Information Used in Judging Impending Collision

Perception ◽  
1979 ◽  
Vol 8 (6) ◽  
pp. 647-658 ◽  
Author(s):  
William Schiff ◽  
Mary Lou Detwiler
Keyword(s):  
Lower Order ◽  
Visual Information ◽  
Relative Rate ◽  
Angular Size ◽  
Absolute Amount ◽  
Two Dimensional ◽  
Collision Time ◽  
Size Change ◽  
Human Infants ◽  
Time To Collision

Many subhuman species and human infants, children, and adults can use two-dimensional information of relative rate of angular-size change to anticipate collisions between the self and approaching objects or surfaces. But extant studies have not determined what information is used when subjects view simulated approach events providing two-dimensional information and three-dimensional information (distance and distance change), as well as lower-order visual information contained in real approach events. Three experiments suggest that, given these several possibilities, adults' judgments of collision time are best predicted by two-dimensional spatiotemporal values which are invariant over object sizes, distances traversed, approach velocities, and several lower-order variables such as absolute angular size. However, collision time is substantially underestimated, with absolute amount of underestimation increasing as a function of actual time-to-collision. Large constant errors and loss of judgment linearity beyond about 10 s to contact time suggest that current models of human performance based on use of time-to-collision information require modified assumptions of operator efficiency.

Audiovisual Integration of Time-to-Contact Information for Approaching Objects

2016 ◽  
Vol 29 (4-5) ◽  
pp. 365-395 ◽  
Author(s):  
Patricia R. DeLucia ◽  
Doug Preddy ◽  
Daniel Oberfeld
Keyword(s):  
Visual Information ◽  
Visual Cues ◽  
Relative Rate ◽  
Rate Of Change ◽  
Audiovisual Integration ◽  
Reliable Information ◽  
Auditory Modality ◽  
Visual Condition ◽  
Time To Collision ◽  
Expansion Pattern

Previous studies of time-to-collision (TTC) judgments of approaching objects focused on effectiveness of visual TTC information in the optical expansion pattern (e.g., visual tau, disparity). Fewer studies examined effectiveness of auditory TTC information in the pattern of increasing intensity (auditory tau), or measured integration of auditory and visual TTC information. Here, participants judged TTC of an approaching object presented in the visual or auditory modality, or both concurrently. TTC information provided by the modalities was jittered slightly against each other, so that auditory and visual TTC were not perfectly correlated. A psychophysical reverse correlation approach was used to estimate the influence of auditory and visual cues on TTC estimates. TTC estimates were shorter in the auditory than the visual condition. On average, TTC judgments in the audiovisual condition were not significantly different from judgments in the visual condition. However, multiple regression analyses showed that TTC estimates were based on both auditory and visual information. Although heuristic cues (final sound pressure level, final optical size) and more reliable information (relative rate of change in acoustic intensity, optical expansion) contributed to auditory and visual judgments, the effect of heuristics was greater in the auditory condition. Although auditory and visual information influenced judgments, concurrent presentation of both did not result in lower response variability compared to presentation of either one alone; there was no multimodal advantage. The relative weightings of heuristics and more reliable information differed between auditory and visual TTC judgments, and when both were available, visual information was weighted more heavily.

scholarly journals Imagens táteis tridimensionais: um modelo para a tradução tátil a partir de imagens estáticas bidimensionais | Three-dimensional tactile images: a model for tactile translation from two-dimensional static images

2017 ◽  
Vol 14 (2) ◽  
pp. 234-252
Author(s):  
Emilia Christie Picelli Sanches ◽  
Claudia Mara Scudelari Macedo ◽  
Juliana Bueno
Keyword(s):  
Visual Information ◽  
Three Dimensional ◽  
Information Design ◽  
Blind People ◽  
Two Dimensional ◽  
Test Results ◽  
Visual Content ◽  
Tactile Sense ◽  
Digital Modelling ◽  
Static Images

A acessibilidade na educação de pessoas cegas é um direito que deve ser cumprido. Levando-se em consideração que o design da informação almeja transmitir uma informação de forma efetiva ao receptor, e que uma imagem estática precisa ser adaptada para que um aluno cego tenha acesso a esse conteúdo visual, propõe-se uma maneira de traduzir a informação visual para o tátil. O propósito deste artigo, então, é apresentar um modelo para tradução de imagens estáticas bidimensionais em imagens táteis tridimensionais. Por isso, parte de uma breve revisão da literatura sobre cegueira, percepção tátil e imagens táteis. Na sequência, apresenta o modelo de tradução em três partes: (1) recomendações da literatura; (2) estrutura e (3) modelo preliminar para teste. Depois, descreve o teste do modelo realizado com dois designers com habilidades de modelagem digital (potenciais usuários). Como resultado dos testes, obtiveram-se duas modelagens distintas, uma utilizando da elevação e outra utilizando texturas, porém, os dois participantes realizaram com sucesso a tarefa pretendida. Ainda, a partir dos resultados dos obtidos, também, foi possível perceber falhas no modelo que necessitam ser ajustadas para as próximas etapas da pesquisa.+++++Accessibility in education of blind people is a right that must be fulfilled. Considering that information design aims to transmit an information in an effective way to the receiver, and that a static image needs to be adapted so that a blind student can have access to this visual content, it is proposed a way to translate the visual information to the tactile sense. The purpose of this paper is to present a translating model of static two-dimensional images into three-dimensional tactile images. First, it starts from a brief literature review aboutblindness, tactile perception and tactile images. Second, it presents the translating model in three sections: (1) literature recommendations; (2) structure and (3) finished model for testing. Then, it describes the tests with the model and two designers with digital modelling abilities (potential users). As a result from the tests, two distinct models were obtained, one using elevation and other using textures, although, both participants successfully made the intended task. Also from the test results, it was possible to perceive flaws on the model that need to be adjusted for the next steps of the research.

