Euclidean Cues versus Affine or Projective Invariants in the Visual Perception of Three-Dimensional Distances

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 171-171 ◽  
Author(s):  
J Wagemans ◽  
S Tibau
Keyword(s):  
Visual Perception ◽  
Three Dimensional ◽  
Time Frame ◽  
The Other ◽  
Relative Importance ◽  
Conic Sections ◽  
Projective Invariants ◽  
Segment Size ◽  
Structural Invariance ◽  
Over Time

Lappin and Fuqua (1983 Science221 480 – 482) reported accurate measurement of three-dimensional (3-D) distances and suggested that performance was based on structural invariance of patterns undergoing perspective transformations. We wanted to replicate their basic findings and test specific hypotheses about the use of Euclidean cues versus affine or projective invariants. The displays consisted of orthographic and perspective projections of three collinear dots rotating rigidly around a fixed centre in a plane slanted 45° in depth. Observers were asked to decide whether the middle of the three dots was exactly centred in 3-D space between the other two dots. The visible rotation segments were 120°, 160°, or 200° and the displacements were 2%, 4%, or 6%. Although our untrained observers performed more poorly overall than Lappin's well-practiced observers, two main results were replicated. First, there was no effect of segment size, which suggests that Euclidean cues were not used. Second, there was no difference between orthographic and perspective displays, which suggests that the invariants used must be projective, not affine. Additional experiments will be performed to investigate the relative importance of invariants such as cross ratios, which are based on the positions of the dots within each time frame, versus invariants of the conic sections, which are based on the elliptic traces of the dots formed over time.

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.

scholarly journals The Green Deal and the Resilience of EU-Russian Energy Relations

2021 ◽  
Vol 16 (3) ◽  
pp. 108-123
Author(s):  
Tatiana Romanova ◽  
Keyword(s):  
Natural Gas ◽  
The Other ◽  
Relative Importance ◽  
Internal Constraints ◽  
The Third ◽  
Governance Practices ◽  
New Challenges ◽  
Energy Relations ◽  
Over Time ◽  
The Eu

In this article, the influence of the European Union’s (EU) Green Deal on its energy relations with Russia is analyzed. Two models of resilience are identified in the EU’s discourse. One aims at achieving resilience at the level of the EU’s energy sector (the “microsystem” for the purpose of this study) while destroying the system of EU-Russia relations (the “macrosystem”). The other aims at achieving resilience in the micro- and macrosystem at the same time. Empirically, the study relies on EU documents and speeches by its national and supranational representatives. Three cases are studied. The first covers competition of two models of resilience in the principles that the EU defined for its relations with Russia. The second case involves investments that slow down the development of renewable sources of energy in favour of natural gas. This case demonstrates how resilience can be achieved as a return to the previous pattern (bouncing back). Although it can be achieved both at the EU-only level and at the level of the EU and its relations with Russia, it clearly favours the latter. The third case involves the import of hydrogen, which creates possibilities for resilience both at the microsystem alone and at the micro- and macrosystems at the same time. This latter option is achieved through adaptation to new challenges (bouncing forward). The author concludes by comparing the two models of resilience. The model that prioritizes the microsystem’s resilience and challenges the macrosystem is based on the synthesis of environmental and geopolitical logics. The other model is based on economic and market logics, but the EU’s normative leadership is a prerequisite. The EU’s discourse demonstrates the viability of both models and related governance practices. Most likely, the two models will co-exist, but their relative importance will vary over time. This variation will be primarily determined by the EU’s internal constraints. However, Russia’s policy can facilitate the model of resilience, achieved in both the micro- and macrosystem.

Speed and Eccentricity Tuning Reveal a Central Role for the Velocity-Based Cue to 3D Visual Motion

2010 ◽  
Vol 104 (5) ◽  
pp. 2886-2899 ◽  
Author(s):  
Thaddeus B. Czuba ◽  
Bas Rokers ◽  
Alexander C. Huk ◽  
Lawrence K. Cormack
Keyword(s):  
Visual Perception ◽  
Moving Objects ◽  
Visual Motion ◽  
Three Dimensional ◽  
Building Blocks ◽  
3D Motion ◽  
Direction Discrimination ◽  
Retinal Motion ◽  
Wide Range ◽  
Over Time

Two binocular cues are thought to underlie the visual perception of three-dimensional (3D) motion: a disparity-based cue, which relies on changes in disparity over time, and a velocity-based cue, which relies on interocular velocity differences. The respective building blocks of these cues, instantaneous disparity and retinal motion, exhibit very distinct spatial and temporal signatures. Although these two cues are synchronous in naturally moving objects, disparity-based and velocity-based mechanisms can be dissociated experimentally. We therefore investigated how the relative contributions of these two cues change across a range of viewing conditions. We measured direction-discrimination sensitivity for motion though depth across a wide range of eccentricities and speeds for disparity-based stimuli, velocity-based stimuli, and “full cue” stimuli containing both changing disparities and interocular velocity differences. Surprisingly, the pattern of sensitivity for velocity-based stimuli was nearly identical to that for full cue stimuli across the entire extent of the measured spatiotemporal surface and both were clearly distinct from those for the disparity-based stimuli. These results suggest that for direction discrimination outside the fovea, 3D motion perception primarily relies on the velocity-based cue with little, if any, contribution from the disparity-based cue.

