scholarly journals Generalized Confidence Intervals for Zero-Inflated Pareto Distribution

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3272
Author(s):  
Xiao Wang ◽  
Xinmin Li
Keyword(s):  
Confidence Intervals ◽  
Pareto Distribution ◽  
Interval Estimation ◽  
Phone Call ◽  
Simulation Studies ◽  
Excess Zeros ◽  
Advantages And Disadvantages ◽  
Generalized Confidence Intervals ◽  
The Mean ◽  
Generalized Pivotal Quantities

This paper considers interval estimations for the mean of Pareto distribution with excess zeros. Three approaches for interval estimation are proposed based on fiducial generalized pivotal quantities (FGPQs), respectively. Simulation studies are performed to assess the performance of the proposed methods, along with three measurements to determine comparisons with competing approaches. The advantages and disadvantages of each method are provided. The methods are illustrated using a real phone call dataset.

Confidence Intervals for the Mean of Lognormal Data with Excess Zeros

2006 ◽  
Vol 48 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Lili Tian ◽  
Jianrong Wu
Keyword(s):  
Confidence Intervals ◽  
Excess Zeros ◽  
The Mean

scholarly journals The change in estimate method for selecting confounders: A simulation study

2021 ◽  
pp. 096228022110342
Author(s):  
Denis Talbot ◽  
Awa Diop ◽  
Mathilde Lavigne-Robichaud ◽  
Chantal Brisson
Keyword(s):  
Confidence Intervals ◽  
Simulation Study ◽  
Mean Squared Error ◽  
Real Data ◽  
Significance Test ◽  
Simulation Studies ◽  
Squared Error ◽  
Estimate Method ◽  
The Mean ◽  
Work And Health

Background The change in estimate is a popular approach for selecting confounders in epidemiology. It is recommended in epidemiologic textbooks and articles over significance test of coefficients, but concerns have been raised concerning its validity. Few simulation studies have been conducted to investigate its performance. Methods An extensive simulation study was realized to compare different implementations of the change in estimate method. The implementations were also compared when estimating the association of body mass index with diastolic blood pressure in the PROspective Québec Study on Work and Health. Results All methods were susceptible to introduce important bias and to produce confidence intervals that included the true effect much less often than expected in at least some scenarios. Overall mixed results were obtained regarding the accuracy of estimators, as measured by the mean squared error. No implementation adequately differentiated confounders from non-confounders. In the real data analysis, none of the implementation decreased the estimated standard error. Conclusion Based on these results, it is questionable whether change in estimate methods are beneficial in general, considering their low ability to improve the precision of estimates without introducing bias and inability to yield valid confidence intervals or to identify true confounders.

Interval estimation for the mean of lognormal data with excess zeros

2013 ◽  
Vol 83 (11) ◽  
pp. 2447-2453 ◽  
Author(s):  
Xinmin Li ◽  
Xiaohua Zhou ◽  
Lili Tian
Keyword(s):  
Interval Estimation ◽  
Excess Zeros ◽  
The Mean

scholarly journals Generalized fiducial inference on the mean of zero-inflated Poisson and Poisson hurdle models

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yixuan Zou ◽  
Jan Hannig ◽  
Derek S. Young
Keyword(s):  
Confidence Intervals ◽  
Truncated Distribution ◽  
Excess Zeros ◽  
Fiducial Inference ◽  
Hurdle Models ◽  
Count Distribution ◽  
Degenerate Distribution ◽  
Probability Mass ◽  
The Mean ◽  
Inference Methods

AbstractZero-inflated and hurdle models are widely applied to count data possessing excess zeros, where they can simultaneously model the process from how the zeros were generated and potentially help mitigate the effects of overdispersion relative to the assumed count distribution. Which model to use depends on how the zeros are generated: zero-inflated models add an additional probability mass on zero, while hurdle models are two-part models comprised of a degenerate distribution for the zeros and a zero-truncated distribution. Developing confidence intervals for such models is challenging since no closed-form function is available to calculate the mean. In this study, generalized fiducial inference is used to construct confidence intervals for the means of zero-inflated Poisson and Poisson hurdle models. The proposed methods are assessed by an intensive simulation study. An illustrative example demonstrates the inference methods.

