29 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Statistical Models"  
Results: 1 - 24 next
open access

Ten new checks to assess the statistical quality of Monte Carlo solutions in MCNP

Description: The central limit theorem can be applied to a Monte Carlo solution if: The random variable x has a finite mean and a finite variance; and the number N of independent observations grows large. When these two conditions are satisfied, a confidence interval based on the normal distribution with a specified coverage probability can be formed. The first requirement is generally satisfied by the knowledge of the type of Monte Carlo tally being used. The Monte Carlo practitioner has only a limited num… more
Date: February 1, 1994
Creator: Forster, R. A.; Booth, T. E. & Pederson, S. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Evaluation of the cover cracking potential due to ground subsidence at UMTRA Project disposal cells

Description: The US Department of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project requires that mill tailings, containing low-level radioactive uranium mill tailings and other waste, be stabilized and controlled by placement in an encapsulated disposal cell. The cover of the cell is a multi-layer system which includes a low-permeability earthen radon/infiltration barrier, a bedding layer, and a erosion protection layer. The radon/infiltration barrier is designed to limit the radon flux and re… more
Date: March 1, 1994
Creator: Claire, R. F.; Kuo, J. C. & Wanket, D. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Statistical and computational challenges in physical mapping

Description: One of the great success stories of modern molecular genetics has been the ability of biologists to isolate and characterize the genes responsible for serious inherited diseases like Huntington`s disease, cystic fibrosis, and myotonic dystrophy. Instrumental in these efforts has been the construction of so-called {open_quotes}physical maps{close_quotes} of large regions of human chromosomes. Constructing a physical map of a chromosome presents a number of interesting challenges to the computati… more
Date: June 1, 1994
Creator: Nelson, D. O. & Speed, T. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Design of UMTRA covers to mitigate the effect of frost penetration

Description: The Uranium Mill Tailings Remedial Action (UMTRA) Project, contracted by the US Department of Energy (DOE), requires construction of disposal cells for residual radioactive materials from abandoned uranium mill tailings. A disposal cell consists of contaminated material placed within a stabilized embankment with a top cover. The embankment and cover should be effective for up to 1000 years, to the extent reasonably achievable, and in any case for at least 200 years. The embankment cover usually… more
Date: March 1, 1994
Creator: Banani, A. M. & Claire, R. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The role of variation, error, and complexity in manufacturing defects

Description: Variation in component properties and dimensions is a widely recognized factor in product defects which can be quantified and controlled by Statistical Process Control methodologies. Our studies have shown, however, that traditional statistical methods are ineffective in characterizing and controlling defects caused by error. The distinction between error and variation becomes increasingly important as the target defect rates approach extremely low values. Motorola data substantiates our thesis… more
Date: March 1, 1994
Creator: Hinckley, C. M. & Barkan, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Professional judgment in the Data Quality Objectives process: A Bayesian approach to screening assessment

Description: The Data Quality Objectives (DQO) process provides a logical planning structure for specifying the optimal sample allocation for defensible decision making, depending on acceptable levels of decision uncertainty and anticipated sampling and measurement errors. These planning inputs must be established prior to designing the data collection activity. Application of the DQO process has traditionally been performed under the framework of Classical statistical theory; elicited decision errors have … more
Date: May 1, 1994
Creator: Black, P. K.; Neptune, M. D.; Ryti, R. T. & Hickmott, D. D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Numerical simulation of nocturnal drainage flows in an idealized valley-tributary system

Description: During 1984 and 1988 a substantial amount of meteorological field data was collected in the Brush Creek valley area of western Colorado as a part of the Atmospheric Science in Complex Terrain (ASCOT) program. This field experiment was designed to investigate the characteristics of nocturnal drainage flows in valleys as well as valley tributaries and sidewalls. The data collected during the Brush Creek experiment has been used to study a variety of nocturnal flow phenomena including: velocity an… more
Date: May 1, 1994
Creator: O`Steen, L. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Tests of a homogeneous Poisson process against clustering and other alternatives

Description: This report presents three closely related tests of the hypothesis that data points come from a homogeneous Poisson process. If there is too much observed variation among the log-transformed between-point distances, the hypothesis is rejected. The tests are more powerful than the standard chi-squared test against the alternative hypothesis of event clustering, but not against the alternative hypothesis of a Poisson process with smoothly varying intensity.
Date: May 1, 1994
Creator: Atwood, C. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Petroleum marketing monthly, May 1994