Anatomical segregation of two cortical visual pathways in the macaque monkey

1990 ◽  
Vol 4 (6) ◽  
pp. 555-578 ◽  
Author(s):  
Anne Morel ◽  
Jean Bullier
Keyword(s):  
Visual Information ◽  
Striate Cortex ◽  
Small Region ◽  
Macaque Monkey ◽  
Two Dimensional ◽  
Inferotemporal Cortex ◽  
Fast Blue ◽  
Prestriate Cortex ◽  
Inferior Parietal Cortex ◽  
Diamidino Yellow

AbstractA number of lines of evidence suggest that, in the macaque monkey, inferior parietal and inferotemporal cortices process different types of visual information. It has been suggested that visual information reaching these two subdivisions follows separate pathways from the striate cortex through the prestriate cortex. We examined directly this possibility by placing injections of the retrograde fluorescent tracers, fast blue and diamidino yellow, in inferior parietal and inferotemporal cortex and examining the spatial pattern of cortical areas containing labeled cells in two-dimensional reconstructions of the cortex.The results of injections in inferotemporal cortex show that TEO receives afferents from areas V2, ventral V3, V3A, central V4, V4t, and DPL in prestriate cortex and from areas IPa, PGa, and FST in the superior temporal sulcus (STS). Area TEp receives afferents only from V4 in prestriate cortex and from IPa, PGa, and FST in the anterior STS. Area TEa receives no prestriate input and is innervated by IPa, PGa, FST, and TPO in the anterior STS.The results of injections in inferior parietal cortex demonstrate that POa receives afferents from dorsal V3, V3A, peripheral V4, DPL, and PO in prestriate cortex, from MST and *VIP and from IPa, PGa, TPO, and FST in anterior STS. Area PGc (corresponding to 7a) is innervated by PO, MST, and by TPO in the anterior STS.Examination of the two-dimensional reconstructions of the pattern of labeling after combined injections of fast blue and diamidino yellow in areas POa and TEO revealed that these areas are principally innervated by different prestriate areas. Only a small region, centered on area V3A and extending into V4 and DPL, contained cells labeled by either injection as well as a small number of double-labeled cells. In contrast, areas POa and TEO receive afferents from extensive common regions in the anterior STS corresponding to areas IPa, PGa, and FST.These results directly demonstrate that visual information from the striate cortex reaches inferior parietal and inferotemporal cortices through largely separate prestriate cortical pathways. On the other hand, both parietal and inferotemporal cortices receive common inputs from extensive regions in the anterior STS which may play a role in linking the processing occurring in these two cortical subdivisions of the visual system.

Lateral geniculate neurons in behaving primates. I. Responses to two-dimensional stimuli

1991 ◽  
Vol 66 (3) ◽  
pp. 777-793 ◽  
Author(s):  
J. W. McClurkin ◽  
T. J. Gawne ◽  
B. J. Richmond ◽  
L. M. Optican ◽  
D. L. Robinson
Keyword(s):  
Receptive Field ◽  
Visual Information ◽  
Receptive Fields ◽  
Nonlinear Behavior ◽  
Temporal Patterns ◽  
Two Dimensional ◽  
Visual Responses ◽  
Linear Summation ◽  
Lateral Geniculate ◽  
Opposite Contrast

