Academic literature on the topic 'Restricted estimator (RE)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Restricted estimator (RE).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Restricted estimator (RE)"
1
Preuß, M., and A. Ziegler. "A Simplification and Implementation of Random-effects Meta-analyses Based on the Exact Distribution of Cochran’s Q." Methods of Information in Medicine 53, no. 01 (2014): 54–61. http://dx.doi.org/10.3414/me13-01-0073.
Full textAbstract:
SummaryBackground: The random-effects (RE) model is the standard choice for meta-analysis in the presence of heterogeneity, and the stand ard RE method is the DerSimonian and Laird (DSL) approach, where the degree of heterogeneity is estimated using a moment-estimator. The DSL approach does not take into account the variability of the estimated heterogeneity variance in the estimation of Cochran’s Q. Biggerstaff and Jackson derived the exact cumulative distribution function (CDF) of Q to account for the variability of Ť 2.Objectives: The first objective is to show that the explicit numerical computation of the density function of Cochran’s Q is not required. The second objective is to develop an R package with the possibility to easily calculate the classical RE method and the new exact RE method.Methods: The novel approach was validated in extensive simulation studies. The different approaches used in the simulation studies, including the exact weights RE meta-analysis, the I 2 and T 2 estimates together with their confidence intervals were implemented in the R package metaxa.Results: The comparison with the classical DSL method showed that the exact weights RE meta-analysis kept the nominal type I error level better and that it had greater power in case of many small studies and a single large study. The Hedges RE approach had inflated type I error levels. Another advantage of the exact weights RE meta-analysis is that an exact confidence interval for T 2is readily available. The exact weights RE approach had greater power in case of few studies, while the restricted maximum likelihood (REML) approach was superior in case of a large number of studies. Differences between the exact weights RE meta-analysis and the DSL approach were observed in the re-analysis of real data sets. Application of the exact weights RE meta-analysis, REML, and the DSL approach to real data sets showed that conclusions between these methods differed.Conclusions: The simplification does not require the calculation of the density of Cochran’s Q, but only the calculation of the cumulative distribution function, while the previous approach required the computation of both the density and the cumulative distribution function. It thus reduces computation time, improves numerical stability, and reduces the approximation error in meta-analysis. The different approaches, including the exact weights RE meta-analysis, the I 2 and T 2estimates together with their confidence intervals are available in the R package metaxa, which can be used in applications.
2
Latimer, NR, IR White, KR Abrams, and U. Siebert. "Causal inference for long-term survival in randomised trials with treatment switching: Should re-censoring be applied when estimating counterfactual survival times?" Statistical Methods in Medical Research 28, no. 8 (June 25, 2018): 2475–93. http://dx.doi.org/10.1177/0962280218780856.
Full textAbstract:
Treatment switching often has a crucial impact on estimates of effectiveness and cost-effectiveness of new oncology treatments. Rank preserving structural failure time models (RPSFTM) and two-stage estimation (TSE) methods estimate ‘counterfactual’ (i.e. had there been no switching) survival times and incorporate re-censoring to guard against informative censoring in the counterfactual dataset. However, re-censoring causes a loss of longer term survival information which is problematic when estimates of long-term survival effects are required, as is often the case for health technology assessment decision making. We present a simulation study designed to investigate applications of the RPSFTM and TSE with and without re-censoring, to determine whether re-censoring should always be recommended within adjustment analyses. We investigate a context where switching is from the control group onto the experimental treatment in scenarios with varying switch proportions, treatment effect sizes, treatment effect changes over time, survival function shapes, disease severity and switcher prognosis. Methods were assessed according to their estimation of control group restricted mean survival that would be observed in the absence of switching, up to the end of trial follow-up. We found that analyses which re-censored usually produced negative bias (i.e. underestimating control group restricted mean survival and overestimating the treatment effect), whereas analyses that did not re-censor consistently produced positive bias which was often smaller in magnitude than the bias associated with re-censored analyses, particularly when the treatment effect was high and the switching proportion was low. The RPSFTM with re-censoring generally resulted in increased bias compared to the other methods. We believe that analyses should be conducted with and without re-censoring, as this may provide decision-makers with useful information on where the true treatment effect is likely to lie. Incorporating re-censoring should not always represent the default approach when the objective is to estimate long-term survival times and treatment effects.
