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in subjects: "Probability"

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Why projects often fail even with high cost contingencies

In this note we assume that the individual risks have been adequately quantified and the total project cost contingency adequately computed to ensure an agreed-to probability or confidence level that the total project cost estimate will not be exceeded. But even projects that implement such a process are likely to result in significant cost overruns and/or project failure if the project manager allocates the contingencies to the individual subsystems. The intuitive and mathematically valid solu… more

Date: February 28, 2002

Creator: Kujawski, Edouard

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Measurement of the t{bar t} cross section at {radical}s = 1.96 TeV

A measurement of the t{bar t} cross section at {radical}s = 1.96 TeV is carried out on data samples of {approx}40 pb{sup -1} in dilepton channels (e{mu}, ee and {mu}{mu}) and lepton+jets channels using two complementary approaches: a fully topological analysis and a soft-muon-tag. Overall, 17 events are observed with an expected background of 6.5 {+-} 0.6. This excess corresponds to an observation probability of three standard deviations and the measured t{bar t} cross section is: {sigma}{sub p… more

Date: July 29, 2003

Creator: al., Victor Abazov et

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Sensors for Screening and Surveillance

Much attention, in fact an entire session at this conference, is being devoted to protecting the United States against human threats--individuals who may pose a danger by their mere presence on US soil. However, tomorrow's terrorists will employ weapons in their attacks, and we must also be diligent in preventing these weapons from reaching their targets. Sensors can play an important role in detecting these weapons before they achieve their desired effects. A sensor system can best be understo… more

Date: March 5, 2002

Creator: Dye, D. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Estimation of upper bound probabilities for rare events resulting from nearby explosions

It is sometimes necessary to deploy, transport and store weapons containing high explosives (HE) in proximity. Accident analyses of these activities may include nearby explosion scenarios in which fragments from an exploding (donor) weapon impact a second (acceptor) weapon. Weapon arrays are designed to miti- gate consequences to potential acceptor weapons, but unless initiation of an accep- tor's HE is impossible, outcomes such as detonation must be considered. This paper describes an approach… more

Date: September 19, 1998

Creator: Luck, L.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Class-specific Error Bounds for Ensemble Classifiers

The generalization error, or probability of misclassification, of ensemble classifiers has been shown to be bounded above by a function of the mean correlation between the constituent (i.e., base) classifiers and their average strength. This bound suggests that increasing the strength and/or decreasing the correlation of an ensemble's base classifiers may yield improved performance under the assumption of equal error costs. However, this and other existing bounds do not directly address applica… more

Date: October 6, 2009

Creator: Prenger, Ryan J.; Lemmond, Tracy D.; Varshney, Kush R.; Chen, Barry Y. & Hanley, William G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

On thermodynamic and microscopic reversibility

The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversib… more

Date: July 12, 2011

Creator: Crooks, Gavin E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Confidence Probability versus Detection Probability

In a discovery sampling activity the auditor seeks to vet an inventory by measuring (or inspecting) a random sample of items from the inventory. When the auditor finds every sample item in compliance, he must then make a confidence statement about the whole inventory. For example, the auditor might say: ''We believe that this inventory of 100 items contains no more than 5 defectives with 95% confidence.'' Note this is a retrospective statement in that it asserts something about the inventory af… more

Date: August 18, 2005

Creator: Axelrod, M

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Waste Package Misload Probability

The objective of this calculation is to calculate the probability of occurrence for fuel assembly (FA) misloads (i.e., Fa placed in the wrong location) and FA damage during FA movements. The scope of this calculation is provided by the information obtained from the Framatome ANP 2001a report. The first step in this calculation is to categorize each fuel-handling events that occurred at nuclear power plants. The different categories are based on FAs being damaged or misloaded. The next step is t… more

Date: November 20, 2001

Creator: Knudsen, J.K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Statistical Correlations and Intensity Spiking in the Sase Fel.

