Determination of Measurement Data Quality and Establishment of Achievable Goals for Environmental Measurements

2008 ◽  
pp. 41-41-12
Author(s):  
WJ Mitchell ◽  
RC Rhodes ◽  
FF McElroy
Keyword(s):  
Data Quality ◽  
Measurement Data

scholarly journals Effect of data quality on estimates of farm infectiousness trends in the UK 2001 foot-and-mouth disease epidemic

2006 ◽  
Vol 4 (13) ◽  
pp. 235-241 ◽  
Author(s):  
Nicholas J Savill ◽  
Darren J Shaw ◽  
Rob Deardon ◽  
Michael J Tildesley ◽  
Matthew J Keeling ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Data Quality ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Inaccurate Data ◽  
Foot And Mouth ◽  
The Uk ◽  
Parameter Values

Most of the mathematical models that were developed to study the UK 2001 foot-and-mouth disease epidemic assumed that the infectiousness of infected premises was constant over their infectious periods. However, there is some controversy over whether this assumption is appropriate. Uncertainty about which farm infected which in 2001 means that the only method to determine if there were trends in farm infectiousness is the fitting of mechanistic mathematical models to the epidemic data. The parameter values that are estimated using this technique, however, may be influenced by missing and inaccurate data. In particular to the UK 2001 epidemic, this includes unreported infectives, inaccurate farm infection dates and unknown farm latent periods. Here, we show that such data degradation prevents successful determination of trends in farm infectiousness.

Evaluation of Actual Geometric Tolerances Using Coordinate Measuring Machine Data

1989 ◽  
Author(s):  
W. H. ElMaraghy ◽  
Z. Wu ◽  
H. A. ElMaraghy
Keyword(s):  
Three Dimensional ◽  
Measurement Data ◽  
Simulated Data ◽  
Coordinate Measuring Machine ◽  
Optimization Techniques ◽  
Test Cases ◽  
Tolerance Zone ◽  
Geometric Tolerances ◽  
Measuring Machine

Abstract This paper focuses on the development of a procedure and algorithms for the systematic comparison of geometric variations of measured features with their specified geometric tolerances. To automate the inspection of mechanical parts, it is necessary to analyze the measurement data captured by coordinate measuring machines (CMM) in order to detect out-of-tolerance conditions. A procedure for determining the geometric tolerances from the measured three dimensional coordinates on the surface of a cylindrical feature is presented. This procedure follows the definitions of the geometric tolerances used in the current Standards, and is capable of determining the value of each geometric tolerance from the composite 3-D data. The developed algorithms adopt the minimum tolerance zone criterion. Nonlinear numerical optimization techniques are used to fit the data to the minimum tolerance zone. Two test cases are given in the paper which demonstrate the successful determination of geometric tolerances from given simulated data.

A Methodology to Assure Measurement Data Quality for Key Engineering Materials

2010 ◽  
Vol 108-111 ◽  
pp. 972-978
Author(s):  
Ying Su ◽  
Jing Hua Huang ◽  
Latif Al-Hakim
Keyword(s):  
Decision Making ◽  
Data Quality ◽  
Measurement Data ◽  
Limited Attention ◽  
Decision Making Process ◽  
Precision Determination ◽  
Accuracy And Precision ◽  
Process Documentation ◽  
Engineering Materials

Purpose – Only limited attention has been paid to the issue of Measurement Data Quality (MDQ) in a metrology context. To address this critique of the literature a methodology to assure MDQ was proposed. Methodology – The study proposes a methodology which consists of four steps can be used to 1 identify the importance of a measurement (identification), 2 determine accuracy and precision (determination), 3 evaluate the criticality of the measurement to its impact on the final result (evaluation) and 4 record the facts that influenced the decision making process (documentation). Findings –When followed and properly documented, these four steps can help ensure our measurements are valid and worthwhile. Identifying the important measurements that are made, determining the level of accuracy required and then using the proper tools to make the measurements will yield valid, useful results.

Accurate Determination of Object Position from Imprecise Data

1998 ◽  
Vol 120 (4) ◽  
pp. 559-564 ◽  
Author(s):  
K. C. Gupta ◽  
P. Chutakanonta
Keyword(s):  
Accurate Determination ◽  
Measurement Data ◽  
Decomposition Methods ◽  
Basic Method ◽  
Random Errors ◽  
Object Position ◽  
Cad Cam ◽  
Simulator Design ◽  
Vehicle Simulator

The problem of accurate determination of object position from imprecise and excess measurement data arises in kinematics, biomechanics, robotics, CAD/CAM and flight/vehicle simulator design. Several methods described in the literature are reviewed. Two new methods which take advantage of the modern matrix oriented software (e.g., MATLAB, IMSL, EISPACK) are presented and compared with a “basic” method. It is found that both of the proposed decomposition methods (I: SVD/QR and II: SVD/QS) give better absolute results than a “basic” method available from the text books. On a relative basis, the second method (SVD/QS Decomposition) gives slightly better results than the first method (SVD/QR Decomposition). Examples are presented for the cases when the points chosen are nearly dependent and when the independent points have small random errors in their coordinates.

Reconnaissance 3-D Seismic as a Modern Exploration Tool

1988 ◽  
Vol 6 (2) ◽  
pp. 118-125
Author(s):  
D.J. Norris
Keyword(s):  
Data Quality ◽  
Accurate Determination ◽  
Considerable Improvement ◽  
Critical Parameters ◽  
Near Surface ◽  
Line Spacing ◽  
Line Separation ◽  
Exploration Tool ◽  
Reliable Interpretation

TCPL has recently carried out ‘reconnaissance or exploration’ 3-D surveys, in three different blocks, each designed to solve a different type of problem. In each case a considerable improvement in data quality and the resulting structural/stratigraphic interpretation was achieved. The Kupe South structure is a wrench-induced feature cross-cut by numerous small-medium faults. Stratigraphic changes across the prospect produce a variable quality seismic event at the top reservoir level. The Pataka Prospect comprises a narrow horst block trend within the Oakura fault zone, offshore New Plymouth. Accurate determination of potential reserves required a reliable interpretation of the fault configuration, and the amount of displacement of the reservoir horizon by the critical faults. The Waitara Prospect is affected by a ‘no-data’ zone possibly associated with volcanics in the near surface. It was necessary to define the extent and nature of the no-data zone and to calculate the effect of the interpreted volcanics on the time structure map. Prior to the surveys we modelled the effects of such critical parameters as sail-line separation, final interpolation spacing and the dimensions of the 3-D grids using existing 2-D data. Good results were obtained with a wider line spacing than is strictly required for true 3-D. Whilst the Reconnaissance 3-D method has not removed all of the difficulties with interpretation, a considerable improvement was obtained in data quality and ease of interpretation.

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