Homography parameters estimation for superposition multidimensional television signals with automatic matching reference points

2021 ◽  
Author(s):  
alphiya I. diyazitdinova
Keyword(s):  
Parameters Estimation ◽  
Reference Points ◽  
Automatic Matching

scholarly journals A 2D Markerless Gait Analysis Methodology: Validation on Healthy Subjects

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Andrea Castelli ◽  
Gabriele Paolini ◽  
Andrea Cereatti ◽  
Ugo Della Croce
Keyword(s):  
Gait Analysis ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Video Camera ◽  
Standing Position ◽  
Parameters Estimation ◽  
Reference Points ◽  
Analysis Methodology ◽  
Spatiotemporal Parameters ◽  
The Cost

A 2D markerless technique is proposed to perform lower limb sagittal plane kinematic analysis using a single video camera. A subject-specific, multisegmental model of the lower limb was calibrated with the subject in an upright standing position. Ankle socks and underwear garments were used to track the feet and pelvis segments, whereas shank and thigh segments were tracked by means of reference points identified on the model. The method was validated against a marker based clinical gait model. The accuracy of the spatiotemporal parameters estimation was found suitable for clinical use (errors between 1% and 3% of the corresponding true values). Comparison analysis of the kinematics patterns obtained with the two systems revealed high correlation for all the joints(0.82<R2<0.99). Differences between the joint kinematics estimates ranged from 3.9 deg to 6.1 deg for the hip, from 2.7 deg to 4.4 deg for the knee, and from 3.0 deg to 4.7 deg for the ankle. The proposed technique allows a quantitative assessment of the lower limb motion in the sagittal plane, simplifying the experimental setup and reducing the cost with respect to traditional marker based gait analysis protocols.

Reference Coordinate System Requirements for Geophysics

1975 ◽  
Vol 26 ◽  
pp. 87-92
Author(s):  
P. L. Bender
Keyword(s):  
Coordinate System ◽  
Polar Motion ◽  
Main Part ◽  
Measurement Techniques ◽  
Reference Points ◽  
Angular Motion ◽  
Coordinate Systems ◽  
Axis Of Rotation ◽  
The Earth ◽  
Fixed System

AbstractFive important geodynamical quantities which are closely linked are: 1) motions of points on the Earth’s surface; 2)polar motion; 3) changes in UT1-UTC; 4) nutation; and 5) motion of the geocenter. For each of these we expect to achieve measurements in the near future which have an accuracy of 1 to 3 cm or 0.3 to 1 milliarcsec.From a metrological point of view, one can say simply: “Measure each quantity against whichever coordinate system you can make the most accurate measurements with respect to”. I believe that this statement should serve as a guiding principle for the recommendations of the colloquium. However, it also is important that the coordinate systems help to provide a clear separation between the different phenomena of interest, and correspond closely to the conceptual definitions in terms of which geophysicists think about the phenomena.In any discussion of angular motion in space, both a “body-fixed” system and a “space-fixed” system are used. Some relevant types of coordinate systems, reference directions, or reference points which have been considered are: 1) celestial systems based on optical star catalogs, distant galaxies, radio source catalogs, or the Moon and inner planets; 2) the Earth’s axis of rotation, which defines a line through the Earth as well as a celestial reference direction; 3) the geocenter; and 4) “quasi-Earth-fixed” coordinate systems.When a geophysicists discusses UT1 and polar motion, he usually is thinking of the angular motion of the main part of the mantle with respect to an inertial frame and to the direction of the spin axis. Since the velocities of relative motion in most of the mantle are expectd to be extremely small, even if “substantial” deep convection is occurring, the conceptual “quasi-Earth-fixed” reference frame seems well defined. Methods for realizing a close approximation to this frame fortunately exist. Hopefully, this colloquium will recommend procedures for establishing and maintaining such a system for use in geodynamics. Motion of points on the Earth’s surface and of the geocenter can be measured against such a system with the full accuracy of the new techniques.The situation with respect to celestial reference frames is different. The various measurement techniques give changes in the orientation of the Earth, relative to different systems, so that we would like to know the relative motions of the systems in order to compare the results. However, there does not appear to be a need for defining any new system. Subjective figures of merit for the various system dependon both the accuracy with which measurements can be made against them and the degree to which they can be related to inertial systems.The main coordinate system requirement related to the 5 geodynamic quantities discussed in this talk is thus for the establishment and maintenance of a “quasi-Earth-fixed” coordinate system which closely approximates the motion of the main part of the mantle. Changes in the orientation of this system with respect to the various celestial systems can be determined by both the new and the conventional techniques, provided that some knowledge of changes in the local vertical is available. Changes in the axis of rotation and in the geocenter with respect to this system also can be obtained, as well as measurements of nutation.