scholarly journals A Survey of Stakeholder Visualization Approaches

2016 ◽  
Vol 2 (1,2) ◽  
Author(s):  
Martin Cenek ◽  
Ondřej Částek
Keyword(s):  
Three Dimensional ◽  
The Other ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Advantages And Disadvantages ◽  
The Third ◽  
Model Based ◽  
The Relationship ◽  
Over Time

The aim of this paper is to present an overview of studies for the representation/visualization of stakeholders with a proposal of our own method of visualization. The following text examines the existing representational methods and at the same time critically evaluates their advantages and disadvantages. In addition, our own proposed approach is also presented.The need to develop visualization methods for use in the concept of stakeholders has been accepted by researchers, and it is possible to encounter number of various alternatives which have been applied more or less successfully. The shared weakness of the majority of the models is that they only represent two main attributes simultaneously. When such models do contain three variables, then the third one is only a complementary aspect of the relationship compared to the two dominant attributes.Our proposed visualisation model based on three Mitchell´s (1997) stakeholder attributes should overcome the before mentioned disadvantage. Also, it takes into account the development over time in accordance with the dynamic of the relationships with the stakeholders. Therefore, the proposed three-dimensional model meets these needs and simultaneously removes the shortcomings of the other models, which are identified in our overview presented in this paper.

scholarly journals INTEGRATED KNOWLEDGE ON A THREE-DIMENSIONAL BASIS: THE FOUNDATION OF THE CONSERVATION PROJECT AND POSSIBLE IMPLICATIONS IN THE BIM AREA THE CASE OF THE PORTRAIT ROOM OF PALAZZO BOREA D'OLMO IN SANREMO

2019 ◽  
Vol XLII-2/W11 ◽  
pp. 339-344
Author(s):  
C. Campanella ◽  
S. Alauria ◽  
L. Amatori
Keyword(s):  
Cultural Heritage ◽  
Contextual Information ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Time Frame ◽  
The Other ◽  
Actual State ◽  
Historical Period ◽  
Cognitive Approach ◽  
Construction Techniques

<p><strong>Abstract.</strong> This involved a sort of preventive diagnostics based on the historical knowledge of the building, on the construction techniques and on the compositional style, on the other hand on diagnostic imaging using photographic techniques developed from the early 1800s.<br />The preliminary cognitive approach, the stylistic identification, the classification of method, the historical reading, the critical analysis of the historical and compositional genesis of the building, the careful reading of the pathogenesis in progress, mark, from the mid-800 in then, the evolution of the concept of restoration that will take shape from time to time from what was "before" and only secondarily from what "is now". This perhaps unconscious diagnostic reading of the artifact (first artistic, then monumental and finally as a cultural testimony) has, in fact, involved generations of restorers painting the landscape of the restoration sometimes in different way, with results that well we know.<br />In fact, almost never the fathers of restoration (or anti-restoration) explicitly touch the issues of preventive diagnosis, but certainly base their theories and their "restoration" on the observation of the factory, on the knowledge of construction techniques and historical period of belonging.</p><p>The things begin to change starting from the first Charter of Restoration of 1883 with the enlargement of the diagnostic project (which finds paternity starting from the 1972 Italian Charter, which embraces many disciplines: from photography to relief, from chemistry to physics, from the historical reading to the knowledge of the materials, from the identification of the material pathogenesis to the reading of the static and structural framework of the buildings.<br />With the passing of time and the explosion of science and technology in the field of cultural heritage all aspects related to preliminary knowledge aimed at their conservation evolve exponentially especially with the advent of electronics. Starting from the 60s of the 1900s, equipment with great calculation capacity and small dimensions was born, a real springboard for the new techniques of surveying by means of a laser scanner, photographic socket and photogrammetric restitution.<br />Tools and techniques of restitution settle and even more solidly base the knowledge base linked to the project of conservation and enhancement of cultural heritage.</p><p>Base of support and extraction of selected data and / or dedicated to the project continuously interface with the disciplines of knowledge that are now more and more "forced" to the table of confrontation to reveal information hidden in the folds of time.<br />A recent work on an eighteenth-century Sanremese building it gives us information on the complexity of the construction of a process of knowledge articulated, composed of several activities to be correlated and integrated continuously, one in the other to try to give answers on evident problems of degradation never fully documented.</p><p>The study, performed in a rather limited time frame, focused on the Hall of family portraits seriously degraded by "accidents of various kinds". The work was based on the three-dimensional conception of the acquired data, allowing to investigate the hall as an articulated organism, supporting the technicians in the three-dimensional understanding of the asset, constituting a complete database of the actual state, becoming support of the results of the various surveys conducted for the knowledge of the asset.<br />In this cognitive path, the BIM method is understood as the possibility of constructing the "as built" model, complete not only of the dimensional graphic data of the asset, but also of those that contribute to the determination of the actual state. The graphic aspect of the model must be connected with historical, material, degradation, contextual information, with the results of any specialized investigations conducted.<br />Only then will the BIM model of a historic building be the complete database, the "medical record" of its state of health, complete with diagnosis, care, indications of maintenance that can be shared and questioned over time.</p>

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.

