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81.
82.
Variable precision rough set theory and data discretisation: an application to corporate failure prediction 总被引:1,自引:0,他引:1
Since the seminal work of Pawlak (International Journal of Information and Computer Science, 11 (1982) 341–356) rough set theory (RST) has evolved into a rule-based decision-making technique. To date, however, relatively little empirical research has been conducted on the efficacy of the rough set approach in the context of business and finance applications. This paper extends previous research by employing a development of RST, namely the variable precision rough sets (VPRS) model, in an experiment to predict between failed and non-failed UK companies. It also utilizes the FUSINTER discretisation method which neglates the influence of an ‘expert’ opinion. The results of the VPRS analysis are compared to those generated by the classical logit and multivariate discriminant analysis, together with more closely related non-parametric decision tree methods. It is concluded that VPRS is a promising addition to existing methods in that it is a practical tool, which generates explicit probabilistic rules from a given information system, with the rules offering the decision maker informative insights into classification problems. 相似文献
83.
Dr. Antje Mahayni Dipl.-Volksw. Michael Suchanecki 《Zeitschrift für Betriebswirtschaft》2006,76(4):347-372
Zusammenfassung Turbo-Zertifikate geh?ren derzeit zu den beliebtesten strukturierten Produkten für Privatanleger. Sie lassen sich als Spezialformen
von Barrier-Optionen auffassen. In Bezug auf das Produktdesign ist das Verh?ltnis von Kursschranke und Basispreis von Bedeutung.
Unter Ausnutzung der Put-Call-Symmetrie wird gezeigt, dass eine geeignete Wahl der Ausstattungsmerkmale dem Emittenten eine semi-statische überabsicherung in Standard-Optionen
erm?glicht, die bezüglich einer ganzen Modellklasse gültig ist. Im Gegensatz zu der in der Praxis g?ngigen Preisstellung kann
eine Absicherung der Zahlungsverpflichtungen im Allgemeinen nicht unabh?ngig von der Volatilit?t erfolgen.
Product design and semi-static hedging of turbo-certificates
Summary Turbo-Certificates are one of the most popular structured equity products for private investors in Germany. They can be regarded as special forms of barrier options. For the design of these products, the relation between the barrier level and the strike price is especially important. By using the put-call-symmetry, we show that by a certain choice of these parameters, the issuer is able to obtain an almost static (super-) hedge in standard option contracts which is valid for a general class of models. It turns out that in contrast to the pricing rule which is often used in practice, the issuer can neither hedge a single certificate nor a portfolio of certificates independent of the volatility.
相似文献
84.
This paper reports the results of three studies conducted to develop, refine, and validate a scale which assessed heterosexual adults' attitudes toward same-sex marriage, the Attitude Toward Same-Sex Marriage Scale (ASSMS). The need for such a scale is evidenced in the increasing importance of same-sex marriage in the political arena of the United States and other nations, as well as the growing body of empirical research examining same-sex marriage and related issues (e.g., Lannutti, 2005; Solomon, Rothblum, & Balsam, 2004). The results demonstrate strong reliability, convergent validity, and predictive validity for the ASSMS and suggest that the ASSMS may be adapted to measure attitudes toward civil unions and other forms of relational recognition for same-sex couples. Gender comparisons using the validated scale showed that in college and non-college samples, women had a significantly more positive attitude toward same-sex marriage than did men. 相似文献
85.
We investigate mortality differentials by marital status among older age groups using a database of mortality rates by marital status at ages 40 and over for seven European countries with 1 billion person-years of exposure. The mortality advantage of married people, both men and women, continues to increase up to at least the age group 85-89, the oldest group we are able to consider. We find the largest absolute differences in mortality levels between marital status groups are at high ages, and that absolute differentials are: (i) greater for men than for women; (ii) similar in magnitude across countries; (iii) increase steadily with age; and (iv) are greatest at older age. We also find that the advantage enjoyed by married people increased over the 1990s in almost all cases. We note that results for groups such as older divorced women need to be interpreted with caution. 相似文献
86.
In 1960 Levene suggested a potentially robust test of homogeneity of variance based on an ordinary least squares analysis of variance of the absolute values of mean-based residuals. Levene's test has since been shown to have inflated levels of significance when based on the F-distribution, and tests a hypothesis other than homogeneity of variance when treatments are unequally replicated, but the incorrect formulation is now standard output in several statistical packages. This paper develops a weighted least squares analysis of variance of the absolute values of both mean-based and median-based residuals. It shows how to adjust the residuals so that tests using the F -statistic focus on homogeneity of variance for both balanced and unbalanced designs. It shows how to modify the F -statistics currently produced by statistical packages so that the distribution of the resultant test statistic is closer to an F-distribution than is currently the case. The weighted least squares approach also produces component mean squares that are unbiased irrespective of which variable is used in Levene's test. To complete this aspect of the investigation the paper derives exact second-order moments of the component sums of squares used in the calculation of the mean-based test statistic. It shows that, for large samples, both ordinary and weighted least squares test statistics are equivalent; however they are over-dispersed compared to an F variable. 相似文献
87.
Emotion Regulation in Low-income Preschoolers 总被引:2,自引:0,他引:2
The present study was concerned with identifying the causes of low-income preschoolers' negative emotions and their most common regulation responses. The relations of family socialization practices and temperament to the children's emotion regulation skills were also examined. Ninety predominantly minority low-income preschoolers (46 boys) and their mothers participated. During visits to the children's preschools, observers watched for expressions of anger and sadness, and recorded the causes of the displays and the children's reactions. Mothers reported on their emotion socialization and discipline practices and their children's temperament. Although the children expressed more anger than sadness, they used more constructive reactions in response to sadness and more non-constructive reactions in response to anger. Maternal reports of appropriate family emotion were associated with low levels of non-constructive regulation responses to anger and sadness whereas reports of inconsistent parental discipline were generally associated with non-constructive regulation responses. All in all, the findings of this study are in accord with findings on middle-income children and indicate that low- and middle-income children are more alike than different with regard to the regulation of negative emotion in the peer environment. 相似文献
88.
89.
Popular or media portrayals have suggested that many suburban housewives are dissatisfied with a number of aspects of their lives. This claim was investigated by surveying two groups of Brisbane women. Data obtained firstly from a sample at a shopping town and secondly from the members of a women's social club suggests that the dissatisfaction with the role of housewife expressed in the media may be overstated. Women find a lack of social contacts with others to be acute but report satisfaction with other aspects of their lives. Tentative solutions to facilitate social contacts between women are suggested. 相似文献
90.
Michael S. Rendall 《Demography》1999,36(3):369-376
I analyze the prevalence of single motherhood among black and non-Hispanic white women in terms of differences in entry and exit. Higher initial entry rates among black women, especially through unpartnered childbearing, account for slightly more than half the difference between blacks and whites in the prevalence of single motherhood. The remainder of the difference is due to black single mothers' much lower rates of exit through union formation and to their very high rates of reentry through dissolution of these later unions. Entry and exit rates through the 1990s imply a widening racial gap. 相似文献