On Modeling Correlated Random Variables in Risk Assessment

Monte Carlo methods in risk assessment are finding increasingly widespread application. With the recognition that inputs may be correlated, the incorporation of such correlations into the simulation has become important. Most implementations rely upon the method of Iman and Conover for generating correlated random variables. In this work, alternative methods using copulas are presented for deriving correlated random variables. It is further shown that the particular algorithm or assumption used may have a substantial effect on the output results, due to differences in higher order bivariate moments.     

The past, present, and future of sex segregation methodoloqy

We review the logic underlying margin-free analyses of sex segregation arrays. In the course of our review, we show that the Karmel-MacLachlan decomposition does not live up to its margin-free billing, as the index upon which it rests, I _p , is itself margin-sensitive. Moreover, because the implicit individualism of D is necessarily inconsistent with margin-free analysis, the field would do well to abandon not merely the Karmel-MacLachlan decomposition but all related efforts to purge marginal dependencies from D-inspired measures. The criticisms that Watts (1998) levels against our log-multiplicative approach are likewise unconvincing. We demonstrate that our preferred models pass the test of organizational equivalence, that the “problem? of zero cells can be solved by applying well-developed methods for ransacking incomplete or sparse tables, and that simple log-multiplicative models can be readily devised to analyze disaggregate arrays. We illustrate these conclusions by analyzing a new cross-national archive of detailed segregation data.     

Quantification of hand grasp force using a pressure mapping system

The goal of this study was to use a pressure sensor to measure the force distribution and contact area of the hand when gripping, pushing, and pulling a cylinder. Data was collected from 10 subjects with no hand impairments and from 1 subject with rheumatoid arthritis (RA). Subjects grasped an aluminum cylinder wrapped with a Tekscan pressure sensor and performed each trial at 25%, 50%, and 100% maximum voluntary exertion. A relationship was found between increasing exertion and increasing hand area with increasing hand contact area. The force distribution maps showed the thenar region of the hand exerts the most force during pushing while the metacarpal joint line exerts the highest force during pulling. The third and fourth phalange were found to exert the highest phalange force during gripping. The force distribution maps from the RA subject showed higher thumb forces and distal phalange forces, relative to the entire phalange, compared to the non-impaired subjects. This suggests that the RA subject compensates for the lack of phalange function with the regions of the hand that still function. Future studies should sample individuals with a larger hand area range and sample more individuals with RA.     

Design and ergonomics of package inserts of drugs in Brazil: a reality in construction

This research deals with the design of leaflets of medicines, evidencing the problems resulting from the lack of Brazilian normalization to promote the use of the graphical representation of instructional texts warnings. It approaches studies related to the effectiveness and efficiency of information systems, highlighting the semiotics and the cultural and informational ergonomics. The analysis of the context uses as method, an analytical study on selected warnings of thirty leaflets of medicines, followed by interviews lead with the public managers involved with the regulation of the pharmaceutical companies, and two experiments with users performed in city of Recife, in State of Pernambuco: one aiming at to identify how they interact with the leaflets of medicines, and the second one testing their understanding concerning standardized illustrations in the United States and the South Africa. The results show the need for improvements in presentation and graphic representation of leaflets of medicines, powering them to the role of communication, to ensure the consumption of medicine safely by its users. The conclusion congregates parameters and recommendations for the graphic representation of warnings in leaflets of medicines in Brazil.     

Mind‐Mindedness as a Multidimensional Construct: Appropriate and Nonattuned Mind‐Related Comments Independently Predict Infant–Mother Attachment in a Socially Diverse Sample

In a socially diverse sample of 206 infant–mother pairs, we investigated predictors of infants’ attachment security at 15 months, with a particular emphasis on mothers’ tendency to comment appropriately or in a non‐attuned manner on their 8‐month‐olds’ internal states (so‐called mind‐mindedness). Multinomial logistic regression analyses showed that higher scores for appropriate mind‐related comments and lower scores for non‐attuned mind‐related comments distinguished secure‐group mothers from their counterparts in the insecure‐avoidant, insecure‐resistant, and insecure‐disorganized groups. Higher scores for appropriate mind‐related comments and lower scores for non‐attuned mind‐related comments also independently predicted dichotomous organized/disorganized attachment. General maternal sensitivity predicted neither attachment security nor organization, although sensitivity was found to relate to dichotomous secure/insecure attachment specifically in the context of low socioeconomic status. The findings highlight how appropriate and non‐attuned mind‐related comments make independent contributions to attachment and suggest that mind‐mindedness is best characterized as a multidimensional construct.     

In search of the ideal measure of accuracy for subnational demographic forecasts

We examine nonlinear transformations of the forecasterror distribution in hopes of finding a summary errormeasure that is not prone to an upward bias and usesmost of the information about that error. MAPE, thecurrent standard for measuring error, often overstatesthe error represented by most of the values becausethe distribution underlying the MAPE is right skewedand truncated at zero. Using a modification to theBox-Cox family of nonlinear transformations, wetransform these skewed forecast error distributionsinto symmetrical distributions for a wide range ofsize and growth rate conditions. We verify thissymmetry using graphical devices and statisticaltests; examine the transformed errors to determine ifre-expression to the scale of the untransformed errorsis necessary; and develop and implement a procedurefor the re-expression. The MAPE-R developed by ourprocess is lower than the MAPE based on theuntransformed errors and is more consistent with arobust estimator of location.