scholarly journals VALIDATION OF LIDAR SURVEY DATA BY COMPARISON OF SEVERAL UNCERTAINTY MODELS

2020 ◽  
Vol XLIII-B3-2020 ◽  
pp. 1385-1390
Author(s):  
N. Seube
Keyword(s):  
Point Cloud ◽  
A Priori ◽  
A Posteriori ◽  
Data Set ◽  
Timing Errors ◽  
Beam Incidence ◽  
A Priori Uncertainty ◽  
Uncertainty Models ◽  
Attitude Uncertainty ◽  
The Relationship

Abstract. This paper introduce a new method for validating the precision of an airborne or a mobile LiDAR data set. The proposed method is based on the knowledge of an a Combined Standard Measurement Uncertainty (CSMU) model which describes LiDAR point covariance matrix and thus uncertainty ellipsoid. The model we consider includes timing errors and most importantly the incidence of the LiDAR beam. After describing the relationship between the beam incidence and other variable uncertainty (especially attitude uncertainty), we show that we can construct a CSMU model giving the covariance of each oint as a function of the relative geometry between the LiDAR beam and the point normal. The validation method we propose consist in comparing the CSMU model (predictive a priori uncertainty) t the Standard Deviation Alog the Surface Normal (SDASN), for all set of quasi planr segments of the point cloud. Whenever the a posteriori (i.e; observed by the SDASN) level of uncertainty is greater than a priori (i.e; expected) level of uncertainty, the point fails the validation test. We illustrate this approach on a dataset acquired by a Microdrones mdLiDAR1000 system.

John Stuart Mill's Method In Principle and Practice: A Review of the Evidence

1999 ◽  
Vol 21 (4) ◽  
pp. 369-397 ◽  
Author(s):  
Samuel Hollander ◽  
Sandra Peart
Keyword(s):  
Economic Theory ◽  
Political Economy ◽  
A Priori ◽  
A Posteriori ◽  
Actual Case ◽  
Apparent Position ◽  
Starting Point ◽  
Definition Of ◽  
Sharp Criticism ◽  
The Relationship

Our concern is John Stuart Mill's methodological pronouncements, his actual practice, and the relationship between them. We argue that verification played a key role in Mill's method, both in principle and in practice. Our starting point is the celebrated declaration regarding verification in the essay On the Definition of Political Economy; and on the Method of Investigation Proper to It (1836/ 1967; hereafter Essay): “By the method à priori we mean … reasoning from an assumed hypothesis; which … is the essence of all science which admits of general reasoning at all. To verify the hypothesis itself à posteriori, that is, to examine whether the facts of any actual case are in accordance with it, is no part of the business of science at all, but of the application of science” (Mill 1836/1967, p. 325). The apparent position that the basic economic theory is impervious to predictive failure emerges also in a sharp criticism of the à posteriori method:

scholarly journals Setting a Bonus-Malus Scale in the Presence of Other Rating Factors: Taylor's Work Revisited

2003 ◽  
Vol 33 (2) ◽  
pp. 419-436 ◽  
Author(s):  
Sandra Pitrebois ◽  
Michel Denuit ◽  
Jean-François Walhin
Keyword(s):  
A Priori ◽  
A Posteriori ◽  
Data Set ◽  
Simulation Procedure

In this paper, we propose an analytic analogue to the simulation procedure described in Taylor (1997). We apply the formulas to a Belgian data set and discuss the interaction between a priori and a posteriori ratemakings.

scholarly journals Setting a Bonus-Malus Scale in the Presence of Other Rating Factors: Taylor's Work Revisited

2003 ◽  
Vol 33 (02) ◽  
pp. 419-436 ◽  
Author(s):  
Sandra Pitrebois ◽  
Michel Denuit ◽  
Jean-François Walhin
Keyword(s):  
A Priori ◽  
A Posteriori ◽  
Data Set ◽  
Simulation Procedure

In this paper, we propose an analytic analogue to the simulation procedure described in Taylor (1997). We apply the formulas to a Belgian data set and discuss the interaction between a priori and a posteriori ratemakings.

scholarly journals FICTIONING SOCIAL THEORY: THE USE OF FICTION TO ENRICH, INFORM, AND CHALLENGE THE THEORETICAL IMAGINATION. Introduction

Digithum ◽  
2019 ◽  
Author(s):  
Olli Pyyhtinen
Keyword(s):  
Social Science ◽  
Social Theory ◽  
A Priori ◽  
Sociological Imagination ◽  
A Posteriori ◽  
Special Issue ◽  
Clear Cut ◽  
Social Scientific ◽  
Relationship Of ◽  
The Relationship

The introduction to the special issue taps into discussions about the inseparability of science and fiction. Commencing from the idea that scientific statements are distinguished from fiction only a posteriori, not a priori, the piece asks, how fiction could be used as a theoretical resource in social scientific thinking. Could it inform, enrich, extend, intensify, and challenge the sociological imagination? Besides rejecting any clear-cut separation of social science and fictional and artistic forms, the text seeks to unsettle our certainty as to what counts as “fact” and what as “fiction” in the first place. It also suggests that examining the relationship of sociology and fictional and artistic forms helps us unsettle the institutionalized disciplinary ways of ordering knowledge and thought and that there may be a poetics or fiction to be uncovered in sociological scholarship, as sociology is also a form of storytelling.

scholarly journals On the relationship between tropospheric CO and CO<sub>2</sub> during KORUS-AQ and its role in constraining anthropogenic CO<sub>2</sub>

