Information-based thinning of point processes and its application to shock models

Thinning of point processes is a useful operation that is implemented in various stochastic models. When the initial point process is the nonhomogeneous Poisson process (NHPP), the thinned processes are also nonhomogeneous Poisson processes independent of each other. The crucial assumption in deriving this result is that the corresponding classification of events is independent of all other events, including the history of the process. However, in practice, this classification is often dependent on the history. In our paper, we define and describe the thinned processes for the history-dependent case using different levels of available information. We also discuss the applications of the obtained general results to the corresponding shocks models.     

European Influence in Ukrainian Modernist Prose

Abstract

Digital technologies make possible new ways of managing folklore field recordings. Two programmers, a graduate student, and the author developed a database that allows the user to go directly to the point in a sound file where a particular topic is discussed. This is a research tool and the task here was to create a modified site for the general public. The technique used was crowdsourcing, asking the public to transcribe and translate songs, stories, and accounts of belief. The project revealed how heritage issues affect public participation. People who expressed initial enthusiasm were reluctant to participate because they were timid about their language knowledge. Paradoxically, formal instruction leads to the timidity we observed. People who did contribute to our project transcribed and translated songs only. Language is retained in song even as it is lost elsewhere. Songs are also familiar material, associated with the past. Contributions driven by interest in new material directly from Ukraine did not materialize. A romanticized image of the past and suspicions that Ukraine has been Sovietized and Russified encourage preservation of the old and work against interest in the new.     

Optimal Abort Rules for Multiattempt Missions

Many real‐world systems use mission aborts to enhance their survivability. Specifically, a mission can be aborted when a certain malfunction condition is met and a risk of a system loss in the case of a mission continuation becomes too high. Usually, the rescue or recovery procedure is initiated upon the mission abort. Previous works have discussed a setting when only one attempt to complete a mission is allowed and this attempt can be aborted. However, missions with a possibility of multiple attempts can occur in different real‐world settings when accomplishing a mission is really important and the cost‐related and the time‐wise restrictions for this are not very severe. The probabilistic model for the multiattempt case is suggested and the tradeoff between the overall mission success probability (MSP) and a system loss probability is discussed. The corresponding optimization problems are formulated. For the considered illustrative example, a detailed sensitivity analysis is performed that shows specifically that even when the system's survival is not so important, mission aborting can be used to maximize the multiattempt MSP.     

A mixed-method exploration of functioning in Safe Schools/Healthy Students partnerships

This paper presents a mixed-method approach to measuring the functioning of Safe Schools/Healthy Students (SS/HS) Initiative partnerships. The SS/HS national evaluation team developed a survey to collect partners’ perceptions of functioning within SS/HS partnerships. Average partnership functioning scores were used to rank each site from lowest to highest. Sites with the most favorable perceptions of partnership functioning were defined as having average scores in the top 10% (n = 10) and sites with the least favorable perceptions of partnership functioning were defined as having average scores in the bottom 10% (n = 10). Qualitative data for these 20 sites were inductively open coded for emergent themes and analyzed for patterns using grounded theory approach. Six themes emerged that distinguished sites reporting the most favorable and least favorable perceptions of partnership functioning: partner engagement, facilitators, barriers, shared decision making, partnership structure, and sustainability. Sites reporting the most favorable perceptions of partnership functioning effectively utilized collaboration processes that facilitate coalition building, such as shared decision making, effective communication, and developing a clearly defined structure. Qualitative themes from this analysis provide evidence of validity for the partnership functioning scale used and illustrate distinguishing features between sites with the most favorable and least favorable perceptions of partnership functioning.     

On damage accumulation and biological aging

If biological aging is understood as some process of damage accumulation, it does not necessarily lead to increasing mortality rate. Within the framework of suggested models and relevant examples we show that even for the monotonically increasing degradation, the mortality rate can, at least, ultimately decrease. Aging properties of systems with imperfect repair are also studied. It is shown that for some models of imperfect repair the corresponding age process is monotone and stable. This means that as t→∞$t\to \infty$, degradation slows down, which results in the mortality rate deceleration and its possible convergence to a constant.     