1. Using behaving monkeys, we studied the visual responses of single neurons in the parvocellular layers of the lateral geniculate nucleus (LGN) to a set of two-dimensional black and white patterns. We found that monkeys could be trained to make sufficiently reliable and stable fixations to enable us to plot and characterize the receptive fields of individual neurons. A qualitative examination of rasters and a statistical analysis of the data revealed that the responses of neurons were related to the stimuli. 2. The data from 5 of the 13 "X-like" neurons in our sample indicated the presence of antagonistic center and surround mechanisms and linear summation of luminance within center and surround mechanisms. We attribute the lack of evidence for surround antagonism in the eight neurons that failed to exhibit center-surround antagonism either to a mismatch between the size of the pixels in the stimuli and the size of the receptive field or to the lack of a surround mechanism (i.e., the type II neurons of Wiesel and Hubel). 3. The data from five other neurons confirm and extend previous reports indicating that the surround regions of X-like neurons can have nonlinearities. The responses of these neurons were not modulated when a contrast-reversing, bipartite stimulus was centered on the receptive field, which suggests a linear summation within the center and surround mechanisms. However, it was frequently the case for these neurons that stimuli of identical pattern but opposite contrast elicited responses of similar polarity, which indicates nonlinear behavior. 4. We found a wide variety of temporal patterns in the responses of individual LGN neurons, which included differences in the magnitude, width, and number of peaks of the initial on-transient and in the magnitude of the later sustained component. These different temporal patterns were repeatable and clearly different for different visual patterns. These results suggest that visual information may be carried in the shape as well as in the amplitude of the response waveform.

Scaling of detonation velocity in cylinder and slab geometries for ideal, insensitive and non-ideal explosives

2015 ◽  
Vol 773 ◽  
pp. 224-266 ◽  
Author(s):  
Scott I. Jackson ◽  
Mark Short
Keyword(s):  
Phase Velocity ◽  
Detonation Velocity ◽  
Lower Order ◽  
Higher Order ◽  
Slab Thickness ◽  
Two Dimensional ◽  
Order Model ◽  
Scaling Behaviour ◽  
Geometric Scaling ◽  
Shock Curvature

Experiments were conducted to characterize the detonation phase-velocity dependence on charge thickness for two-dimensional detonation in condensed-phase explosive slabs of PBX 9501, PBX 9502 and ANFO. In combination with previous diameter-effect measurements from a cylindrical rate-stick geometry, these data permit examination of the relative scaling of detonation phase velocity between axisymmetric and two-dimensional detonation. We find that the ratio of cylinder radius ($R$) to slab thickness ($T$) at each detonation phase velocity ($D_{0}$) is such that $R(D_{0})/T(D_{0})<1$. The variation in the $R(D_{0})/T(D_{0})$ scaling is investigated with two detonation shock dynamics (DSD) models: a lower-order model relates the normal detonation velocity to local shock curvature, while a higher-order model includes the effect of front acceleration and transverse flow. The experimentally observed $R(D_{0})/T(D_{0})$ (${<}1$) scaling behaviour for PBX 9501 and PBX 9502 is captured by the lower-order DSD theory, revealing that the variation in the scale factor is due to a difference in the slab and axisymmetric components of the curvature along the shock in the cylindrical geometry. The higher-order DSD theory is required to capture the observed $R(D_{0})/T(D_{0})$ (${<}1$) scaling behaviour for ANFO. An asymptotic analysis of the lower-order DSD formulation describes the geometric scaling of the detonation phase velocity between the cylinder and slab geometries as the detonation phase velocity approaches the Chapman–Jouguet value.

A Class of Hybrid DG/FV Methods for Conservation Laws III: Two-Dimensional Euler Equations

2012 ◽  
Vol 12 (1) ◽  
pp. 284-314 ◽  
Author(s):  
Laiping Zhang ◽  
Wei Liu ◽  
Lixin He ◽  
Xiaogang Deng
Keyword(s):  
Euler Equations ◽  
Lower Order ◽  
Wave Interaction ◽  
Weak Shock ◽  
Higher Order ◽  
Two Dimensional ◽  
Dynamic Reconstruction ◽  
Third Order ◽  
Dg Method ◽  
Hybrid Grids

AbstractA concept of “static reconstruction” and “dynamic reconstruction” was introduced for higher-order (third-order or more) numerical methods in our previous work. Based on this concept, a class of hybrid DG/FV methods had been developed for one-dimensional conservation law using a “hybrid reconstruction” approach, and extended to two-dimensional scalar equations on triangular and Cartesian/triangular hybrid grids. In the hybrid DG/FV schemes, the lower-order derivatives of the piece-wise polynomial are computed locally in a cell by the traditional DG method (called as “dynamic reconstruction”), while the higher-order derivatives are re-constructed by the “static reconstruction” of the FV method, using the known lower-order derivatives in the cell itself and in its adjacent neighboring cells. In this paper, the hybrid DG/FV schemes are extended to two-dimensional Euler equations on triangular and Cartesian/triangular hybrid grids. Some typical test cases are presented to demonstrate the performance of the hybrid DG/FV methods, including the standard vortex evolution problem with exact solution, isentropic vortex/weak shock wave interaction, subsonic flows past a circular cylinder and a three-element airfoil (30P30N), transonic flow past a NACA0012 airfoil. The accuracy study shows that the hybrid DG/FV method achieves the desired third-order accuracy, and the applications demonstrate that they can capture the flow structure accurately, and can reduce the CPU time and memory requirement greatly than the traditional DG method with the same order of accuracy.

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