# Library

Statistics Body of Knowledge - our library content below focuses on the topics in this listing.

Webinars

### Probability of Detection Analysis for Eddy Current Inspection Systems

Fall 2011 Mini-Paper

by Brown, Jennifer;

Eddy Current (EC) inspection is a Nondestructive Testing (NDT) method commonly used for flight quality assurance of commercial, military, and rocket engine hardware. One application of EC inspection is to detect surface or near-surface anomalies before they grow to a critical length which could impact the structural integrity of the hardware. EC inspection uses the principal of electromagnetism or the production of a magnetic field by current flowing in a conductor. Anything placed in the magnetic field that has electric and/or magnetic properties will change the field and produce an EC signal. Understanding the relationship between crack size and system response is the basis for determining the detection capability of an EC system. For a given EC system, the relationship between the EC response and crack size can be evaluated by scanning a set of standard specimens with a known number and distribution of crack sizes. The results are analyzed using the "a-hat versus a" analysis method to

• Filetype: pdf
• Publish date: 2011-10
• Keywords:Nondestructive Testing (NDT), Nondestructive Evaluation (NDE), Probability of Detection (POD), Regression, Maximum likelihood estimation, Censoring, Eddy Current Inspection, Residuals

### Autocorrelated Data and SPC

Mini Paper Taken from the Summer 1993 Newsletter

by William H. Woodall and Frederick W. Faltin

This paper explains time dependent autocorrelation and proposes ways to deal with its effects on statistical control charts...

• Filetype: pdf
• Publish date: 1993-06
• Keywords:Autocorrelation, Control charts, Shewhart chart, X bar, CUSUM chart, Exponentially weighted moving average (EWMA) chart, Residuals

### The Great Stem and Leaf Plot Debate

Basic Tools Taken from the Summer 1991 Newsletter

by Troxell, Joseph;

This article discusses the benefits of stem and leaf plots and provides instructions on how to construct them...

• Filetype: pdf
• Publish date: 1991-06
• Keywords:Stem and Leaf Diagram, Histogram, Standard deviation, Normal plots, Normal distribution, Residuals, Exploratory Data Analysis (EDA)