Category Overlap and Numerical Estimation: Evidence for a Retrieval-Insensitive Distribution Matching Process

2007 ◽  
Author(s):  
Norman R. Brown ◽  
Robert B. Latimer
Keyword(s):  
Numerical Estimation ◽  
Matching Process ◽  
Distribution Matching

Under- and Over-Estimation

2011 ◽  
Vol 58 (1) ◽  
pp. 39-49 ◽  
Author(s):  
Virginie Crollen ◽  
Julie Castronovo ◽  
Xavier Seron
Keyword(s):  
Empirical Data ◽  
Accurate Estimation ◽  
Numerical Estimation ◽  
Production Task ◽  
Estimation Task ◽  
Reproduction Task ◽  
Perception Task ◽  
Adult Participants ◽  
Mapping Hypothesis ◽  
Task Perception

Over the last 30 years, numerical estimation has been largely studied. Recently, Castronovo and Seron (2007) proposed the bi-directional mapping hypothesis in order to account for the finding that dependent on the type of estimation task (perception vs. production of numerosities), reverse patterns of performance are found (i.e., under- and over-estimation, respectively). Here, we further investigated this hypothesis by submitting adult participants to three types of numerical estimation task: (1) a perception task, in which participants had to estimate the numerosity of a non-symbolic collection; (2) a production task, in which participants had to approximately produce the numerosity of a symbolic numerical input; and (3) a reproduction task, in which participants had to reproduce the numerosity of a non-symbolic numerical input. Our results gave further support to the finding that different patterns of performance are found according to the type of estimation task: (1) under-estimation in the perception task; (2) over-estimation in the production task; and (3) accurate estimation in the reproduction task. Moreover, correlation analyses revealed that the more a participant under-estimated in the perception task, the more he/she over-estimated in the production task. We discussed these empirical data by showing how they can be accounted by the bi-directional mapping hypothesis ( Castronovo & Seron, 2007 ).

Pattern Recognition for Classification and Matching of Car Tires

2005 ◽  
Vol 33 (1) ◽  
pp. 2-17 ◽  
Author(s):  
D. Colbry ◽  
D. Cherba ◽  
J. Luchini
Keyword(s):  
Computer Vision ◽  
Feature Extraction ◽  
Pattern Matching ◽  
Fourier Transforms ◽  
Two Dimensions ◽  
Multiple Sources ◽  
Matching Process ◽  
Visual Searches ◽  
New Feature ◽  
2D Fft

Abstract Commercial databases containing images of tire tread patterns are currently used by product designers, forensic specialists and product application personnel to identify whether a given tread pattern matches an existing tire. Currently, this pattern matching process is almost entirely manual, requiring visual searches of extensive libraries of tire tread patterns. Our work explores a first step toward automating this pattern matching process by building on feature analysis techniques from computer vision and image processing to develop a new method for extracting and classifying features from tire tread patterns and automatically locating candidate matches from a database of existing tread pattern images. Our method begins with a selection of tire tread images obtained from multiple sources (including manufacturers' literature, Web site images, and Tire Guides, Inc.), which are preprocessed and normalized using Two-Dimensional Fast Fourier Transforms (2D-FFT). The results of this preprocessing are feature-rich images that are further analyzed using feature extraction algorithms drawn from research in computer vision. A new, feature extraction algorithm is developed based on the geometry of the 2D-FFT images of the tire. The resulting FFT-based analysis allows independent classification of the tire images along two dimensions, specifically by separating “rib” and “lug” features of the tread pattern. Dimensionality of (0,0) indicates a smooth treaded tire with no pattern; dimensionality of (1,0) and (0,1) are purely rib and lug tires; and dimensionality of (1,1) is an all-season pattern. This analysis technique allows a candidate tire to be classified according to the features of its tread pattern, and other tires with similar features and tread pattern classifications can be automatically retrieved from the database.

Numerical estimation of volatility values from discretely observed diffusion data

2006 ◽  
Vol 9 (4) ◽  
pp. 1-36 ◽  
Author(s):  
Jakša Cvitanic ◽  
Boris Rozovskii ◽  
Ilya Zaliapin
Keyword(s):  
Numerical Estimation ◽  
Diffusion Data

Radiometric resolution and dynamic range of aerial and space images, obtained for monitoring and mapping purposes

2020 ◽  
Vol 964 (10) ◽  
pp. 40-48
Author(s):  
I.A. Anikeeva
Keyword(s):  
Dynamic Range ◽  
Numerical Estimation ◽  
Space Images