2020 ◽  
Author(s):  
Wenfu Tang ◽  
Benjamin Gaubert ◽  
Louisa Emmons ◽  
Yonghoon Choi ◽  
Joshua P. DiGangi ◽  
...  
Keyword(s):  
East Asia ◽  
Flux Distribution ◽  
A Priori ◽  
Co2 Flux ◽  
Fossil Fuel Combustion ◽  
Aircraft Measurements ◽  
A Posteriori ◽  
Community Atmosphere Model ◽  
The Relationship

Abstract. While the complementarity of CO data in monitoring CO2 from fossil-fuel combustion (ffCO2) is widely known, a rigorous demonstration of its use in reducing uncertainties on top-down regional ffCO2 emissions is still warranted. Here, we report a case study investigating the regional covariation of observed and modeled abundances of CO, CO2, and ffCO2 and demonstrating its implication to joint CO:CO2 inversions. We use data from a recent aircraft field campaign (KORUS-AQ) conducted over Korea and neighboring regions on May 2016 for this case study. We use the Community Atmosphere Model with Chemistry (CAM-Chem) to simulate CO, CO2, ffCO2 and associated source tags, using a posteriori fluxes from global CO2 flux inversions and CO emissions independently calibrated against CO data. Among other model-data comparisons, CAM-Chem simulations show an underestimation in CO2 (1 ppm), CO (24 ppb) and ffCO2 (1 ppm) against aircraft measurements. These are all within the range of model and data uncertainties. Although the overall observed enhancement ratio, ΔCO⁄ΔCO2 (~ 13.3 &amp;om; 0.21 ppb/ppm), is well captured by CAM-Chem (~ 13.8 &amp;pm; 0.23 ppb/ppm), we find an overestimation (29 ppb/ppm) for air samples between 2 to 3 km, where East Asian influence is substantial (35 %). The contribution of ffCO2 from Korea and Japan is smaller (30 %) and localized below 3 km, suggesting that regional ffCO2 and background and non-ffCO2 cannot be neglected in interpreting observed enhancements in this region. These spatial variations translate in the joint CO:CO2 inversion to increases in a posteriori ffCO2 estimates from East Asia (27 % &amp;pm; 24 %) and Korea and Japan (9 % &amp;pm; 17 %). This is consistent (albeit larger in 1-sigma uncertainty) with our estimate using 14CO2 data (27 % &amp;pm; 9 % and 10 % &amp;pm; 3 %, respectively). In contrast, the inversion using only CO2 data shows a decrease by ~ 5 % &amp;pm; 27 % in East Asia and ~ 6 % &amp;pm; 19 % in Korea and Japan. Our results show that inversions using both CO2 and CO can be an effective approach in constraining ffCO2 when the regional variations of CO and CO2 relationships are appropriately accounted for. Although this further points to the potential of augmenting current observing system of CO2 with CO for global inverse analyses of ffCO2 from different regions of the globe, we highlight the need to verify the spatiotemporal distribution of the covariation of CO with CO2 in both regional and global models. We caution its use for constraining local ffCO2, unless the spatiotemporal a priori flux distribution and surface processes are reasonably represented, as they may confound the analysis. These have important implications on inversion studies using columnar data from satellite observations, especially for regions lacking necessary verification measurements.

Effects of a Priori Liking on the Elicitation of Mimicry

2010 ◽  
Vol 57 (6) ◽  
pp. 412-418 ◽  
Author(s):  
Mariëlle Stel ◽  
Rick B. van Baaren ◽  
Jim Blascovich ◽  
Eric van Dijk ◽  
Cade McCall ◽  
...  
Keyword(s):  
A Priori ◽  
The Relationship

Mimicry and prosocial feelings are generally thought to be positively related. However, the conditions under which mimicry and liking are related largely remain unspecified. We advance this specification by examining the relationship between mimicry and liking more thoroughly. In two experiments, we manipulated an individual’s a priori liking for another and investigated whether it influenced mimicry of that person. Our experiments demonstrate that in the presence of a reason to like a target, automatic mimicry is increased. However, mimicry did not decrease when disliking a target. These studies provide further evidence of a link between mimicry and liking and extend previous research by showing that a certain level of mimicry even occurs when mimicry behavior is inconsistent with one’s goals or motivations.

Method for measuring distortions of a speech signal during its transmission over a communication channel to a biometric identification system

2020 ◽  
pp. 65-72
Author(s):  
V. V. Savchenko ◽  
A. V. Savchenko
Keyword(s):  
Speech Signal ◽  
Communication Channel ◽  
Speaker Identification ◽  
A Priori ◽  
Small Samples ◽  
Practical Implementation ◽  
Identification System ◽  
New Information ◽  
Discrimination Criterion ◽  
A Priori Uncertainty

This paper is devoted to the presence of distortions in a speech signal transmitted over a communication channel to a biometric system during voice-based remote identification. We propose to preliminary correct the frequency spectrum of the received signal based on the pre-distortion principle. Taking into account a priori uncertainty, a new information indicator of speech signal distortions and a method for measuring it in conditions of small samples of observations are proposed. An example of fast practical implementation of the method based on a parametric spectral analysis algorithm is considered. Experimental results of our approach are provided for three different versions of communication channel. It is shown that the usage of the proposed method makes it possible to transform the initially distorted speech signal into compliance on the registered voice template by using acceptable information discrimination criterion. It is demonstrated that our approach may be used in existing biometric systems and technologies of speaker identification.

Sign in / Sign up

Export Citation Format

Share Document