Description: The Petroleum Marketing Monthly (PMM) provides information and statistical data on a variety of crude oils and refined petroleum products. The publication presents statistics on crude oil costs and refined petroleum products sales for use by industry, government, private sector analysts, educational institutions, and consumers. Data on crude oil include the domestic first purchase price, the f.o.b. and landed cost of imported crude oil, petroleum product sales data include motor gasoline, disti… more
Date: May 26, 1994
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A combined Shewhart-CUSUM procedure with application to groundwater monitoring

Description: A combined Shewhart CUSUM statistical process control procedure is being implemented at Savannah River Site for monitoring groundwater effluent concentrations. The procedure is being developed for the Environmental Monitoring Section and will be available to yield information on remediation performance in real-time for improved decision making. The method is outlined and an application given to monitoring trichloroethylene concentrations at a Savannah River Site point of compliance well. The co… more
Date: August 1, 1994
Creator: Harris, S. P. & Tuckfield, R. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Comparison of different statistical models of turbulence by similarity methods

Description: The process of implosion by inertial confinement is perturbed by hydrodynamic instabilities such as Rayleigh-Taylor, Richtmyer-Meshkov and Kelvin-Helmholtz instabilities. They may generate turbulent flow, causing the mixing of constituents and the degradation of the symmetry of the implosion. The authors extend Barenblatt`s study (1983) of a one-equation turbulence model to a variety of two-equation models. They consider the problem of the propagation of incompressible turbulence generated by a… more
Date: May 1, 1994
Creator: Cherfils, C. & Harrison, A. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Markov Chain Model for evaluating the effectiveness of randomized surveillance procedures

Description: A Markov Chain Model has been developed to evaluate the effectiveness of randomized surveillance procedures. The model is applicable for surveillance systems that monitor a collection of assets by randomly selecting and inspecting the assets. The model provides an estimate of the detection probability as a function of the amount of time that an adversary would require to steal or sabotage the asset. An interactive computer code has been written to perform the necessary computations.
Date: January 1, 1994
Creator: Edmunds, T. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

GIS analysis of the siting criteria for the Mixed and Low-Level Waste Treatment Facility and the Idaho Waste Processing Facility

Description: This report summarizes a study conducted using the Arc/Info{reg_sign} geographic information system (GIS) to analyze the criteria used for site selection for the Mixed and Low-Level Waste Treatment Facility (MLLWTF) and the Idaho Waste Processing Facility (IWPF). The purpose of the analyses was to determine, based on predefined criteria, the areas on the INEL that best satisfied the criteria. The coverages used in this study were produced by importing the AutoCAD files that produced the maps fo… more
Date: January 1, 1994
Creator: Hoskinson, R. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Statistical parameter selection for RMS Lg amplitudes

Description: The Lg regional phase as a measure of seismic magnitude has a long history, beginning with Aki (1969). Aki`s theoretical work was refined by Herrmann (1980), and by Nuttli (1986, 1988). Nuttli used as a measure of magnitude, the third largest amplitude (peak-to-peak) in the 3.6 to 3.2 km/sec velocity (time) window. This measurement was corrected for instrument response, geometrical spreading, and anelastic attenuation, as calculated from information measured in the Lg coda, then extrapolated ba… more
Date: May 1, 1994
Creator: Hagedorn, D. N.; Anderson, K. K. & Simpson, D. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Dynamic Bayesian Filtering for Real-Time Seismic Analyses

Description: State space modeling, which includes techniques such as the Kalman filter, has been used to analyze many non-stationary time series. The ability of these dynamic models to adapt and track changes in the underlying process makes them attractive for application to the real-time analysis of three-component seismic waveforms. The authors are investigating the application of state space models formulated as Bayesian time series models to phase detection, polarization, and spectrogram estimation of s… more
Date: April 1, 1994
Creator: Blough, D. K.; Rohay, A. C.; Anderson, K. K. & Nicholson, W. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Model documentation: Natural Gas Transmission and Distribution Model of the National Energy Modeling System; Volume 1

