Academic literature on the topic 'Unbiased interval estimates'

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Journal articles on the topic "Unbiased interval estimates"

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Skalski, John R., Annette Hoffmann, Bruce H. Ransom, and Tracey W. Steig. "Fixed-Location Hydroacoustic Monitoring Designs for Estimating Fish Passage Using Stratified Random and Systematic Sampling." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 6 (1993): 1208–21. http://dx.doi.org/10.1139/f93-137.

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Five alternative finite sampling designs are compared using 15 d of 24-h continuous hydroacoustic data to identify the most favorable approach to fixed-location hydroacoustic monitoring of salmonid outmigrants. Four alternative approaches to systematic sampling are compared among themselves and with stratified random sampling (STRS). Stratifying systematic sampling (STSYS) on a daily basis is found to reduce sampling error in multiday monitoring studies. Although sampling precision was predictable with varying levels of effort in STRS, neither magnitude nor direction of change in precision was
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Zarrukh Rakhimov. "Simulation study on bootstrap confidence intervals in linear models: Case of heteroscedasticity." World Journal of Advanced Research and Reviews 23, no. 3 (2024): 2250–59. http://dx.doi.org/10.30574/wjarr.2024.23.3.2866.

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OLS models have several assumptions for its interval estimations to be unbiased and efficient. Non-constant variance of residuals can cause serious issues in making inferences on coefficients as well as interval estimations. In this paper, we discuss the presence of heteroscedasticity in a linear model and suggest a paired bootstrap approach as an assumption-free approach on constructing confidence intervals. We carry a simulation study to compare bootstrap confidence intervals to traditional intervals. We conclude bootstrap intervals, though not perfect, can give better interval estimates whe
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Zarrukh, Rakhimov. "Simulation study on bootstrap confidence intervals in linear models: Case of heteroscedasticity." World Journal of Advanced Research and Reviews 23, no. 3 (2024): 2250–59. https://doi.org/10.5281/zenodo.14964580.

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OLS models have several assumptions for its interval estimations to be unbiased and efficient. Non-constant variance of residuals can cause serious issues in making inferences on coefficients as well as interval estimations. In this paper, we discuss the presence of heteroscedasticity in a linear model and suggest a paired bootstrap approach as an assumption-free approach on constructing confidence intervals. We carry a simulation study to compare bootstrap confidence intervals to traditional intervals. We conclude bootstrap intervals, though not perfect, can give better interval estimates whe
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Shu, Yu, Aiyi Liu, and Zhaohai Li. "Point and interval estimation of accuracies of a binary medical diagnostic test following group sequential testing." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 366, no. 1874 (2008): 2335–45. http://dx.doi.org/10.1098/rsta.2008.0041.

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When hypotheses concerning the sensitivity and specificity of a binary medical diagnostic test are simultaneously tested using a group sequential procedure, constructing point and interval estimates of the parameters is challenging because there is no unique way to order sample points in the two-dimensional space. In this paper, upon termination of a group sequential procedure, we compare the bias and mean squared errors of the maximum-likelihood and Rao–Blackwell unbiased estimators of sensitivity and specificity. Confidence intervals (CIs) of the two parameters were constructed using normal
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Rakhimov, Zarrukh, and Nilufar Rahimova. "LINEAR REGRESSION WITH DATA MISSING NOT AT RANDOM: BOOTSTRAP APPROACH." Iqtisodiy taraqqiyot va tahlil 2, no. 4 (2024): 492–502. http://dx.doi.org/10.60078/2992-877x-2024-vol2-iss4-pp492-502.

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OLS regressions have a set of assumption in order to have its point and interval estimates to be unbiased and efficient. Data missing not at random (MNAR) can pose serious estimations issues in the linear regression. In this study we evaluate the performance of OLS confidence interval estimates with MNAR data. We also suggest bootstrapping as a remedy for such data cases and compare the traditional confidence intervals against bootstrap ones. As we need to know the true parameters, we carry out a simulations study. Research results indicate that both approaches show similar results having simi
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Martin, Robert F. "General Deming Regression for Estimating Systematic Bias and Its Confidence Interval in Method-Comparison Studies." Clinical Chemistry 46, no. 1 (2000): 100–104. http://dx.doi.org/10.1093/clinchem/46.1.100.

