The current Situational Space Awareness (SSA) is faced with a huge task of tracking the increasing number of space objects. The tracking of space objects requires frequent and accurate monitoring for orbit maintenance and collision avoidance using methods for statistical orbit determination. Statistical orbit determination enables us to obtain…

Spatial or temporal data mining tasks are performed in the context of the relevant space, defined by a spatial neighborhood, and the relevant time period, defined by a specific time interval. Furthermore, when mining large spatio-temporal datasets, interesting patterns typically emerge where the dataset is most dynamic. This dissertation is…

Objective: This study addresses if deficits in cognitive, attention, and inhibitory control performance in adults with ADHD are better explained by the disorder itself or by comorbid conditions. Method Adult patients with ADHD ("n" = 352) and controls ("n" = 94) were evaluated in the ADHD program of a tertiary hospital. The…

Youths with high (N = 52) or low cognitive vulnerability (N = 48) for depression were selected from a larger sample (N = 515) of students (7-10 years old), based on their attributional style (AS), negative cognitions (NC), and/or self-competence (SC). Long-term effects of cognitive vulnerabilities on depressive symptoms were examined in a 3-year,…

Tests of model misfit are often performed to validate the use of a particular model in item response theory. Douglas and Cohen (2001) introduced a general nonparametric approach for detecting misfit under the two-parameter logistic model. However, the statistical properties of their approach, and empirical comparisons to other methods, have not…

We are delighted to welcome you to the International Psychological Applications Conference and Trends 2014, taking place in Porto, Portugal, from 4 to 6 of April. Psychology, in our time, offers a large range of scientific fields where it can be applied. The goal of understanding individuals and groups (mental functions and behavioral…

We are delighted to welcome you to the International Psychological Applications Conference and Trends (InPACT) 2016, taking place in Lisbon, Portugal, from 30 of April to 2 of May, 2016. Psychology, nowadays, offers a large range of scientific fields where it can be applied. The goal of understanding individuals and groups (mental functions and…

This study is intended to provide researchers with empirically derived guidelines for conducting factor analytic studies in research contexts that include dichotomous and continuous levels of measurement. This study is based on the hypotheses that ordinary least squares (OLS) factor analysis will yield more accurate parameter estimates than…

The New Opportunities Initiative (NOI) is a Portuguese flagship programme to recognise and accredit prior learning (RPL, APL) and to endow low-skilled adults with upper secondary qualifications, which is defined as the minimum entry threshold to the exercise of a full citizenship in a knowledge-rich society. NOI's major achievement has been its…

A new test assembly algorithm based on a Monte Carlo random search is presented in this article. A major advantage of the Monte Carlo test assembly over other approaches (integer programming or enumerative heuristics) is that it performs a uniform sampling from the item pool, which provides every feasible item combination (test) with an equal…

Americans like to believe that theirs is the land of opportunity, but the hard facts are that children born into poor families in the United States tend to stay poor and children born into wealthy families generally stay rich. Other countries have shown more success at lessening the effects of inequality on mobility--possibly by making public…

This article shows how a multivariate approximate degrees of freedom procedure based on the Welch-James procedure as simplified by S. Johansen (1980) can be applied to the analysis of repeated measures designs without assuming covariance homogeneity. A Monte Carlo study illustrates the approach. (SLD)

Experimental work on ultrafiltration is presented to illustrate the practical and theoretical principles of this separation technique. The laboratory exercise comprises experiments with pure water and with aqueous "Saccharomyces cerevisiae" (from commercial Baker's yeast) suspensions. With this work students detect the characteristic phenomena…

Tested empirically the applicability of a method developed by S. Mattson for generating data on latent variables with controlled skewness and kurtosis of the observed variables. Monte Carlo simulation results suggest that Mattson's method appears to be a good approach to generate data with defined levels of skewness and kurtosis. (SLD)

A method for estimating the first eigenvalue of random data correlation matrices is reported, and its precision is demonstrated via comparison to the method of S. J. Allen and R. Hubbard (1986). Data generated in Monte Carlo simulations with 10 sample sizes reaching up to 1,000 were used. (SLD)