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Khalidi identifies cognition with Marrian computation. He further argues that Marrian levels of inquiry should be interpreted ontologically as corresponding to distinct semi‐closed causal domains. But this counterintuitively places the causal domain of representations outside of cognition proper. A closer look at Khalidi's account of concepts shows that these allegedly separate Marrian domains are more tightly integrated than he allows. Theories of concepts converge on algorithmic‐representational models rather than computational ones. This suggests that we should reject the wholesale identification of cognition with computation. [ABSTRACT FROM AUTHOR]

Neuroscientists have in recent years turned to building models that aim to generate predictions rather than explanations. This "predictive turn" has swept across domains including law, marketing, and neuropsychiatry. Yet the norms of prediction remain undertheorized relative to those of explanation. I examine two styles of predictive modeling and show how they exemplify the normative dynamics at work in prediction. I propose an account of how predictive models, conceived of as technological devices for aiding decision-making, can come to be adequate for purposes that are defined by both their guiding research questions and their larger social context of application. [ABSTRACT FROM AUTHOR]

Natural kind concepts have the function of tracking categories that exist independently of our beliefs and purposes. But not all ways of tracking categories in the natural world involve conceiving of them as natural kinds. Anthropic concepts represent groups of natural, mind‐independent entities that are apt for serving various human interests, goals, and projects. They represent the natural world under a practical mode of presentation, as a set of material resources that can be transformed to further a host of functions and ends. I argue that cross‐cultural studies of traditional ecological knowledge provide evidence that many chemical, mineral, and biological concepts that are frequently taken to be natural kind concepts turn out on closer inspection to be anthropic concepts. Anthropic concepts are distinguished from artifact concepts, and a form of realism about the anthropic kinds that they refer to is defended. [ABSTRACT FROM AUTHOR]

In this review paper, we review methods for interactive particle rendering techniques, multi-view particle visualization systems, multivariate visualization techniques, and methods for correlation visualizations. Visualization is vital for gaining insight into particle data. Multivariate particle data are generated to understand different aspects of the underlying physics. The visualization of multivariate particle data is typically performed in multiple linked view systems (multi-view systems) that render particles of interest that are selected by the user interactively with brushing-and-linking. To this end, the non-spatial aspects of particles are explored with multivariate visualization methods, e.g., scatter plots, scatter plot matrix, parallel coordinates, dimensional reduction and radial plots. [ABSTRACT FROM AUTHOR]

Abstract: There is an ongoing discussion in the visualization community about the relevant factors that render a visualization effective, expressive, memorable, aesthetically pleasing, etc. These factors lead to a large design space for visualizations. To explore this design space, qualitative research methods based on observations and interviews are often necessary. We describe an interview method that allows us to systematically acquire and assess important factors from subjective answers by interviewees. To this end, we adopt the repertory grid methodology in the context of visualization. It is based on the personal construct theory: each personality interprets a topic based on a set of personal, basic constructs expressed as contrasts. For the individual interpretation of visualizations, this means that these personal terms can be very different, depending on numerous influences, such as the prior experiences of the interviewed person. We present an interviewing process, visual interface, and qualitative and quantitative analysis procedures that are specifically devised to fit the needs of visualization applications. A showcase interview with 15 typical static information visualizations and 10 participants demonstrates that our approach is effective in identifying common constructs as well as individual differences. In particular, we investigate differences between expert and nonexpert interviewees. Finally, we discuss the differences to other qualitative methods and how the repertory grid can be embedded in existing theoretical frameworks of visualization research for the design process. [ABSTRACT FROM AUTHOR]

In recent decades, attempts to explain autism have been frustrated by the heterogeneous nature of its behavioral symptoms and the underlying genetic, neural, and cognitive mechanisms that produce them. This has led some to propose eliminating the category altogether. The eliminativist inference relies on a conception of psychiatric categories as kinds defined by their underlying mechanistic structure. I review the evidence for eliminativism and propose an alternative model of the family of autisms. On this account, autism is a network category defined by a set of idealized exemplars linked by multiple levels of theoretically significant properties. I argue that this network model better captures the empirical phenomena, the historical growth of the category, and the ways the category has been shaped by social norms and interests. Finally, I defend a realist interpretation of network categories against the challenge from eliminativists. [ABSTRACT FROM PUBLISHER]

