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1.
In this article, we construct two likelihood‐based confidence intervals (CIs) for a binomial proportion parameter using a double‐sampling scheme with misclassified binary data. We utilize an easy‐to‐implement closed‐form algorithm to obtain maximum likelihood estimators of the model parameters by maximizing the full‐likelihood function. The two CIs are a naïve Wald interval and a modified Wald interval. Using simulations, we assess and compare the coverage probabilities and average widths of our two CIs. Finally, we conclude that the modified Wald interval, unlike the naïve Wald interval, produces close‐to‐nominal CIs under various simulations and, thus, is preferred in practice. Utilizing the expressions derived, we also illustrate our two CIs for a binomial proportion parameter using real‐data example. 相似文献
2.
《Socio》2021
Our study focuses on two data set, the former provides the expenditures for several services for each family and the latter contains socio-demographic variables for the same statistical units. The main aim is to analyze, in a Correspondence Analysis context, the service expenditure of families based on the whole given data-set under two types of constraints: the global relative expenses for a given service and the global relative expenses for a given socio-demographic category. The purpose of measuring the relationship between expenditure on social services and the socio-demographic characteristics of families is conducted in an exploratory and predictive perspective. A new approach is then introduced which ensures compliance with the required constraints. Moreover, through a procedure, we have obtained a table of regression coefficients. This table shows interesting properties and it is easy to interpret. Finally, the performance of the results has been evaluated using computer-based resampling techniques. 相似文献
3.
Estimation with longitudinal Y having nonignorable dropout is considered when the joint distribution of Y and covariate X is nonparametric and the dropout propensity conditional on (Y,X) is parametric. We apply the generalised method of moments to estimate the parameters in the nonignorable dropout propensity based on estimating equations constructed using an instrument Z, which is part of X related to Y but unrelated to the dropout propensity conditioned on Y and other covariates. Population means and other parameters in the nonparametric distribution of Y can be estimated based on inverse propensity weighting with estimated propensity. To improve efficiency, we derive a model‐assisted regression estimator making use of information provided by the covariates and previously observed Y‐values in the longitudinal setting. The model‐assisted regression estimator is protected from model misspecification and is asymptotically normal and more efficient when the working models are correct and some other conditions are satisfied. The finite‐sample performance of the estimators is studied through simulation, and an application to the HIV‐CD4 data set is also presented as illustration. 相似文献
4.
首先设计了第三方物流供应商的评价指标体系;然后运用CCSD模型确定指标的客观权重,并分析了方案排序和最优方案保持不变的权重范围;最后进行实证研究,为企业选择第三方物流供应商提供了理论依据。 相似文献
5.
Abstract The methodological discussion in D e R oos -S chaafsma (1981) Section 6 is continued by proposing asymptotic methods as a substitute for laborious confidence interval computations. 相似文献
6.
Martin Kroh 《Quality and Quantity》2006,40(2):225-244
Incomplete data is a common problem of survey research. Recent work on multiple imputation techniques has increased analysts’
awareness of the biasing effects of missing data and has also provided a convenient solution. Imputation methods replace non-response
with estimates of the unobserved scores. In many instances, however, non-response to a stimulus does not result from measurement
problems that inhibit accurate surveying of empirical reality, but from the inapplicability of the survey question. In such
cases, existing imputation techniques replace valid non-response with counterfactual estimates of a situation in which the
stimulus is applicable to all respondents. This paper suggests an alternative imputation procedure for incomplete data for
which no true score exists: multiple complete random imputation, which overcomes the biasing effects of missing data and allows
analysts to model respondents’ valid ‘I don’t know’ answers. 相似文献
7.
8.
A new technique for assessing the sensitivity and stability of efficiency classifications in Data Envelopment Analysis (DEA) is presented. Here developed for the ratio (CCR) model, this technique extends easily to other DEA variants. An organization's input-outut vector serves as the center for a cell within which the organization's classification remains unchanged under perturbations of the data. For the l1, l and generalized l norms, the radius of the maximal cell can be computed using linear programming formulations. This radius can be interpreted as a measure of the classification's stability, especially with respect to errors in the data.Abraham Charnes passed away December 19, 1992. 相似文献
9.