scholarly journals Generalized Confidence Intervals for Intra- and Inter-subject Coefficients of Variation in Linear Mixed-effects Models

2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Johannes Forkman
Keyword(s):  
Confidence Intervals ◽  
Random Effects ◽  
Variance Components ◽  
Mixed Effects ◽  
Mixed Effects Models ◽  
Linear Mixed Effects Models ◽  
Linear Mixed Effects ◽  
Coefficients Of Variation ◽  
Generalized Confidence Intervals ◽  
Generalized Pivotal Quantities

Abstract Linear mixed-effects models are linear models with several variance components. Models with a single random-effects factor have two variance components: the random-effects variance, i. e., the inter-subject variance, and the residual error variance, i. e., the intra-subject variance. In many applications, it is practice to report variance components as coefficients of variation. The intra- and inter-subject coefficients of variation are the square roots of the corresponding variances divided by the mean. This article proposes methods for computing confidence intervals for intra- and inter-subject coefficients of variation using generalized pivotal quantities. The methods are illustrated through two examples. In the first example, precision is assessed within and between runs in a bioanalytical method validation. In the second example, variation is estimated within and between main plots in an agricultural split-plot experiment. Coverage of generalized confidence intervals is investigated through simulation and shown to be close to the nominal value.

scholarly journals FIXED-B ASYMPTOTICS FOR THE STUDENTIZED MEAN FROM TIME SERIES WITH SHORT, LONG, OR NEGATIVE MEMORY

2011 ◽  
Vol 28 (2) ◽  
pp. 471-481 ◽  
Author(s):  
Tucker McElroy ◽  
Dimitris N. Politis
Keyword(s):  
Time Series ◽  
Confidence Intervals ◽  
Long Memory ◽  
Variance Estimation ◽  
Simulation Studies ◽  
Sample Mean ◽  
Memory Time ◽  
Negative Memory ◽  
Short Memory ◽  
The Mean

This paper considers the problem of variance estimation for the sample mean in the context of long memory and negative memory time series dynamics, adopting the fixed-bandwidth approach now popular in the econometrics literature. The distribution theory generalizes the short memory results of Kiefer and Vogelsang (2005, Econometric Theory 21, 1130–1164). In particular, our results highlight the dependence on the kernel (we include flat-top kernels), whether or not the kernel is nonzero at the boundary, and, most important, whether or not the process is short memory. Simulation studies support the importance of accounting for memory in the construction of confidence intervals for the mean.

Advantages and limitations of the endoscopic tympanoscopy a prospective study

2020 ◽  
Vol 1 (1) ◽  
pp. 012-017
Author(s):  
Najib Zouhair ◽  
Anass Chaouki ◽  
Amine M’khatri ◽  
Youssef Oukessou ◽  
Sami Rouadi ◽  
...  
Keyword(s):  
Middle Ear ◽  
Operating Time ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Invasive Approach ◽  
Intraoperative Bleeding ◽  
Advantages And Disadvantages ◽  
Early Return ◽  
The Mean ◽  
Endoscopic Tympanoplasty