3
Sekulić, Jovana, and Feđa Netjasov. "Modelling of runway excursions using Fault Tree Analysis." Tehnika 76, no. 4 (2021): 475–82. http://dx.doi.org/10.5937/tehnika2104475s.
Full textAbstract:
Runway excursion (RE) is recognized as one of the main Airport Safety Issues. It can be defined as an event in which an aircraft veers-off or overruns the runway surface during either takeoff or landing. In this paper an application of Fault Tree Analysis (FTA) method on RE events is presented. FTA belongs to quantitative class of causal methods. It estimates the risk of incident or accident according to estimation of probability of occurrence of each cause of an event. It might be restricted to pure statistical analysis based on the available data or combine these data with expert judgment on the accident causes. The aim of this paper is to identify potential causal factors. In order to illustrate FTA application on RE, two models were developed: one for landing and other for take-off. Application of FTA has shown what are the most critical causal factors whose knowledge allows developing certain measures to reduce the risk of RE.
4
Chen, Shiyi, and Amelia U. Santos-Paulino. "Energy consumption restricted productivity re-estimates and industrial sustainability analysis in post-reform China." Energy Policy 57 (June 2013): 52–60. http://dx.doi.org/10.1016/j.enpol.2012.08.060.
Full text
5
Mortimer, Suzanne I., and J. W. James. "Changes in genetic parameters under restricted index selection." Genetical Research 49, no. 2 (April 1987): 129–34. http://dx.doi.org/10.1017/s0016672300026926.
Full textAbstract:
SummaryThe ability of restricted selection indices to prevent genetic change in a restricted trait over several generations of selection was studied using deterministic computer models. Four loci, two affecting each trait independently, and two pleiotropic loci, one affecting each trait in the same direction, and one with opposite effects, were modelled. In general, continued effectiveness of the restriction was achieved only when the restricted trait was affected by only one locus. In some conditions (equal gene frequencies), an independent locus and one pleiotropic locus affecting the restricted trait allowed maintenance of the restriction. The results suggest that long-term restriction may be very difficult without re-estimation of parameters.
6
Kitamura, Nobutaka, Shinya Ohkouchi, Ryushi Tazawa, Haruyuki Ishii, Toshinori Takada, Takuro Sakagami, Takahiro Tanaka, and Koh Nakata. "Incidence of autoimmune pulmonary alveolar proteinosis estimated using Poisson distribution." ERJ Open Research 5, no. 1 (February 2019): 00190–2018. http://dx.doi.org/10.1183/23120541.00190-2018.
Full textAbstract:
The incidence and prevalence of autoimmune pulmonary alveolar proteinosis in Japan were previously estimated to be 0.49 and 6.2 per million, respectively. Thereafter, an increase in serological diagnosis forced a re-estimation of the incidence based on more contemporaneous data using more robust methods.Sera of 702 patients were positive for granulocyte-macrophage colony-stimulating factor autoantibody during the 2006–2016 period (group A). Of these patients, 43 were actively surveyed in Niigata prefecture (group B) for estimation of the incidence. To estimate the survival period, 103 patients (group C) were investigated retrospectively for the 1999–2017 period using restricted mean survival time.In group A, the number of patients diagnosed in each prefecture was closely correlated with the corresponding population, indicating no regional integration of onset. In group B, a total of 43 patients were diagnosed, the annual number followed a Poisson distribution and the incidence was thus estimated to be 1.65 per million. In group C, the retrospective cohort study revealed the mean survival period to be 16.1 years. Taken together, the prevalence was estimated to be 26.6 per million, indicating that the previous data for incidence and prevalence was an underestimation.
7
Miranda, Judith C., José M. León, Camillo Pieramati, Mayra M. Gómez, Jesús Valdés, and Cecilio Barba. "Estimation of Genetic Parameters for Peak Yield, Yield and Persistency Traits in Murciano-Granadina Goats Using Multi-Traits Models." Animals 9, no. 7 (July 1, 2019): 411. http://dx.doi.org/10.3390/ani9070411.