Comparing occurrence rates of events of interest in science, business, and medicine is an important topic. Because count data are often under‐reported, we desire to account for this error in the response when constructing interval estimators. In this article, we derive a Bayesian interval for the difference of two Poisson rates when counts are potentially under‐reported. The under‐reporting causes a lack of identifiability. Here, we use informative priors to construct a credible interval for the difference of two Poisson rate parameters with under‐reported data. We demonstrate the efficacy of our new interval estimates using a real data example. We also investigate the performance of our newly derived Bayesian approach via simulation and examine the impact of various informative priors on the new interval. 相似文献
10.
The length of repeated hypercalcemia free periods of patients with bone metastasis of breast cancer with at least one hypercalcemic event was modelled according to a generalized linear mixed model formulated in terms of transition probabilities and according to a latent variable model. In the former case the periods were assumed to be lognormally distributed with two variance components (patients and residue). In the latter case the conditional intensity given a patient was assumed to be the intensity of the Weibull distribution, while the random patient effect (frailty) was assumed to be drawn from a gamma distribution. In both cases the selection of only patients with at least one hypercalcemic event was taken into consideration. In both models the variance of the patient effect turned out to be negligible. For the second and later periods the Weibull appeared to fit better than the lognormal model. For the first period there was almost no information available. 相似文献
11.
在数据挖掘过程中需要挑选出与目标维度相关的维度,可以通过相关行业的经验挑选,也可采用相关性方法挑选。文章通过对比2种方法在直投市场客户目标选取中的运用,得出比较结论,并对使用这2种方法同的结果作了对比。 相似文献
12.
针对当前刑侦海量档案数据信息,首先在分析其数据跨平台、复杂化和多样性特点的基础上,设计了刑侦数据仓库的概念模型、逻辑模型和物理模型;接着针对刑侦数据仓库及数据挖掘技术,对已有的刑侦档案数据进行信息整合和数据挖掘,获取大量的有用知识,这些知识在促进刑侦研究工作的同时,对一线的实际刑侦工作具有很大的参考价值;最后,文章给出了面向刑侦档案数据信息的仓库模型,针对其数据挖掘系统框架提出了相应的数据挖掘方法,为进一步的刑侦数据信息联机分析处理和有用信息挖掘以及为公安安全防范决策服务。 相似文献
13.
In many surveys, imputation procedures are used to account for non‐response bias induced by either unit non‐response or item non‐response. Such procedures are optimised (in terms of reducing non‐response bias) when the models include covariates that are highly predictive of both response and outcome variables. To achieve this, we propose a method for selecting sets of covariates used in regression imputation models or to determine imputation cells for one or more outcome variables, using the fraction of missing information (FMI) as obtained via a proxy pattern‐mixture (PMM) model as the key metric. In our variable selection approach, we use the PPM model to obtain a maximum likelihood estimate of the FMI for separate sets of candidate imputation models and look for the point at which changes in the FMI level off and further auxiliary variables do not improve the imputation model. We illustrate our proposed approach using empirical data from the Ohio Medicaid Assessment Survey and from the Service Annual Survey. 相似文献
14.
物流产业融合模式的选择是物流产业融合的实践环节之一,其正确选择可以促进物流企业的发展和物流产业的升级。在物流企业对物流产业融合模式选择的过程中,企业之间存在博弈关系。在不完全信息条件下,物流产业融合模式的选择与企业的产业延伸能力相关,取决于物流需求和双赢的利益,是一个循环往复的过程。 相似文献
15.
In toxicity studies, model mis‐specification could lead to serious bias or faulty conclusions. As a prelude to subsequent statistical inference, model selection plays a key role in toxicological studies. It is well known that the Bayes factor and the cross‐validation method are useful tools for model selection. However, exact computation of the Bayes factor is usually difficult and sometimes impossible and this may hinder its application. In this paper, we recommend to utilize the simple Schwarz criterion to approximate the Bayes factor for the sake of computational simplicity. To illustrate the importance of model selection in toxicity studies, we consider two real data sets. The first data set comes from a study of dietary fortification with carbonyl iron in which the Bayes factor and the cross‐validation are used to determine the number of sub‐populations in a mixture normal model. The second example involves a developmental toxicity study in which the selection of dose–response functions in a beta‐binomial model is explored. 相似文献
16.