Neuroscience constrains psychology, but stating these constraints with precision is not simple. Here I consider whether mechanistic analysis provides a useful way to integrate models of cognitive and neural structure. Recent evidence suggests that cognitive systems map onto overlapping, distributed networks of brain regions. These highly entangled networks often depart from stereotypical mechanistic behaviors. While this casts doubt on the prospects for classical mechanistic integration of psychology and neuroscience, I argue that it does not impugn a realistic interpretation of either type of model. Cognitive and neural models may depict different, but equally real, causal structures within the mind/brain. [ABSTRACT FROM AUTHOR]

We instrument Group Diagrams (GDs) to reduce clutter in sets of eye-tracking scanpaths. Group Diagrams consist of trajectory subsets that cover, or represent, the whole set of trajectories with respect to some distance measure and an adjustable distance threshold. The original GDs allow for an application of various distance measures. We implement the GD framework and evaluate it on scanpaths that were collected by a former user study on public transit maps. We find that the Fréchet distance is the most appropriate measure to get meaningful results, yet it is flexible enough to cover outliers. We discuss several implementation-specific challenges and improve the scalability of the algorithm. To evaluate our results, we conducted a qualitative study with a group of eye-tracking experts. Finally, we note that our enhancements are also beneficial within the original problem setting, suggesting that our approach might be applicable to various types of input data. Eye tracking on a public transit map of Warsaw. Input scanpaths (left), and simplified Group Diagram (right). [ABSTRACT FROM AUTHOR]

In many research fields, eye tracking has become an established method to analyze the distribution of visual attention in various scenarios. In the near future, eye tracking is expected to become ubiquitous, recording massive amounts of data in everyday situations. To make use of this data, new approaches for personal visual analytics will be necessary to make the data accessible, allowing nonexpert users to re-experience interesting events and benefit from self-reflection. This article discusses how eye tracking fits in the context of personal visual analytics, the challenges that arise with its application to everyday situations, and the research perspectives of personal eye tracking. As an example, the authors present a technique for representing areas of interest (AOIs) from multiple videos: the AOI cloud. They apply this technique to examine a user's personal encounters with other people. [ABSTRACT FROM PUBLISHER]

Christopher Gauker proposes that all cognition can be divided into nonconceptual image-based thought and conceptual language-based thought. The division between the two hinges on the representational powers of their respective mediums. I argue that a richer variety of representational states and processes is necessary in order to explain both human and nonhuman cognition. There are aspects of nonhuman cognition that cannot be explained simply by images, and there are aspects of human conceptual thought, particularly those dealing with causal reasoning, that push us towards positing abstract systems of representation that are neither imagistic nor linguistic. Conceptual thought, then, occurs in its own proprietary inner code, not in images or words. [ABSTRACT FROM PUBLISHER]

The geodesic equation of the Alcubierre warp spacetime is converted into its non-affinely parametrized form for a detailed discussion of the motion of particles and the visual effects as observed by a traveller inside the warp bubble or a person looking from outside. To include gravitational lensing for point-like light sources, we present a practical approach using the Jacobi equation and the Sachs bases. Additionally, we consider the dragging and geodesic precession of particles due to the warp bubble. [ABSTRACT FROM AUTHOR]

The view that special science properties are multiply realizable has been attacked in recent years by Shapiro, Bechtel and Mundale, Polger, and others. Focusing on psychological and neuroscientific properties, I argue that these attacks are unsuccessful. By drawing on interspecies physiological comparisons I show that diverse physical mechanisms can converge on common functional properties at multiple levels. This is illustrated with examples from the psychophysics and neuroscience of early vision. This convergence is compatible with the existence of general constraints on the evolution of cognitive systems, and does not involve any ad hoc typing of coarse-grained higher level properties. The mechanisms that realize these common higher level properties are really distinct by the criteria laid down by critics of multiple realizability. Finally, I present an account of how such functional properties might constitute special science kinds by playing a central explanatory role in a range of cognitive models. Behavioral science kinds in particular are the functionally defined constituents picked out by our most successful models of the multilevel systems and mechanisms that explain cognitive capacities. 1 Reduction Versus Elimination, Redux2 The Eyes of Others3 Unity Through Constraint?4 Justifying Taxonomic Mismatches5 Further Conditions on Multiple Realization6 Explanatory Taxonomy and the Special Sciences7 Conclusions [ABSTRACT FROM PUBLISHER]