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Abstract Background: Various forms of least-squares regression analyses are used to estimate average systematic error (bias) and its confidence interval in method-comparison studies. When assumptions that underlie a particular regression method are inappropriate for the data, errors in estimated statistics result. In this report, I present an improved method for regression analysis that is free from the usual simplifying assumptions and is generally applicable to linearly related method-comparison data. Methods: Theoretical equations based on the Deming approach, further developed by physicist
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Knapp, S. J., W. C. Bridges-Jr, and M. H. Yang. "Nonparametric confidence interval estimators for heritability and expected selection response." Genetics 121, no. 4 (1989): 891–98. http://dx.doi.org/10.1093/genetics/121.4.891.

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Abstract Statistical methods have not been described for comparing estimates of family-mean heritability (H) or expected selection response (R), nor have consistently valid methods been described for estimating R intervals. Nonparametric methods, e.g., delete-one jackknifing, may be used to estimate variances, intervals, and hypothesis test statistics in estimation problems where parametric methods are unsuitable, nonrobust, or undefinable. Our objective was to evaluate normal-approximation jackknife interval estimators for H and R using Monte Carlo simulation. Simulations were done using norm
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Almetwally, Ehab M., Refah Alotaibi, and Hoda Rezk. "Estimation and Prediction for Alpha-Power Weibull Distribution Based on Hybrid Censoring." Symmetry 15, no. 9 (2023): 1687. http://dx.doi.org/10.3390/sym15091687.

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This work discusses the issues of estimation and prediction when lifespan data following alpha-power Weibull distribution are observed under Type II hybrid censoring. We calculate point and related interval estimates for both issues using both non-Bayesian and Bayesian methods. Using the Newton–Raphson technique under the classical approach, we compute maximum likelihood estimates for point estimates in the estimation problem. Under the Bayesian approach, we compute Bayes estimates under informative and non-informative priors using the symmetric loss function. Using the Fisher information matr
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Morris, Sara R., David A. Liebner, Amanda M. Larracuente, Erica M. Escamilla, and H. David Sheets. "Multiple-Day Constancy as an Alternative to Pooling for Estimating Mark-Recapture Stopover Length in Nearctic-Neotropical Migrant Landbirds." Auk 122, no. 1 (2005): 319–28. http://dx.doi.org/10.1093/auk/122.1.319.

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Abstract Capture-mark-recapture models require estimation of parameters that may be either constant or time-dependent. Open-population models have been adapted for use in estimating stopover duration of migratory songbirds. However, with data collected over an extended period or with relatively few recaptures, small sample sizes may preclude use of fully time-dependent models. Pooling is commonly used to reduce the number of parameters estimated in time-dependent models. In pooling, all captures and recaptures during a specified interval are treated as a single capture event, which results in
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Ghafouri-Kesbi, Farhad, Moradpasha Eskandarinasab, and Ahmad Hassanabadi. "Short-term selection for yearling weight in a small-experimental Iranian Afshari sheep flock." Canadian Journal of Animal Science 89, no. 3 (2009): 301–7. http://dx.doi.org/10.4141/cjas08059.

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A selection experiment was initiated in 2000 in an Afshari sheep flock at the department of animal breeding and genetics of the University of Zanjan, Iran. The aim was to evaluate the response of Afshari sheep to selection for yearling live weight. Here, we evaluate the results of this breeding program obtained between 2000 and 2005. Traits studied were birth weight (BW), weaning weight (WW), yearling weight (YW), average daily gain from birth to weaning (WWDG) and average daily gain from weaning to yearling age (YWDG). Mixed model methodology based on a multi-trait animal model was employed t
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Dissertations / Theses on the topic "Unbiased interval estimates"

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Liao, Chien-Chih, and 廖芊帙. "Robustness of confidence intervals for a normal mean and some interval estimators, powerful unbiased tests under skew-normal model." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/60341660789345941535.

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碩士<br>國立東華大學<br>應用數學系<br>97<br>In this thesis, we first study the robustness of confidence intervals for normal mean against skew-normality, then we study some inferential problems for the skewness parameter under skew-normal model. The confidence intervals of normal means are widely used in statistical analyses. Various robustness against the departure of normality has been considered in the literature. Here we consider the robustness of confidence intervals of normal mean under skew-normality. Based on theoretical derivations and simulation studies, we find that the coverage probabilities o
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Book chapters on the topic "Unbiased interval estimates"

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Varoquaux, Gael, and Olivier Colliot. "Evaluating Machine Learning Models and Their Diagnostic Value." In Machine Learning for Brain Disorders. Springer US, 2012. http://dx.doi.org/10.1007/978-1-0716-3195-9_20.

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AbstractThis chapter describes model validation, a crucial part of machine learning whether it is to select the best model or to assess performance of a given model. We start by detailing the main performance metrics for different tasks (classification, regression), and how they may be interpreted, including in the face of class imbalance, varying prevalence, or asymmetric cost–benefit trade-offs. We then explain how to estimate these metrics in an unbiased manner using training, validation, and test sets. We describe cross-validation procedures—to use a larger part of the data for both traini
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Kuznetsov Nickolay. "Evaluation of the Reliability of Repairable s &mdash; t Networks by Fast Simulation Method." In NATO Science for Peace and Security Series - D: Information and Communication Security. IOS Press, 2014. https://doi.org/10.3233/978-1-61499-391-9-120.

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A network with unreliable edges is considered. All failed edges can be repaired. Distribution functions of failure-free operation and repair time of edges are supposed to be of general type. A fast simulation method producing unbiased estimates for the network failure (interruption of connection between two given nodes s and t in a given time interval) is developed. It is proved that under some weak conditions these estimates have a bounded relative error with increasing reliability of components. Numerical examples demonstrate the efficiency of the proposed method.
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Hankin, David G., Michael S. Mohr, and Ken B. Newman. "Equal probability sampling." In Sampling Theory. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198815792.003.0003.

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This chapter presents a formal quantitative treatment of material covered conceptually in Chapter 2, all with respect to equal probability with replacement (SWR) and without replacement selection simple random sampling, (SRS) of samples of size n from a finite population of size N. Small sample space examples are used to illustrate unbiasedness of mean-per-unit estimators of the mean, total and proportion of the target variable, y, for SWR and SRS. Explicit formulas for sampling variance indicate how estimator uncertainty depends on finite population variance, sample size and sampling fraction
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Hankin, David G., Michael S. Mohr, and Ken B. Newman. "Systematic sampling." In Sampling Theory. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198815792.003.0004.

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In many contexts it is difficult or impossible to select a simple random sample. For example, the number of units in the finite population, N, may not be known in advance, or it may not be feasible to assign labels to all units in the population and to select an SRS from these labels (e.g., crabs within boxes on a fishing vessel). Instead, one may select a random start, r, on the integers 1 through k and then select that unit and every kth unit thereafter for inclusion in the sample. This selection method, called linear systematic sampling, results in an extremely restricted randomization—ther
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"and Var[νˆ ] = 4σ + l ) (l −2(1 + c . Similarly, when σˆ ≤ 0.04, νˆ = δˆ + σˆ − 0.04(c ) (7.12) is an estimate for the constant-scaled metric in accordance with FDA Guidance (2001) using a REML UN model. This estimate is asymptoti-cally normally distributed and unbiased with E[νˆ ] = δ +σ −σ − 0.04(c ) and Var[νˆ ] = 4σ . To assess PBE we ‘plug-in’ estimates of δ and the variance components and calculate the upper bound of an asymptotic 90% confidence interval. If this upper bound is below zero we declare that PBE has been shown. Using the code in Appendix B and the data in Section 7.2, we obtain the value −1.90 for log(AUC) and the value −0.95 for log(Cmax). As both of these are below zero, we can declare that T and R are PBE. 7.5.2 PBE using a replicate design Here we fit the same REML UN model as defined in Section 7.4. Let νˆ = δˆ + σˆ + σˆ − (1 + c )(σˆ + σˆ ) (7.13) be an estimate for the reference-scaled metric in accordance with FDA Guidance (2001) when (σˆ + σˆ > 0.04 and using a REML UN model. Then, this estimate is asymptotically normally distributed, un-biased with E[νˆ ] = δ +σ − (1 + c ) and has variance of Var[νˆ ] = 4σ + l + (1 + c ) (l )+ 2l −2(1+c −2(1 + c + 2(1 + c ) (l ) When σˆ + σˆ ≤ 0.04, let νˆ = δˆ + σˆ + σˆ − (σˆ + σˆ )− 0.04(c ) (7.14) be an estimate for the constant-scaled metric in accordance with FDA." In Design and Analysis of Cross-Over Trials. Chapman and Hall/CRC, 2003. http://dx.doi.org/10.1201/9781420036091-24.