In the linear regime before saturation, we describe the statistical correlations in the narrow band chaotic output of the SASE FEL. At a fixed position along the undulator axis, we derive joint probability distributions for the intensity in the output pulse to have values I{sub 1} and I{sub 2} at times t{sub 1} and t{sub 2}, and for the spectral intensity to have values {tilde I}{sub 1} and {tilde I}{sub 2} at frequencies {omega}{sub 1} and {omega}{sub 2}. Probability distributions for the peak… more

Date: September 19, 2001

Creator: Krinsky, S. & Gluckstern, R. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Damage Identification with Linear Discriminant Operators

This paper explores the application of statistical pattern recognition and machine learning techniques to vibration-based damage detection. First, the damage detection process is described in terms of a problem in statistical pattern recognition. Next, a specific example of a statistical-pattern-recognition-based damage detection process using a linear discriminant operator, ''Fisher's Discriminant'', is applied to the problem of identifying structural damage in a physical system. Accelerometer… more

Date: February 8, 1999

Creator: Farrar, C. R.; Nix, D. A.; Duffey, T. A.; Cornwell, P. J. & Pardoen, G. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Inferences from Rossi Traces.

The authors an uncertainty analysis of data taken using the Rossi technique, in which the horizontal oscilloscope sweep is driven sinusoidally in time ,while the vertical axis follows the signal amplitude. The analysis is done within a Bayesian framework. Complete inferences are obtained by tilting the Markov chain Monte Carlo technique, which produces random samples from the posterior probability distribution expressed in terms of the parameters.

Date: September 8, 2000

Creator: Hanson, Kenneth M. & Booker, Jane M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Statistical Correlations and Intensity Spiking in the Sase Fel.

Date: September 19, 2001

Creator: Krinsky, S. & Gluckstern, R. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Experimental Design for a Sponge-Wipe Study to Relate the Recovery Efficiency and False Negative Rate to the Concentration of a Bacillus anthracis Surrogate for Six Surface Materials

Two concerns were raised by the Government Accountability Office following the 2001 building contaminations via letters containing Bacillus anthracis (BA). These included the: 1) lack of validated sampling methods, and 2) need to use statistical sampling to quantify the confidence of no contamination when all samples have negative results. Critical to addressing these concerns is quantifying the probability of correct detection (PCD) (or equivalently the false negative rate FNR = 1 − PCD). The … more

Date: December 16, 2010

Creator: Piepel, Gregory F.; Amidan, Brett G.; Krauter, Paula & Einfeld, Wayne

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A Unified Monte Carlo Approach to Fast Neutron Cross Section Data Evaluation.

A unified Monte Carlo (UMC) approach to fast neutron cross section data evaluation that incorporates both model-calculated and experimental information is described. The method is based on applications of Bayes Theorem and the Principle of Maximum Entropy as well as on fundamental definitions from probability theory. This report describes the formalism, discusses various practical considerations, and examines a few numerical examples in some detail.

Date: March 3, 2008

Creator: Smith, D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Accounting for false negatives in hotspot detection

Hotspot sampling designs are used in environmental sampling to identify the location of one (or more) contiguous regions of elevated contamination. These regions are known as hotspots. The problem of how to calculate the probability of detecting an elliptical hotspot using a rectangular or triangular grid of sampling points was addressed by Singer and Wickman in 1969. This approach presumed that any sample which coincided with a hotspot would detect the hotspot without error. However, for many … more

Date: August 28, 2007

Creator: Sego, Landon H. & Wilson, John E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Probability Estimation of CO2 Leakage Through Faults at Geologic Carbon Sequestration Sites

Leakage of CO{sub 2} and brine along faults at geologic carbon sequestration (GCS) sites is a primary concern for storage integrity. The focus of this study is on the estimation of the probability of leakage along faults or fractures. This leakage probability is controlled by the probability of a connected network of conduits existing at a given site, the probability of this network encountering the CO{sub 2} plume, and the probability of this network intersecting environmental resources that m… more

Date: November 1, 2008

Creator: Zhang, Yingqi; Oldenburg, Curt; Finsterle, Stefan; Jordan, Preston & Zhang, Keni

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Characterizing fault-plume intersection probability for geologic carbon sequestration risk assessment

Leakage of CO{sub 2} out of the designated storage region via faults is a widely recognized concern for geologic carbon sequestration. The probability of such leakage can be separated into the probability of a plume encountering a fault and the probability of flow along such a fault. In the absence of deterministic fault location information, the first probability can be calculated from regional fault population statistics and modeling of the plume shape and size. In this study, fault statistic… more