Description: The Natural Gas Transmission and Distribution Model (NGTDM) is a component of the National Energy Modeling System (NEMS) used to represent the domestic natural gas transmission and distribution system. NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the Energy Information Administration (EIA) and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. This report documents the arc… more
Date: February 24, 1994
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Fuzzy-algebra uncertainty analysis for abnormal-environment safety assessment

Description: Many safety (risk) analyses depend on uncertain inputs and on mathematical models chosen from various alternatives, but give fixed results (implying no uncertainty). Conventional uncertainty analyses help, but are also based on assumptions and models, the accuracy of which may be difficult to assure. Some of the models and assumptions that on cursory examination seem reasonable can be misleading. As a result, quantitative assessments, even those accompanied by uncertainty measures, can give unw… more
Date: January 1, 1994
Creator: Cooper, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Table of nuclear masses according to the 1994 Thomas-Fermi model

Description: In order to formulate a statistical model of nuclear properties the authors combine the Thomas-Fermi assumption of two fermions per h{sup 3} of phase space with an effective interaction between nucleons that contains seven adjustable parameters. After allowing for shell effects, an even-odd correction and a congruence energy ({open_quotes}Wigner Term{close_quotes}), six of the seven parameters were fitted to 1654 ground state masses of nuclei with N, Z {ge} 8, together with a constraint that en… more
Date: December 1, 1994
Creator: Myers, W. D. & Swiatecki, W. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Sandia National Laboratories analysis code data base

Description: Sandia National Laboratories, mission is to solve important problems in the areas of national defense, energy security, environmental integrity, and industrial technology. The Laboratories` strategy for accomplishing this mission is to conduct research to provide an understanding of the important physical phenomena underlying any problem, and then to construct validated computational models of the phenomena which can be used as tools to solve the problem. In the course of implementing this stra… more
Date: November 1, 1994
Creator: Peterson, C. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Hits per trial: Basic analysis of binomial data

Description: This report presents simple statistical methods for analyzing binomial data, such as the number of failures in some number of demands. It gives point estimates, confidence intervals, and Bayesian intervals for the failure probability. It shows how to compare subsets of the data, both graphically and by statistical tests, and how to look for trends in time. It presents a compound model when the failure probability varies randomly. Examples and SAS programs are given.
Date: September 1, 1994
Creator: Atwood, C. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Events in time: Basic analysis of Poisson data

Description: The report presents basic statistical methods for analyzing Poisson data, such as the member of events in some period of time. It gives point estimates, confidence intervals, and Bayesian intervals for the rate of occurrence per unit of time. It shows how to compare subsets of the data, both graphically and by statistical tests, and how to look for trends in time. It presents a compound model when the rate of occurrence varies randomly. Examples and SAS programs are given.
Date: September 1, 1994
Creator: Engelhardt, M. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Choice of computer software for analysis of spectra from the Multi-Spectral Logging System

Description: We have investigated the range of software available for determination of elemental concentration from gamma-ray spectra, to learn which are most suitable for use with the Multi-spectral Logging System being developed for the Department of Energy. We believe that the spectrum fitting method will be more satisfactory than the peak-matching method.
Date: July 1, 1994
Creator: Hearst, J. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Controlled Field Study for Validation of Vadose Zone Transport Models

Description: Prediction of radionuclide migration through soil and groundwater requires models which have been tested under a variety of conditions. Unfortunately, many of the existing models have not been tested in the field, partly because such testing requires accurate and representative data. This report provides the design of a large scale field experiment representative, in terms of,surface area and depth of vadose zone, of an actual disposal area. Experiments are proposed which will yield documented … more
Date: August 1, 1994
Creator: Wierenga, P. J.; Warrick, A. W.; Yeh, T. C. & Hills, R. G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Adaptive measurement control for calorimetric assay

Description: The performance of a calorimeter is usually evaluated by constructing a Shewhart control chart of its measurement errors for a collection of reference standards. However, Shewhart control charts were developed in a manufacturing setting where observations occur in batches. Additionally, the Shewhart control chart expects the variance of the charted variable to be known or at least well estimated from previous experimentation. For calorimetric assay, observations are collected singly in a time s… more
Date: October 1, 1994
Creator: Glosup, J. G. & Axelrod, M. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen