A Note on Patterns of Wear Within the Tread Area

1979 ◽  
Vol 7 (1) ◽  
pp. 3-13
Author(s):  
F. C. Brenner ◽  
A. Kondo
Keyword(s):  
Content Analysis ◽  
Groove Depth ◽  
Climatic Data ◽  
Periodic Behavior ◽  
Harmonic Content ◽  
Straight Line ◽  
Data Points

Abstract Tread wear data are frequently fitted by a straight line having average groove depth as the ordinate and mileage as the abscissa. The authors have observed that the data points are not randomly scattered about the line but exist in runs of six or seven points above the line followed by the same number below the line. Attempts to correlate these cyclic deviations with climatic data failed. Harmonic content analysis of the data for each individual groove showed strong periodic behavior. Groove 1, a shoulder groove, had two important frequencies at 40 960 and 20 480 km (25 600 and 12 800 miles); Grooves 2 and 3, the inside grooves, had important frequencies at 10 240, 13 760, and 20 480 km (6400, 8600, and 12 800 miles), with Groove 4 being similar. A hypothesis is offered as a possible explanation for the phenomenon.

scholarly journals Modified Regression Model for the Logan Plot

2002 ◽  
Vol 22 (2) ◽  
pp. 240-244 ◽  
Author(s):  
József Varga ◽  
Zsolt Szabo
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Graphical Model ◽  
Logan Plot ◽  
Positron Emission ◽  
Straight Line ◽  
Binding Data ◽  
Data Points ◽  
Voxel Data

Logan's graphical model is a robust estimation of the total distribution volume (DVt) of reversibly bound radiopharmaceuticals, but the resulting DVt values decrease with increasing noise. The authors hypothesized that the noise dependence can be reduced by a linear regression model that minimizes the sum of squared perpendicular rather than vertical ( y) distances between the data points and fitted straight line. To test the new method, 15 levels of simulated noise (repeated 2,000 times) were added to synthetic tissue activity curves, calculated from two different sets of kinetic parameters. Contrary to the traditional method, there was no ( P > 0.05) or dramatically decreased noise dependence with the perpendicular model. Real dynamic 11C (+) McN5652 serotonin transporter binding data were processed either by applying Logan analysis to average counts of large areas or by averaging the Logan slopes of individual-voxel data. There were no significant differences between the parameters when the perpendicular regression method was used with both approaches. The presented experiments show that the DVt calculated from the Logan plot is much less noise dependent if the linear regression model accounts for errors in both the x and y variables, allowing fast creation of unbiased parametric images from dynamic positron-emission tomography studies.

The Role and Characteristics of Tactile Graphics in Secondary Mathematics and Science Textbooks in Braille

2012 ◽  
Vol 106 (9) ◽  
pp. 543-554 ◽  
Author(s):  
Derrick W. Smith ◽  
Sinikka M. Smothers
Keyword(s):  
Content Analysis ◽  
Data Analysis ◽  
Comparative Analysis ◽  
Secondary Mathematics ◽  
Likert Scale ◽  
Science Textbooks ◽  
Data Points ◽  
Strongly Agree ◽  
Mathematics And Science ◽  
Tactile Graphics

IntroductionThe purpose of the study presented here was to determine how well tactile graphics (specifically data analysis graphs) in secondary mathematics and science braille textbooks correlated with the print graphics.MethodA content analysis was conducted on 598 separate data analysis graphics from 10 mathematics and science textbooks. The researchers (the authors) cross-validated the findings through a comparative analysis of the tactile graphics of five shared textbooks.ResultsDiscrepancies were found between the print graphic and the tactile graphic in 12.5% of the sample. The most common discrepancy was differences in how data lines and data points were individualized in the print graphic compared to the tactile graphic. On the basis of the reviews of the graphics, the researchers answered a 5-point Likert-scale question (from 1 = strongly disagree to 5 = strongly agree) asking if the “tactile graphic is a valid representation of the print graphic.” The overall score for the sample was 3.71 (SD = 1.60), with a Krippendorff alpha of 0.6328 (the measure of disagreement and alpha > 0.70 are consider moderate).DiscussionThe findings demonstrate that while the majority of tactile graphics have good correlations to their print counterparts, there is still room for improvement. Some transcribers omitted a tactile graphic without providing a reason. Forty graphics (6.7%) were omitted from the braille transcription. Two textbooks were missing more than 85% of the tactile graphics of the data graphs.Implications for PractitionersTactile graphics in math and science books are important for a student to understand. Although most transcribers do an excellent job of creating valid tactile graphics, problems with many graphics still exist in textbooks. Practitioners need constantly to review the tactile graphics that are used in all classrooms and be prepared to create their own if needed.

