Modified maximum likelihood estimator under the Jones and Faddy's skew t-error distribution for censored regression model

It is well-known that classical Tobit estimator of the parameters of the censored regression (CR) model is inefficient in case of non-normal error terms. In this paper, we propose to use the modified maximum likelihood (MML) estimator under the Jones and Faddy''s skew t-error distribution, which covers a wide range of skew and symmetric distributions, for the CR model. The MML estimators, providing an alternative to the Tobit estimator, are explicitly expressed and they are asymptotically equivalent to the maximum likelihood estimator. A simulation study is conducted to compare the efficiencies of the MML estimators with the classical estimators such as the ordinary least squares, Tobit, censored least absolute deviations and symmetrically trimmed least squares estimators. The results of the simulation study show that the MML estimators work well among the others with respect to the root mean square error criterion for the CR model. A real life example is also provided to show the suitability of the MML methodology.     

Factors that influence elementary school teachers’ attitudes towards inclusion of visually impaired children in Turkey

There is a scarcity of research on inclusion of visually impaired children in Turkey. Specifically, a gap exists concerning the attitudes of elementary school teachers towards the inclusion of visually impaired children in mainstream schools. This article uses data from two questionnaires, leveraging the responses of 253 teachers from rural and urban areas. The results demonstrate that elementary school teachers commonly hold positive attitudes towards the inclusion of visually impaired children and that teachers’ initial and in-service training about inclusion positively influenced their attitudes. Our findings are in contrast with earlier research which argues that teachers do not hold positive attitudes to inclusion, and highlights that a key barrier to inclusion stems from elementary school teachers feeling unprepared to teach visually impaired children. We conclude that greater post-qualification training is required to enable teachers to operationalise different approaches that facilitate the inclusion of visually impaired children.     

Charity Social Media Marketing and Its Influence on Charity Brand Image,Brand Trust,and Donation Intention

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This study aims to identify the outline of charity social media marketing (SMM) and to determine to what extent it...     

A Monte Carlo simulation study on partially adaptive estimators of linear regression models

This paper presents a comprehensive comparison of well-known partially adaptive estimators (PAEs) in terms of efficiency in estimating regression parameters. The aim is to identify the best estimators of regression parameters when error terms follow from normal, Laplace, Student's t, normal mixture, lognormal and gamma distribution via the Monte Carlo simulation. In the results of the simulation, efficient PAEs are determined in the case of symmetric leptokurtic and skewed leptokurtic regression error data. Additionally, these estimators are also compared in terms of regression applications. Regarding these applications, using certain standard error estimators, it is shown that PAEs can reduce the standard error of the slope parameter estimate relative to ordinary least squares.     

Implementation of holonic scheduling and control in flow-line manufacturing systems: die-casting case study

The success of a flow-line manufacturing system depends on effective production scheduling and control. However, it has been found that current flow-line manufacturing scheduling and control algorithms lack the flexibility to handle interruptions or resource breakdowns; hence, system performance drops automatically and rapidly when interruptions occur. The objective of this research is to investigate if the performance of a flow-line manufacturing system can be improved by integrating agent-based, holonic scheduling and production control. A holonic manufacturing scheduling model has been developed and implemented into a die-casting manufacturing flow line throughout a simulation model. The analysis takes into account the comparisons of overall performances of the system models with the holonic scheduling and conventional scheduling approaches. Simulation results indicate that the holonic manufacturing scheduling and control can significantly increase the uptime efficiency and the production rate of the flow-line manufacturing system.     

The PEARL Model of Sustainable Development

This paper addresses perception (P), environment (E), action (A), relationship (R), and locality (L) as the social indicators of sustainable development (SD), the capital letters of which label the PEARL model. The paper refers to PEARL with regard to three aspects to elaborate the promises and limits of the model. Theoretically; it discusses comprehensiveness of the model. Pedagogically; it focuses on how the PEARL might facilitate learning, teaching and recalling fundaments of SD. Practically; it searches whether the model is appropriate for indexing and assessment. The PEARL brings out the significance of perceptions for SD and promises pedagogical contribution. The model, within this sense, appears as a qualitative understanding of SD which proposes a schematic framework to facilitate teaching and learning of its content. The analysis also points to likelihood of a quantitative PEARL index that is appropriate for assessment and measurement for individuals, institutions and regions.     

Robust Estimation for Parameters of the Extended Burr Type III Distribution

We consider various robust estimators for the extended Burr Type III (EBIII) distribution for complete data with outliers. The considered robust estimators are M-estimators, least absolute deviations, Theil, Siegel's repeated median, least trimmed squares, and least median of squares. Before we perform the aforementioned estimators for the EBIII, we adapt the quantiles method to the estimation of the shape parameter k of the EBIII. The simulation results show that the considered robust estimators generally outperform the existing estimation approaches for data with upper outliers, with certain of them retaining a relatively high degree of efficiency for small sample sizes.