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"Guidance FDA (2001) using a REML UN model. Then, this estimate is asymptotically normally distributed, unbiased with E[νˆ ] = δ +σ − (σ )− 0.04(c ) and has variance of Var[νˆ ] = 4σ δ + l + 2l − 2l + 2l To assess PBE we ‘plug-in’ estimates of δ and the variance components and calculate the upper bound of an asymptotic 90% confidence interval. If this upper bound is below zero we declare that PBE has been shown. Using the code in Appendix B and the data in Section 7.4, we obtain the value −0.24 for log(AUC) and the value −0.19 for log(Cmax). As both of these are below zero, we can declare that T and R are PBE. 7.6 ABE for a replicate design Although ABE can be assessed using a 2× 2 design, it can also be as-sessed using a replicate design. If a replicate design is used the number of subjects can be reduced to up to half that required for a 2 × 2 de-sign. In addition it permits the estimation of σ and σ . The SAS code to assess ABE for a replicate design is given in Appendix B. Using the data from Section 7.4, the 90% confidence interval for µ is (−0.1697,−0.0155) for log(AUC) and (−0.2474,−0.0505) for log(Cmax). Exponentiating the limits to obtain confidence limits for exp(µ ), gives (0.8439,0.9846) for AUC and (0.7808,0.9508) for Cmax. Only the first of these intervals is contained within the limits of 0.8 to 1.25, there-fore T cannot be considered average bioequivalent to R. To calculate the power for a replicate design with four periods and with a total of n subjects we can still use the SAS code given in Section 7.3, if we alter the formula for the variance of a difference of two obser-vations from the same subject. This will now be σ +σ instead of σ , where σ is the subject-by-formulation interaction. Note the use of σ rather than 2σ as used in the RT/TR design. This is a result of the estimator using the average of two measurements on each treatment on each subject. One advantage of using a replicate design is that the number of sub-jects needed can be much smaller than that needed for a 2×2 design. As an example, suppose that σ = 0, and we take σ = 0.355 and α = 0.05, as done in Section 7.3. Then a power of 90.5% can be achieved with only 30 subjects, which is about half the number (58) needed for the 2 × 2 design." In Design and Analysis of Cross-Over Trials. Chapman and Hall/CRC, 2003. http://dx.doi.org/10.1201/9781420036091-25.