Date: November 1, 2008

Creator: Jordan, Preston D.; Oldenburg, Curtis M. & Nicot, Jean-Philippe

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Large Releases from CO2 Storage Reservoirs: A Discussion ofNatural Analogs, FEPS, and Modeling Needs

While the purpose of geologic storage in deep saline formations is to trap greenhouse gases underground, the potential exists for CO{sub 2} to escape from the target reservoir, migrate upward along permeable pathways, and discharge at the land surface. In this paper, we evaluate the potential for such CO{sub 2} discharges based on the analysis of natural analogs, where large releases of gas have been observed. We are particularly interested in circumstances that could generate sudden, possibly … more

Date: November 1, 2005

Creator: Birkholzer, J.; Pruess, K.; Lewicki, J. L.; Rutqvist, J.; Tsang, C-F. & Karimjee, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Material-based Stratification

A simple probability model was applied to detection sampling in a room or space in which different surface materials are present. The model assesses the overall detection capability when the sampling and analytical methods have different performance properties for the different materials. The results suggest that some common sampling strategies may not be ideal. In particular: (1) In a single room or area that includes different surface types with different detection properties, do not use a si… more

Date: May 31, 2007

Creator: MacQueen, D H

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The Application of Reliability-Based Design Factors In Stress Corrosion Cracking Evaluations

First-order reliability methodology (FORM) is used to develop reliability-based design factors for deterministic analyses of stress corrosion cracking. The basic elements of FORM as applied to structural reliability problems are reviewed and then employed specifically to stress corrosion cracking evaluations. Failure due to stress corrosion cracking is defined as crack initiation followed by crack growth to a critical depth. The stress corrosion cracking process is thus represented in terms of … more

Date: December 20, 2001

Creator: Friedman, E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Analysis of Wind Power and Load Data at Multiple Time Scales

In this study we develop and apply new methods of data analysis for high resolution wind power and system load time series, to improve our understanding of how to characterize highly variable wind power output and the correlations between wind power and load. These methods are applied to wind and load data from the ERCOT region, and wind power output from the PJM and NYISO areas. We use a wavelet transform to apply mathematically well-defined operations of smoothing and differencing to the time… more

Date: December 20, 2010

Creator: Coughlin, Katie & Eto, J.H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Computing and Visualizing Reachable Volumes for Maneuvering Satellites

Detecting and predicting maneuvering satellites is an important problem for Space Situational Awareness. The spatial envelope of all possible locations within reach of such a maneuvering satellite is known as the Reachable Volume (RV). As soon as custody of a satellite is lost, calculating the RV and its subsequent time evolution is a critical component in the rapid recovery of the satellite. In this paper, we present a Monte Carlo approach to computing the RV for a given object. Essentially, o… more

Date: September 11, 2011

Creator: Jiang, M.; de Vries, W. H.; Pertica, A. J. & Olivier, S. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Model Components of the Certification Framework for Geologic Carbon Sequestration Risk Assessment

We have developed a framework for assessing the leakage risk of geologic carbon sequestration sites. This framework, known as the Certification Framework (CF), emphasizes wells and faults as the primary potential leakage conduits. Vulnerable resources are grouped into compartments, and impacts due to leakage are quantified by the leakage flux or concentrations that could potentially occur in compartments under various scenarios. The CF utilizes several model components to simulate leakage scena… more

Date: June 1, 2009

Creator: Oldenburg, Curtis M.; Bryant, Steven L.; Nicot, Jean-Philippe; Kumar, Navanit; Zhang, Yingqi; Jordan, Preston et al.

Item Type: Book

Partner: UNT Libraries Government Documents Department

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The Design and Analysis of Salmonid Tagging Studies in the Columbia Basin : Volume XVII : Effects of Ocean Covariates and Release Timing on First Ocean-Year Survival of Fall Chinook Salmon from Oregon and Washington Coastal Hatcheries.

Effects of oceanographic conditions, as well as effects of release-timing and release-size, on first ocean-year survival of subyearling fall chinook salmon were investigated by analyzing CWT release and recovery data from Oregon and Washington coastal hatcheries. Age-class strength was estimated using a multinomial probability likelihood which estimated first-year survival as a proportional hazards regression against ocean and release covariates. Weight-at-release and release-month were found t… more

Date: May 1, 2001

Creator: Burgess, Caitlin & Skalski, John R.

Item Type: Report

Partner: UNT Libraries Government Documents Department