The Spatial Characteristics of Tactile Form Perception

Perception ◽  
1983 ◽  
Vol 12 (5) ◽  
pp. 615-626 ◽  
Author(s):  
Simon R Oldfield ◽  
John R Phillips
Keyword(s):  
Coordinate System ◽  
Mirror Image ◽  
Form Perception ◽  
Spatial Characteristics ◽  
Tactual Perception ◽  
Spatial Coordinate ◽  
Spatial Coordinates ◽  
Object Form ◽  
Skin Receptors

The perceived orientation of a raised letterform indenting the skin of the finger reverses (from normal to its mirror-image) when the letter is held in contact with the finger and both are rotated through 180° about the axis of the finger. Thus, though the pattern of stimulated skin receptors remains constant, the perceived orientation of the letter reverses. On the basis of this observation it is proposed that tactual perception of object form involves assignment of a spatial coordinate system within which the patterns of skin stimulation are interpreted. In experiments in which the orientations of letters and subjects are systematically varied within the environment, the occurrence or nonoccurrence of reversal in perceived orientation of letters has been used to investigate the origin of the proposed spatial coordinate system; that is, whether it is assigned with respect to the observer (egocentrically) or with respect to the environment (geocentrically). The results indicate that the assignment of coordinates is determined by both egocentric and geocentric factors. It is proposed that the reversal phenomena observed in these experiments, and in experiments of others which involve drawing characters on the skin, are consistent with Gibson's proposal that it is object form which is directly perceived, but that this involves interpretation of the patterns of skin stimulation within a framework of spatial coordinates.

Păstoritul de pe Valea Argeșului – coordonate spațiale

2020 ◽  
Vol 34 ◽  
pp. 39-70
Author(s):  
Cristian Micu
Keyword(s):  
Field Research ◽  
Essential Elements ◽  
Mountain Area ◽  
Pastoral System ◽  
Spatial Coordinate ◽  
Spatial Coordinates ◽  
Village Communities ◽  
The Right ◽  
The Village ◽  
Daily Travel

"Shepherding on Argeș Valley – spatial coordinates This paper presents the essential elements that define the spatial coordinate characteristic of shepherding which is practised in the sub-Carpathian villages on the Argeș Valley, following the documentary attestations of the villages, the genesis and evolution of the village boundaries, the evolution of land ownership and the right to use lands (in condominium or individually). Also within the spatial coordinate, there are researched the traditional ways in which the potential of the rural land fund is highlighted, as a result of its geomorphological, pedological, climatic qualities, etc., the study taking into consideration all the areal types with pastoral potential, not only those on the administrative territory of the villages, but also those in the mountain area destined for summer grazing. If for the presentation of origins, attestations, borderline fixation of the villages from the studied areal, documents, monographic studies and other categories of specialized works have been used, for the understanding of the manner of pastoral, individual and especially collective exploitation of the land fund by the village communities, of valorizing the fodder qualities of the different types of surfaces, it was necessary to carry out field research in the three targeted villages: Albeștii de Argeș, Corbeni and Arefu, all in the Argeș County. The visit of sheepfolds from Lespezi, Lipitoarea, Ciocanu, Podeanu, Oticu, in the alpine hollow of the Făgăraș Mountains, were necessary both for studying some elements related to the spatial coordinate (sheepfold location, daily travel routes, travel routes from the village hearth to the mountains, etc.) as well as for conducting interviews, based on an elaborate questionnaire, interviews generating unique and extremely useful information also for researching the other coordinates of the pastoral system practiced in the area. Keywords: shepherding, Argeș Valley, spatial coordinate, pastoral system, field research "

scholarly journals Relativistic Reference Frames in Astrometry

1986 ◽  
Vol 7 ◽  
pp. 101-102
Author(s):  
C A Murray
Keyword(s):  
Coordinate System ◽  
Reference Frames ◽  
Inertial Frame ◽  
Space Time ◽  
Clock Time ◽  
Local Inertial Frame ◽  
Incoming Photon ◽  
Inertial Frames ◽  
Spatial Coordinates