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"ances and covariances obtained from REML are normally distributed with expectation vector and variance-covariance matrix equal to the fol-low  ing, r  espectiv    ely,   When σˆ > 0.04, let νˆ = δˆ + σˆ + σˆ − 2ωˆ + σˆ − (1 + c (7.6) be an estimate for the (7.3) reference-scaled metric in accordance with FDA Guidance (2001) and using a REML UN model. Then (Patter-son, 2003; Patterson and Jones, 2002b), this estimate is asymptotically normally distributed and unbiased with E[νˆ ] = δ +σ − (1 + c and Var[νˆ ] = 4σ + l + 4l + (1 + c ) (l )+ 2l −2(1+c − 2(1+c +4(1+c −2(1+c . Similarly, for the constant-scaled metric, when σˆ ≤ 0.04, νˆ = δˆ + σˆ + σˆ − 2ωˆ + σˆ − σˆ − 0.04(c ) (7.7) E[νˆ ] = δ +σ − 0.04(c ) Var[νˆ ] = 4σ + l + 4l + 2l − 2l − 4l + 4l − 2l . The required asymptotic upper bound √ of the 90% confidence interval can √ then be calculated as νˆ + 1.645× V̂ ar[νˆ ] or νˆ + 1.645× V̂ ar[νˆ ], where the variances are obtained by ‘plugging in’ the estimated values of the variances and covariances obtained from SAS proc mixed into the formulae for Var[νˆ ] or Var[νˆ ]. The necessary SAS code to do this is given in Appendix B. The output reveals that σˆ = 0.0714 and the upper bound is−0.060 for log(AUC). For log(Cmax), σˆ = 0.1060 and the upper bound is −0.055. As both of these upper bounds are below zero, IBE can be claimed." In Design and Analysis of Cross-Over Trials. Chapman and Hall/CRC, 2003. http://dx.doi.org/10.1201/9781420036091-22.

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"strate IBE the upper bound of a 90% confidence interval for the above aggregate metric must fall below 2.49. The required upper bound can be calculated in at least three different ways: (1) method-of-moments estimation with a Cornish-Fisher approx-imation (Hyslop et al., 2000; FDA Guidance, 2001), (2) bootstrapping (FDA Guidance, 1997), and (3) by asymptotic approximations to the mean and variance of ν and ν (Patterson, 2003; Patterson and Jones, 2002b,c). Method (1) derives from theory that assumes the inde-pendence of chi-squared variables and is more appropriate to the analysis of a parallel group design. Hence it does not fully account for the within-subject correlation that is present in data obtained from cross-over tri-als. Moreover, the approach is potentially sensitive to bias introduced by missing data and imbalance in the study data (Patterson and Jones, 2002c). Method (2), which uses the nonparametric percentile bootstrap method (Efron and Tibshirani, 1993), was the earliest suggested method of calculating the upper bound (FDA Guidance, 1997), but it has sev-eral disadvantages. Among these are that it is computationally intensive and it introduces randomness into the final calculated upper bound. Re-cent modifications to ensure consistency of the bootstrap (Shao et al., 2000) do not appear to protect the Type I error rate (Patterson and Jones, 2002c) around the mixed-scaling cut-off (0.04) unless calibration (Efron and Tibshirani, 1993) is used. Use of such a calibration technique is questionable if one is making a regulatory submission. Hence, we pre-fer to use method (3) and will illustrate its use shortly. We note that this method appears to protect against inflation of the Type I error rate in IBE and PBE testing, and the use of REML ensures unbiased esti-mates (Patterson and Jones, 2002c) in data sets with missing data and imbalance, a common occurrence in cross-over designs, (Patterson and Jones, 2002a,b). In general (Patterson and Jones, 2002a), cross-over tri-als that have been used to test for IBE and PBE have used sample sizes in excess of 20 to 30 subjects, so asymptotic testing is not unreasonable, and there is a precedent for the use of such procedures in the study of pharmacokinetics (Machado et al., 1999). We present findings here based on asymptotic normal theory using REML and not taking into account shrinkage (Patterson and Jones, 2002b,c). It is possible to account for this factor using the approach of Harville and Jeske (1992); see also Ken-ward and Roger (1997). However, this approach is not considered here in the interests of space and as the approach described below appears to control the Type I error rate for sample sizes as low as 16 (Patterson and Jones, 2002c). In a 2 × 2 cross-over trial it is not possible to estimate separately the within-and between-subject variances and hence a replicate design, where subjects receiving each formulation more than once is required." In Design and Analysis of Cross-Over Trials. Chapman and Hall/CRC, 2003. http://dx.doi.org/10.1201/9781420036091-19.

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Conference papers on the topic "Unbiased interval estimates"

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Zhang, Yunong, and Kaisi Huang. "Unbiased Estimators for Uniform Distribution Applied to Interval Estimation of Transition or Beginning Year About World Reserve Currency." In 2024 20th International Conference on Natural Computation, Fuzzy Systems and Knowledge Discovery (ICNC-FSKD). IEEE, 2024. http://dx.doi.org/10.1109/icnc-fskd64080.2024.10702315.

