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81.
The main models of machine learning are briefly reviewed and considered for building a classifier to identify the Fragile X Syndrome (FXS). We have analyzed 172 patients potentially affected by FXS in Andalusia (Spain) and, by means of a DNA test, each member of the data set is known to belong to one of two classes: affected, not affected. The whole predictor set, formed by 40 variables, and a reduced set with only nine predictors significantly associated with the response are considered. Four alternative base classification models have been investigated: logistic regression, classification trees, multilayer perceptron and support vector machines. For both predictor sets, the best accuracy, considering both the mean and the standard deviation of the test error rate, is achieved by the support vector machines, confirming the increasing importance of this learning algorithm. Three ensemble methods - bagging, random forests and boosting - were also considered, amongst which the bagged versions of support vector machines stand out, especially when they are constructed with the reduced set of predictor variables. The analysis of the sensitivity, the specificity and the area under the ROC curve agrees with the main conclusions extracted from the accuracy results. All of these models can be fitted by free R programs.  相似文献   
82.
It is well known that many aggregation rules are manipulable through strategic behaviour. Typically, the aggregation rules considered in the literature are social choice correspondences. In this paper the aggregation rules of interest are social welfare functions (SWFs). We investigate the problem of constructing a SWF that is non-manipulable. In this context, individuals attempt to manipulate a social ordering as opposed to a social choice. Using techniques from an ordinal version of fuzzy set theory, we introduce a class of ordinally fuzzy binary relations of which exact binary relations are a special case. Operating within this family enables us to prove an impossibility theorem. This theorem states that all non-manipulable SWFs are dictatorial, provided that they are not constant. This theorem uses a weaker transitivity condition than the one in Perote-Peña and Piggins (J Math Econ 43:564–580, 2007), and the ordinal framework we employ is more general than the cardinal setting used there. We conclude by considering several ways of circumventing this impossibility theorem.  相似文献   
83.
In this article, we explore the impacts that education expansion and increased levels in educational homogamy have had on couples’ isolated illiteracy rates, defined as the proportion of illiterates in union that are married to an illiterate partner. First, we develop the methodology to decompose isolated illiteracy rates into two main components: one related to level of homogamy among illiterates, and the other related to the educational distribution of the spouses. Second, we use harmonized international census microdata from IPUMS and DHS data for 73 countries and 217 samples to investigate which of the two components is more important in shaping the level of isolated illiteracy. Our results indicate that the expansion of literacy has been more powerful than the increases in the tendency toward homogamy in its impact on isolated illiteracy rates. As the percentage of illiterates decreases over time, an increasingly large proportion of them marry literate individuals, showing that opportunities for intermarriage among illiterates expand despite the strengthening of homogamy.  相似文献   
84.
对苏州地铁某车站明挖基坑施工进行跟踪监测,及时掌握围护结构变形、支撑内力的变化动态,以指导施工确保基坑稳定。经过对比分析基坑有、无加固措施的变形和支撑内力的变化特征表明:基坑外水泥土搅拌桩加固措施的设置,可以有效地减小围护结构的水平变形,并且能够阻碍边坡滑移破坏面的发展,减小作用于地下连续墙上面的土压力,使得内支撑上的最大轴力减小。  相似文献   
85.
This article studies robustification strategies for the linear model in the presence of outliers. The advantages of an internal analysis of the robustness of least squares for a given sample are pointed out. The application of this methodology is illustrated by building an explicit model of the determinants of rental housing values in the Madrid Metropolitan Area.  相似文献   
86.
The present study examined the role of social problem-solving abilities in the coping strategies used by 310 female social work students from Spain. Results from comparative analyses of the coping strategies, used by students to deal with stressful situations, indicated the greater use of functional forms of coping (eg problem solving and cognitive restructuring), compared to dysfunctional forms of coping (eg problem avoidance and wishful thinking). Moreover, results from regression analyses indicated that constructive social problem-solving abilities, namely, positive problem orientation and rational problem solving, predicted the use of functional coping strategies (eg problem solving, cognitive restructuring, and express emotions). Alternatively, one damaging social problem-solving ability, namely, negative problem orientation, predicted the use of dysfunctional coping strategies (eg problem avoidance, wishful thinking, self criticism, and social withdrawal). Taken together, these findings provide an important first step for understanding what and how social problem-solving abilities might inform how social work students cope with stressful situations as they arise. Some implications for social work education and training are discussed.  相似文献   
87.
A qualitative study was carried out in four municipalities in four different conflict zones in Colombia. Intrafamilial violence and gender violence are studied through the testimonies of the people interviewed. The impact was analysed in terms of the exercise of control over the civilian population by paramilitaries in relation to subjectivity, the family, social networks and the prevailing moral order. In effect, the strengthening of barriers between traditional gender identities has enabled a de-structuring of traditional masculinity through moral co-optation, the reinforcement of traditional feminine identity and the objectification of the sexuality of young women, at the same time as they are manipulated sexually and emotionally. In general, strong legitimation of the model of the armed fighter as a paradigm of masculinity is found in children. In addition, the de-structuring of the family and its manipulation as a means of influence over civil society is one of the strategies employed for the installation of a regime of terror that fractures social networks. It does this through the erosion of confidence and the legitimation and mystification of the power of an actor whose mediation in inter-family and micro-social conflicts has been legitimated, instrumentalizing and scaling up traditional violence, taking advantage of the power vacuum and moral weaknesses in local culture.  相似文献   
88.
2007年6月5-6日,由教育部省属高校人文社会科学重点研究基地深圳大学中国经济特区研究中心主办的"2007中国经济特区论坛暨纪念香港回归10周年学术研讨会"在深圳大学召开。新华社香港分社原副社长、浙江大学原党委书记张浚生,原深圳  相似文献   
89.
论文在河北科技师范学院大学生消费状况的调查资料基础上,分析了当代大学生的消费结构、消费特点以及存在的问题,并提出了以下几点建议:大学生自己要树立合理的消费观念,父母要注重培养孩子正确的消费观念,高校要健全奖学金和贷款等方面的管理制度,社会要规范大学生的消费市场秩序.  相似文献   
90.
Gamson’s law and hedonic games   总被引:1,自引:1,他引:0  
This note adds one celebrated coalition formation game due to Gamson (Am Soc Rev 26:373–382 1961a, Am Soc Rev 26:565–573, 1961b) in the list of applications of the theory of hedonic games explored by Banerjee et al. (Soc Choice Welf 18:135–153, 2001) and Bogomolnaia and Jackson (Games Econ Behav 38: 204–230, 2002). We apply their results to study the original Gamson game and offer extensions both to a multi-dimensional characteristics space and to an infinite number of players.  相似文献   
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