Astrometry can be defined as the measurement of space-time coordinates of photon events. For example, in principle, in classical optical astrometry, we measure the components of velocity, and hence the direction, of an incoming photon with respect to an instrumental coordinate system, and the clock time, at the instant of detection. The observer’s coordinate system at any instant can be identified with a local inertial frame. In the case of interferometric observations, the measurements are of clock times of arrival of a wavefront at two detectors whose spatial coordinates are specified with respect to instantaneous inertial frames.

Non-central-symmetric solution to time-fractional diffusion-wave equation in a sphere under Dirichlet boundary condition

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Yuriy Povstenko
Keyword(s):  
Wave Equation ◽  
Hankel Transform ◽  
Fractional Diffusion ◽  
Radial Coordinate ◽  
Legendre Transform ◽  
Diffusion Wave ◽  
Spatial Coordinate ◽  
The Laplace Transform ◽  
Spatial Coordinates ◽  
Finite Hankel Transform

AbstractThe time-fractional diffusion-wave equation is considered in a sphere in the case of three spatial coordinates r, µ, and φ. The Caputo fractional derivative of the order 0 < α ≤ 2 is used. The solution is found using the Laplace transform with respect to time t, the finite Fourier transform with respect to the angular coordinate φ, the Legendre transform with respect to the spatial coordinate µ, and the finite Hankel transform of the order n + 1/2 with respect to the radial coordinate r. In the central symmetric case with one spatial coordinate r the obtained result coincides with that studied earlier. Numerical results are illustrated graphically.

scholarly journals Genetic Algorithm in the Computation of the Camera External Orientation

2012 ◽  
Vol 9 ◽  
pp. 5-16
Author(s):  
Rudolf Urban ◽  
Martin Štroner
Keyword(s):  
Genetic Algorithm ◽  
Coordinate System ◽  
Control Points ◽  
Generic Algorithm ◽  
Matrix Inverse ◽  
Computation Procedure ◽  
Spatial Coordinate ◽  
The Matrix ◽  
Computer Based ◽  
Calculation Models

The article addresses the solution of the external orientation of the camera by means of a generic algorithm which replaces complicated calculation models using the matrix inverse. The computation requires the knowledge of four control points in the spatial coordinate system and the image coordinate system. The computation procedure fits very well computer-based solutions thanks to it being very simple.

scholarly journals Development of Periodic Unsteady Turbulent Wakes in a Curved Channel at Zero Streamwise Pressure Gradient

1994 ◽  
Author(s):  
M. T. Schobeiri ◽  
J. John
Keyword(s):  
Pressure Gradient ◽  
Coordinate System ◽  
Reynolds Stress ◽  
Temporal Distribution ◽  
Curved Channel ◽  
Spatial Coordinate ◽  
Curved Channels ◽  
Turbulent Wakes ◽  
Streamwise Pressure Gradient ◽  
Hot Film

The development of turbomachinery wake flows is influenced by streamline curvature and streamwise pressure gradient. This paper is a part of a comprehensive experimental and analytical study on the development of the steady and periodic unsteady turbulent wakes in curved channels at different longitudinal (streamwise) pressure gradients. The development of periodic unsteady wakes in a curved channel at zero longitudinal pressure gradient is reported in this paper. Instantaneous velocity components of the periodic wakes, measured using a X-hot-film probe, are analyzed by employing phase-averaging techniques. The temporal distribution of phase-averaged velocity and Reynolds stress components obtained in stationary frame of reference are transformed to a relative spatial coordinate system. The profiles of the velocity and Reynolds stress distribution in relative spatial coordinate system and similarity coordinates are consistent with the measurements of the wake development behind stationary cylinder in the same curved channel.