Emotional Impact Feedback Changes How We Remember Negative Autobiographical Experiences

2010 ◽  
Vol 57 (5) ◽  
pp. 354-359 ◽  
Author(s):  
Melanie K. T. Takarangi ◽  
Deryn Strange
Keyword(s):  
Well Being ◽  
The Other ◽  
Personal Perspective ◽  
Emotional Impact ◽  
Potential Mechanism ◽  
Negative Experiences ◽  
Negative Memory ◽  
The Relationship ◽  
Negative Memories ◽  
Over Time

When people are told that their negative memories are worse than other people’s, do they later remember those events differently? We asked participants to recall a recent negative memory then, 24 h later, we gave some participants feedback about the emotional impact of their event – stating it was more or less negative compared to other people’s experiences. One week later, participants recalled the event again. We predicted that if feedback affected how participants remembered their negative experiences, their ratings of the memory’s characteristics should change over time. That is, when participants are told that their negative event is extremely negative, their memories should be more vivid, recollected strongly, and remembered from a personal perspective, compared to participants in the other conditions. Our results provide support for this hypothesis. We suggest that external feedback might be a potential mechanism in the relationship between negative memories and psychological well-being.

Opponent Center-Surround Contrast: Colour to Grey Conversion

2020 ◽  
Vol 2020 (1) ◽  
pp. 105-108
Author(s):  
Ali Alsam
Keyword(s):  
Evolutionary Algorithms ◽  
Three Dimensional ◽  
The State ◽  
Colour Space ◽  
Vision Science ◽  
State Of Art ◽  
Over Time

Vision is the science that informs us about the biological and evolutionary algorithms that our eyes, opticnerves and brains have chosen over time to see. This article is an attempt to solve the problem of colour to grey conversion, by borrowing ideas from vision science. We introduce an algorithm that measures contrast along the opponent colour directions and use the results to combine a three dimensional colour space into a grey. The results indicate that the proposed algorithm competes with the state of art algorithms.

An Efficient Multiple Description Coding for Multi-View Video Based on the Correlation of Spatial Polyphase Transformed Subsequences

2019 ◽  
Vol 63 (5) ◽  
pp. 50401-1-50401-7 ◽  
Author(s):  
Jing Chen ◽  
Jie Liao ◽  
Huanqiang Zeng ◽  
Canhui Cai ◽  
Kai-Kuang Ma
Keyword(s):  
Video Transmission ◽  
Video Sequence ◽  
Three Dimensional ◽  
The Other ◽  
Multiple Description Coding ◽  
Multiple Description ◽  
Prediction Mode ◽  
Gradient Based ◽  
Directional Interpolation ◽  
Description Coding

Abstract For a robust three-dimensional video transmission through error prone channels, an efficient multiple description coding for multi-view video based on the correlation of spatial polyphase transformed subsequences (CSPT_MDC_MVC) is proposed in this article. The input multi-view video sequence is first separated into four subsequences by spatial polyphase transform and then grouped into two descriptions. With the correlation of macroblocks in corresponding subsequence positions, these subsequences should not be coded in completely the same way. In each description, one subsequence is directly coded by the Joint Multi-view Video Coding (JMVC) encoder and the other subsequence is classified into four sets. According to the classification, the indirectly coding subsequence selectively employed the prediction mode and the prediction vector of the counter directly coding subsequence, which reduces the bitrate consumption and the coding complexity of multiple description coding for multi-view video. On the decoder side, the gradient-based directional interpolation is employed to improve the side reconstructed quality. The effectiveness and robustness of the proposed algorithm is verified by experiments in the JMVC coding platform.

Coevolution

2017 ◽  
Author(s):  
Avi Max Spiegel
Keyword(s):  
The Other ◽  
The Political ◽  
Over Time ◽  
Islamist Movements

This chapter seeks to understand how Islamist movements have evolved over time, and, in the process, provide important background on the political and religious contexts of the movements in question. In particular, it shows that Islamist movements coevolve. Focusing on the histories of Morocco's two main Islamist movements—the Justice and Spirituality Organization, or Al Adl wal Ihsan (Al Adl) and the Party of Justice and Development (PJD)—it suggests that their evolutions can only be fully appreciated if they are relayed in unison. These movements mirror one another depending on the competitive context, sometimes reflecting, sometimes refracting, sometimes borrowing, sometimes adapting or even reorganizing in order to keep up with the other.

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