Immigration policy and immigrant quality: empirical evidence from Canada

This paper examines the earnings of foreign-born and native-born men in an attempt to evaluate whether the decline in the quality of Canadian immigrants is related to changes in the country-of-origin mix and the class (type) mix of immigrants. Based on a human capital interpretation, higher quality immigrants are defined as immigrants who have smaller on-entry earnings differentials and have earnings that grow at a faster rate (relative to native-born Canadians). The analysis consists of two parts. The first part is based on individual data on earnings and socio-economic characteristics collected in the 1971 and 1986 Canadian Censuses. Earnings equations are estimated for 16 country-of-origin immigrant groups. These regressions are then used to construct a cohort-specific measure of immigrant quality based on the earnings differential between foreign-born and native-born Canadians. In the second part of the analysis, additional regression equations are estimated, pertaining to the period 1968 to 1985, that relate these Census-based measures of immigrant quality to the country-of-origin and class mix of immigrants. In this analysis, unpublished data, supplied by theDepartment of Employment and Immigration, describing the distribution of immigrants across the three main immigrant classes is used. Overall, the analysis confirms that there has been a sharp secular decline in the quality of Canadian immigrants and suggests that it is related to changes in both the country-of-origin and class mix of immigrants.Earlier versions of this paper were presented at the meetings of the Canadian Economics Association and the European Society for Population Economics. The comments of Martin Browning, John Ermisch and two anonymous referees are gratefully acknowledged. Of course, all remaining errors and shortcomings are the sole responsibility of the authors.     

Prisons and their perceived impact on the local community: A case study

This paper examines some of the central concerns expressed by residents over the presence of penal institutions within their community, and looks at some of the factors which may influence the type and intensity of those concerns. Using existing survey data collected in the lower Fraser Valley region of British Columbia, Canada, four generic factors of perceived impact are identified: concern for family safety; concern for general quality of life; concern for value of neighbourhood, and concern for neigh-bourhood instability. Three hypotheses are then examined, relating these four concerns to the respondents' history of victimization, physical proximity to the institutions, and current position in family life cycle.     

Cohort Perspectives on Women’s Educational Attainment and the Timing of Parenthood in Ghana

This paper examines the effects of womens educational attainment on the timing of parenthood across successive generations of women in Ghana. Given the more enhanced career opportunities in recent years, we argue that the opportunity cost of parenthood may be higher for contemporary educated women, and as such, they are expected to delay parenthood for longer periods than their counterparts in the past. Using data from the 1998 Ghana Demographic and Health Survey, we found that while higher maternal education associates with delayed parenthood, significant cohort differences were noticeable. Consistent with our expectations, the effect of higher educational attainment was substantially greater among younger women, indicating a longer transition to parenthood. Implications of the findings are discussed.     

Burn-in for Eliminating Weak Items in Heterogeneous Populations

Burn-in is a method of eliminating early failures in populations of manufactured items. To burn-in a component or a system means to subject it to a ‘‘simulated operation’’ for some time (prior to its actual field use). Various optimal burn-in problems have been intensively studied in the literature under the assumption of decreasing or bathtub-shaped failure rates. However, most of these studies have been conducted for homogeneous populations. In this paper, we discuss burn-in for heterogeneous populations and develop approaches that minimize the risks of selecting items with large levels of individual failure rates. Using simple examples, we consider the optimal burn-in time, which minimizes these risks.     

Two Poems on the Death of Akhmatova: Dialogues,Private Codes,and the Myth of Akhmatova’s Orphans

Abstract

In Serhiy Zhadan’s recent novel Voroshylovhrad (2010), memory and emptiness form a duality of being and non-being, as represented by remembering and forgetting. This framework is proposed here as a metaphor for understanding some of the challenges facing Ukraine today. Using the concept of post-socialist memory as an entry point, this article positions Voroshylovhrad at the productive intersection of memory and literature, offers interpretations for several crucial scenes of the narrative, and contends that the novel recalibrates common paradigms of separation from a traumatic past. Finally, an argument is put forth that the book’s textual voids cast the reader as a key agent of recollection. This analysis of literary mechanisms involved in the memoryemptiness dichotomy contributes to an on-going exploration of strategies contemporary Ukrainian writers employ to engage in cultural and historical discourses, as well as to the studies of memory and literature in the post-Soviet regions of the world.