30 Matching Results

Search Results

Advanced search parameters have been applied.

in subjects: "Uncertainty-Analysis."

open access

Acceptance Performance Test Guideline for Utility Scale Parabolic Trough and Other CSP Solar Thermal Systems: Preprint

Prior to commercial operation, large solar systems in utility-size power plants need to pass a performance acceptance test conducted by the engineering, procurement, and construction (EPC) contractor or owners. In lieu of the present absence of ASME or other international test codes developed for this purpose, the National Renewable Energy Laboratory has undertaken the development of interim guidelines to provide recommendations for test procedures that can yield results of a high level of accu… more

Date: August 1, 2011

Creator: Mehos, M. S.; Wagner, M. J. & Kearney, D. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

ASSESSMENT OF UNCERTAINTY IN THE RADIATION DOSES FOR THE TECHA RIVER DOSIMETRY SYSTEM

In order to provide more accurate and precise estimates of individual dose (and thus more precise estimates of radiation risk) for the members of the ETRC, a new dosimetric calculation system, the Techa River Dosimetry System-2009 (TRDS-2009) has been prepared. The deterministic version of the improved dosimetry system TRDS-2009D was basically completed in April 2009. Recent developments in evaluation of dose-response models in light of uncertain dose have highlighted the importance of differen… more

Date: October 23, 2009

Creator: Napier, Bruce A.; Degteva, M. O.; Anspaugh, L. R. & Shagina, N. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

ATR 2A/2B As-Run Neutronics Uncertainty Analysis

Summary report of activities of FUJI-A assignee Hiroshi Sagara.

Date: October 1, 2009

Creator: Sagara, Hiroshi & Chang, Gray S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Conceptual and computational basis for the quantification of margins and uncertainty.

In 2001, the National Nuclear Security Administration of the U.S. Department of Energy in conjunction with the national security laboratories (i.e, Los Alamos National Laboratory, Lawrence Livermore National Laboratory and Sandia National Laboratories) initiated development of a process designated Quantification of Margins and Uncertainty (QMU) for the use of risk assessment methodologies in the certification of the reliability and safety of the nation's nuclear weapons stockpile. This presenta… more

Date: June 1, 2009

Creator: Helton, Jon Craig (Arizona State University, Tempe, AZ)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Development of Performance Acceptance Test Guidelines for Large Commercial Parabolic Trough Solar Fields: Preprint

Prior to commercial operation, large solar systems in utility-size power plants need to pass a performance acceptance test conducted by the EPC contractor or owners. In lieu of the present absence of engineering code developed for this purpose, NREL has undertaken the development of interim guidelines to provide recommendations for test procedures that can yield results of a high level of accuracy consistent with good engineering knowledge and practice. The fundamental differences between accep… more

Date: December 1, 2010

Creator: Kearney, D. & Mehos, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Error analysis in wind turbine field testing

In wind turbine field testing, one of the most important issues is understanding and accounting for data errors. Extended dynamic testing of wind turbines requires a thorough uncertainty analysis and a regimen of quality assurance steps in order to preserve accuracy. Test objectives need to be identified to determine the accuracy requirements of any data measurement, collection, and analysis process. Frequently, the uncertainty analysis reveals that the major sources of error can be allowed for… more

Date: August 1, 1994

Creator: McNiff, B & Simms, D

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

An example uncertainty and sensitivity analysis at the Horonobe site for performance assessment calculations.

Given pre-existing Groundwater Modeling System (GMS) models of the Horonobe Underground Research Laboratory (URL) at both the regional and site scales, this work performs an example uncertainty analysis for performance assessment (PA) applications. After a general overview of uncertainty and sensitivity analysis techniques, the existing GMS sitescale model is converted to a PA model of the steady-state conditions expected after URL closure. This is done to examine the impact of uncertainty in s… more

Date: August 1, 2004

Creator: James, Scott Carlton

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Experimental uncertainty estimation and statistics for data having interval uncertainty.

This report addresses the characterization of measurements that include epistemic uncertainties in the form of intervals. It reviews the application of basic descriptive statistics to data sets which contain intervals rather than exclusively point estimates. It describes algorithms to compute various means, the median and other percentiles, variance, interquartile range, moments, confidence limits, and other important statistics and summarizes the computability of these statistics as a function… more

Date: May 1, 2007

Creator: Kreinovich, Vladik (Applied Biomathematics, Setauket, New York); Oberkampf, William Louis (Applied Biomathematics, Setauket, New York); Ginzburg, Lev (Applied Biomathematics, Setauket, New York); Ferson, Scott (Applied Biomathematics, Setauket, New York) & Hajagos, Janos (Applied Biomathematics, Setauket, New York)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Extended Forward Sensitivity Analysis for Uncertainty Quantification

This report presents the forward sensitivity analysis method as a means for quantification of uncertainty in system analysis. The traditional approach to uncertainty quantification is based on a “black box” approach. The simulation tool is treated as an unknown signal generator, a distribution of inputs according to assumed probability density functions is sent in and the distribution of the outputs is measured and correlated back to the original input distribution. This approach requires large… more

Date: September 1, 2008

Creator: Zhao, Haihua & Mousseau, Vincent A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Extension and Enhancement Methods for Setting Data Quality Objectives

The project developed statistical tools for the application of decision theory and operations research methods, including cost-benefit analysis, to the DQO process for environmental clean up. A pilot study was conducted, using these methods at the Hanford site, to estimate vadose zone contamination plumes under the SX tank farm, and to help plan further sampling.