Abstract: According to the hypothesis of extended cognition (HEC), parts of the extrabodily world can constitute cognitive operations. I argue that the debate over HEC should be framed as a debate over the location and bounds of cognitive systems. The “Goldilocks problem” is how to demarcate these systems in a way that is neither too restrictive nor too permissive. I lay out a view of systems demarcation on which cognitive systems are sets of mechanisms for producing cognitive processes that are bounded by transducers and effectors: structures that turn physical stimuli into representations, and representations into physical effects. I show how the transducer–effector view can stop the problem of uncontrolled cognitive spreading that faces HEC, and illustrate its advantages relative to other views of system individuation. Finally, I argue that demarcating systems by transducers and effectors is not question-begging in the context of a debate over HEC. [ABSTRACT FROM AUTHOR]

We present a novel approach to finding critical points in cell-wise barycentrically or bilinearly interpolated vector fields on surfaces. The Poincaré index of the critical points is determined by investigating the qualitative behavior of 0-level sets of the interpolants of the vector field components in parameter space using precomputed combinatorial results, thus avoiding the computation of the Jacobian of the vector field at the critical points in order to determine its index. The locations of the critical points within a cell are determined analytically to achieve accurate results. This approach leads to a correct treatment of cases with two first-order critical points or one second-order critical point of bilinearly interpolated vector fields within one cell, which would be missed by examining the linearized field only. We show that for the considered interpolation schemes determining the index of a critical point can be seen as a coloring problem of cell edges. A complete classification of all possible colorings in terms of the types and number of critical points yielded by each coloring is given using computational group theory. We present an efficient algorithm that makes use of these precomputed classifications in order to find and classify critical points in a cell-by-cell fashion. Issues of numerical stability, construction of the topological skeleton, topological simplification, and the statistics of the different types of critical points are also discussed. [ABSTRACT FROM AUTHOR]

In this response, I do four things. First, I defend the claim that the action compatibility effect does not distinguish between embodied and traditional accounts of language comprehension. Second, I present neuroimaging and neuropsychological results that seem to support the traditional account. Third, I argue that metaphorical language poses no special challenge to the arguments I gave against embodied theories of comprehension. Fourth, I lay out the architecture of language I advocate and suggest the sorts of data that would decide between traditional and embodied accounts. [Copyright &y& Elsevier]

Traditionally, the language faculty was supposed to be a device that maps linguistic inputs to semantic or conceptual representations. These representations themselves were supposed to be distinct from the representations manipulated by the hearer’s perceptual and motor systems. Recently this view of language has been challenged by advocates of embodied cognition. Drawing on empirical studies of linguistic comprehension, they have proposed that the language faculty reuses the very representations and processes deployed in perceiving and acting. I review some of the evidence and arguments in favor of the embodied view of language comprehension, and argue that none of it is conclusive. Moreover, the embodied view itself blurs two important distinctions: first, the distinction between linguistic comprehension and its typical consequences; and second, the distinction between representational content and vehicles. Given that these distinctions are well-motivated, we have good reason to reject the embodied view of linguistic understanding. [Copyright &y& Elsevier]

The optical appearance of the stellar sky for an observer in the vicinity of a black hole is dominated by bending of light, the frequency shift, and the magnification caused by gravitational lensing and aberration. Due to the finite aperture of an observer's eye or a telescope, Fraunhofer diffraction has to be taken into account. We have used high performance graphics hardware and developed a program that enables the user to interactively explore the stellar sky in the vicinity of a Schwarzschild black hole. To do so, we determine what an observer, who can either move quasistatically around the black hole or follow a timelike radial geodesic, would actually see. [ABSTRACT FROM AUTHOR]

