scholarly journals Phenomenal Causality and Sensory Realism

i-Perception ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 204166952092703
Author(s):  
Kristof Meding ◽  
Sebastian A. Bruijns ◽  
Bernhard Schölkopf ◽  
Philipp Berens ◽  
Felix A. Wichmann
Keyword(s):  
Visual Perception ◽  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Perception Of Causality ◽  
Phenomenal Causality ◽  
Intuitive Physics ◽  
Three Dimensional Presentation ◽  
Cue Conflict ◽  
Motion Dynamics

One of the most important tasks for humans is the attribution of causes and effects in all wakes of life. The first systematical study of visual perception of causality—often referred to as phenomenal causality—was done by Albert Michotte using his now well-known launching events paradigm. Launching events are the seeming collision and seeming transfer of movement between two objects—abstract, featureless stimuli (“objects”) in Michotte’s original experiments. Here, we study the relation between causal ratings for launching events in Michotte’s setting and launching collisions in a photorealistically computer-rendered setting. We presented launching events with differing temporal gaps, the same launching processes with photorealistic billiard balls, as well as photorealistic billiard balls with realistic motion dynamics, that is, an initial rebound of the first ball after collision and a short sliding phase of the second ball due to momentum and friction. We found that providing the normal launching stimulus with realistic visuals led to lower causal ratings, but realistic visuals together with realistic motion dynamics evoked higher ratings. Two-dimensional versus three-dimensional presentation, on the other hand, did not affect phenomenal causality. We discuss our results in terms of intuitive physics as well as cue conflict.

Three-Dimensional Reconstruction of Two Forms of the Chaperonin GRO EL

1990 ◽  
Vol 48 (1) ◽  
pp. 258-259
Author(s):  
J.L. Carrascosa ◽  
G. Abella ◽  
S. Marco ◽  
M. Muyal ◽  
J.M. Carazo
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Series Method ◽  
Three Dimensional Reconstruction ◽  
Structural Components ◽  
E Coli ◽  
Dimensional Reconstruction ◽  
Morphogenetic Factors ◽  
Tilt Series

Chaperonins are a class of proteins characterized by their role as morphogenetic factors. They trantsiently interact with the structural components of certain biological aggregates (viruses, enzymes etc), promoting their correct folding, assembly and, eventually transport. The groEL factor from E. coli is a conspicuous member of the chaperonins, as it promotes the assembly and morphogenesis of bacterial oligomers and/viral structures.We have studied groEL-like factors from two different bacteria:E. coli and B.subtilis. These factors share common morphological features , showing two different views: one is 6-fold, while the other shows 7 morphological units. There is also a correlation between the presence of a dominant 6-fold view and the fact of both bacteria been grown at low temperature (32°C), while the 7-fold is the main view at higher temperatures (42°C). As the two-dimensional projections of groEL were difficult to interprete, we studied their three-dimensional reconstruction by the random conical tilt series method from negatively stained particles.

scholarly journals On the Kirchhoff-Love Hypothesis (Revised and Vindicated)

2021 ◽  
Author(s):  
Olivier Ozenda ◽  
Epifanio G. Virga
Keyword(s):  
Free Energy ◽  
Dimension Reduction ◽  
Three Dimensional ◽  
Energy Functional ◽  
The Other ◽  
Variational Model ◽  
Two Dimensional ◽  
Elastic Plates ◽  
Kinematic Constraint ◽  
Free Energy Functional

AbstractThe Kirchhoff-Love hypothesis expresses a kinematic constraint that is assumed to be valid for the deformations of a three-dimensional body when one of its dimensions is much smaller than the other two, as is the case for plates. This hypothesis has a long history checkered with the vicissitudes of life: even its paternity has been questioned, and recent rigorous dimension-reduction tools (based on standard $\varGamma $ Γ -convergence) have proven to be incompatible with it. We find that an appropriately revised version of the Kirchhoff-Love hypothesis is a valuable means to derive a two-dimensional variational model for elastic plates from a three-dimensional nonlinear free-energy functional. The bending energies thus obtained for a number of materials also show to contain measures of stretching of the plate’s mid surface (alongside the expected measures of bending). The incompatibility with standard $\varGamma $ Γ -convergence also appears to be removed in the cases where contact with that method and ours can be made.