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Laeri, Franco, and André Noack. "Maximum Entropy Analysis of Dynamic Light Scattering Signals." In Optical Fabrication and Testing. Optica Publishing Group, 1988. http://dx.doi.org/10.1364/oft.1988.tha11.

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Glass transition temperatures of thin polymer coatings (similar to the coating of a magnetic storage disc) on alumina substrates have been evaluated with dynamic light scattering methods. At this temperature the correlation time of the thermodynamical fluctuations in the polymer increases and so the spectrum of the dynamic light scattering signal changes accordingly. In practise only partial knowledge of the autocorrelation function exists, usually based on a finite series of data samples taken in a finite intervall. In the common analysis the autocorrelation function is set zero for all lags
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Munoz-diaz, Jorge, and Oscar Ibarra-manzano. "Determining optimum sampling intervals for the local clock states estimated with an unbiased fir algorithm: an applied software." In 2006 Multiconference on Electronics and Photonics. IEEE, 2006. http://dx.doi.org/10.1109/mep.2006.335645.

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Passano, Elizabeth, and Philippe Mainc¸on. "Estimating Long-Term Distributions of Extreme Response of a Catenary Riser." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-50151.

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The purpose of this paper is to present a method for efficient and unbiased estimation of the long-term extreme response distribution of a catenary riser. In this approach a computationally inexpensive, nonlinear response predictor is used to estimate the response in all sea states, thus allowing selection of relevant sea states and intervals within sea states for detailed, nonlinear finite element simulations. This method requires significantly less simulation time than the conventional approach with extensive nonlinear simulations of many sea states. The method is applied to a catenary riser
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Grosu, Corina, and Marta Grosu. "FAKE WARNING: PLAYING WITH IMPRECISE PREDICTIONS." In eLSE 2018. ADL Romania, 2018. http://dx.doi.org/10.12753/2066-026x-18-037.

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Probabilistic models play a major role in risk assessment and prevention of disastrous consequences of extreme events such as volcano eruptions, earthquakes and tsunami. Probabilistic models play a major role in risk assessment and prevention of disastrous consequences of extreme events such as volcano eruptions, earthquakes and tsunami. The prognoses issued according to these models offer, as a principal result, early warnings concerning the approaching disaster. Nevertheless, false warnings may also appear, leading to unnecessary panic and waves of painful emotions which all deprive society
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Kevin, D. A., V. J. Aimikhe, and C. C. Ikeokwu. "A Machine Learning Approach to Determining the CO2 Adsorption Capacity of Coconut Shell-Derived Activated Carbon." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2024. http://dx.doi.org/10.2118/221740-ms.

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Abstract Coconut shell-derived activated carbon is widely used for the adsorption of gaseous contaminants including CO2 capture applications due to its availability, low costs, high surface area and tunable porous structure. However, determining the adsorption capacity of activated carbons through experimentation is challenging due to time constraints and the required equipment and experimental costs. This study aimed to develop a machine-learning model correlating the pore size distribution, pore volume, surface area, temperature, and pressure of activated carbons to their CO2 adsorption capa
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Sviridov, Mikhail, Dmitry Kushnir, Anton Mosin, Danil Nemuschenko, and Michael Rabinovich. "High-Performance Stochastic Inversion for Real-Time Processing of LWD Ultradeep Azimuthal Resistivity Data." In 2023 SPWLA 64th Annual Symposium. Society of Petrophysicists and Well Log Analysts, 2023. http://dx.doi.org/10.30632/spwla-2023-0082.

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Logging-while-drilling (LWD) ultradeep azimuthal resistivity (UDAR) tools become an essential part of well placement because they are deep enough to explore the reservoir as a whole and expose it in a similar scale with seismic sections. Due to the increased formation volume being investigated, UDAR measurements depend on many formation parameters and require multilayer models to be interpreted, as well as effective inversion approaches. Stochastic inversion algorithms have many advantages and are used extensively in field applications. Working with multiparametric models, these algorithms mig
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Sudev, L. J., and H. V. Ravindra. "Tool Wear Estimation in Drilling Using Acoustic Emission Signal by Multiple Regression and GMDH." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-66756.

