Quantile hidden semi-Markov models for multivariate time series

Statistics and Computing - Parametric regression, such as linear regression, plays an important role in statistics. The use of parametric regression models typically involves the specification of a...     

Kicking someone in cyberspace when they are down: Testing the role of stressor evoked emotions on exposure to workplace cyberbullying

ABSTRACT

New technologies at work broaden the scope of bullying behaviours to the online context, creating opportunities for a new form of bullying to arise – workplace cyberbullying. So far, knowledge on the factors contributing to workplace cyberbullying has been lacking. Within this emerging research line, the Emotion Reaction model, specifically focused on workplace cyberbullying, was put forward. In this study, we test the model’s main proposition regarding exposure to workplace cyberbullying; namely, that stressors evoked emotions predict exposure to cyberbullying and that this relation is moderated by emotion regulation strategies. The model was tested in two steps. First, the model as a whole was tested cross-sectionally. Next, the direction of causality between fear and sadness and exposure to cyberbullying was tested using a cross-lagged panel design. The results provide support for the central role of fear and sadness in the relationship between work stressors and cyberbullying exposure and the moderating role of reappraisal. No moderating effect of suppression was observed. In addition, support is found for the causal claim that fear and sadness predict cyberbullying exposure. The results and their implications are discussed.     

Job insecurity,perceived employability and targets' and perpetrators' experiences of workplace bullying

Abstract

We aimed to investigate (1) the association between job insecurity and workplace bullying from the perspective of both targets and perpetrators and (2) perceived employability as a moderator of these relationships. We argue that job insecurity is associated with social or interpersonal strain as in the case of workplace bullying. Furthermore, workers who feel that they have alternative opportunities for employment may find it easier to cope with insecurity. Stated differently, we aimed to investigate whether the relationship between job insecurity and workplace bullying depended on the level of perceived employability. Hypotheses were tested among 693 workers who participated in a survey on the quality of working life. They were employed at establishments of two Belgian organizations from the textile industry (N=189) and financial services (N=505). We found that that job insecurity was associated with targets' and perpetrators' reports of workplace bullying. The interaction between job insecurity and perceived employability did not contribute to targets' reports of workplace bullying. However, it was related to perpetrators' reports of workplace bullying. Interestingly, the relationship between job insecurity and workplace bullying was stronger under the condition of high versus low employability. This hints at the idea that there could be a “dark side” to employability.     

A generalized least squares estimation method for VARMA models

In this paper a new generalized least squares procedure for estimating VARMA models is proposed. This method differs from existing ones in explicitly considering the stochastic structure of the approximation error that arises when lagged innovations are replaced with lagged residuals obtained from a long VAR. Simulation results indicate that this method performs better than the Double Regression method and similar to Mauricio's (1995) exact maximum likelihood estimation procedure.     

Parametric multi-attribute utility functions for optimal profit under risk constraints

We provide an economic interpretation of the practice consisting in incorporating risk measures as constraints in an expected prospect maximization problem. For what we call the infimum of expectations class of risk measures, we show that if the decision maker (DM) maximizes the expectation of a random prospect under constraint that the risk measure is bounded above, he then behaves as a “generalized expected utility maximizer” in the following sense. The DM exhibits ambiguity with respect to a family of utility functions defined on a larger set of decisions than the original one; he adopts pessimism and performs first a minimization of expected utility over this family, then performs a maximization over a new decisions set. This economic behaviour is called “maxmin under risk” and studied by Maccheroni (Econ Theory 19:823–831, 2002). As an application, we make the link between an expected prospect maximization problem, subject to conditional value-at-risk being less than a threshold value, and a non-expected utility economic formulation involving “loss aversion”-type utility functions.     

分批整经机性能研究和改进设想

本文对影响整经机质量的几个方面提出改进设想，从理论上进行分析，并通过实践使改进取得了良好的效果。     

Combining genotype groups and recursive partitioning: an application to human immunodeficiency virus type 1 genetics data

Summary.  Understanding the relationship between human immunodeficiency virus type 1 genotypic markers of resistance and response to therapy presents an analytic challenge because of the high dimensionality of the viral genome and the complex interactions across sites on the genome. Recursive partitioning is a natural approach to classifying patients on the basis of covariates that capture information on the variability of a response variable and is therefore well suited to handling both of these features of the problem. In the human immunodeficiency virus genetics setting, we aim to classify patients on the basis of the genotypic characteristics of their infecting viral population so that the resulting groups explain the most variability in drug susceptibility phenotype. Recursive partitioning is also informative in identifying meaningful genotypic patterns that define the resulting classes. By combining dimension reduction techniques with recursive partitioning we can arrive at different classification schemes which are potentially more informative. Furthermore, the use of weighted distance metrics in the clustering algorithm allows us to update and potentially to improve on this classification scheme. An illustration of the relative benefits of the various approaches is provided by using 2559 protease sequences and the corresponding 50% inhibitory concentrations for Indinavir.     

“互联网+教育”赋能乡村教师队伍建设:宁夏示范实证

乡村教师是发展更加公平更有质量乡村教育的基础支撑,是推进乡村振兴的重要力量。随着“互联网+教育”的深入推进,以互联网、人工智能、5G等新技术助推乡村教师队伍建设的优势凸显,城市、乡村学校网络互联、统一教育云平台互通、教育资源共享的教育应用生态,有效推动了城乡学校结对共建、互助共进,实现了优质教育资源在区域内共享。城乡学校结对建立智能同步课堂,实现教师“智能手拉手”,有效破解了乡村教师队伍结构性短缺的难题,促进了乡村教师队伍质量稳步提升。地处中国西部地区的宁夏回族自治区,抢抓建设“互联网+教育”示范区的时代机遇,进行了有益探索:为教育均衡发展筑基铺路,为乡村教师队伍建设打通“信息高速通道”;重视教师能力提升工程,为乡村教师队伍建设提供“驾驶技能”;创新“互联网+教育”推进机制,助力乡村教师队伍质量提升。在乡村教师队伍建设方面,宁夏发挥了“示范”作用,形成了可借鉴的实践经验:集中力量,小省也能办大事;及时出台政策,实施保障措施;整合多方力量,促进“大联通”;构建教育云平台,形成应用新常态;增设“空中课堂”,推行“网上走教”新形式,形成对乡村教师队伍的有效补充。     

论图书馆电子文献网络检索系统建设

高校图书馆数字化、网络化建设,赋予了图书馆新的内涵,为读者提供了电子文献信息资源的快速阅览和检索。本文对图书馆电子文献网络检索系统的建设,以及所需设备的选型和配置,谈了自己的意见。