Full textAbstract:
This paper studies parameters of a lactation curve such as peak yield (PY) and persistency (P), which do not conform to the usual selection criteria in the Murciano-Granadina (MG) breed, but are considered to be an alternative to benefit animal welfare without reducing production. Using 315,663 production records (of 122,883 animals) over a period of 24 years (1990–2014), genetic parameters were estimated with uni-, bi- and multivariate analysis using multiple trait derivative free restricted maximum likelihood (MTDFREML). The heritability (h2)/repeatability (re) of PY, yield (Y) and P was estimated as 0.13/0.19, 0.16/0.25 and 0.08/0.09 with the uni-trait and h2 of bi- and multi-traits analysis ranging from 0.16 to 0.17 of Y, while that of PY and Y remained constant. Genetic correlations were high between PY–Y (0.94 ± 0.011) but low between PY–P (–0.16 ± 0.054 to –0.17 ± 0.054) and between Y–P (–0.06 ± 0.058 to –0.05 ± 0.058). Estimates of h2/re were low to intermediate. The selection for Y–PY or both can be implemented given the genetic correlation between these traits. PY–P and Y–P showed low to negligible correlation values indicating that if these traits are implemented in the early stages of evaluation, they would not be to the detriment of PY–Y. The combination of estimated breeding values (EBVs) for all traits would be a good criterion for selection.
8
Schoeman, S. J., and G. G. Jordaan. "Animal x testing environment interaction on postweaning liveweight gains of young bulls." Australian Journal of Agricultural Research 49, no. 4 (1998): 607. http://dx.doi.org/10.1071/a97102.
Full textAbstract:
Postweaning liveweight gain records of 1610 young bulls obtained both in feedlot and under pasture were used to estimate (co)variance components using a multivariate restricted maximum likelihood analysis. The pedigree file included 3477 animals. Heritability estimates for liveweights and gain in both environments correspond to most previously reported estimates. The genetic correlation of gain between the 2 environments was -0·12, suggesting a large genotype testing environment interaction and re-ranking of animal breeding values across environments. Results of this analysis suggest the need for environment-specific breeding values for postweaning gain.
9
BAI, XIUQIN, and WEIXING SONG. "Comparison study on the confidence intervals in linear regression models with restricted parameter space." Journal of Statistical Research 52, no. 2 (March 11, 2019): 115–27. http://dx.doi.org/10.47302/jsr.2018520201.
Full textAbstract:
This paper proposes an empirical likelihood confidence region for the regression coefficients in linear regression models when the regression coefficients are subjected to some equality constraints. The shape of the confidence set does not depend on the re-parametrization of the regression model induced by the equality constraint. It is shown that the asymptotic coverage rate attains the nominal confidence level and the Bartlett correction can successfully reduce the coverage error rate from $O(n^{-1})$ to $O(n^{-2})$, where n denotes the sample size. Simulation studies are conducted to evaluate the finite sample performance of the proposed empirical likelihood empirical confidence estimation procedure. Finally, a comparison study is conducted to compare the finite sample performance of the proposed and the classical ellipsoidal confidence sets based on normal theory.
10
Fajardo, Gladys, and H. Hörnicke. "Problems in estimating the extent of coprophagy in the rat." British Journal of Nutrition 62, no. 3 (November 1989): 551–61. http://dx.doi.org/10.1079/bjn19890057.
Full textAbstract:
The quantity of re-ingested faeces was calculated by comparing faecal dry matter of unrestricted rats and coprophagy-restricted rats after correcting for differences in food intake. Due to high day-to-day variations of produced and re-ingested faeces it was not possible to calculate precisely the extent of coprophagy of an individual rat at a particular day with this difference method. Reliable quantitative estimates require at least two rats and a collection period of 7 d. When fed on a nutritionally complete diet, rats re-ingested 0-11 % of their faeces. When fed on low-protein diets (66 g egg albumin/kg) or diets diluted with 200 g cellulose/kg, coprophagy was not significantly increased. A high re-ingestion rate (6–25 %) was observed with thiamin and pantothenic acid deficiencies. After re-ingestion of faeces had been prevented for 1 week, the amount of faeces re-ingested during the subsequent week without tail-cups was increased twofold. It is concluded that rats are able to regulate the amount of faeces eaten precisely according to their requirements.