Date: March 1, 2000

Creator: Goodman, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Ideas underlying quantification of margins and uncertainties(QMU): a white paper.

This report describes key ideas underlying the application of Quantification of Margins and Uncertainties (QMU) to nuclear weapons stockpile lifecycle decisions at Sandia National Laboratories. While QMU is a broad process and methodology for generating critical technical information to be used in stockpile management, this paper emphasizes one component, which is information produced by computational modeling and simulation. In particular, we discuss the key principles of developing QMU inform… more

Date: September 1, 2006

Creator: Helton, Jon Craig; Trucano, Timothy Guy & Pilch, Martin M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Illustration of sampling-based approaches to the calculation of expected dose in performance assessments for the proposed high level radioactive waste repository at Yucca Mountain, Nevada.

A deep geologic repository for high level radioactive waste is under development by the U.S. Department of Energy at Yucca Mountain (YM), Nevada. As mandated in the Energy Policy Act of 1992, the U.S. Environmental Protection Agency (EPA) has promulgated public health and safety standards (i.e., 40 CFR Part 197) for the YM repository, and the U.S. Nuclear Regulatory Commission has promulgated licensing standards (i.e., 10 CFR Parts 2, 19, 20, etc.) consistent with 40 CFR Part 197 that the DOE m… more

Date: April 1, 2007

Creator: Helton, Jon Craig & Sallaberry, Cedric J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Improving Thermal Model Prediction Through Statistical Analysis of Irradiation and Post-Irradiation Data from AGR Experiments

As part of the Research and Development program for Next Generation High Temperature Reactors (HTR), a series of irradiation tests, designated as Advanced Gas-cooled Reactor (AGR), have been defined to support development and qualification of fuel design, fabrication process, and fuel performance under normal operation and accident conditions. The AGR tests employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule and instrumented with thermocouples (TC) embedded in graphit… more

Date: October 1, 2012

Creator: Pham, Dr. Binh T.; Hawkes, Grant L. & Einerson, Jeffrey J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Incorporating uncertainty in RADTRAN 6.0 input files.

Uncertainty may be introduced into RADTRAN analyses by distributing input parameters. The MELCOR Uncertainty Engine (Gauntt and Erickson, 2004) has been adapted for use in RADTRAN to determine the parameter shape and minimum and maximum of the distribution, to sample on the distribution, and to create an appropriate RADTRAN batch file. Coupling input parameters is not possible in this initial application. It is recommended that the analyst be very familiar with RADTRAN and able to edit or creat… more

Date: February 1, 2010

Creator: Dennis, Matthew L.; Weiner, Ruth F. & Heames, Terence John (Alion Science and Technology)

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A methodology for selecting an optimal experimental design for the computer analysis of a complex system

Investigation and evaluation of a complex system is often accomplished through the use of performance measures based on system response models. The response models are constructed using computer-generated responses supported where possible by physical test results. The general problem considered is one where resources and system complexity together restrict the number of simulations that can be performed. The levels of input variables used in defining environmental scenarios, initial and bounda… more

Date: February 3, 2000

Creator: RUTHERFORD,BRIAN M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Rate Coeﬃcient Measurements and Theoretical Analysis of the OH + (E)‑CF₃CH==CHCF₃ Reaction

Rate coeﬃcients, k, for the gas-phase reaction of the OH radical with (E)CF3CHCHCF3 ((E)-1,1,1,4,4,4-hexaﬂuoro-2-butene, HFO-1336mzz(E)) were measured over a range of temperatures (211−374 K) and bath gas pressures (20−300 Torr; He, N2) using a pulsed laser photolysis−laser-induced ﬂuorescence (PLP−LIF) technique. k1(T) was independent of pressure over this range of conditions with k1(296 K) = (1.31 ± 0.15) × 10−13 cm3 molecule−1 s−1 and k1(T) = (6.94 ± 0.80) × 10−13exp[−(496 ± 10)/T] cm 3 mol… more

Date: March 22, 2018

Creator: Baasandorj, Munkhbayar; Marshall, Paul; Waterland, Robert L.; Ravishankara, A. R. & Burkholder, James B. (James Bart), 1954-

Item Type: Article

Partner: UNT College of Science

open access

Representation of analysis results involving aleatory and epistemic uncertainty.