Cognitive Reflection Effects on Time Discounting

2018 ◽  
Vol 39 (2) ◽  
pp. 99-106 ◽  
Author(s):  
Michał Białek ◽  
Przemysław Sawicki
Keyword(s):  
Individual Differences ◽  
Individual Difference ◽  
Delay Discounting ◽  
Reference Point ◽  
Reference Points ◽  
Cognitive Reflection Test ◽  
Process Information ◽  
Time Discounting ◽  
Cognitive Reflection ◽  
The Way

Abstract. In this work, we investigated individual differences in cognitive reflection effects on delay discounting – a preference for smaller sooner over larger later payoff. People are claimed to prefer more these alternatives they considered first – so-called reference point – over the alternatives they considered later. Cognitive reflection affects the way individuals process information, with less reflective individuals relying predominantly on the first information they consider, thus, being more susceptible to reference points as compared to more reflective individuals. In Experiment 1, we confirmed that individuals who scored high on the Cognitive Reflection Test discount less strongly than less reflective individuals, but we also show that such individuals are less susceptible to imposed reference points. Experiment 2 replicated these findings additionally providing evidence that cognitive reflection predicts discounting strength and (in)dependency to reference points over and above individual difference in numeracy.

Multiple reference points in pay satisfaction assessments

1997 ◽  
Author(s):  
Lisa Ordonez ◽  
Terry Connolly ◽  
Richard Coughlan
Keyword(s):  
Reference Points ◽  
Pay Satisfaction ◽  
Multiple Reference

‘[T]his world is now thy pilgrimage’: William Michael Rossetti's Cognitive Maps of France and Italy

2018 ◽  
Vol 8 (1) ◽  
pp. 84-99
Author(s):  
Eleonora Sasso
Keyword(s):  
Cognitive Linguistics ◽  
Venice Lagoon ◽  
Cognitive Map ◽  
Reference Points ◽  
Late Nineteenth Century ◽  
Mental Picture ◽  
Historical Figures ◽  
Starting Point ◽  
Cognitive Semantic ◽  
St Helena

This paper takes as its starting point the conceptual metaphor ‘life is a journey’ as defined by Lakoff and Johnson (1980) in order to advance a new reading of William Michael Rossetti's Democratic Sonnets (1907). These political verses may be defined as cognitive-semantic poems, which attest to the centrality of travel in the creation of literary and artistic meaning. Rossetti's Democratic Sonnets is not only a political manifesto against tyranny and oppression, promoting the struggle for liberalism and democracy as embodied by historical figures such as Napoleon, Mazzini, Cavour, and Garibaldi; but it also reproduces Rossetti's real and imagined journeys throughout Europe in the late nineteenth century. This essay examines these references in light of the issues they raise, especially the poet as a traveller and the journey metaphor in poetry. But its central purpose is to re-read Democratic Sonnets as a cognitive map of Rossetti's mental picture of France and Italy. A cognitive map, first theorised by Edward Tolman in the 1940s, is a very personal representation of the environment that we all experience, serving to navigate unfamiliar territory, give direction, and recall information. In terms of cognitive linguistics, Rossetti is a figure whose path is determined by French and Italian landmarks (Paris, the island of St. Helena, the Alps, the Venice Lagoon, Mount Vesuvius, and so forth), which function as reference points for orientation and are tied to the historical events of the Italian Risorgimento. Through his sonnets, Rossetti attempts to build into his work the kind of poetic revolution and sense of history which may only be achieved through encounters with other cultures.

Automatic Parameters Estimation of the D. Klatt Phoneme Duration Model

Informatica ◽  
2016 ◽  
Vol 27 (3) ◽  
pp. 573-586
Author(s):  
Pijus Kasparaitis ◽  
Margarita Beniušė
Keyword(s):  
Parameters Estimation ◽  
Duration Model
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