Sight distance red zones on combined horizontal and sag vertical curves

1998 ◽  
Vol 25 (4) ◽  
pp. 621-630 ◽  
Author(s):  
Yasser Hassan ◽  
Said M Easa
Keyword(s):  
Quantitative Analysis ◽  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Horizontal Curve ◽  
Sight Distance ◽  
Stopping Sight Distance ◽  
Three Dimensional Models ◽  
Highway Alignment ◽  
Current Standards

Coordination of highway horizontal and vertical alignments is based on subjective guidelines in current standards. This paper presents a quantitative analysis of coordinating horizontal and sag vertical curves that are designed using two-dimensional standards. The locations where a horizontal curve should not be positioned relative to a sag vertical curve (called red zones) are identified. In the red zone, the available sight distance (computed using three-dimensional models) is less than the required sight distance. Two types of red zones, based on stopping sight distance (SSD) and preview sight distance (PVSD), are examined. The SSD red zone corresponds to the locations where an overlap between a horizontal curve and a sag vertical curve should be avoided because the three-dimensional sight distance will be less than the required SSD. The PVSD red zone corresponds to the locations where a horizontal curve should not start because drivers will not be able to perceive it and safely react to it. The SSD red zones exist for practical highway alignment parameters, and therefore designers should check the alignments for potential SSD red zones. The range of SSD red zones was found to depend on the different alignment parameters, especially the superelevation rate. On the other hand, the results showed that the PVSD red zones exist only for large values of the required PVSD, and therefore this type of red zones is not critical. This paper should be of particular interest to the highway designers and professionals concerned with highway safety.Key words: sight distance, red zone, combined alignment.

scholarly journals A Possible Three-Dimensional Mechanism for Oscillating Wobbles in Tropical Cyclone–Like Vortices with Concentric Eyewalls

2018 ◽  
Vol 75 (7) ◽  
pp. 2157-2174 ◽  
Author(s):  
Konstantinos Menelaou ◽  
M. K. Yau ◽  
Tsz-Kin Lai
Keyword(s):  
Tropical Cyclone ◽  
Nonlinear Model ◽  
Three Dimensional ◽  
The Other ◽  
Sensitivity Analyses ◽  
Two Dimensional ◽  
Triggering Mechanism ◽  
Eigenmode Analysis ◽  
Concentric Eyewalls ◽  
Third Dimension

Abstract It is known that concentric eyewalls can influence tropical cyclone (TC) intensity. However, they can also influence TC track. Observations indicate that TCs with concentric eyewalls are often accompanied by wobbling of the inner eyewall, a motion that gives rise to cycloidal tracks. Currently, there is no general consensus of what might constitute the dominant triggering mechanism of these wobbles. In this paper we revisit the fundamentals. The control case constitutes a TC with symmetric concentric eyewalls embedded in a quiescent environment. Two sets of experiments are conducted: one using a two-dimensional nondivergent nonlinear model and the other using a three-dimensional nonlinear model. It is found that when the system is two-dimensional, no wobbling of the inner eyewall is triggered. On the other hand, when the third dimension is introduced, an amplifying wobble is evident. This result contradicts the previous suggestion that wobbles occur only in asymmetric concentric eyewalls. It also contradicts the suggestion that environmental wind shear can be the main trigger. Examination of the dynamics along with complementary linear eigenmode analysis revealed the triggering mechanism to be the excitation of a three-dimensional exponentially growing azimuthal wavenumber-1 instability. This instability is induced by the coupling of two baroclinic vortex Rossby waves across the moat region. Additional sensitivity analyses involving reasonable modifications to vortex shape parameters, perturbation vertical length scale, and Rossby number reveal that this instability can be systematically the most excited. The growth rates are shown to peak for perturbations characterized by realistic vertical length scales, suggesting that this mechanism can be potentially relevant to actual TCs.

Vision

2018 ◽  
Author(s):  
Nico Orlandi
Keyword(s):  
Visual Perception ◽  
Cognitive Science ◽  
Three Dimensional ◽  
Psychological State ◽  
Psychological Process ◽  
Two Dimensional ◽  
Vision Science ◽  
Psychological Theories ◽  
Black Surface ◽  
Obvious Manner