Dissertations / Theses on the topic "Restricted estimator (RE)"
1
Hoque, Zahirul. "Improved estimation for linear models under different loss functions." University of Southern Queensland, Faculty of Sciences, 2004. http://eprints.usq.edu.au/archive/00001438/.
Full textAbstract:
This thesis investigates improved estimators of the parameters of the linear regression models with normal errors, under sample and non-sample prior information about the value of the parameters. The estimators considered are the unrestricted estimator (UE), restricted estimator (RE), shrinkage restricted estimator (SRE), preliminary test estimator (PTE), shrinkage preliminary test estimator (SPTE), and shrinkage estimator (SE). The performances of the estimators are investigated with respect to bias, squared error and linex loss. For the analyses of the risk functions of the estimators, analytical, graphical and numerical procedures are adopted. In Part I the SRE, SPTE and SE of the slope and intercept parameters of the simple linear regression model are considered. The performances of the estimators are investigated with respect to their biases and mean square errors. The efficiencies of the SRE, SPTE and SE relative to the UE are obtained. It is revealed that under certain conditions, SE outperforms the other estimators considered in this thesis. In Part II in addition to the likelihood ratio (LR) test, the Wald (W) and Lagrange multiplier (LM) tests are used to define the SPTE and SE of the parameter vector of the multiple linear regression model with normal errors. Moreover, the modified and size-corrected W, LR and LM tests are used in the definition of SPTE. It is revealed that a great deal of conflict exists among the quadratic biases (QB) and quadratic risks (QR) of the SPTEs under the three original tests. The use of the modified tests reduces the conflict among the QRs, but not among the QBs. However, the use of the size-corrected tests in the definition of the SPTE almost eliminates the conflict among both QBs and QRs. It is also revealed that there is a great deal of conflict among the performances of the SEs when the three original tests are used as the preliminary test statistics. With respect to quadratic bias, the W test statistic based SE outperforms that based on the LR and LM test statistics. However, with respect to the QR criterion, the LM test statistic based SE outperforms the W and LM test statistics based SEs, under certain conditions. In Part III the performance of the PTE of the slope parameter of the simple linear regression model is investigated under the linex loss function. This is motivated by increasing criticism of the squared error loss function for its inappropriateness in many real life situations where underestimation of a parameter is more serious than its overestimation or vice-versa. It is revealed that under the linex loss function the PTE outperforms the UE if the nonsample prior information about the value of the parameter is not too far from its true value. Like the linex loss function, the risk function of the PTE is also asymmetric. However, if the magnitude of the scale parameter of the linex loss is very small, the risk of the PTE is nearly symmetric.
Conference papers on the topic "Restricted estimator (RE)"
1
Rowe, Stephen T., and Kim M. Zielinski. "The Use of Visualization Techniques to Plan, Design, and Permit Pipeline Projects." In 2008 7th International Pipeline Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ipc2008-64146.
Full textAbstract:
Because pipeline routing, design, and permitting is complex and often controversial, it is advantageous to utilize new technologies to expedite the overall process. Potential pipeline routes can be modeled in a Geographic Information System (GIS) to facilitate early identification of engineering and environmental constraints. This allows time for preliminary engineering and permitting, avoiding time-consuming and costly re-routing later on. Why take the planning, design, and permitting into a virtual world? A primary advantage of a virtual GIS model is based on the way humans process information. It is estimated that 50% of the brain’s neurons are involved in vision. Two-dimensional (2D) and three-dimensional (3D) visualizations simulate spatial reality, thus allowing the viewer to quickly recognize and understand complex concepts such as changes in elevation or tree growth over time. This is especially true of 3D displays, which involve a larger portion of the brain in the problem solving process (Swanson, 2002). Using spatial visualizations—or geo-visualizations—engineers, planners, and environmental scientists involved in pipeline permitting can quickly and easily identify engineering and environmental constraints along a route and may be more effective in conveying their plan to stakeholders. Many pipeline routes are inaccessible due to either rough terrain or restricted access. Virtual routes can be evaluated by the design team without each team member travelling to the project location, saving valuable project time and reducing project budget. Once a GIS model for the entire route is created, 2D and 3D illustrations allow a project proponent to “sell” a particular alternative or project mitigation to permitting agencies and stakeholders, and potentially accelerate the overall permitting process.
