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61.
Remarriages end in divorce more often than first marriages, so many stepchildren experience multiple parental divorces and the potential loss of significant family ties. Although there is substantial research on parent–child relationships after divorce, little is known about stepparent–stepchild relationships after divorce. Therefore, the authors conducted a grounded theory study of 41 adults who had undergone a stepfamily dissolution to explore their experiences with former stepparents. Postdivorce relationships with former stepparents are a function of whether stepchildren thought of their former stepparents as kin. Postdivorce step‐relationships were based on whether the stepchild had claimed the stepparent as kin, had once claimed them as kin but disclaimed them after the divorce, or had never claimed them as family members (unclaimed stepparents). Emotional reactions to parental divorce, patterns of support or resource exchanges, and parental encouragement or discouragement for continuing step‐relationships were identified. Implications for families, practitioners, and researchers are discussed.  相似文献   
62.
Compared to the remarkable progress in risk analysis of normal accidents, the risk analysis of major accidents has not been so well‐established, partly due to the complexity of such accidents and partly due to low probabilities involved. The issue of low probabilities normally arises from the scarcity of major accidents’ relevant data since such accidents are few and far between. In this work, knowing that major accidents are frequently preceded by accident precursors, a novel precursor‐based methodology has been developed for likelihood modeling of major accidents in critical infrastructures based on a unique combination of accident precursor data, information theory, and approximate reasoning. For this purpose, we have introduced an innovative application of information analysis to identify the most informative near accident of a major accident. The observed data of the near accident were then used to establish predictive scenarios to foresee the occurrence of the major accident. We verified the methodology using offshore blowouts in the Gulf of Mexico, and then demonstrated its application to dam breaches in the United Sates.  相似文献   
63.
Large‐scale outages on real‐world critical infrastructures, although infrequent, are increasingly disastrous to our society. In this article, we are primarily concerned with power transmission networks and we consider the problem of allocation of generation to distributors by rewiring links under the objectives of maximizing network resilience to cascading failure and minimizing investment costs. The combinatorial multiobjective optimization is carried out by a nondominated sorting binary differential evolution (NSBDE) algorithm. For each generators–distributors connection pattern considered in the NSBDE search, a computationally cheap, topological model of failure cascading in a complex network (named the Motter‐Lai [ML] model) is used to simulate and quantify network resilience to cascading failures initiated by targeted attacks. The results on the 400 kV French power transmission network case study show that the proposed method allows us to identify optimal patterns of generators–distributors connection that improve cascading resilience at an acceptable cost. To verify the realistic character of the results obtained by the NSBDE with the embedded ML topological model, a more realistic but also more computationally expensive model of cascading failures is adopted, based on optimal power flow (namely, the ORNL‐Pserc‐Alaska) model). The consistent results between the two models provide impetus for the use of topological, complex network theory models for analysis and optimization of large infrastructures against cascading failure with the advantages of simplicity, scalability, and low computational cost.  相似文献   
64.
Young people are exposed to and engage in online risky activities, such as disclosing personal information and making unknown friends online. Little research has examined the psychological mechanisms underlying young people's online risk taking. Drawing on fuzzy trace theory, we examined developmental differences in adolescents’ and young adults’ online risk taking and assessed whether differential reliance on gist representations (based on vague, intuitive knowledge) or verbatim representations (based on specific, factual knowledge) could explain online risk taking. One hundred and twenty two adolescents (ages 13–17) and 172 young adults (ages 18–24) were asked about their past online risk‐taking behavior, intentions to engage in future risky online behavior, and gist and verbatim representations. Adolescents had significantly higher intentions to take online risks than young adults. Past risky online behaviors were positively associated with future intentions to take online risks for adolescents and negatively for young adults. Gist representations about risk negatively correlated with intentions to take risks online in both age groups, while verbatim representations positively correlated with online risk intentions, particularly among adolescents. Our results provide novel insights about the underlying mechanisms involved in adolescent and young adults’ online risk taking, suggesting the need to tailor the representation of online risk information to different age groups.  相似文献   
65.
We introduce a new statistic, ‘spectral goodness of fit’ (SGOF) to measure how well a network model explains the structure of the pattern of ties in an observed network. SGOF provides a measure of fit analogous to the standard R2 in linear regression. Additionally, as it takes advantage of the properties of the spectrum of the graph Laplacian, it is suitable for comparing network models of diverse functional forms, including both fitted statistical models and algorithmic generative models of networks. After introducing, defining, and providing guidance for interpreting SGOF, we illustrate the properties of the statistic with a number of examples and comparisons to existing techniques. We show that such a spectral approach to assessing model fit fills gaps left by earlier methods and can be widely applied.  相似文献   
66.
This reflective discussion draws on data from a collaborative enquiry into kinship or family and friends practice. It introduces perspectives from complexity and chaos theory as a way of re‐examining the challenges of kinship practice. The discussion highlights the enduring challenges for practitioners, not least, managing anxiety and uncertainty, sustaining continuity and containment, becoming experienced and taking account of the complex developmental needs of the children and their families. The discussion particularly raises questions about appropriate settings for practitioners to undertake such a demanding area of child and family social work.  相似文献   
67.
Abstract

In this article we develop the minimax estimation approach of general linear models to the semiparametric linear models when the parameters are simultaneously constrained by an ellipsoid and linear restrictions. Combining sample information and prior constraints the minimax estimator is obtained and compared with partially least square estimator by theoretical and simulation methods.  相似文献   
68.
针对消费者对转换成本和价格属性具有显著性偏好的实际情况,基于显著性理论对垄断双边平台企业的转换成本和定价策略问题进行了研究。研究发现:1)在显著性偏好非对称型市场上,对价格敏感的一方收取的价格最低,对高转换成本的一方收取的价格最高,而在显著性偏好对称型市场上,平台的最优价格位于非对称型市场之间,但是对价格敏感型市场收取的价格低于转换成本敏感型市场的价格。2)在高转换成本的市场,平台利润最低;低转换成本市场平台利润最高,而混合型情况的最优利润位于这两者之间。该研究结论说明平台企业应该采取措施来降低用户加入平台的转换成本,从而增加利润,这与现实的案例研究结论相吻合。  相似文献   
69.
This qualitative study examines the narratives of seven heterosexual, cisgender individuals who identify both as persons of color and as positively disposed toward LGB and transgender-identified persons. Using psycho-discursive qualitative methodology, the authors will present the narrative strategies taken up by these positively disposed cisgender heterosexuals of color as they attempt to position themselves as supportive of LGB and transgender persons while negotiating the discourse of heteronormativity. The three narrative strategies have been titled differentiation, empathy, and coherence. In addition to mapping the three narrative strategies, the authors also explore why informants may choose certain strategies over others and argue that the intersection of social identities must be considered when attempting to understand social oppression. Implications for the human services fields will be discussed.  相似文献   
70.
本体诗歌翻译理论主要探讨译文与原文在形式与内容上的关系。译文与原文应该达到形似还是神似,译者应该求真还是求美,这是翻译界一直争论的话题。按照“形似与神似,求真与求美”的关系来分析江枫先生对艾米莉·狄金森的两首诗歌“暴风雨夜”和“篱笆那边”的翻译,可以看出,标点符号、遣词、诗歌的韵式和诗人的创作风格等方面体现了江枫译文的特点和风格:译文选词简单但富有张力,行文简约而内敛,与原诗风格颇似;但由于过于追求简约而稍显生硬和晦涩。总之,江枫的译文是形似与神似结合的典范,体现其“形似而后神似”的主张以及“简约而忠实”的风格,但并未完全实现“求真与求美”的完美结合。  相似文献   
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