Why do things look to us as they do? This question, formulated by psychologist Kurt Koffka, identifies the main problematic of vision science. Consider looking at a black cat. We tend to see both the cat and its colour as the same at different times. Despite the ease with which this perception occurs, the process by which we perceive is fairly complex. The initial stimulation that gives rise to seeing, consists in a pattern of light that projects on the retina – a light-sensitive layer of the eye. The so-called ‘retinal image’ is a two-dimensional projection that does not correspond in any obvious manner to the way things look. It is not three-dimensional, coloured and shaped in a similar fashion to the objects of our experience. Indeed the light projected from objects is not just different from what we see, it is also both continuously changing and ambiguous. Because the cat moves around, the light it reflects changes from moment to moment. The cat’s projection on the retina correspondingly changes in size. We do not, however, see the cat as changing in size. We tend to see it as size-constant and uniformly coloured through time. How do we explain this constancy? Along similar lines, the cat’s white paws cause on the retina a patch of light that differs in intensity from the rest. This patch could also be caused by a change in illumination. A black surface illuminated very brightly can look like a white surface illuminated very dimly. This means that the light hitting the retina from the paws is underdetermined – it does not uniquely specify what is present. But, again, we tend to see the paws as consistently white. We do not see them as shifting from being white to being black, but illuminated brightly. How do we explain this stability? A central aim of theories of vision is to answer these questions. The science that attempts to address these queries is interdisciplinary. Traditionally, philosophical theories of vision have influenced psychological theories and vice versa. The collaboration between these disciplines eventually developed into what is now known as cognitive science. Cognitive science includes – in addition to philosophy and psychology – computer science, linguistics and neuroscience. Cognitive scientists aim primarily to understand the process by which we see. Philosophers are interested in this topic particularly as it connects to understanding the nature of our acquaintance with reality. Theories of vision differ along many dimensions. Giving a full survey is not possible in this entry. One useful difference is whether a theory presumes that visual perception involves a psychological process. Psychological theories of vision hold that in achieving perception – which is itself a psychological state – the organism uses other psychological material. Opponents of psychological theories prefer to make reference to physiological, mechanical and neurophysiological explanations.

scholarly journals Dynamo in the Presence of Differential Rotation

1976 ◽  
Vol 71 ◽  
pp. 345-351
Author(s):  
S. I. Vainshtein
Keyword(s):  
Axial Symmetry ◽  
Three Dimensional ◽  
Positive Answer ◽  
The Other ◽  
Two Dimensional ◽  
Toroidal Vortex ◽  
Complex Motion ◽  
Dynamo Theory ◽  
Density Inhomogeneity ◽  
Rotating Star

It is well know that the ‘dynamo’ theory has a number of vetoes; e.g. axisymmetric, two-dimensional, central-symmetric, etc. dynamo are impossible. In principle, the problem is essentially three-dimensional in any coordinate system. This is the main difficulty of both the theory itself and its possible applications. In fact, one prefers to believe that, for example, a non-rigid body-rotating star or convection in the Earth's nucleus possesses axis symmetry. However, due to the above vetoes one has to add finer effects (Coriolis strength, density, inhomogeneity) to create asymmetrical convection. On the other hand, the authors try to find the most simple movements with minimum deviations from axial symmetry. Thus, the Herzenberg's dynamo (Herzenberg, 1958) is realized by two rotating cylinders, axes of which are parallel to each other (see also Galaitis, 1973; Galaitis and Freinberg, 1974), the Lortz's dynamo-spiral movement (Lortz, 1968; Ponomarenko, 1973). Nevertheless, the mentioned vetoes possess a common feature, the assumption regarding the symmetry extends both to the movement and to the field. Hence, it makes sense to raise a question whether symmetric movements are able to generate an asymmetric field. A positive answer to this question, in particular, is given by Tverskoy's model (Tverskoy, 1966) – the toroidal vortex. The latter possesses axial symmetry. Nevertheless, the toroidal vortex is a complex motion; we will proceed along the path of a minimum simplification.

Poly[deca-μ2-cyanido-dicyanidobis(μ2-ethylenediamine)bis(ethylenediamine)tricadmium(II)dicobalt(III)]: a two-dimensional coordination polymer

2009 ◽  
Vol 65 (3) ◽  
pp. m118-m120
Author(s):  
Olha Sereda ◽  
Helen Stoeckli-Evans
Keyword(s):  
Coordination Polymer ◽  
Network Structure ◽  
General Position ◽  
Rotation Axis ◽  
Three Dimensional ◽  
The Other ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Asymmetric Unit ◽  
Dimensional Network

