Robust signed-rank estimation and variable selection for semi-parametric additive partial linear models

A fully nonparametric model may not perform well or when the researcher wants to use a parametric model but the functional form with respect to a subset of the regressors or the density of the errors is not known. This becomes even more challenging when the data contain gross outliers or unusual observations. However, in practice the true covariates are not known in advance, nor is the smoothness of the functional form. A robust model selection approach through which we can choose the relevant covariates components and estimate the smoothing function may represent an appealing tool to the solution. A weighted signed-rank estimation and variable selection under the adaptive lasso for semi-parametric partial additive models is considered in this paper. B-spline is used to estimate the unknown additive nonparametric function. It is shown that despite using B-spline to estimate the unknown additive nonparametric function, the proposed estimator has an oracle property. The robustness of the weighted signed-rank approach for data with heavy-tail, contaminated errors, and data containing high-leverage points are validated via finite sample simulations. A practical application to an economic study is provided using an updated Canadian household gasoline consumption data.     

Outlaws or in-laws? Queer theory, LGBT studies, and religious studies

Many queer theorists, like many queer activists and perhaps many LGBT people in general, regard religion as so inimical to their purposes and lives that it is not even worthy of critique; references to religion in queer theory, queer studies, and even LGBT studies are usually sparse, brief, and generally derogatory. Likewise, within most of the field of religious studies, queerness is rarely an issue of concern or even consciousness except in the context of organizational tensions over the proper roles of "homosexuals." While there is a growing body of work that brings these two fields together, the study of religion seems to be adapting only haltingly and partially to contemporary developments inLGBTstudies and queer theory. This essay assesses the current state of the "proto-fields" of LGBT studies and queer studies in religion, offers suggestions for new directions in the future, and considers the potential benefits of the interaction of these fields.     

Women's experience of revealing perinatal bladder function--implications for midwifery care

Comments of women engaged in a longitudinal study of urinary leaking from first trimester to 12 months following birth provide the data for this paper. Useful insights into the factors contributing to the maintenance of silence and ways to break the barriers to discussion of urinary incontinence before, during and following pregnancy were revealed. Given the prevalence of 30% of Australian women experiencing urinary leaking following pregnancy, it is imperative that midwives engage in discussion and support prevention of this unwelcome outcome of childbirth.     

Master Production Rescheduling Policy in Capacity-Constrained Just-In-Time Make-To-Stock Environments

This paper describes a simulation experiment to evaluate the relative effectiveness of rescheduling policies in capacity-constrained, just-in-time (JIT) make-to-stock production environments. Three performance measures were analyzed: average finished goods inventory, total units of sales lost, and a measure of schedule instability. Among the three loading methods we studied (level loading, front loading, and back loading), none was superior across all three performance measures. Level loading was the most robust, while back loading had an interaction effect with forecasting model and capacity level. Time fence scenario was found not to be as significant a factor in system performance as reported by previous research. Once an acceptable time fence scenario is selected, attempts to optimize this factor do not appear to offer significant improvement. It was found that higher demand variation, larger forecast errors, and tight capacity lead to the degradation of system performance. Judicious use of slack capacity helps a system to incorporate the periodic schedule changes typical of JIT systems.     

Master Production Scheduling Under Rolling Planning Horizons with Fixed Order Intervals

Fixed interval scheduling is studied in the context of a rolling horizon framework that is developed by building on previous work in the master scheduling area. The rolling horizon framework includes a stationary scheduling model which uses the “time fencing’concept by partitioning the planning horizon into three sections. The lengths of these sections and the frequency at which the stationary problem is updated and resolved are discussed as parameters of the rolling horizon model. Two different interpretations of the freeze interval parameter are examined, enabling confirmation and clarification of results presented in an earlier study. Details are given for three methods of calculating safety stocks as a function of rolling horizon parameters, including a method which results in optimal safety stock levels. A comparison of the safety stock methods shows that the constant safety stock method can result in inventories that are significantly above optimal under certain conditions, whereas the constant service level method consistently yields nearly optimal results.