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The cutting tool is the only element in a machine tool that requires frequent changes due to failure. Drill bit wear can cause catastrophic failure that can result in considerable damage to the work piece and the machine tool. Hence, there is an imperative need to keep a watch on the condition of the cutting tools during the machining process. Over the years, a wide variety of on-line or off-line techniques have been investigated for monitoring abnormal cutting tools. A variety of signals such as tool-tip temperature, forces, power, thrust, torque, vibrations, shock pulse, Acoustic Emission (A
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Sviridov, Mikhail, Anton Mosin, Sergey Lebedev, and Ron Thompson. "VENDOR-NEUTRAL STOCHASTIC INVERSION OF LWD DEEP AZIMUTHAL RESISTIVITY DATA AS A STEP TOWARD EFFICIENCY STANDARDIZATION OF GEOSTEERING SERVICES." In 2021 SPWLA 62nd Annual Logging Symposium Online. Society of Petrophysicists and Well Log Analysts, 2021. http://dx.doi.org/10.30632/spwla-2021-0103.

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While proactive geosteering, special inversion algorithms are used to process the readings of logging-while-drilling resistivity tools in real-time and provide oil field operators with formation models to make informed steering decisions. Currently, there is no industry standard for inversion deliverables and corresponding quality indicators because major tool vendors develop their own device-specific algorithms and use them internally. This paper presents the first implementation of vendor-neutral inversion approach applicable for any induction resistivity tool and enabling operators to stand
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Zhang, Junjing, Manabu Nozaki, Nola R. Zwarich, et al. "Improved Evaluation Methodology of Fractured Horizontal Well Performance: New Method to Measure the Effect of Gel Damage and Cyclic Stress on Fracture Conductivity." In SPE Western Regional Meeting. SPE, 2023. http://dx.doi.org/10.2118/212977-ms.

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Abstract In thinly bedded sandstone reservoirs, hydraulic fractures are required in horizontal wells to connect isolated pay intervals and to improve the volumetric sweep efficiency during waterflooding. This study presents a new, more robust way to evaluate gel damage and cyclic stress in the laboratory. Results from the laboratory evaluation are validated with field production data. Standard ISO/API tests are adequate at comparing proppant types but do not accurately predict resultant conductivity in a well as they do not account for several in-situ damage mechanisms. With a limited number o
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Reports on the topic "Unbiased interval estimates"

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Kott, Phillip S. The Degrees of Freedom of a Variance Estimator in a Probability Sample. RTI Press, 2020. http://dx.doi.org/10.3768/rtipress.2020.mr.0043.2008.

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Inferences from probability-sampling theory (more commonly called “design-based sampling theory”) often rely on the asymptotic normality of nearly unbiased estimators. When constructing a two-sided confidence interval for a mean, the ad hoc practice of determining the degrees of freedom of a probability-sampling variance estimator by subtracting the number of its variance strata from the number of variance primary sampling units (PSUs) can be justified by making usually untenable assumptions about the PSUs. We will investigate the effectiveness of this conventional and an alternative method fo
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Weller, Joel I., Ignacy Misztal, and Micha Ron. Optimization of methodology for genomic selection of moderate and large dairy cattle populations. United States Department of Agriculture, 2015. http://dx.doi.org/10.32747/2015.7594404.bard.

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Abstract:
The main objectives of this research was to detect the specific polymorphisms responsible for observed quantitative trait loci and develop optimal strategies for genomic evaluations and selection for moderate (Israel) and large (US) dairy cattle populations. A joint evaluation using all phenotypic, pedigree, and genomic data is the optimal strategy. The specific objectives were: 1) to apply strategies for determination of the causative polymorphisms based on the “a posteriori granddaughter design” (APGD), 2) to develop methods to derive unbiased estimates of gene effects derived from SNP chips
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