The title coordination polymer, [Cd3Co2(CN)12(C2H8N2)4]n, has an infinite two-dimensional network structure. The asymmetric unit is composed of two crystallographically independent CdIIatoms, one of which is located on a twofold rotation axis. There are two independent ethylenediamine (en) ligands, one of which bis-chelates to the Cd atom that sits in a general position, while the other bridges this Cd atom to that sitting on the twofold axis. The Cd atom located on the twofold rotation axis is linked to four equivalent CoIIIatomsviacyanide bridges, while the Cd atom that sits in a general position is connected to three equivalent CoIIIatomsviacyanide bridges. In this way, a series of trinuclear, tetranuclear and pentanuclear macrocycles are linked to form a two-dimensional network structure lying parallel to thebcplane. In the crystal structure, these two-dimensional networks are linkedviaN—H...N hydrogen bonds involving an en NH2H atom and a cyanide N atom, leading to the formation of a three-dimensional structure. This coordination polymer is only the second example involving a cyanometallate where the en ligand is present in both chelating and bridging coordination modes.

scholarly journals Mechanisms of Up-Valley Winds

2004 ◽  
Vol 61 (24) ◽  
pp. 3097-3111 ◽  
Author(s):  
Gabriele Rampanelli ◽  
Dino Zardi ◽  
Richard Rotunno
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Free Atmosphere ◽  
Valley Wind ◽  
Main Contributor ◽  
Physical Mechanisms ◽  
Thermally Driven ◽  
Hydrostatic Approximation ◽  
Temperature Contrast

Abstract The basic physical mechanisms governing the daytime evolution of up-valley winds in mountain valleys are investigated using a series of numerical simulations of thermally driven flow over idealized three-dimensional topography. The three-dimensional topography used in this study is composed of two, two-dimensional topographies: one a slope connecting a plain with a plateau and the other a valley with a horizontal floor. The present two-dimensional simulations of the valley flow agree with results of previous investigations in that the heated sidewalls produce upslope flows that require a compensating subsidence in the valley core bringing down potentially warmer air from the stable free atmosphere. In the context of the three-dimensional valley–plain simulations, the authors find that this subsidence heating in the valley core is the main contributor to the valley– plain temperature contrast, which, under the hydrostatic approximation, is the main contributor to the valley– plain pressure difference that drives the up-valley wind.

Study of the Effect of Boundary Conditions on Residual Stresses in Welding Using Element Birth and Element Movement Techniques

2003 ◽  
Vol 125 (4) ◽  
pp. 432-439 ◽  
Author(s):  
Ihab F. Z. Fanous ◽  
Maher Y. A. Younan ◽  
Abdalla S. Wifi
Keyword(s):  
Residual Stresses ◽  
Boundary Conditions ◽  
Three Dimensional ◽  
Welding Process ◽  
Computation Time ◽  
The Other ◽  
Two Dimensional ◽  
The Media ◽  
Three Dimensional Models ◽  
Element Movement

The structure in which the welding process is performed highly affects the residual stresses generated in the welding. This effect is simulated by choosing the appropriate boundary conditions in modeling the welding process. The major parameters of the boundary conditions are the method by which the base metal is being fixed and the amount of heat being applied through the torch. Other parameters may include the coefficients of thermal heat loss from the plate which may simulate the media in which the welding is taking place. In modeling the welding process, two-dimensional forms of approximation were developed in analyzing most of the models of such problem. Three-dimensional models analyzing the welding process were developed in limited applications due to its high computation time and cost. With the development of new finite element tools, namely the element movement technique developed by the authors, full three-dimensional analysis of the welding process is becoming in hand. In the present work, three different boundary conditions shall be modeled comparing their effect on the welding. These boundary conditions shall be applied to two models of the welding process: one using the element birth technique and the other using the element movement technique showing the similarity in their responses verifying the effectiveness of the latter being accomplished in a shorter time.

Visual Behavior and Motor Responses of Novice and Experienced Wheelchair Tennis Players Relative to the Service Return

2007 ◽  
Vol 24 (3) ◽  
pp. 254-271 ◽  
Author(s):  
Raúl Reina ◽  
Francisco J. Moreno ◽  
David Sanz
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Visual Behavior ◽  
Tennis Players ◽  
Motor Responses

The purpose of this study was to determine visual behavior and motor responses between experienced and novice wheelchair tennis players relative to the return in tennis. Novice (n = 7) and Experienced (n = 5) wheelchair tennis players took part in the study. Two series of serves performed to the forehand and the backhand sides were examined in both groups. One series was performed in a video-based setting (two dimensional) and the other one on court (three dimensional). Experienced participants focused initially on the head/shoulders and the free-arm, while novice players focused on the expected ball toss area or followed the ball from the toss to the apex. Results suggest that the experienced players obtain useful information from racket-arm cues during the stroke phase. They also performed faster motor responses as well.

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