scholarly journals Intra Prediction of Depth Picture with Plane Modeling

Symmetry ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 715 ◽  
Author(s):  
Dong-seok Lee ◽  
Soon-kak Kwon
Keyword(s):  
Coordinate System ◽  
Mean Squared Error ◽  
Plane Surface ◽  
Prediction Method ◽  
Block Size ◽  
Intra Prediction ◽  
Variable Size ◽  
Depth Prediction ◽  
Object Form ◽  
Camera Coordinate System

In this paper, an intra prediction method is proposed for coding of depth pictures using plane modelling. Each pixel in the depth picture is related to the distance from a camera to an object surface, and pixels corresponding to a flat surface of an object form a relationship with the 2D plane surface. The plane surface can be represented by a simple equation in the 3D camera coordinate system in such a way that the coordinate system of depth pixels can be transformed to the camera coordinate system. This paper finds the parameters which define the plane surface closest to given depth pixels. The plane model is then used to predict the depth pixels on the plane surface. A depth prediction method is also devised for efficient intra prediction of depth pictures, using variable-size blocks. For prediction with variable-size blocks, the plane surface that occupies a large part of the picture can be predicted using a large block size. The simulation results of the proposed method show that the mean squared error is reduced by up to 96.6% for a block size of 4 × 4 pixels and reduced by up to 98% for a block size of 16 × 16, compared with the intra prediction modes of H.264/AVC and H.265/HEVC.

scholarly journals Mathematical Model of Human Semicircular Canal Spatial Attitude 

2021 ◽  
Author(s):  
Shu-zhi Wu ◽  
Ping Lin ◽  
Yan-yan Zheng ◽  
Yi-fei Zhou ◽  
Xiao-kai Yang
Keyword(s):  
Mathematical Model ◽  
Coordinate System ◽  
Semicircular Canal ◽  
Average Method ◽  
Vestibular Function ◽  
Semicircular Canals ◽  
Normal Vector ◽  
Spatial Coordinate ◽  
Average Value ◽  
Plane Normal

Abstract Located deep in the temporal bone, the semicircular canal is a subtle structure that requires a spatial coordinate system for measurement and observation. In this study,Fifty-five semicircular canal and eyeball models were obtained by segmentation of MRI data. The spatial coordinate system was established by taking the top of the common crus and the bottom of eyeball as the horizontal plane. Firstly, the plane equation is calculated according to the centerline of the semicircular canals. Then, according to the parameters of the plane equation, the plane normal vectors are obtained. Finally, the average unit normal vector of each semicircular canal plane can be obtained by calculating the average value of the vectors. It is more intuitive and accurate to calculate the average normal vector of semicircular canal plane with the vector average method, which is different from the angular average method in different degrees. The mathematical model of semicircular canal spatial attitude established in this study is more reliable, which can guide the vestibular function examination, and also help guide the diagnosis and treatment of BPPV.

MOTION EQUATION OF TOOTH BLADE OF SPIRAL-PLATE WORKING UNIT IN SPACE

2016 ◽  
Vol 11 (1) ◽  
pp. 66-69 ◽  
Author(s):  
Шириязданов ◽  
Rustem Shiriyazdanov ◽  
Пикмуллин ◽  
Gennadiy Pikmullin ◽  
Юнусов ◽  
...  
Keyword(s):  
Coordinate System ◽  
Logarithmic Spiral ◽  
Helix Angle ◽  
Motion Equation ◽  
Cutting Edge ◽  
Helical Surface ◽  
Spatial Coordinate ◽  
Spiral Plate ◽  
Angle Of Rotation

The article deals with the spiral-plate working unit, configured with teeth, the cutting edge (blade) of which is made on site (curve) of the logarithmic spiral. Each helix of studied working unit (taking into account properties of a helical surface or a line) is set at an angle and lift the helix has an angle of rotation generator (i.e., the helix angle of twist). In this case, to create the motion equation of any point of the teeth’s motion, the working unit is in the spatial coordinate system 0xyz so that the origin was in his heart.

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