Content analysis of child user and carer perspectives of ankle–foot orthoses

2020 ◽  
pp. 030936462095290
Author(s):  
David Lahoud ◽  
Christine HE Teng ◽  
Erez Nusem ◽  
Joshua Burns ◽  
Cara Wrigley ◽  
...  
Keyword(s):  
Content Analysis ◽  
User Experience ◽  
Secondary Data ◽  
Foot Orthoses ◽  
Ankle Foot Orthosis ◽  
Online Platforms ◽  
Ankle Foot Orthoses ◽  
Data Points ◽  
Negative Feelings ◽  
Foot Orthosis

Background: The evaluation of ankle–foot orthoses is primarily focused on biomechanical performance, with comparatively less studies pertaining to users’ quality of life and experiential factors. Objectives: To investigate how child users regard acquisition and use of ankle–foot orthoses through the perspectives of child users, parents/carers and practitioners. Study design: Inductive content analysis of secondary data. Methods: Child user and parent/carer perspectives, as communicated by them and by practitioners, were collected from online platforms and formal publications. Data and themes were analysed through an inductive approach. Investigator triangulation was used to increase trustworthiness and reduce bias. Results: We found and analysed 223 data points from 30 informal online platforms and 15 formal publications. These data clustered into five key themes relating to user experience with ankle–foot orthoses, including materials, structure, aesthetics, service and impact. Child users had mixed opinions about ankle–foot orthoses, reporting satisfaction with the functional improvements resulting from ankle–foot orthosis wear, while noting negative feelings from the experience of acquiring and using the device. Conclusion: This research suggests that considering the five themes in ankle–foot orthosis provision could improve the child user experience, inform future ankle–foot orthosis design, and improve clinical outcomes.

Harmonic content analysis by analog mixing

1983 ◽  
Vol 21 (5) ◽  
pp. 330-332
Author(s):  
Harry A. Ashworth ◽  
Harold B. Lefcourt
Keyword(s):  
Content Analysis ◽  
Harmonic Content

The Discrimination of Dynamic Orientation Changes in Gratings

Perception ◽  
1995 ◽  
Vol 24 (6) ◽  
pp. 665-679 ◽  
Author(s):  
Michael J Wright ◽  
Kevin N Gurney
Keyword(s):  
Spatial Frequency ◽  
Visual Memory ◽  
Frequency Function ◽  
Short Isis ◽  
Angular Rotation ◽  
Spatial Frequencies ◽  
Straight Line ◽  
Order Of Magnitude ◽  
Data Points ◽  
Best Fitting

Thresholds were measured for discrimination of direction of a step angular rotation of gratings. The addition of simultaneous phase displacements (translation) had little effect on rotation thresholds for gratings over a considerable range; discrimination of rotation is unaffected by random directional translations an order of magnitude larger. Angular rotation discrimination thresholds increased with interstimulus interval (ISI). Thus discrimination is based at short ISIs (180 ms or less) on a percept of rotary motion, but at ISIs of several seconds by a spatial strategy (comparing static component orientations) relying on visual memory. Data points for the short-ISI region fell below the best-fitting straight line, and the slope of the short-ISI region of the curve was steeper than that of the long-ISI region. However, when either compound or simple gratings with uncorrelated spatial frequencies were used in the two stimulus frames, there was no evidence for a separate function at short ISIs. Orientation-change thresholds were measured for simple gratings as a function of contrast and spatial frequency. The contrast function showed saturation and the spatial frequency function was U-shaped. Rotation sensitivity for gratings is thus similar in its spatiotemporal properties to translation sensitivity. The findings support the proposal that rotation discrimination (at short ISIs) is achieved by a template mechanism combining signals from different directional detectors, rather than by cognitive comparison of the outputs of the directional mechanisms themselves.

