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1.
Glob Pediatr Health ; 11: 2333794X241258142, 2024.
Article in English | MEDLINE | ID: mdl-38846062

ABSTRACT

Objective. To describe heated humidified high-flow nasal cannulas (HHHFNC) utilization in level III neonatal intensive care units (NICUs) in Saudi Arabia. Methods. A prospective cross-sectional study using an electronic web-based questionnaire. The survey targeted level III NICUs hospitals using HHHFNCs, covering HHHFNC availability, protocols, patient characteristics, and indications. It also collected opinions on the benefits of HHHFNCs compared to nasal continuous positive airway pressure (nCPAP). Results. Out of 47 government-level III neonatal intensive care units, 35 (74%) responded to the survey. Among the included units, 46% had guidelines for HHHFNC use. Additionally, 51% reported using HHHFNC in infants of all gestational ages. The primary indication for HHHFNC use was weaning off nCPAP (34%), with 60% of the respondents noting its advantages for kangaroo care and breastfeeding. Conclusion. HHHFNC are increasingly prevalent in NICUs in Saudi Arabia. However, there remain no clear policies or guidelines regarding their use in preterm infants.

2.
Cureus ; 16(4): e58714, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38779289

ABSTRACT

Introduction Obstructive sleep apnea (OSA) is prevalent among children, impacting their well-being. Obesity and related morbidity may lead to serious health disorders. In obese children, OSA may be a risk factor for systemic diseases that negatively affect their quality of life. This study explored the correlation between obesity and OSA among children aged five to 14 years in Tabuk, Saudi Arabia. Methods This cross-sectional study employed an online questionnaire for the parents of 517 children, assessing sociodemographic variables, medical history, and OSA symptoms. The data analysis used Statistical Product and Service Solutions (SPSS; IBM SPSS Statistics for Windows, Armonk, NY) software, employing descriptive and inferential statistics. Results The children were predominantly male (281, 54.4%) and from Tabuk (405, 78.3%), with 158 (30.6%) classified as obese. Symptoms such as snoring (191, 36.9%), daytime fatigue (195, 37.7%), and impact on daily activities (79, 15.3%) were prevalent. OSA scores significantly correlated with BMI categories (p < 0.001), family history of OSA (p < 0.001), and medical conditions including diabetes, hypertension, and high cholesterol (p < 0.05). Correlations showed weak positive associations of age (ρ = 0.159) and height (ρ = 0.229) with OSA score, whereas a strong correlation existed between weight (ρ = 0.531) and OSA score (p < 0.001). Conclusion Obesity demonstrated a strong association with OSA severity among children in Tabuk. Higher BMI categories, a family history of OSA, and certain medical conditions correlated significantly with increased OSA scores. Although age and height displayed weaker associations, weight emerged as a major contributing factor to OSA severity. These findings emphasize the importance of addressing obesity in managing pediatric OSA, advocating for early interventions to mitigate its impact on children's health and well-being.

3.
Cureus ; 16(1): e51570, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38313921

ABSTRACT

BACKGROUND: Assessing the neuromechanical coupling of inspiratory muscles during mechanical ventilation (MV) could reveal the physiological mechanism of MV failure. This study examined the respiratory neuromechanical characteristics between MV liberation success and failure. METHODS: This is an observational prospective study that included patients during their ventilator liberation process. Assessment of surface electromyography (sEMG) of inspiratory muscles, including the diaphragm and extra-diaphragmatic (scalene, sternocleidomastoid, and parasternal) muscles, was performed 15 minutes after the initiation of spontaneous breathing trials. Neuromechanical efficiency of the diaphragm (NMEDia) and extra-diaphragmatic muscles (NMEExtra) were compared in patients who were successfully liberated from MV with those who failed MV liberation within 72 hours after extubation. RESULTS: A total of 45 patients were enrolled and 28 were female (67%). The sample median age was 63 (IQR 47, 69) years old. One-third of patients failed MV liberation within 72 hours of their spontaneous breathing trials (SBTs). NMEDia was significantly lower in patients who failed MV liberation with a root mean square of (M 0.27), (IQR 0.21, 0.37) compared with (M 0.371), (IQR 0.3, 0.631) for the success group (p=0.0222). The area under the curve for NMEDia was lower in the failure group (M 0.270), (IQR 0.160, 0.370) and (M 0.485), (IQR 0.280, 0.683) for the success group (p=0.024). However, NMEExtra was not statistically different between the two groups. CONCLUSION: Reduced NMEDia is a predictor of MV liberation failure. NMEExtra was not a major contributor to MV liberation outcomes. Further studies should assess the performance of inspiratory muscles NME indices to predict MV liberation outcomes.

