Time‐change models for asymmetric processes

Many records in environmental sciences exhibit asymmetric trajectories. The physical mechanisms behind these records may lead for example to sample paths with different characteristics at high and low levels (up–down asymmetries) or in the ascending and descending phases leading to time irreversibility (front–back asymmetries). Such features are important for many applications, and there is a need for simple and tractable models that can reproduce them. In this paper, we explore original time‐change models where the clock is a stochastic process that depends on the observed trajectory. The ergodicity of the proposed model is established under general conditions, and this result is used to develop nonparametric estimation procedures based on the joint distribution of the process and its derivative. The methodology is illustrated on meteorological and oceanographic data sets. We show that, combined with a marginal transformation, the proposed methodology is able to reproduce important characteristics of the data set such as marginal distributions, up‐crossing intensity, and up–down and front–back asymmetries.     

Tempered Mittag-Leffler Lévy processes

In this article, we introduce tempered Mittag-Leffler Lévy processes (TMLLP). TMLLP is represented as tempered stable subordinator delayed by a gamma process. Its probability density function and Lévy density are obtained in terms of infinite series and Mittag-Leffler function, respectively. Asymptotic forms of the tails and moments are given. A step-by-step procedure of the parameters estimation and simulation of sample paths is given. We also provide main results available for Mittag-Leffler Lévy processes (MLLP) and some extensions which are not available in a collective way in a single article. Our results generalize and complement the results available on Mittag-Leffler distribution and MLLP in several directions. Further, the asymptotic forms of the moments of the first-exit times of the TMLLP are also discussed.     

High value manufacturing (HVM) in the UK: case studies and focus group insights

This paper studies the internal mechanisms that allow organisations to become high value manufacturing (HVM). Using a qualitative methodology, three UK manufacturing companies formed in-depth case studies with semi-structured interviews, observations and historical data. The HVM value matrix of Martinez and co-workers is used to categorise each organisation’s value proposition. Wider benchmarking of the three organisations was carried out against a focus group with an additional seven manufacturing organisations. Thus, data from 10 manufacturing organisations are included in this research. The cases follow the ‘customer intimacy’ HVM discipline. The business processes supporting these value propositions were identified. Interestingly, each organisation’s desired value proposition differs from their current one. ‘Technological integrators’ predominantly rely on new product development (NPD) and Strategy processes, whereas ‘Socialisors’ rely predominantly on Strategy and Customer Relationship processes. Companies can use the findings to better understand their current HVM value proposition and, where necessary, plan their transition to a future desired HVM value proposition.     

日内知情交易概率测度及事件影响研究

在EKOP模型测度PIN的基础上,通过建立时变交易到达率模型,滚动计算日内知情交易概率,并将PIN测度与事件研究相结合,对比了不同规模公司股票在事件日前后PIN的变化情况。实证结果表明我国股市存在信息泄露情况,尤其是小规模公司股票在公告日前一天知情交易明显增加;前一笔知情交易对当前非知情交易有削弱作用,但对当前知情交易有加强作用,可以进一步解释交易的集簇现象：日内PIN对信息的刻画更加准确,但也发现在公共事件发生后第二天PIN仍会增加,这表明市场上存在信息的学习者,需要对引起PIN增加的原因进行更准确的分析。     

Parenting in the Context of Deportation Risk

Nearly 5.1 million children younger than age 18 live with at least one undocumented parent, about 7% of the U.S. child population. Between 2010 and 2013, an estimated 300,000 parents of U.S. citizen children were deported. Raising children in the context of deportation risk increases overall parenting stress for undocumented Latino parents. To investigate this and understand the experience of undocumented parenting, the authors interviewed 70 undocumented parents in two Southwest cities from 2012 to 2013. The authors frame their analysis using the lens of the problem of “illegality.” There are three domains of stressors associated with parenting in the context of deportation risk: trapped parenting, threat of family separation, and altered family processes. The authors discuss these findings in the context of the literature on undocumented families and parenting stress and connect these findings to the current sociopolitical context experienced by Latino families in the United States .     

Model selection for Lévy measures in diffusion processes with jumps from discrete observations

We deal with parametric inference and selection problems for jump components in discretely observed diffusion processes with jumps. We prepare several competing parametric models for the Lévy measure that might be misspecified, and select the best model from the aspect of information criteria. We construct quasi-information criteria (QIC), which are approximations of the information criteria based on continuous observations.     

Communicative Correlates of Satisfaction,Family Identity,and Group Salience in Multiracial/Ethnic Families

Guided by the Common Ingroup Identity Model ( S. L. Gaertner & J. F. Dovidio, 2000 ) and Communication Accommodation Theory ( C. Shepard, H. Giles, & B. A. LePoire, 2001 ), we examined the role of identity accommodation, supportive communication, and self‐disclosure in predicting relational satisfaction, shared family identity, and group salience in multiracial/ethnic families. Additionally, we analyzed the association between group salience and relational outcomes as well as the moderating roles of multiracial/ethnic identity and marital status. Individuals who have parents from different racial/ethnic groups were invited to complete questionnaires on their family experiences. Participants (N = 139) answered questions about relationships with mothers, fathers, and grandparents. The results of the multilevel modeling analyses are discussed in terms of implications for understanding multiracial/ethnic families and family functioning.     

Violence in the name of god? A framing processes approach to the Islamic State in Iraq and Syria

Since summer 2014, the insurgent group ‘Islamic State in Iraq and Syria’ (ISIS) has become a major concern for international politics and global security due to its rapid territorial gains, violent operations and the propagation of Salafi-jihadist ideology. This study aims to enhance the academic understanding of ISIS by demystifying the ideological reasoning behind its use of violence. It therefore investigates the link between structural factors that served ISIS’s evolution, its ideological outlook and the significance of this ideology to legitimize violent action. As its theoretical basis, the study employs framing processes within the study of social movements. Methodologically, discursive frame analysis serves to explore the relation of ISIS’s ideology to structural events and experiences to better understand how the group justifies violence. Therefore, the study draws on audio speeches and issues of the magazines Dabiq and Dar al-Islam published by ISIS, which are examined on the rhetoric of othering, collective identity and justifying violence. It is argued that ISIS constructs a collective action frame which creates a social reality that bestows the group with a rationale for action. ISIS’s ideology, based on Islamic symbolism, presents an interpretative lens which assigns meaning to the structural environment of ISIS’s emergence. In this context, violence is justified as a necessity to defend Islam and as an obligation for the true Muslim believer. The discussion concludes that ISIS’s ideology legitimizes the very existence of the group and conceals its mundane struggle for power, territory and wealth through reference to divine authority.     

A backward construction and simulation of correlated Poisson processes

In this paper, we consider a generalisation of the backward simulation method of Duch et al. [New approaches to operational risk modeling. IBM J Res Develop. 2014;58:1–9] to build bivariate Poisson processes with flexible time correlation structures, and to simulate the arrival times of the processes. The proposed backward construction approach uses the Marshall–Olkin bivariate binomial distribution for the conditional law and some well-known families of bivariate copulas for the joint success probability in lieu of the typical conditional independence assumption. The resulting bivariate Poisson process can exhibit various time correlation structures which are commonly observed in real data.