Comparison of Kernel Discriminant Coordinates Algorithms

The construction of kernel discriminant coordinates reduces to the solution of a generalized eigenvalue problem in which both matrices are nonnegative definite. Six different algorithms for solving that problem are described, and the performance of these algorithms is tested on 26 different datasets. The percentage of misclassifications using a linear discriminant function is noted, and the algorithms’ running times are ascertained. Classification is also performed in the space of classical discriminant coordinates.     

Fitting Generalized Hyperbolic processes - New insights for generating initial values

The fitting of Lévy processes is an important field of interest in both option pricing and risk management. In literature, a large number of fitting methods requiring adequate initial values at the start of the optimization procedure exists. A so-called simplified method of moments (SMoM) generates by assuming a symmetric distribution these initial values for the Variance Gamma process, whereby the idea behind can be easily transferred to the Normal Inverse Gaussian process. However, the characteristics of the Generalized Hyperbolic process prevent such an easy adaption. Therefore, we provide by applying a Taylor series approximation for the modified Bessel function of the third kind, a Tschirnhaus transformation and a symmetric distribution assumption, a SMOM for the Generalized Hyperbolic distribution. Our simulation study compares the results of our SMoM with the results of the maximum likelihood estimation. The results show that our proposed approach is an appropriate and useful way for estimating Generalized Hyperbolic process parameters and significantly reduces estimation time.     

Leadership Styles as Predictors of Self‐reported and Observed Workplace Bullying

The connection between leadership or management style, on the one hand, and perceptions of bullying, on the other, has received little attention within bullying research. Hence, the aim of this study is to examine the relationship between subordinates' ratings of their immediate superiors' behaviours, and both perceived exposure and claims of observations of bullying at work. Based on a sampling process which emphasized randomness and representativeness, the responses from 5288 respondents in Great Britain taking part in a nationwide study on psychosocial issues at work were included in the analysis. Bullying correlated with all four leadership styles measured. Yet, ‘non‐contingent punishment’ emerged as the strongest predictor of self‐perceived exposure to bullying, while autocratic leadership was the strongest predictor of observed bullying. Hence, while observers particularly associate bullying with autocratic or tyrannical leader behaviour, targets relate bullying more to non‐contingent punishment, i.e. an unpredictable style of leadership, where punishment is meted out or delivered on leaders' own terms, independent of the behaviour of subordinates. In addition, laissez‐faire leadership emerged as a predictor of self‐reported as well as observed bullying. Thus, leadership styles seem to play an important but complex role in the bullying process.     

Emotional intelligence and leadership emergence in small groups

We report the findings from two studies that examine the association between emotional intelligence and leadership emergence in small groups. In both studies, members of groups completed measures of emotional intelligence and other individual differences prior to working on a group project. Their peers rated their leadership emergence at the conclusion of the project. Overall emotional intelligence and a number of its dimensions were associated with leadership emergence over and above cognitive intelligence, personality traits, and gender. These findings were observed when emotional intelligence was measured with an ability test but not when it was measured with a self-report scale. Among the dimensions of emotional intelligence, the ability to understand emotions was most consistently associated with leadership emergence.     

Are national levels of employee harassment cultural covariations of climato-economic conditions?

Conflict in a workgroup turns into harassment if a group member is persistently confronted with negative acts with few possibilities to retaliate. Cross-national differences in such intragroup harassment are considerable but wait to be understood. In this study, survey data from 44,836 employees in 44 countries revealed that a cultural in-group orientation was associated with lower employee harassment. In addition, and in agreement with Van de Vliert's climato-economic theory of culture, workforces reported more harassment in poorer countries with more demanding climates of colder-than-temperate winters, hotter-than-temperate summers, or both. Finally, it was found that the impact of climato-economic hardships on harassment suppressed the impact of cultural in-group orientation on harassment. Using the regression equation obtained for the sample of 44 countries, national levels of employee harassment for a broader pool of 103 countries were estimated and scrutinized for their validity for future research. Data from the World Values Surveys were used to validate the estimations. The results provide the basis for a further hypothesis, that employee harassment is more prevalent in countries with either survival or self-expression cultures than in countries with cultures that are intermediate between those two extremes. The results have implications for prevention and remedial measures.     