4.
Heliyon ; 10(3): e25802, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38371973

ABSTRACT

The system or unit survives when strength is more significant than the stress enjoined. This procedure is usually used in many companies to test their product. The reliability or the quality of the scheme or component is described by the parameters of stress-strength reliability (R=P(X>Y)) where X denotes strength and Y indicates stress. In this article, we adopted the statistical inference of R while the two arbitrary factors X and Y are independent and approach the Lomax lifetime distribution with common scale parameters. Also, the strength and stress variables are subjected to a partial step-stress-quickened life experiment. The classical estimation and Bayes method create the point estimate of R. Confidence intervals of R are computed with asymptotic distribution, bootstrap technique, and Bayesian credible intervals. All results are evaluated and compared under an extensive simulation study. Finally, the lifetime data sets generated from the Lomax distribution are used to analyze the system's reliability by estimating R.

5.
Tob Induc Dis ; 21: 168, 2023.
Article in English | MEDLINE | ID: mdl-38098748

ABSTRACT

INTRODUCTION: Electronic cigarette (e-cigarette) use is gaining popularity among adults. Monitoring e-cigarette-induced respiratory symptoms is crucial for both clinical and regulatory purposes. We systematically reviewed the current literature to understand the prevalence of respiratory symptoms among exclusive e-cigarette users, dual users, and former smokers. METHODS: Databases searched included PubMed, CINAHL, Cochrane Library, Embase, and Scopus. We included all English-language, empirical quantitative articles that explored the prevalence of e-cigarette-related respiratory symptoms. Random-effects models were utilized in conducting the meta-analyses. The quality of identified studies was evaluated using the NIH Study Quality Assessment Tools. This study is registered with PROSPERO(#CRD42020165973). RESULTS: The literature search identified 1240 references. After removing duplicates and screening for eligibility, 168 studies were included in the final review. The majority of included studies reported a wide range of adverse respiratory symptoms. The respiratory symptoms were prevalent among the exclusive e-cigarette users, dual users, and those who switched from combustible cigarettes to e-cigarettes. Further, out of the RCT studies, 5 were rated as good quality, while 3 were rated as fair. Among the observational studies, 24 were rated as good quality, and 9 were rated as fair. The two experimental studies were both rated as fair quality. CONCLUSIONS: Continued monitoring of respiratory symptoms among e-cigarette users is warranted. Due to the heterogeneity and inconsistencies among studies, which limit result interpretation and highlight the need for studies assessing causal inference, further research using robust study designs is essential. This will provide clinicians with comprehensive knowledge about the potential respiratory risks of e-cigarette use.

6.
Medicine (Baltimore) ; 102(43): e35816, 2023 Oct 27.
Article in English | MEDLINE | ID: mdl-37904391

ABSTRACT

There is a paucity of research on knowledge, practice, counseling confidence, and intention to use ask, advice, and refer (AAR) model of smoking cessation among respiratory therapists (RTs). Thus, we aimed to analyze the characteristics and factors that may influence them. We collected data using online questionnaires from convenience sample of active licensed RTs in Saudi Arabia. We included 206 participants. A descriptive analysis of the demographic information and characteristics of smoking cessation counseling practices and confidence were conducted. Multiple linear regression was used to test whether demographic variables and AAR model components significantly predicted the RTs' calculated cumulative score of tobacco counseling confidence skills. Our results showed a deficiency in tobacco knowledge among RTs. Most RTs did not have certifications or attend lectures or seminars related to tobacco treatment. RTs were unfamiliar with the smoking cessation program contact information and mobile smoking cessation clinics but reported a high tobacco counseling confidence score. Clinical experience (P = .008), familiarity with smoking cessation program contact information (P = .02), inquiry regarding smoking status (P < .001), and advice regarding smoking status (P = .03) significantly predicted tobacco counseling confidence levels in RTs. RT experience, knowledge, and awareness of smoking cessation programs could enhance the confidence level among them in implementing AAR model.