Conceptual atomists argue that most of our concepts are primitive. I take up three arguments that have been thought to support atomism and show that they are inconclusive. The evidence that allegedly backs atomism is equally compatible with a localist position on which concepts are structured representations with complex semantic content. I lay out such a localist position and argue that the appropriate position for a non-atomist to adopt is a pluralist view of conceptual structure. I show several ways in which conceptual pluralism provides an advantage in satisfying the empirical and philosophical demands on a theory of conceptual structure and content. [ABSTRACT FROM AUTHOR]

In contrast to 2D scatterplots, the existing 3D variants have the advantage of showing one additional data dimension, but suffer from inadequate spatial and shape perception and therefore are not well suited to display structures of the underlying data. We improve shape perception by applying a new illumination technique to the pointcloud representation of 3D scatterplots. Points are classified as locally linear, planar, and volumetric structures—according to the eigenvalues of the inverse distance-weighted covariance matrix at each data element. Based on this classification, different lighting models are applied: codimension-2 illumination, surface illumination, and emissive volumetric illumination. Our technique lends itself to efficient GPU point rendering and can be combined with existing methods like semi-transparent rendering, halos, and depth or attribute based color coding. The user can interactively navigate in the dataset and manipulate the classification and other visualization parameters. We demonstrate our visualization technique by showing examples of multi-dimensional data and of generic pointcloud data. [ABSTRACT FROM AUTHOR]

We extend the rendering technique for continuous scatterplots to allow for a broad class of interpolation methods within the spatial grid instead of only linear interpolation. To do this, we propose an approach that projects the image of a cell from the spatial domain to the scatterplot domain. We approximate this image using either the convex hull or an axis-aligned rectangle that forms a tight fit of the projected points. In both cases, the approach relies on subdivision in the spatial domain to control the approximation error introduced in the scatterplot domain. Acceleration of this algorithm in homogeneous regions of the spatial domain is achieved using an octree hierarchy. The algorithm is scalable and adaptive since it allows us to balance computation time and scatterplot quality. We evaluate and discuss the results with respect to accuracy and computational speed. Our methods are applied to examples of 2-D transfer function design. [ABSTRACT FROM AUTHOR]

We present a design technique for colors with the purpose of lowering the energy consumption of the display device. Our approach is based on a screen space variant energy model. The result of our design is a set of distinguishable iso-lightness colors guided by perceptual principles. We present two variations of our approach. One is based on a set of discrete user-named (categorical) colors, which are analyzed according to their energy consumption. The second is based on the constrained continuous optimization of color energy in the perceptually uniform CIELAB color space. We quantitatively compare our two approaches with a traditional choice of colors, demonstrating that we typically save approximately 40 percent of the energy. The color sets are applied to examples from the 2D visualization of nominal data and volume rendering of 3D scalar fields. [ABSTRACT FROM AUTHOR]

Computers have added many new possibilities to the tool box used for visualizing science in general and relativity in particular. We present some new results from our own work: (2 + 1) dimensional Minkowski diagrams showing two spatial dimensions, extended wormhole visualization, and the illustration of accretion discs by using the approximation via a rigidly rotating disc of dust. We also discuss some related examples from our earlier work, such as interactive and immersive visualization, or the visualization of the warp drive metric. [ABSTRACT FROM AUTHOR]

Certain of our concepts are innate, but many others are learned. Despite the plausibility of this claim, some have argued that the very idea of concept learning is incoherent. I present a conception of learning that sidesteps the arguments against the possibility of concept learning, and sketch several mechanisms that result in the generation of new primitive concepts. Given the rational considerations that motivate their deployment, I argue that these deserve to be called learning mechanisms. I conclude by replying to the objections that these mechanisms cannot produce genuinely new content and cannot be part of genuinely cognitive explanations. [ABSTRACT FROM AUTHOR]

