排序方式: 共有8条查询结果,搜索用时 0 毫秒
1
1.
Abdelbaset Abdalla 《Journal of Statistical Computation and Simulation》2019,89(14):2782-2800
Despite the popularity and importance, there is limited work on modelling data which come from complex survey design using finite mixture models. In this work, we explored the use of finite mixture regression models when the samples were drawn using a complex survey design. In particular, we considered modelling data collected based on stratified sampling design. We developed a new design-based inference where we integrated sampling weights in the complete-data log-likelihood function. The expectation–maximisation algorithm was developed accordingly. A simulation study was conducted to compare the new methodology with the usual finite mixture of a regression model. The comparison was done using bias-variance components of mean square error. Additionally, a simulation study was conducted to assess the ability of the Bayesian information criterion to select the optimal number of components under the proposed modelling approach. The methodology was implemented on real data with good results. 相似文献
2.
Three forms of a general null hypothesis Ho on the factorial parameters of a general asymmetrical factorial paired comparison experiment are considered. A class of partially balanced designscorresponding to each form of H0 is constructed and the A,D and ioptimal design, minimizing the trace, determinant and largest eigenvalue of a defined covariance matrix of related maximumlikelihoodestimators, in that class is determined. Moreover, the optimal design in each class maximizes the noncentrality parameter λ2 of the asymptotic noncentral chi-square distribution of the likelihood ratiostatistic -2 log λ for testing Ho under defined local alternatives. These results apply directly to symmetrical factorial paired comparison experiments as special casesExamples are given forillustrating applications of the developed results 相似文献
3.
de Barros Pimenta A Santos SM de Jesus MC Borges MM de Oliveira Marques GL Abdalla EJ 《Work (Reading, Mass.)》2012,41(Z1):5681-5683
The generation growing and diversified of Municipal Solid Waste is configured as an environmental problem, economic and social deterioration, especially, by application of inappropriate management of them. Faced with this urban context, the research in development presents as specific objective assessment of the quality of life of the gatherers of recyclable materials were active in the city of Juiz de Fora, in the brazilian state of Minas Gerais. In addition, the objective is, still, the recognition of the activity of sorting performed by "scavengers" in order to maximize the reduction, reuse and recycling energy and material waste daily. The proposed methodology is based on the application of the questionnaire Word Health Organization Quality of Life (WHOQOL-100), prepared by the World Health Organization, in order to value the quality of life of the gatherers of recyclable materials, involved, even in educational workshops in order to discuss and organize strategies of health care and scouting to the basement to public policies. 相似文献
4.
Abdalla T. El-Helbawy 《Journal of statistical planning and inference》1984,10(1):105-113
A general approach for comparing designs of paired comparison experiments on the basis of the asymptotic relative efficiencies, in the Bahadur sense, of their respective likelihood ratio tests is discussed and extended to factorials. Explicit results for comparing five designs of 2q factorial paired comparison experiments are obtained. These results indicate that some of the designs which require comparison of fewer distinct pairs of treatments than does the completely balanced design are, generally, more efficient for detecting main effects and/or certain interactions. The developments of this paper generalize the work of Littell and Boyett (1977) for comparing two designs of R x C factorial paired comparison experiments. 相似文献
5.
Ibrahim Mohamed Abdalla Mohammed A. Al‐Waqfi Rafiq H. Hijazi Taoufik Zoubeidi 《LABOUR》2010,24(2):163-177
Using data from a sample of 1,099 workers, this paper investigates the determinants of employment and wages for workers in the United Arab Emirates. The paper further examines the wage distribution and the decomposition of the wage gap between the public and the private sectors. Results of the study are consistent with the dual labour market theory and indicate that the labour market in the United Arab Emirates is segmented based on sectors (public versus private) and types of workers (nationals versus non‐nationals). The study concludes with a discussion of the implication of these findings for the effectiveness of labour and economic policy. 相似文献
6.
On the wald,lagrangian multiplier and likelihood ratio tests when the information matrix is singular
Summary Modified formulas for the Wald and Lagrangian multiplier statistics are introduced and considered together with the likelihood
ratio statistics for testing a typical null hypothesisH
0 stated in terms of equality constraints. It is demonstrated, subject to known standard regularity conditions, that each of
these statistics and the known Wald statistic has the asymptotic chi-square distribution with degrees of freedom equal to
the number of equality constraints specified byH
0 whether the information matrix is singular or nonsingular. The results of this paper include a generalization of the results
of Sively (1959) concerning the equivalence of the Wald, Lagrange multiplier and likelihood ratio tests to the case of singular
information matrices. 相似文献
7.
Four general classes of partially balanced designs for 2n factorials, corresponding to four different forms of a general null hypothesis H on factorial effects, are presented. For the typical design in each class, the simplified form of the non-centrality parameter λ2 of the asymptotic chi-square distribution of the likelihood ratio statistic for testing the corresponding form of H0 is derived under defined local alternatives. Optimal designs d1 maximizing λ2 in the i-th class and minimizing the trace, determinant and largest eigenvalue of a defined covariance matrix, i =1,…,4, are determined. 相似文献
8.
Ikhlas H Abdalla 《Omega》1983,11(3):263-272
Part of Heller's contingency model of leadership and decision making [11] has been modified. The basic components of the modified part of the model are influence, skill use, job performance and job satisfaction. Data from a study of 97 British and Sudanese managers are used to test the modified model. Positive relationships have been found between the four components. The major findings of this research are that while the strength of the relationship between ‘influence and satisfaction’ on the one hand and ‘skill use and satisfaction’ on the other differs only slightly, the relationship between ‘skill use and performance’ is much stronger and much more established than the relationship between ‘influence and performance’. These results have been established in both the Sudan and Britain. 相似文献
1