Subject(s)
Smoking Cessation , Humans , Smoking Cessation/methods , Cross-Sectional Studies , Intention , Counseling/methods , Allied Health Personnel
7.
Tob Induc Dis ; 21: 116, 2023.
Article in English | MEDLINE | ID: mdl-37745030

ABSTRACT

INTRODUCTION: There is a paucity of studies on e-cigarette use among adults with chronic lung disease. In the present study, we aimed to assess whether psychosocial or cognitive factors elucidate the relationship between chronic lung disease (CLD) and susceptibility to e-cigarette use and whether the relationship between CLD and e-cigarette use is conditional on the presence of respiratory symptoms. METHODS: We recruited adults aged ≥18 years in Alabama with CLD from university medical clinics (n=140) and individuals without CLD (n=123 as a reference group). Information on sociodemographics, susceptibility to e-cigarette use, psychosocial factors, and cognitive factors were collected. Mediation analysis was used to assess whether the psychosocial factors or cognitive factors explained the association between CLD and susceptibility to using e-cigarettes, and moderation analysis was conducted to determine if respiratory factors would change the association between CLD and susceptibility to e-cigarette use. RESULTS: Psychosocial factors (stress, depression, anxiety) and e-cigarette positive expectancy were notably high among individuals with CLD. Having CLD was associated with a lower likelihood of susceptibility to e-cigarette use. Higher levels of stress, being a smoker, boredom, taste/sensorimotor manipulation, and social facilitation were associated with higher odds of susceptibility to using e-cigarettes among individuals with CLD. Mediation analysis indicated a statistically significant indirect effect of CLD on the susceptibility to using e-cigarettes through stress and boredom reduction. We did not find a statistically significant interaction between CLD and respiratory symptoms affecting susceptibility to using e-cigarettes. CONCLUSIONS: Individuals with CLD often exhibit stress, depression, and a positive view of e-cigarettes but are generally less inclined to use them. Stress, smoking habits, boredom, taste, and social influence can increase their susceptibility to e-cigarette use. Our findings call for further exploration to evaluate the temporal relationship between CLD status, psychosocial factors, cognitive factors, and susceptibility to using e-cigarettes. TRIAL REGISTRATION: The study was registered on ClinicalTrials.gov, on 5 November 2019. Identifier: NCT04151784.

8.
Sci Rep ; 13(1): 12828, 2023 Aug 07.
Article in English | MEDLINE | ID: mdl-37550320

ABSTRACT

This article presents and investigates a modified version of the Weibull distribution that incorporates four parameters and can effectively represent a hazard rate function with a shape resembling a bathtub. Its significance in the fields of lifetime and reliability stems from its ability to model both increasing and decreasing failure rates. The proposed distribution encompasses several well-known models such as the Weibull, extreme value, exponentiated Weibull, generalized Rayleigh, and modified Weibull distributions. The paper derives key mathematical statistics of the proposed distribution, including the quantile function, moments, moment-generating function, and order statistics density. Various mathematical properties of the proposed model are established, and the unknown parameters of the distribution are estimated using different estimation techniques. Furthermore, the effectiveness of these estimators is assessed through numerical simulation studies. Finally, the paper applies the new model and compares it with various existing distributions by analyzing two real-life time data sets.