2
Solomon, Fouad A., Gioia Falcone, and Catalin Teodoriu. "The Need to Understand the Dynamic Interaction Between Wellbore and Reservoir in Liquid Loaded Gas Wells." In ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/omae2008-57427.
Full textAbstract:
Liquid loading in gas wells is a phenomenon where the liquid content of the well is sufficient to create a back pressure (usually dominated by gravitational pressure changes) which restricts, and in some cases even stops, the flow of gas from the reservoir. Liquid loading is an all too common problem in mature gas fields around the world. It is estimated that in the U.S.A. alone, at least 90% of the producing gas wells are operating in liquid loading regime. The phenomenon is more detrimental in tight wells than in prolific wells and it poses a serious problem in subsea tie-backs, where back pressure effects through the risers and the flowlines may have an important role. Such is the importance of liquid loading; the oil and gas industry has devoted a lot of attention to the alleviation of the problem using various measures. However, the fundamental understanding of the associated phenomena is still surprisingly weak. This applies not only to the flows in the wells, but also to how these flows interact with those in the reservoir. It is this latter dynamic interaction that has received the least attention by the industry. Reliable predictive models to link the well dynamics with the intermittent response of a reservoir, that is typical of liquid loading in gas wells, remain unavailable. This paper introduces the complexity of liquid loading and critically reviews recent attempts to model liquid loading and the dynamic interactions between reservoir and wellbore. The paper then illustrates the need for a better understanding of the transient flow phenomena taking place in the near-wellbore region of the reservoir. This includes re-injection of the heavier phase, a phenomenon that has yet to be proven by fluid mechanics.
3
Radulescu, Victorita. "Analyzing the Characteristics of the Turbulent Vortices at Fast Rolling on Solid Surfaces." In ASME 2020 Fluids Engineering Division Summer Meeting collocated with the ASME 2020 Heat Transfer Summer Conference and the ASME 2020 18th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/fedsm2020-20438.
Full textAbstract:
Abstract The present paper illustrates a new method for solving the two-dimensional turbulent fluid flow, for an incompressible fluid, near solid walls. Equations of energy conservation and momentum for thin layers have been used and solved with a slip velocity implemented in the Navier-Stokes equations. As a first step, a pseudo-laminar analysis was made. In parallel, some other models for turbulence were analyzed, to estimate the most appropriate model in conformity with the obtained experimental results. The numerical simulation was performed to investigate the effects of the Reynolds number on the flow characteristics, over a two-dimensional rectangular body and a curved shape surface. It was used the CFD, near the solid surfaces with a strong adverse pressure gradient. The viscous layer is expressed as an integral solution, imposing the wall shear stress as a boundary condition on solid surfaces. The velocity and shear stress are deduced from the Navier-Stokes equations as long as the convergence is reached. Numerical modeling was tested for Reynolds numbers ranging from 2040 to 13000. Firstly, the theoretical model for the flow equations and velocity distribution is described. Some details are presented for estimating as better as possible the wall velocity and the shear stresses. Numerical modeling, with the FEM model, is based on the Galerkin formulation. Some aspects referring to the boundary conditions, for the analyzed cases are also mentioned. The flow is restricted at a central vortex, considered the primary vortex. In turbulent boundary layer, for the analyzed applications were not considered the axial vortices. Some aspects referring to the flow domain and the grid generation are mentioned in a dedicated paragraph. For numerical modeling, firstly was adopted the non-viscous solution, as the initial condition. It depends on the available information concerning the shapes geometry, the curvature radius, and the flow conditions for the considered problems. For the first approximation, was used the integral boundary-layer method, which can provide a proper solution. The advantage consists of reducing the number of iteration to reach the numerically final settlement. If it will be used the integral method, will be provided only an approximate distribution for the edge velocity. Variation of the reattachment length of vortices over the analyzed solid bodies is correlated with the experimental results from the literature. Exclusive analysis of the selected data shows that the turbulent values correlated directly to the body length-b are more accurate than those referring to the dimensionless rapport δ/b. From the analyzed models, the K-ε model presents better agreement with experimental data, also for the negative values of the Reynolds shear stress in the re-attachment point. Finally, some conclusions and references are mentioned.