scholarly journals Is Acceleration Used for Ocular Pursuit and Spatial Estimation during Prediction Motion?

PLoS ONE ◽  
2013 ◽  
Vol 8 (5) ◽  
pp. e63382 ◽  
Author(s):  
Simon J. Bennett ◽  
Nicolas Benguigui
Author(s):  
Simon J. Bennett ◽  
Nicolas Benguigui

Abstract. We examined spatial estimation of accelerating objects (−8, −4, 0, +4, or +8 deg/s2) during occlusion (600, 1,000 ms) in a spatial prediction motion task. Multiple logistic regression indicated spatial estimation was influenced by these factors such that participants estimated objects with positive acceleration to reappear behind less often than those with negative acceleration, and particularly after the longer occlusion. Individual-participant logistic regressions indicated spatial estimation was better predicted by a first-order extrapolation of the occluded object motion based on pre-occlusion velocity rather than a second-order extrapolation that took account of object acceleration. We suggest a general principle of extrapolation is involved in prediction motion tasks whereby there is a contraction of the variable of interest (i.e., displacement in spatial prediction motion and time in temporal prediction motion). Such an approach to extrapolation could be advantageous as it would offer participants better opportunity to correct for an initial estimation error.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Elham Mahmoudi ◽  
Marcel Stepien ◽  
Markus König

PurposeA principle prerequisite for designing and constructing an underground structure is to estimate the subsurface's properties and obtain a realistic picture of stratigraphy. Obtaining direct measure of these values in any location of the built environment is not affordable. Therefore, any evaluation is afflicted with uncertainty, and we need to combine all available measurements, observations and previous knowledge to achieve an informed estimate and quantify the involved uncertainties. This study aims to enhance the geotechnical surveys based on a spatial estimation of subsoil to customised data structures and integrating the ground models into digital design environments.Design/methodology/approachThe present study's objective is to enhance the geotechnical surveys based on a spatial estimation of subsoil to customised data structures and integrating the ground models into digital design environments. A ground model consisting of voxels is developed via Revit-Dynamo to represent spatial uncertainties employing the kriging interpolation method. The local arrangement of new surveys are evaluated to be optimised.FindingsThe visualisation model's computational performance is modified by using an octree structure. The results show that it adapts the structure to be modelled more efficiently. The proposed concept can identify the geological models' risky locations for further geological investigations and reveal an optimised experimental design. The modifications criteria are defined in global and local considerations.Originality/valueIt provides a transparent and repeatable approach to construct a spatial ground model for subsequent experimental or numerical analysis. In the first attempt, the ground model was discretised by a grid of voxels. In general, the required computing time primarily depends on the size of the voxels. This issue is addressed by implementing octree voxels to reduce the computational efforts. This applies especially to the cases that a higher resolution is required. The investigations using a synthetic soil model showed that the developed methodology fulfilled the kriging method's requirements. The effects of variogram parameters, such as the range and the covariance function, were investigated based on some parameter studies. Moreover, a synthetic model is used to demonstrate the optimal experimental design concept. Through the implementation, alternative locations for new boreholes are generated, and their uncertainties are quantified. The impact of the new borehole on the uncertainty measures are quantified based on local and global approaches. For further research to identify the geological models' risky spots, the development of this approach with additional criteria regarding the search neighbourhood and consideration of barriers and trends in real cases (by employing different interpolation methodologies) should be considered.


1982 ◽  
Vol 31 (3) ◽  
pp. 251-255 ◽  
Author(s):  
Joshua Bacon ◽  
Hans Wallach

2001 ◽  
Vol 138 (3) ◽  
pp. 393-397 ◽  
Author(s):  
Kestutis Kveraga ◽  
Robert Fendrich ◽  
Howard Hughes

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