Tympanoplasty is one of the most performed procedures in ENT. The aggressiveness of its microscopic approach has led otologists to adopt the endoscopic approach as a less invasive alternative. The purpose of this work is to appreciate the advantages and disadvantages of this surgical technique. We conducted a prospective descriptive cross-sectional study on 20 interventions within the ENT department of August the 20th 1953 Hospital of Casablanca from April 2019 to June 2019. The average age of operated patients was 36.3 years. Perforations were unilateral in (71%) of the cases with a predominance of the anterior (29%) and subtotal (36%) locations. The tympanoplasties were performed by 3 different senior otologic surgeons, and were left in (57%). The mean operating time was (59.5 min) and the mean anesthesia duration was 75.1 min. Intraoperative vision allowed us to fully visualize the margins of all perforations (100%) and anatomical structures of the middle ear in almost all interventions. The first procedures carried out were filled with difficulties whose management of intraoperative bleeding was the main one in (42.8%) of the cases. (57%) procedures were described as easy. No complication was detected intraoperatively or immediately postoperatively. Endoscopic tympanoplasty has several advantages, including: Minimally invasive approach to the middle ear; panoramic perioperative vision; Gain of operating time; decrease in the duration of anesthesia; Valuable educational tool; postoperative comfort; Decrease in hospital stay and early return to daily activities; Better aesthetic rendering; cost and transportability. However, we also note a number of disadvantages of endoscopic tympanoplasty, particularly: performing the procedure with one hand; difficulty passing through the EAC; 2D vision that alters the perception of depth; management of intraoperative bleeding; fogging; learning curve.

scholarly journals Long-Term Efficacy, Visual Performance and Patient Reported Outcomes with a Trifocal Intraocular Lens: A Six-Year Follow-up

2021 ◽  
Vol 10 (9) ◽  
pp. 2009
Author(s):  
Joaquín Fernández ◽  
Manuel Rodríguez-Vallejo ◽  
Javier Martinez ◽  
Noemi Burguera ◽  
David P. Piñero
Keyword(s):  
Intraocular Lens ◽  
Patient Reported Outcomes ◽  
Phone Call ◽  
Distortion Analysis ◽  
Patient Reported ◽  
Visual Function Questionnaire ◽  
Secondary Objective ◽  
Defocus Curve ◽  
The Mean

(1) Background: To evaluate the efficacy at 6 years postoperative after the implantation of a trifocal intraocular lens (IOL) AT Lisa Tri 839MP. The secondary objective was to evaluate the contrast sensitivity defocus curve (CSDC), light distortion analysis (LDA), and patient reported outcomes (PROs). (2) Methods: Sixty-two subjects participated in phone call interviews to collect data regarding a visual function questionnaire (VF-14), a patient reported spectacle independence questionnaire (PRSIQ), and questions related to satisfaction and decision to be implanted with the same IOL. Thirty-seven of these subjects were consecutively invited to a study visit for measurement of their visual acuity (VA), CSDC, and LDA. (3) Results: The mean monocular distance corrected VA was −0.05, 0.08, and 0.05 logMAR at far and distances of 67 cm and 40 cm, respectively. These VAs were significantly superior to those reported in previous literature (p < 0.05). The total area under the CSDC was 2.29 logCS/m−1 and the light distortion index 18.82%. The mean VF-14 score was 94.73, with 19.4% of subjects requiring spectacles occasionally for near distances, and 88.9% considering the decision of being operated again; (4) Conclusions: Long-term AT LISA Tri 839MP IOL efficacy results were equal or better than those reported 12 months postoperatively in previous studies. The spectacle independence and satisfaction rates were comparable to those reported in short-term studies.

scholarly journals Basis Expansions for Functional Snippets

Biometrika ◽  
2020 ◽  
Author(s):  
Zhenhua Lin ◽  
Jane-Ling Wang ◽  
Qixian Zhong
Keyword(s):  
Data Analysis ◽  
Convergence Rate ◽  
Functional Data Analysis ◽  
Functional Data ◽  
Covariance Function ◽  
Covariance Estimation ◽  
Simulation Studies ◽  
Finite Sample ◽  
Covariance Functions ◽  
The Mean

Summary Estimation of mean and covariance functions is fundamental for functional data analysis. While this topic has been studied extensively in the literature, a key assumption is that there are enough data in the domain of interest to estimate both the mean and covariance functions. In this paper, we investigate mean and covariance estimation for functional snippets in which observations from a subject are available only in an interval of length strictly (and often much) shorter than the length of the whole interval of interest. For such a sampling plan, no data is available for direct estimation of the off-diagonal region of the covariance function. We tackle this challenge via a basis representation of the covariance function. The proposed estimator enjoys a convergence rate that is adaptive to the smoothness of the underlying covariance function, and has superior finite-sample performance in simulation studies.

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