9.
BMC Pediatr ; 23(1): 357, 2023 07 13.
Article in English | MEDLINE | ID: mdl-37442954

ABSTRACT

BACKGROUND: With the advances in neonatal intensive care, the survival rate of extremely preterm infants is increasing. However, bronchopulmonary dysplasia (BPD) remains a major cause of morbidity among infants in this group. This study examined the changes in respiratory support modalities, specifically heated humidified high-flow nasal cannula (HHHFNC), and their association with BPD incidence among preterm infants born at < 29 weeks of gestation. METHOD: This population-based retrospective cohort study included infants born at < 29 weeks of gestation between 2016 and 2020. Data regarding the use and duration of respiratory support modalities were obtained, including mechanical ventilation, continuous positive airway pressure, HHHFNC, and low-flow oxygen therapy. Additionally, the incidence of BPD was determined in the included infants. Trend analysis for each respiratory support modality and BPD incidence rate was performed to define the temporal changes associated with changes in BPD rates. In addition, a logistic regression model was developed to identify the association between BPD and severity grade using HHHFNC. RESULTS: Three Hundred and sixteen infants were included in this study. The use and duration of HHHFNC therapy increased during the study period. Throughout the study period, the overall incidence of BPD was 49%, with no significant trends. The BPD rate was significantly higher in the infants who received HHHFNC than in those who did not (52% vs. 39%, P = 0.03). Analysis of BPD severity grades showed that both grade 1 BPD (34% vs. 21%, P = 0.03) and grade 2 BPD (12% vs. 1%, P < 0.01) were significantly more common among infants who received HHHFNC than among those who did not. In contrast, the incidence of grade 3 BPD was lower in infants who received HHFNC (6% vs. 17%, P < 0.01). The duration in days of HHHFNC was found to significantly predict BPD incidence (OR 1.04 [95%CI: 1.01-1.06], P < 0.01) after adjusting for confounding variables. CONCLUSION: The use of HHHFNC in extremely preterm infants born at < 29 weeks of gestation is increasing. There was a significant association between the duration of HHHFNC therapy and the development of BPD in extremely preterm infants born at < 29 weeks of gestation.


Subject(s)
Bronchopulmonary Dysplasia , Respiratory Distress Syndrome, Newborn , Infant , Infant, Newborn , Humans , Bronchopulmonary Dysplasia/epidemiology , Bronchopulmonary Dysplasia/etiology , Incidence , Respiratory Distress Syndrome, Newborn/therapy , Retrospective Studies , Infant, Extremely Premature
10.
Sci Rep ; 13(1): 12243, 2023 07 28.
Article in English | MEDLINE | ID: mdl-37507438

ABSTRACT

The paper presents a novel statistical approach for analyzing the daily coronavirus case and fatality statistics. The survival discretization method was used to generate a two-parameter discrete distribution. The resulting distribution is referred to as the "Discrete Marshall-Olkin Length Biased Exponential (DMOLBE) distribution". Because of the varied forms of its probability mass and failure rate functions, the DMOLBE distribution is adaptable. We calculated the mean and variance, skewness, kurtosis, dispersion index, hazard and survival functions, and second failure rate function for the suggested distribution. The DI index demonstrates that the proposed model can represent both over-dispersed and under-dispersed data sets. We estimated the parameters of the DMOLBE distribution. The behavior of ML estimates is checked via a comprehensive simulation study. The behavior of Bayesian estimates is checked by generating 10,000 iterations of Markov chain Monte Carlo techniques, plotting the trace, and checking the proposed distribution. From simulation studies, it was observed that the bias and mean square error decreased with an increase in sample size. To show the importance and flexibility of DMOLBE distribution using two data sets about deaths due to coronavirus in China and Pakistan are analyzed. The DMOLBE distribution provides a better fit than some important discrete models namely the discrete Burr-XII, discrete Bilal, discrete Burr-Hatke, discrete Rayleigh distribution, and Poisson distributions. We conclude that the new proposed distribution works well in analyzing these data sets. The data sets used in the paper was collected from 2020 year.


Subject(s)
COVID-19 , Humans , Bayes Theorem , COVID-19/epidemiology , Computer Simulation , Probability , Markov Chains , Monte Carlo Method
11.
Microorganisms ; 11(4)2023 Apr 03.
Article in English | MEDLINE | ID: mdl-37110362

ABSTRACT

Evidence from the literature suggests an association between the microbiome and asthma development. Here, we aimed to identify the current evidence for the association between asthma and the upper airway, lower airway and/or the gut microbiome. An electronic systemic search of PubMed, EBSCO, Science Direct and Web of Science was conducted until February 2022 to identify the eligible studies. The Newcastle-Ottawa Scale and the Systematic Review Centre for Laboratory Animal Experimentation risk of the bias tools were used to assess quality of included studies. Twenty-five studies met the inclusion criteria. Proteobacteria and Firmicutes were identified as being significantly higher in the asthmatic children compared with the healthy controls. The high relative abundance of Veillonella, Prevotella and Haemophilus in the microbiome of the upper airway in early infancy was associated with a higher risk of asthma development later in life. The gut microbiome analyses indicated that a high relative abundance of Clostridium in early childhood might be associated with asthma development later in life. The findings reported here serve as potential microbiome signatures associated with the increased risk of asthma development. There is a need for large longitudinal studies to further identify high-risk infants, which will help in design strategies and prevention mechanisms to avoid asthma early in life.