在数据挖掘过程中需要挑选出与目标维度相关的维度,可以通过相关行业的经验挑选,也可采用相关性方法挑选。文章通过对比2种方法在直投市场客户目标选取中的运用,得出比较结论,并对使用这2种方法同的结果作了对比。 相似文献
17.
This paper discusses the importance of managing data quality in academic research in its relation to satisfying the customer. This focus is on the data completeness objectivedimension of data quality in relation to recent advancements which have been made in the development of methods for analysing incomplete multivariate data. An overview and comparison of the traditional techniques with the recent advancements are provided. Multiple imputation is also discussed as a method of analysing incomplete multivariate data, which can potentially reduce some of the biases which can occur from using some of the traditional techniques. Despite these recent advancements in the analysis of incomplete multivariate data, evidence is presented which shows that researchers are not using these techniques to manage the data quality of their current research across a variety of academic disciplines. An analysis is then provided as to why these techniques have not been adopted along with suggestions to improve the frequency of their use in the future.
Source-Reference. The ideas for this paper originated from research work on David J. Fogarty's Ph.D. dissertation. The subject area is the use of advanced techniques for the imputation of incomplete multivariate data on corporate data warehouses. 相似文献
18.
We propose a family of regression models to adjust for nonrandom dropouts in the analysis of longitudinal outcomes with fully observed covariates. The approach conceptually focuses on generalized linear models with random effects. A novel formulation of a shared random effects model is presented and shown to provide a dropout selection parameter with a meaningful interpretation. The proposed semiparametric and parametric models are made part of a sensitivity analysis to delineate the range of inferences consistent with observed data. Concerns about model identifiability are addressed by fixing some model parameters to construct functional estimators that are used as the basis of a global sensitivity test for parameter contrasts. Our simulation studies demonstrate a large reduction of bias for the semiparametric model relatively to the parametric model at times where the dropout rate is high or the dropout model is misspecified. The methodology's practical utility is illustrated in a data analysis. 相似文献
19.
Jacopo Cimadomo 《Journal of economic surveys》2016,30(2):302-326
This paper surveys the empirical research on fiscal policy analysis based on real‐time data. This literature can be broadly divided into four groups that focus on: (1) the statistical properties of revisions in fiscal data; (2) the political and institutional determinants of projection errors by governments; (3) the reaction of fiscal policies to the business cycle and (4) the use of real‐time fiscal data in structural vector autoregression (VAR) models. It emerges that, first, fiscal revisions are large and initial releases are biased estimates of final values. Secondly, strong fiscal rules and institutions lead to more accurate releases of fiscal data and smaller deviations of fiscal outcomes from government plans. Thirdly, the cyclical stance of fiscal policies is estimated to be more ‘counter‐cyclical’ when real‐time data are used instead of ex post data. Fourthly, real‐time data can be useful for the identification of fiscal shocks. Finally, it is shown that existing real‐time fiscal data sets cover only a limited number of countries and variables. For example, real‐time data for developing countries are generally unavailable. In addition, real‐time data on European countries are often missing, especially with respect to government revenues and expenditures. Therefore, more work is needed in this field. 相似文献
20.
Tobias Rydén 《Metrika》1998,47(1):119-145
For a recursive maximum-likelihood estimator with step lengths decaying as 1/n, an adaptive matrix needs to be incorporated to obtain asymptotic efficiency. Ideally, this matrix should be chosen as the inverse Fisher information matrix, which is usually very difficult to compute for incomplete data models. In this paper we give conditions under which the observed information can be incorporated into the recursive procedure to yield an efficient estimator, and we also investigate the finite sample properties of these estimators by simulation. 相似文献