Night work and symptoms of anxiety and depression among nurses: A longitudinal study

Over the last few decades, night work has been found to be associated with negative somatic consequences; however, there is less knowledge about its impact on mental health. In a sample of 633 Norwegian nurses, we investigated by means of latent growth curve modelling whether different work schedules predicted differences in baseline values of anxiety and depressive symptoms, and trajectories of these over a two-year span. All participants completed the Hospital Anxiety and Depression Scale as part of a larger survey conducted during the winters of 2009, 2010 and 2011. The results revealed that night workers and nurses who changed from day work to night work during the study period did not differ from day workers either in terms of baseline symptoms of anxiety or depression, or in terms of trajectories of these symptoms. However, nurses who changed from night work to day work reported a significant decrease in symptoms of both anxiety and depression over time compared to day workers. Furthermore, supporting previous work, languidity was related to higher anxiety and depression and hardiness to lower levels of those symptoms. Possible mechanisms underlying the results are discussed.     

The Benefits and Costs of Using Metadata to Improve Enterprise Document Search

The literature shows that there are many problems with enterprise document search. Studies reveal that typical knowledge workers spend between 10% and 20% of their time searching for documents they never find. While many argue that metadata can improve enterprise document search, in reality few organizations use metadata. This represents a missed opportunity. This article describes the results of two experiments that use simulation to evaluate the actual impact of metadata on the costs and benefits of enterprise search. The first study provides quantitative evidence of the increase in recall and precision that stems from the use of metadata‐enhanced document searches. The second study demonstrates that simple metadata structures can be nearly as effective as complex ones, implying that the cost of creating and maintaining metadata is likely to be lower than generally thought. This is the first study to provide explicit quantitative evidence of the gains that can be achieved from the use of metadata, and one of only a handful of studies that examines the cost of creating and maintaining metadata.     

Workplace bullying as predicted by non-prototypicality,group identification and norms: a self-categorisation perspective

ABSTRACT

Research and theory on deviance in work groups suggest that non-prototypical members risk devaluation and mistreatment by their peers. Drawing on the self-categorisation theory, we propose and test a contextual model to explain workplace bullying from a target perspective, using non-prototypicality as a predictor and social identification and anti-bullying norms at the work group level as two- and three-way cross-level moderators. Multilevel modelling and a sample of employees from the university sector in the Low Lands (n?=?572) was employed. In line with our first hypothesis, we found that risk of exposure to workplace bullying is particularly high for non-prototypical work group members. We also hypothesised that work group social identification would facilitate bullying of non-prototypical members, while anti-bullying norms would buffer it. Results showed, however, that both conditions acted as buffering moderators on the main association. Lastly, the combination of the two also entailed a cross-level three-way interaction effect, showing that non-prototypicality is associated with bullying only in work groups characterised by low levels on both moderators. These novel and partly unexpected results demonstrate the relevance and significance of group level explanations for workplace bullying, holding significant implications for scholars and practitioners.     

Emigration from Canada in the 1960s

Summary Emigration from Canada can be assessed only by indirect means. Here, survival ratios have been applied to the total population enumerated in the 1961 Census and to particular segments of it, so that a comparison of the calculated numbers in 1971 with the population actually enumerated indicates the volume of emigration during the decade, both in the whole population and in certain groups. Amounting to two-thirds of the number of immigrants during the same period, the estimate for the ten years is exactly double the volume of emigration reported to the Joint Parliamentary Committee on immigration policy of 1975. Since 1971, the level of emigration has probably fallen. Of the 960,000 emigrants during the decade, 42 per cent were Canadian-born. Their favourite destination was the United States; immigrants, on the other hand, tended to return home. Many immigrants now stay in Canada for only a few years. Fewer Canadians emigrate to the United States. These two factors have contributed to a new pattern of emigration, up-to-date details of which will not be ascertained before the Census of 1981.     

Robustness and monotonicity properties of generalized correlation coefficients

A new class of generalized correlation coefficients that contains the Pearson and Kendall statistics as special cases was defined by Chinchilli et al. (2005) and applied to the estimation of correlations coefficients within the context of 2×2 cross-over designs for clinical trials. In this paper, we determine the infinitesimal robustness and local stability properties of these generalized correlation coefficients by deriving their corresponding influence functions. For cases in which the population distribution is a bivariate normal or a mixture of bivariate normal distributions we obtain explicit formulas, and establish monotonicity and sign-reverse rule properties of the generalized correlation coefficients.