12.
PLoS One ; 17(10): e0275001, 2022.
Article in English | MEDLINE | ID: mdl-36201437

ABSTRACT

In the present work, a class of distributions, called new extended family of heavy-tailed distributions is introduced. The special sub-models of the introduced family provide unimodal, bimodal, symmetric, and asymmetric density shapes. A special sub-model of the new family, called the new extended heavy-tailed Weibull (NEHTW) distribution, is studied in more detail. The NEHTW parameters have been estimated via eight classical estimation procedures. The performance of these methods have been explored using detailed simulation results which have been ordered, using partial and overall ranks, to determine the best estimation method. Two important risk measures are derived for the NEHTW distribution. To prove the usefulness of the two actuarial measures in financial sciences, a simulation study is conducted. Finally, the flexibility and importance of the NEHTW model are illustrated empirically using two real-life insurance data sets. Based on our study, we observe that the NEHTW distribution may be a good candidate for modeling financial and actuarial sciences data.


Subject(s)
Family , Models, Statistical , Computer Simulation , Statistical Distributions
13.
Front Public Health ; 10: 922795, 2022.
Article in English | MEDLINE | ID: mdl-35968475

ABSTRACT

In this article, a new hybrid time series model is proposed to predict COVID-19 daily confirmed cases and deaths. Due to the variations and complexity in the data, it is very difficult to predict its future trajectory using linear time series or mathematical models. In this research article, a novel hybrid ensemble empirical mode decomposition and error trend seasonal (EEMD-ETS) model has been developed to forecast the COVID-19 pandemic. The proposed hybrid model decomposes the complex, nonlinear, and nonstationary data into different intrinsic mode functions (IMFs) from low to high frequencies, and a single monotone residue by applying EEMD. The stationarity of each IMF component is checked with the help of the augmented Dicky-Fuller (ADF) test and is then used to build up the EEMD-ETS model, and finally, future predictions have been obtained from the proposed hybrid model. For illustration purposes and to check the performance of the proposed model, four datasets of daily confirmed cases and deaths from COVID-19 in Italy, Germany, the United Kingdom (UK), and France have been used. Similarly, four different statistical metrics, i.e., root mean square error (RMSE), symmetric mean absolute parentage error (sMAPE), mean absolute error (MAE), and mean absolute percentage error (MAPE) have been used for a comparison of different time series models. It is evident from the results that the proposed hybrid EEMD-ETS model outperforms the other time series and machine learning models. Hence, it is worthy to be used as an effective model for the prediction of COVID-19.


Subject(s)
COVID-19 , COVID-19/epidemiology , Forecasting , Humans , Models, Theoretical , Pandemics , Seasons
14.
Comput Math Methods Med ; 2022: 1883491, 2022.
Article in English | MEDLINE | ID: mdl-35637848

ABSTRACT

The bivariate Poisson exponential-exponential distribution is an important lifetime distribution in medical data analysis. In this article, the conditionals, probability mass function (pmf), Poisson exponential and probability density function (pdf), and exponential distribution are used for creating bivariate distribution which is called bivariate Poisson exponential-exponential conditional (BPEEC) distribution. Some properties of the BPEEC model are obtained such as the normalized constant, conditional densities, regression functions, and product moment. Moreover, the maximum likelihood and pseudolikelihood methods are used to estimate the BPEEC parameters based on complete data. Finally, two data sets of real bivariate data are analyzed to compare the methods of estimation. In addition, a comparison between the BPEEC model with the bivariate exponential conditionals (BEC) and bivariate Poisson exponential conditionals (BPEC) is considered.