Procedures are described for the representation of results in analyses that involve both aleatory uncertainty and epistemic uncertainty, with aleatory uncertainty deriving from an inherent randomness in the behavior of the system under study and epistemic uncertainty deriving from a lack of knowledge about the appropriate values to use for quantities that are assumed to have fixed but poorly known values in the context of a specific study. Aleatory uncertainty is usually represented with probab… more

Date: August 1, 2008

Creator: Johnson, Jay Dean (ProStat, Mesa, AZ); Helton, Jon Craig (Arizona State University, Tempe, AZ); Oberkampf, William Louis & Sallaberry, Cedric J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A Resampling Based Approach to Optimal Experimental Design for Computer Analysis of a Complex System

The investigation of a complex system is often performed using computer generated response data supplemented by system and component test results where possible. Analysts rely on an efficient use of limited experimental resources to test the physical system, evaluate the models and to assure (to the extent possible) that the models accurately simulate the system order investigation. The general problem considered here is one where only a restricted number of system simulations (or physical test… more

Date: August 4, 1999

Creator: Rutherford, Brian

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A sampling-based computational strategy for the representation of epistemic uncertainty in model predictions with evidence theory.

Evidence theory provides an alternative to probability theory for the representation of epistemic uncertainty in model predictions that derives from epistemic uncertainty in model inputs, where the descriptor epistemic is used to indicate uncertainty that derives from a lack of knowledge with respect to the appropriate values to use for various inputs to the model. The potential benefit, and hence appeal, of evidence theory is that it allows a less restrictive specification of uncertainty than … more

Date: October 1, 2006

Creator: Johnson, J. D.; Oberkampf, William Louis; Helton, Jon Craig & Storlie, Curtis B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Sensitivity technologies for large scale simulation.

Sensitivity analysis is critically important to numerous analysis algorithms, including large scale optimization, uncertainty quantification,reduced order modeling, and error estimation. Our research focused on developing tools, algorithms and standard interfaces to facilitate the implementation of sensitivity type analysis into existing code and equally important, the work was focused on ways to increase the visibility of sensitivity analysis. We attempt to accomplish the first objective throu… more

Date: January 1, 2005

Creator: Collis, Samuel Scott; Bartlett, Roscoe Ainsworth; Smith, Thomas Michael; Heinkenschloss, Matthias (Rice University, Houston, TX); Wilcox, Lucas C. (Brown University, Providence, RI); Hill, Judith C. (Carnegie Mellon University, Pittsburgh, PA) et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Solution-verified reliability analysis and design of bistable MEMS using error estimation and adaptivity.

This report documents the results for an FY06 ASC Algorithms Level 2 milestone combining error estimation and adaptivity, uncertainty quantification, and probabilistic design capabilities applied to the analysis and design of bistable MEMS. Through the use of error estimation and adaptive mesh refinement, solution verification can be performed in an automated and parameter-adaptive manner. The resulting uncertainty analysis and probabilistic design studies are shown to be more accurate, efficie… more

Date: October 1, 2006

Creator: Eldred, Michael Scott; Subia, Samuel Ramirez; Neckels, David; Hopkins, Matthew Morgan; Notz, Patrick K.; Adams, Brian M. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Summary discussion of the 1996 performance assessment for the Waste Isolation Pilot Plant

The Waste Isolation Pilot Plant (WIPP) is under development by the US Department of Energy (DOE) for the geologic disposal of transuranic waste. The construction of complementary cumulative distribution functions (CCDFs) for total radionuclide release from the WIPP to the accessible environment is described. The resultant CCDFs (1) combine releases due to cuttings and cavings, spallings, direct brine release, and long-term transport in flowing groundwater, (2) fall substantially to the left of … more

Date: May 19, 2000

Creator: HELTON,JON CRAIG; ANDERSON,D. RICHARD; BASABILVAZO,G.; JOW,HONG-NIAN & MARIETTA,MELVIN G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Survey of sampling-based methods for uncertainty and sensitivity analysis.

Sampling-based methods for uncertainty and sensitivity analysis are reviewed. The following topics are considered: (1) Definition of probability distributions to characterize epistemic uncertainty in analysis inputs, (2) Generation of samples from uncertain analysis inputs, (3) Propagation of sampled inputs through an analysis, (4) Presentation of uncertainty analysis results, and (5) Determination of sensitivity analysis results. Special attention is given to the determination of sensitivity a… more

Date: June 1, 2006

Creator: Johnson, Jay Dean; Helton, Jon Craig; Sallaberry, Cedric J. & Storlie, Curt B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Uncertainty Analysis for Broadband Solar Radiometric Instrumentation Calibrations and Measurements: An Update; Preprint

The measurement of broadband solar radiation has grown in importance since the advent of solar renewable energy technologies in the 1970's, and the concern about the Earth's radiation balance related to climate change in the 1990's. In parallel, standardized methods of uncertainty analysis and reporting have been developed. Historical and updated uncertainties are based on the current international standardized uncertainty analysis method. Despite the fact that new and sometimes overlooked sour… more

Date: April 1, 2004

Creator: Myers, D. R.; Reda, I. M.; Wilcox, S. M. & Stoffel, T. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department