Effect of Tire Wear on Wear Rate

1975 ◽  
Vol 3 (4) ◽  
pp. 235-251 ◽  
Author(s):  
F. C. Brenner ◽  
S. R. Scheiner ◽  
A. Kondo
Keyword(s):  
Wear Rate ◽  
Traffic Safety ◽  
Regression Line ◽  
Groove Depth ◽  
Specific Method ◽  
Highway Traffic ◽  
National Highway Traffic Safety ◽  
Geometric Means ◽  
Straight Line ◽  
Stringent Quality

Abstract A question arises as to whether the wear rate of tires is constant under constant conditions and whether the tread life of tires may therefore be projected by linear extrapolation from low mileage tests. A second question arises as to whether commercially produced tires are uniform enough to serve as monitors of environmental change. A third question concerns the specific method of estimating the wear rate. This paper reports the results of experiments conducted on the National Highway Traffic Safety Administration test course designed to supply data relating to these questions. Regression of average groove depth against mileage for each of 27 tires gave a straight line which accounted for over 99% of the variability with a standard deviation of about 2 mils. Tread life projected from a 6400-mile (10 300-km) test gave on the average the same tread life as projected at higher mileages. A bias tire built under stringent quality control specifications and the radial tire selected for monitoring environmental effects were very homogeneous. The bias and belted bias course-monitoring tires were more variable. Various methods of estimating the wear rate and use of the multiplicative model (requiring geometric means) for analysis for factor effects are discussed. The regression line method is chosen for tire rating.

scholarly journals Measures describing curvilinear short fiber distributions

2020 ◽  
Author(s):  
Stefan Hartmann ◽  
Teresa Liese
Keyword(s):  
Short Fiber ◽  
Mean Deviation ◽  
Injection Molding Process ◽  
Molding Process ◽  
Reinforced Plastics ◽  
Straight Line ◽  
Data Points ◽  
Fiber Reinforced Plastics ◽  
Ct Data ◽  
Continuous Interpolation

Abstract In this article, we discuss measures for fibers having a curvilinear shape. This is the case, for example, for man-made cellulose fibers having a weak stiffness. The fibers are bent during the injection molding process of short fiber reinforced plastics. For this purpose, $$\mu $$ μ -CT data can be evaluated and several measures can be introduced defining the geometrical orientation of the fibers. These measures are the length, a mean curvature, and the mean torsion. Furthermore, a mean orientation of a fiber and a mean deviation to a straight line can be defined. Additionally, to these measures, which are based on a continuous interpolation of given data points, discretized quantities only considering the data points are compared. Finally, the distributions of these measures at real $$\mu $$ μ -CT data are provided.

A simple graphic method to assess correlation

2021 ◽  
Vol 10 (1) ◽  
pp. 1-2
Author(s):  
Othmar W Winkler
Keyword(s):  
Correlation Analysis ◽  
Vertical Axis ◽  
Graphic Method ◽  
Data Set ◽  
Visual Appearance ◽  
Straight Line ◽  
Data Points ◽  
The Individual ◽  
Student Grades ◽  
Early English

This study explores the correlation between two variables and to demonstrate a simple graphic method to assess their degree of correlation. Following the lead of early English biometricians, it has been tacitly assumed that the studied variables develop in the same direction: when variable A’s measurements are higher from one object to another, the measurements of variable B, also are higher. The customary measure of co-relation relies on a least squares fitted trend line, then assuming that the trend is more real than, and has priority over the individually recorded data. The situation changes when measurements of variables develop in opposite directions: The very first data set I used to perform a correlation analysis was a study of student grades achieved and the percentage of their having missed classes: the more a student was absent from class, the lower were his achieved grades. In that situation the accepted model of correlation analysis – the mathematically fitted straight line and the squared distance of each student’s record from that line - was not appropriate. The usual correlation coefficient contradicted visual evidence of those data because the model underlying that situation treats the individual data as having more reality value than the general trend, but not as deviations or errors. The visual appearance, the graph of that situation, resembles a rectangular triangle, formed by the horizontal and vertical axis as its catheters, and the hypotenuse formed by a line through and representing the highest data points. This image justifies the expression “Triangular correlation”.

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