Andres Gonzalez

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BACKGROUND Despite the crucial importance of the notion of parallel forms within Classical Test Theory, the degree of parallelism between two forms of a test cannot be directly verified due to the unobservable nature of true scores. We intend to overcome some of the limitations of traditional approaches to analyzing parallelism by using the Differential(More)
BACKGROUND Growing awareness of the negative impacts from the practice of health care on the environment and public health calls for the routine inclusion of life cycle criteria into the decision-making process of device selection. Here we present a life cycle assessment of 2 laryngeal mask airways (LMAs), a one-time-use disposable Unique™ LMA and a(More)
Neural Networks are powerful tools for classification and regression, but it is difficult and time costly to determine the best architecture for a given problem. In this paper, Genetic Algorithms (GA) are used to optimize the architecture of a Multi-Layer Perceptron Neural Network (MLP) in SAS®, in order to improve the predictive power of the credit risk(More)
This paper addresses the problem of supporting accessibility in applications that run in multiple operating environments. It analyzes the commonalities of existing platform-specific Accessibility APIs, and defines a platform-independent accessibility API, the Accessible DOM.The Accessible DOM encompasses the features of existing APIs and overcomes the(More)
Traditionally the cluster analysis has been used as a descriptive tool, in which the algorithm is used to create groups of observations based on their characteristics. In this paper the use of cluster analysis as a part of a predictive algorithm is proposed. This methodology is applied by first determining to which cluster a prospect client belongs, and(More)
In developing a predictive model, the complexity of the population used to build the model can lead to very weak scorecards when a traditional technique such as logistic regression or an MLP neural network is used. For these cases some nontraditional methodologies like boosting could help improve the predictive power of any learning algorithm. The idea(More)
Chartist and fundamentalist models have proven to be capable of replicating stylized facts on speculative markets. In general, this is achieved by specifying nonlinear interactions of otherwise linear asset price expectations of the respective trader groups. This paper investigates whether or not regressive and extrapolative expectations themselves exhibit(More)
Accessibility features in the Adobe Portable Document Format (PDF) help facilitate access to electronic information for people with disabilities. This workshop explores how to create accessible PDF documents, from within Adobe Acrobat and other applications; how to use the Adobe Acrobat PDF accessibility checker and repair workflow; best practices for(More)