Subject(s)
Models, Statistical , Humans , Likelihood Functions , Statistical Distributions
15.
Math Biosci Eng ; 19(6): 6252-6275, 2022 04 18.
Article in English | MEDLINE | ID: mdl-35603400

ABSTRACT

In real-life experiments, collecting complete data is time-, finance-, and resources-consuming as stated by statisticians and analysts. Their goal was to compromise between the total time of testing, the number of units under scrutiny, and the expenditures paid through a censoring scheme. Comparing failure-censored schemes (Type-Ⅱ and Progressive Type-Ⅱ) to Time-censored schemes (Type-Ⅰ), it's worth noting that the former is time-consuming and is no more suitable to be applied in real-life situations. This is the reason why the Type-Ⅰ adaptive progressive hybrid censoring scheme has exceeded other failure-censored types; Time-censored types enable analysts to accomplish their trials and experiments in a shorter time and with higher efficiency. In this paper, the parameters of the inverse Weibull distribution are estimated under the Type-Ⅰ adaptive progressive hybrid censoring scheme (Type-Ⅰ APHCS) based on competing risks data. The model parameters are estimated using maximum likelihood estimation and Bayesian estimation methods. Further, we examine the asymptotic confidence intervals and bootstrap confidence intervals for the unknown model parameters. Monte Carlo simulations are carried out to compare the performance of the suggested estimation methods under Type-Ⅰ APHCS. Moreover, Markov Chain Monte Carlo by applying Metropolis-Hasting algorithm under the square error of loss function is used to compute Bayes estimates and related to the highest posterior density. Finally, two data sets are studied to illustrate the introduced methods of inference. Based on our results, we can conclude that the Bayesian estimation outperforms the maximum likelihood estimation for estimating the inverse Weibull parameters under Type-Ⅰ APHCS.


Subject(s)
Bayes Theorem , Computer Simulation , Likelihood Functions , Markov Chains , Monte Carlo Method
16.
J Healthc Eng ; 2022: 4409336, 2022.
Article in English | MEDLINE | ID: mdl-35087649

ABSTRACT

Natural computing refers to computational processes observed in nature and human-designed computing inspired by nature. In recent times, data fusion in the healthcare sector becomes a challenging issue, and it needs to be resolved. At the same time, intracerebral haemorrhage (ICH) is the injury of blood vessels on the brain cells, which is mainly liable for stroke. X-rays and computed tomography (CT) scans are widely applied for locating the haemorrhage position and size. Since manual segmentation of the CT scans by planimetry by the use of radiologists is a time-consuming process, deep learning (DL) is used to attain effective ICH diagnosis performance. This paper presents an automated intracerebral haemorrhage diagnosis using fusion-based deep learning with swarm intelligence (AICH-FDLSI) algorithm. The AICH-FDLSI model operates on four major stages namely preprocessing, image segmentation, feature extraction, and classification. To begin with, the input image is preprocessed using the median filtering (MF) technique to remove the noise present in the image. Next, the seagull optimization algorithm (SOA) with Otsu multilevel thresholding is employed for image segmentation. In addition, the fusion-based feature extraction model using the Capsule Network (CapsNet) and EfficientNet is applied to extract a useful set of features. Moreover, deer hunting optimization (DHO) algorithm is utilized for the hyperparameter optimization of the CapsNet and DenseNet models. Finally, a fuzzy support vector machine (FSVM) is applied as a classification technique to identify the different classes of ICH. A set of simulations takes place to determine the diagnostic performance of the AICH-FDLSI model using the benchmark intracranial haemorrhage data set. The experimental outcome stated that the AICH-FDLSI model has reached a proficient performance over the compared methods in a significant way.


Subject(s)
Deep Learning , Deer , Algorithms , Animals , Cerebral Hemorrhage/diagnostic imaging , Humans , Tomography, X-Ray Computed/methods
17.
Entropy (Basel) ; 23(12)2021 Nov 26.
Article in English | MEDLINE | ID: mdl-34945883

ABSTRACT

In this article, we introduce a new three-parameter distribution called the extended inverse-Gompertz (EIGo) distribution. The implementation of three parameters provides a good reconstruction for some applications. The EIGo distribution can be seen as an extension of the inverted exponential, inverse Gompertz, and generalized inverted exponential distributions. Its failure rate function has an upside-down bathtub shape. Various statistical and reliability properties of the EIGo distribution are discussed. The model parameters are estimated by the maximum-likelihood and Bayesian methods under Type-II censored samples, where the parameters are explained using gamma priors. The performance of the proposed approaches is examined using simulation results. Finally, two real-life engineering data sets are analyzed to illustrate the applicability of the EIGo distribution, showing that it provides better fits than competing inverted models such as inverse-Gompertz, inverse-Weibull, inverse-gamma, generalized inverse-Weibull, exponentiated inverted-Weibull, generalized inverted half-logistic, inverted-Kumaraswamy, inverted Nadarajah-Haghighi, and alpha-power inverse-Weibull distributions.