The dynamic range and radiometric resolution are among the most important indicators of aerial and space images’ fine quality. Gradation properties are of particular importance for aerial and space images, obtained for monitoring and mapping purposes, because the completeness and quality of the information on the earth’s surface objects depend on them, the accuracy of brightness features reproduction of earth’s surface objects. The author discusses various approaches to defining the concepts of dynamic range and radiometric resolution; the most proper definitions of these terms are given in the context of estimating the image’s gradation properties. The expediency of separating the concepts of nominal, actual and useful (effective) radiometric resolution is shown; their definitions are given. Methods of dynamic range and radio-metric resolution numerical estimation based on a histogram are shown. Absolute and relative indicators are considered. The advantages of using relative indicators are shown. Examples of the dynamic range and radiometric resolution evaluation are given basing upon the images obtained by ‘‘Canopus-B’’ spacecraft.

scholarly journals How Do the Timing and Duration of Courses Affect Participation in Adult Learning and Education? A Panel Analysis

2021 ◽  
pp. 074171362110190
Author(s):  
Fabian Rüter ◽  
Andreas Martin
Keyword(s):  
Adult Education ◽  
Adult Learning ◽  
Fixed Effects ◽  
Research Literature ◽  
Temporal Organization ◽  
Educational Institutions ◽  
Positive Effects ◽  
Matching Process ◽  
Education Participation ◽  
The Impact

Participation in adult learning and education requires the availability of, and accessibility to, learning opportunities provided by educational institutions. One fundamental element is time. Adult learning and education participation can only be realized by successfully matching individual time-availabilities with the temporal organization of provided courses. To address this required matching process, this study contributes to research literature as one of the first studies that investigates the impact of timing and course duration on participation counts (longitudinally). For this, we use organizational data from public adult education centers ( Volkshochschulen—VHS; the main adult education providers in Germany) from 2007 to 2017. Methodologically, random- and fixed-effects models are applied. We find significant positive effects on participation counts between increasing program breadth in terms of temporal formats and increasing average course duration.

scholarly journals Non-random sampling and association tests on realized returns and risk proxies

2021 ◽  
Author(s):  
Frank Ecker ◽  
Jennifer Francis ◽  
Per Olsson ◽  
Katherine Schipper
Keyword(s):  
Random Sampling ◽  
Reference Sample ◽  
Positive Association ◽  
Cost Of Equity ◽  
Association Tests ◽  
Random Samples ◽  
Distribution Matching ◽  
Matched Samples ◽  
Data Requirements ◽  
Selection Of

AbstractThis paper investigates how data requirements often encountered in archival accounting research can produce a data-restricted sample that is a non-random selection of observations from the reference sample to which the researcher wishes to generalize results. We illustrate the effects of non-random sampling on results of association tests in a setting with data on one variable of interest for all observations and frequently-missing data on another variable of interest. We develop and validate a resampling approach that uses only observations from the data-restricted sample to construct distribution-matched samples that approximate randomly-drawn samples from the reference sample. Our simulation tests provide evidence that distribution-matched samples yield generalizable results. We demonstrate the effects of non-random sampling in tests of the association between realized returns and five implied cost of equity metrics. In this setting, the reference sample has full information on realized returns, while on average only 16% of reference sample observations have data on cost of equity metrics. Consistent with prior research (e.g., Easton and Monahan The Accounting Review 80, 501–538, 2005), analysis using the unadjusted (non-random) cost of equity sample reveals weak or negative associations between realized returns and cost of equity metrics. In contrast, using distribution-matched samples, we find reliable evidence of the theoretically-predicted positive association. We also conceptually and empirically compare distribution-matching with multiple imputation and selection models, two other approaches to dealing with non-random samples.

scholarly journals A Novel Global Sensitivity Measure Based on Probability Weighted Moments

Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 90
Author(s):  
Shufang Song ◽  
Lu Wang
Keyword(s):  
Sensitivity Analysis ◽  
Global Sensitivity Analysis ◽  
Small Samples ◽  
Double Loop ◽  
Numerical Estimation ◽  
Global Sensitivity ◽  
Sensitivity Measure ◽  
Probability Weighted Moments ◽  
Input Variables ◽  
Single Set

Global sensitivity analysis (GSA) is a useful tool to evaluate the influence of input variables in the whole distribution range. Variance-based methods and moment-independent methods are widely studied and popular GSA techniques despite their several shortcomings. Since probability weighted moments (PWMs) include more information than classical moments and can be accurately estimated from small samples, a novel global sensitivity measure based on PWMs is proposed. Then, two methods are introduced to estimate the proposed measure, i.e., double-loop-repeated-set numerical estimation and double-loop-single-set numerical estimation. Several numerical and engineering examples are used to show its advantages.

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