4 Matching Results

Search Results

Advanced search parameters have been applied.

Statistical problems in the assessment of nuclear risks

Description: Information on nuclear power plant risk assessment is presented concerning attitudinal problems; and methodological problems involving expert opinions, human error probabilities, nonindependent events, uncertainty analysis, and acceptable risk criteria.
Date: January 1, 1980
Creator: Easterling, R. G.
Partner: UNT Libraries Government Documents Department

A Framework for Model Validation

Description: Computational models have the potential of being used to make credible predictions in place of physical testing in many contexts, but success and acceptance require a convincing model validation. In general, model validation is understood to be a comparison of model predictions to experimental results but there appears to be no standard framework for conducting this comparison. This paper gives a statistical framework for the problem of model validation that is quite analogous to calibration, with the basic goal being to design and analyze a set of experiments to obtain information pertaining to the `limits of error' that can be associated with model predictions. Implementation, though, in the context of complex, high-dimensioned models, poses a considerable challenge for the development of appropriate statistical methods and for the interaction of statisticians with model developers and experimentalists. The proposed framework provides a vehicle for communication between modelers, experimentalists, and the analysts and decision-makers who must rely on model predictions.
Date: February 2, 1999
Creator: Easterling, R.G.
Partner: UNT Libraries Government Documents Department

Agile manufacturing from a statistical perspective

Description: The objective of agile manufacturing is to provide the ability to quickly realize high-quality, highly-customized, in-demand products at a cost commensurate with mass production. More broadly, agility in manufacturing, or any other endeavor, is defined as change-proficiency; the ability to thrive in an environment of unpredictable change. This report discusses the general direction of the agile manufacturing initiative, including research programs at the National Institute of Standards and Technology (NIST), the Department of Energy, and other government agencies, but focuses on agile manufacturing from a statistical perspective. The role of statistics can be important because agile manufacturing requires the collection and communication of process characterization and capability information, much of which will be data-based. The statistical community should initiate collaborative work in this important area.
Date: October 1, 1995
Creator: Easterling, R.G.
Partner: UNT Libraries Government Documents Department

Statistical analysis of hydrologic data for Yucca Mountain; Yucca Mountain Site Characterization Project

Description: The geologic formations in the unsaturated zone at Yucca Mountain are currently being studied as the host rock for a potential radioactive waste repository. Data from several drill holes have been collected to provide the preliminary information needed for planning site characterization for the Yucca Mountain Project. Hydrologic properties have been measured on the core samples and the variables analyzed here are thought to be important in the determination of groundwater travel times. This report presents a statistical analysis of four hydrologic variables: saturated-matrix hydraulic conductivity, maximum moisture content, suction head, and calculated groundwater travel time. It is important to modelers to have as much information about the distribution of values of these variables as can be obtained from the data. The approach taken in this investigation is to (1) identify regions at the Yucca Mountain site that, according to the data, are distinctly different; (2) estimate the means and variances within these regions; (3) examine the relationships among the variables; and (4) investigate alternative statistical methods that might be applicable when more data become available. The five different functional stratigraphic units at three different locations are compared and grouped into relatively homogeneous regions. Within these regions, the expected values and variances associated with core samples of different sizes are estimated. The results provide a rough estimate of the distribution of hydrologic variables for small core sections within each region.
Date: February 1, 1992
Creator: Rutherford, B.M.; Hall, I.J.; Peters, R.R.; Easterling, R.G. & Klavetter, E.A.
Partner: UNT Libraries Government Documents Department