18.
PLoS One ; 16(11): e0258581, 2021.
Article in English | MEDLINE | ID: mdl-34813589

ABSTRACT

This article focus on the analysis of the reliability of multiple identical systems that can have multiple failures over time. A repairable system is defined as a system that can be restored to operating state in the event of a failure. This work under minimal repair, it is assumed that the failure has a power law intensity and the Bayesian approach is used to estimate the unknown parameters. The Bayesian estimators are obtained using two objective priors know as Jeffreys and reference priors. We proved that obtained reference prior is also a matching prior for both parameters, i.e., the credibility intervals have accurate frequentist coverage, while the Jeffreys prior returns unbiased estimates for the parameters. To illustrate the applicability of our Bayesian estimators, a new data set related to the failures of Brazilian sugar cane harvesters is considered.


Subject(s)
Bayes Theorem , Computer Simulation , Models, Statistical , Probability , Sample Size
19.
Comput Intell Neurosci ; 2021: 4227346, 2021.
Article in English | MEDLINE | ID: mdl-34603431

ABSTRACT

For the first time and by using an entire sample, we discussed the estimation of the unknown parameters θ 1, θ 2, and ß and the system of stress-strength reliability R=P(Y < X) for exponentiated inverted Weibull (EIW) distributions with an equivalent scale parameter supported eight methods. We will use maximum likelihood method, maximum product of spacing estimation (MPSE), minimum spacing absolute-log distance estimation (MSALDE), least square estimation (LSE), weighted least square estimation (WLSE), method of Cramér-von Mises estimation (CME), and Anderson-Darling estimation (ADE) when X and Y are two independent a scaled exponentiated inverted Weibull (EIW) distribution. Percentile bootstrap and bias-corrected percentile bootstrap confidence intervals are introduced. To pick the better method of estimation, we used the Monte Carlo simulation study for comparing the efficiency of the various estimators suggested using mean square error and interval length criterion. From cases of samples, we discovered that the results of the maximum product of spacing method are more competitive than those of the other methods. A two real-life data sets are represented demonstrating how the applicability of the methodologies proposed in real phenomena.


Subject(s)
Carbon Fiber , Likelihood Functions , Monte Carlo Method , Reproducibility of Results , Statistical Distributions
20.
Micromachines (Basel) ; 12(6)2021 May 23.
Article in English | MEDLINE | ID: mdl-34071117

ABSTRACT

This numerical study aims to interpret the impact of non-linear thermal radiation on magnetohydrodynamic (MHD) Darcy-Forchheimer Casson-Water/Glycerine nanofluid flow due to a rotating disk. Both the single walled, as well as multi walled, Carbon nanotubes (CNT) are invoked. The nanomaterial, thus formulated, is assumed to be more conductive as compared to the simple fluid. The properties of effective carbon nanotubes are specified to tackle the onward governing equations. The boundary layer formulations are considered. The base fluid is assumed to be non-Newtonian. The numerical analysis is carried out by invoking the numerical Runge Kutta 45 (RK45) method based on the shooting technique. The outcomes have been plotted graphically for the three major profiles, namely, the radial velocity profile, the tangential velocity profile, and temperature profile. For skin friction and Nusselt number, the numerical data are plotted graphically. Major outcomes indicate that the enhanced Forchheimer number results in a decline in radial velocity. Higher the porosity parameter, the stronger the resistance offered by the medium to the fluid flow and consequent result is seen as a decline in velocity. The Forchheimer number, permeability parameter, and porosity parameter decrease the tangential velocity field. The convective boundary results in enhancement of temperature facing the disk surface as compared to the ambient part. Skin-friction for larger values of Forchheimer number is found to be increasing. Sufficient literature is provided in the introduction part of the manuscript to justify the novelty of the present work. The research greatly impacts in industrial applications of the nanofluids, especially in geophysical and geothermal systems, storage devices, aerospace engineering, and many others.

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