A comparison of classification models to identify the Fragile X Syndrome

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.     

Manipulating an aggregation rule under ordinally fuzzy preferences

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.     

The Impact of Educational Homogamy on Isolated Illiteracy Levels

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.     

Robust Methods of Building Regression Models—An Application to thè Housing Sector

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.     

给老外提建议的窍门

案例：主动提出建议 两年前的一次聚会中，笔者结识了来自新西兰的David。David为人很腼腆也很友善。闲聊中，我（何震）得知他是公安大学英语课的外籍教师，而我本人的本科四年就是在“公大”度过的。David谈到，像国内的其他学生一样，除非是课后一对一的私下交流，否则课堂上学生们一般不太愿意主动发言，也不愿意提问和主动参加各种讨论，他为此颇伤脑筋。这时我突然有个想法：“我要验证一下，如果我主动给David提出建议，他的反应将会是什么？是感到自己被冒犯而气愤？还是不以为然或者欣然接受？”     

Examining coping strategies used by Spanish female social work students: evidence for the importance of social problem-solving abilities

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.     

Have we come a long way? Using the Survey of Labour and Income Dynamics to revisit the ‘pin money’ theory

Canada has experienced a lengthy period of economic recovery, since the recession of the early 1990s, and many families’ standard of living has improved. I evaluate the ‘pin money’ hypothesis of the feminist scholarship, which is closely linked to what economists often refer to as an ‘added worker effect’. An improved economy may generate incentives for some married women in various occupations to make significant alterations to their labour market connections. Panel data are used to examine the effects of changes to women's hours, for example, whether some respondents opt out or reduce their hours given the rising incomes of economic partners. The methodology involves the use of two panels of the Statistics Canada, Survey of Labour and Income Dynamics and a random effects probit model to estimate various participation equations of labour decisions over time within a household context. While the findings indicate that a small percentage of married female respondents have reduced their hours, there is stronger evidence that women's contributions to household income appear to be essential to family survival.