J. Walter Larson

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This article is a theoretical basis for the software implementation o f t h e P h ysical-space Statistical Analysis System (PSAS) that is used for atmospheric data analysis at the NASA Data Assimilation OOce (DAO). The PSAS implements a statistical algorithm that combines irregularly spaced observations with a gridded forecast to produce an optimal estimate(More)
Multiphysics and multiscale–or coupled–systems share one fundamental requirement: Construction of coupling mechanisms to implement complex data exchanges between a system's constituent models. I have created a graphical schema for describing coupling workflows that is based on a theoretical framework for describing coupled systems. The schema combines an(More)
Introduction Earth science data span many orders of magnitude in space and time scales. These data are increasingly large and complex, often representing long time series, making them difficult to analyze, visualize, interpret, and understand. Electronic data storage and high performance computing capacity enable creation of large data repositories and(More)
Primary motivations for effective data and process provenance in science are to facilitate validation and reproduction of experiments and to assist in the interpretation of data-analysis outcomes. Central to both these aims is an understanding of the ideas and hypotheses that the data supports, and how those ideas fit into the wider scientific context. Such(More)
Among the areas of emphasis in the language-teaching profession today we find considerable emphasis on (a) evaluation, (b) contextualization, and (c) technology. Although the greater emphasis in language assessment has been on global proficiency, there is also a need to examine specific points of students' language competence in order to help them improve(More)
In this, our third progress report, we examine our progress from the perspective of our original proposal to the Scientific Discovery through Advanced Computing (SciDAC) Program. We attempt to evaluate whether our original objectives were appropriate; to what extent they have evolved and why; what progress has been made toward those objectives; and evaluate(More)