Perceptual identification of talker ethnicity in Vancouver English

Studies of ethnolinguistic variation typically begin by describing the speech production variables used to index social groups. In this study, we begin with indexical recognition – the perceptual identification of speakers’ self‐identified ethnic groups – to determine whether speakers produce ethnolinguistic variation and whether listeners are sensitive to it. Speech samples were recorded from thirty individuals from Metro Vancouver who self‐identified as Chinese, East Indian, or White Canadian. These utterances were used in a perception task where listeners categorized speakers’ ethnicities. Listeners’ social networks were labeled according to the ethnic group with which they reported spending the most time. Analyses indicate that while speakers vary in their productive expression of ethnolinguistic variation, listeners are consistent in their labeling choices. Listener accuracy was higher for voices from the listeners’ reported social group and White voices. These results suggest that familiarity with ethnic groups through social networks and mainstream culture influences indexical recognition.     

Optimal exact designs of experiments via Mixed Integer Nonlinear Programming

Statistics and Computing - Optimal exact designs are problematic to find and study because there is no unified theory for determining them and studying their properties. Each has its own challenges...     

The perceived importance of family‐friendly policies to childbirth decision among Hong Kong women

Wong C‐K, Tang K‐L, Ye S. The perceived importance of family‐friendly policies to childbirth decision among Hong Kong women Int J Soc Welfare 2011: 20: 381–392 © 2010 The Author(s), Journal compilation © 2010 Blackwell Publishing Ltd and the International Journal of Social Welfare. Declining fertility is a problem in many advanced industrialised countries, calling for government action. While positive findings have been established between family policies and fertility levels in European countries, empirical studies on family‐friendly policies and their impact on fertility levels have been few and far between in East Asia. Based on a random telephone survey of 645 young women, this study examined the perceived importance of family‐friendly policies to childbirth among Hong Kong women of childbearing age. Also investigated was whether public policies could have an impact on the decision to have a child. The findings give support to both the risk‐society theory and the rationality theory; family‐friendly policies such as tax credits, extended childcare and flexitime enhance the risk management capacity of women and reduce the cost of child rearing. The study also found that demographic factors such as age, education, and having children or not are significant to the intent to bear children.     

The Effect of Socioeconomic Status and Family Structure on Parental Warmth and Parental Control in a Chinese Context: Implications for Social Work Practice

We report the results of a telephone survey conducted in 2008 in Hong Kong, which aimed to identify Chinese parents' parental warmth and parental control (guan) and to explore their relationship with the sociodemographic characteristics of the parents. The respondents perceived themselves to be warm (mean = 3.44) and educating their child (mean = 3.46). The results of multiple regression analysis showed that the five sociodemographic characteristics explained 15.8% and 8.2% of the variance in parental warmth and guan respectively. The mothers were warmer than the fathers; parents with higher monthly household income, higher educational attainment and with their smallest child young in age were warmer than parents of lower household income, lower educational attainment and with their smallest child older in age. However, parental guan did not vary among the five sociodemographic characteristics except educational attainment. Implications of the study for social work practice are discussed.     

A Double Moving Average Control Chart

The double exponentially weighted moving average (DEWMA) technique has been investigated in recent years for detecting shifts in the process mean and has been shown to be more efficient than the corresponding exponentially weighted moving average (EWMA) technique. In this article, we extend the DEWMA technique of performing exponential smoothing twice to the double moving average (DMA) technique by computing the moving average twice. Using simulation, we show that our proposed DMA chart improves upon the ARL performance of the moving average (MA) chart in detecting mean shifts of small to moderate magnitudes. It is also shown through simulation that, generally, the DMA charts with spans, w = 10 and 15 provide comparable average run length (ARL) performances to the EWMA and cumulative sum (CUSUM) charts, designed for detecting small shifts.     

The Lehmann Model with Time-dependent Covariates

Consider the Lehmann model with time-dependent covariates, which is different from Cox’s model. We find out that (1) the parameter space for β under the Lehmann model is restricted, and the maximum point of the parametric likelihood for β may lie outside the parameter space; (2) for some particular time-dependent covariate, under the standard generalized likelihood the semiparametric maximum likelihood estimator (SMLE) is inconsistent and we propose a modified generalized likelihood which leads to the consistent SMLE.     

A functional coefficient GARCH-M model

ABSTRACT

Motivated by the time varying property of the risk aversion and the functional coefficient regression model, a functional coefficient GARCH-M model is studied. The proposed GARCH-M type model gives a way to study the relationship between risk aversion and certain variable. An approach is given to estimate the model and some theoretical results are obtained. Simulations demonstrate that the method performs well. From the empirical studies, it is shown that the proposed model can better fit the considered data compared to the usual parametric models.     

Estimation of the slope in linear non-normal structural relationships

This paper studies the sensitivity to nonnormality of the normal-theory test for the null hypothesis that the slope is a specific value against a two-sided alternative. Edgeworth expansion and thus the asymptotic variance for the normal-theory maximum likelihood estimator of the slope are derived.     

Time series models with asymmetric innovations

We consider AR(q) models in time series with asymmetric innovations represented by two families ofdistributions: (i) gamma with support IR : (0, ∞), and (ii) generalized logistic with support IR:(-∞,∞). Since the ML (maximum likelihood) estimators are intractable, we derive the MML (modified maximum likelihood) estimators of the parameters and show that they are remarkably efficient besides being easy to compute. We investigate the efficiency properties of the classical LS (least squares) estimators. Their efficiencies relative to the proposed MML estimators are very low.     

An augmented approach to the desirability function

The desirability function is widely used in the engineering field to tackle the problem of optimizing multiple responses simultaneously. This approach does not account for the variability in the predicted responses and minimizing this variability to have narrower prediction intervals is desirable. We propose to add this capability in the desirability function and also incorporate the relative importance of optimizing the multiple responses and minimizing the variances of the predicted responses at the same time. We show that the benefits of our augmented approach using two real data sets by comparing our solutions with those obtained from the desirability approach. In particular, it is shown that our approach offers greater flexibility and the solutions can reduce the variances of all the predicted responses resulting in narrower prediction intervals.