Statistical Methods for Estimating Crack Detection Probabilities

2009 ◽  
pp. 79-79-16 ◽  
Author(s):  
AP Berens ◽  
PW Hovey
Keyword(s):  
Statistical Methods ◽  
Crack Detection ◽  
Detection Probabilities

THE DETECTION PROBABILITY IMPROVEMENT OF THE FAR-SIDE CRACK ON THE HIGH LIFT-OFF USING THE MAGNETIC CAMERA

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4631-4636 ◽  
Author(s):  
JINYI LEE ◽  
JISEONG HWANG
Keyword(s):  
Magnetic Field ◽  
Crack Detection ◽  
Magnetic Lens ◽  
High Lift ◽  
Crack Volume ◽  
Detection Probabilities ◽  
Side Crack ◽  
Lift Off ◽  
Magnetic Camera ◽  
The Relationship

To evaluate cracks using magnetic flux leakage (MFL), the distribution of magnetic field (DMF) near the crack should be quantified. A narrow spatial resolution of DMF is demanded around the crack. Also the lift-off should increase over several mm to protect the sensors from environments such as high temperature, dust, and vibration. Furthermore, the MFL must be amplified to detect a far-side crack because the MFL will concentrate in the ferromagnetic specimen and will be weak. The magnetic camera and magnetic lens could be useful for high lift-off conditions such as in nondestructive testing of a far-side environment. The far-side crack detection probabilities, Max(∂B/∂x) and RMS(∂B/∂x), were improved by about 20~60% by using the magnetic lens. The crack can be easily detected by using the 1/4RMS algorithm. Finally, an equation that expresses the relationship between the volume of crack and Max(∂B/∂x) is proposed. This equation is based on the principle that the magnetic field is inversely proportional to the square of the lift-off and is useful for determining the crack volume when the lift-off is known.

Statistics and parallaxes

1978 ◽  
Vol 48 ◽  
pp. 7-29
Author(s):  
T. E. Lutz
Keyword(s):  
Experimental Design ◽  
Statistical Methods ◽  
Review Paper ◽  
Systematic Errors ◽  
Past Experience ◽  
Random Errors ◽  
Trigonometric Parallaxes ◽  
Systematic And Random Errors

This review paper deals with the use of statistical methods to evaluate systematic and random errors associated with trigonometric parallaxes. First, systematic errors which arise when using trigonometric parallaxes to calibrate luminosity systems are discussed. Next, determination of the external errors of parallax measurement are reviewed. Observatory corrections are discussed. Schilt’s point, that as the causes of these systematic differences between observatories are not known the computed corrections can not be applied appropriately, is emphasized. However, modern parallax work is sufficiently accurate that it is necessary to determine observatory corrections if full use is to be made of the potential precision of the data. To this end, it is suggested that a prior experimental design is required. Past experience has shown that accidental overlap of observing programs will not suffice to determine observatory corrections which are meaningful.

Three-Dimensional Ultrasonic Crack Detection in Anisotropic Materials

1997 ◽  
Vol 9 (2) ◽  
pp. 59-79 ◽  
Author(s):  
J. Mattsson ◽  
A. J. Niklasson ◽  
A. Eriksson
Keyword(s):  
Crack Detection ◽  
Three Dimensional ◽  
Anisotropic Materials

Review of Statistical Methods for Rates and Proportions.

1973 ◽  
Vol 18 (11) ◽  
pp. 562-562
Author(s):  
B. J. WINER
Keyword(s):  
Statistical Methods

Review of Statistical Methods in Education and Psychology.

1996 ◽  
Vol 41 (12) ◽  
pp. 1224-1224
Author(s):  
Terri Gullickson
Keyword(s):  
Statistical Methods
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