereChukwu Chinedu
EbereChukwu Chinedu
QCQueensley C Chukwudum
Queensley C Chukwudum
NANajwan Alsadat
Najwan Alsadat
Okechukwu Jeremiah ObuleziOkechukwu Jeremiah Obulezi
Okechukwu Jeremiah Obulezi
Ehab M. AlmetwallyEhab M. Almetwally
Ehab M. Almetwally
Ahlam H. TolbaAhlam H. Tolba
Ahlam H. Tolba
This article is an extension of the Chris-Jerry distribution (C-JD) in that a two-parameter Chris-Jerry distribution (TPCJD) is suggested and its characteristics are studied. Based on the determined domain of attraction and other major statistical properties, the proposed TPCJD seems to fit into the Gumbel domain. Additionally, it has been confirmed that the stress strength is reliable. The tail study suggests that the TPCJD’s substantial tail makes it suited for a range of applications. The study took into account the single acceptance sampling approach using both simulation and real-life situations. The parameters of the TPCJD were estimated by some classical and Bayesian approaches. The mean squared errors (MSE), linear-exponential, and generalized entropy loss functions were deployed to obtain the Bayesian estimators aided by the Markov chain Monte Carlo (MCMC) simulation. An analysis of lifetime data on two events justified the use of the proposed distribution after comparing the results with some standard lifetime models.

5 November 2025 in Modern Journal of Statistics
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Okechukwu Jeremiah ObuleziOkechukwu Jeremiah Obulezi
Okechukwu Jeremiah Obulezi
This paper introduces the novel, single-parameter Obulezi distribution for modeling lifetime data. We derived its statistical and reliability properties and performed an exhaustive comparison of fifteen parameter estimation techniques via simulation and application to three real datasets. Simulation results confirmed the consistency of all estimators, while empirical analysis showed the Obulezi distribution consistently yielded the lowest standard errors, proving it to be the most precise and stable model compared to competitors. Goodness-of-fit metrics confirmed the \texttt{Obulezi} distribution's superior fit, particularly for data exhibiting an increasing hazard rate. The Obulezi distribution is thus a robust and highly competitive model for parsimonious survival and reliability analysis.

17 September 2024 in Alexandria Engineering Journal
Verified
Journal Article
Open access
DODorathy O. Oramulu
Dorathy O. Oramulu
NANajwan Alsadat
Najwan Alsadat
AKAnoop Kumar
Anoop Kumar
MBMahmoud Mohamed Bahloul
Mahmoud Mohamed Bahloul
Okechukwu Jeremiah ObuleziOkechukwu Jeremiah Obulezi
Okechukwu Jeremiah Obulezi

23 August 2023 in Sustainability
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Ahlam H. TolbaAhlam H. Tolba
Ahlam H. Tolba
COChrisogonus Kelechi Onyekwere
Chrisogonus Kelechi Onyekwere
AEAhmed R. El-Saeed
Ahmed R. El-Saeed
NANajwan Alsadat
Najwan Alsadat
HAHanan Alohali
Hanan Alohali
Okechukwu Jeremiah ObuleziOkechukwu Jeremiah Obulezi
Okechukwu Jeremiah Obulezi
A novel lifetime distribution has been defined and examined in this study. The odd Lindley–Pareto (OLiP) distribution is the name we give to the new distribution. The new density function can be written as an odd Lindley-G distribution with Pareto amplification. The moment-generating function and characteristic function, entropy and asymptotic behavior, order statistics and moments, mode, variance, skewness, and kurtosis are some of the aspects of the OLiP distribution that are discovered. Seven non-Bayesian estimation techniques and Bayesian estimation utilizing Markov chain Monte Carlo were compared for performance. Additionally, when the lifetime test is truncated after a predetermined period, single acceptance sampling plans (SASPs) are created for the newly suggested, OLiP distribution. The median lifetime of the OLiP distribution with pre-specified factors is taken as the truncation time. To guarantee that the specific life test is obtained at the defined risk to the user, the minimum sample size is required. For a particular consumer’s risk, the OLiP distribution’s parameters, and the truncation time, numerical results are obtained. The new distribution is illustrated using mortality rates of COVID-19 patients in Canada and vinyl chloride data in (g/L) from ground-water monitoring wells that are located in clean-up-gradient areas.