Jean Mandler proposes an original and richly detailed theory of how concepts relate to sensory and motor capacities. I focus on her claims about conceptual representations and the processes that produce them. In her view, concepts are declarative representations of object kind information. First, I argue that since sensorimotor representations may be declarative, there is no bar to percepts being constituents of concepts. Second, I suggest that concepts track kinds and other categories not by representing kind information per se, but rather by being subject to the appropriate sort of inferential dispositions. These dispositions themselves may apply equally to perceptual and nonperceptual representations. Third, I argue that Mandler's proposed redescriptive mechanism for producing conceptual primitives can be viewed as a kind of Fodorian triggering device. Hence, there may be less distance between her view and Fodor's than either one has supposed. I suggest that redescription needs to be supplemented with several other kinds of more flexible and open-ended concept learning mechanisms. Finally, I briefly sketch the view of conceptual development that results from adopting these proposals and contrast it with Mandler's. [ABSTRACT FROM AUTHOR]

Concept empiricists are committed to the claim that the vehicles of thought are re-activated perceptual representations. Evidence for empiricism comes from a range of neuroscientific studies showing that perceptual regions of the brain are employed during cognitive tasks such as categorization and inference. I examine the extant neuroscientific evidence and argue that it falls short of establishing this core empiricist claim. During conceptual tasks, the causal structure of the brain produces widespread activity in both perceptual and non-perceptual systems. I lay out several conditions on what is required for a neural state to be a realizer of the functional role played by concepts, and argue that no subset of this activity can be singled out as the unique neural vehicle of conceptual thought. Finally, I suggest that, while the strongest form of empiricism is probably false, the evidence is consistent with several weaker forms of empiricism. [ABSTRACT FROM AUTHOR]

A ‘Radical Simulationist’ account of how folk psychology functions has been developed by Robert Gordon. I argue that Radical Simulationism is false. In its simplest form it is not sufficient to explain our attribution of mental states to subjects whose desires and preferences differ from our own. Modifying the theory to capture these attributions invariably generates innumerable other false attributions. Further, the theory predicts that deficits in mentalizing ought to co-occur with certain deficits in imagining perceptually-based scenarios. I present evidence suggesting that this prediction is false, and outline further possible empirical tests of the theory. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we report on five years of teaching experience with our introductory course “Graphical-Interactive Systems”, which covers basic topics of human–computer interaction and computer graphics for students in the third year of their major in computer science. Although the two fields of human–computer interaction and computer graphics are usually taught in different courses, we believe that they have much in common and can therefore be integrated into a combined course. “Graphical-Interactive Systems” builds a foundation for advanced courses in both disciplines and achieves an efficient use of teaching time due to synergy effects. [Copyright &y& Elsevier]

In this paper, we present a mapping of nonlinear ray tracing to the GPU which avoids any data transfer back to main memory. The rendering process consists of the following parts: ray setup according to the camera parameters, ray integration, ray-object intersection, and local illumination. Bent rays are approximated by polygonal lines that are represented by textures. Ray integration is based on an iterative numerical solution of ordinary differential equations whose initial values are determined during ray setup. To improve the rendering performance, we propose acceleration techniques such as early ray termination and adaptive ray integration. Finally, we discuss a variety of applications that range from the visualization of dynamical systems to the general relativistic visualization in astrophysics and the rendering of the continuous refraction in media with varying density. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image Generation I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism [ABSTRACT FROM AUTHOR]

Dynamical systems theorists (dynamicists) allege that symbolic models of cognition are essentially incomplete because they fail to capture the temporal properties of mental processing. I present two possible interpretations of the dynamicists' argument from time and show that neither one is successful. The disagreement between dynamicists and symbolic theorists rests not on temporal considerations per se, but on differences over the multiple realizability of cognitive states and the proper explanatory goals of psychology. The negative arguments of dynamicists against symbolic models fail, and it is doubtful whether pursuing dynamicists' explanatory goals will lead to a robust psychological theory. [ABSTRACT FROM AUTHOR]

Fodor offers a novel argument against Bare-bones Concept Pragmatism (BCP). He alleges that there are two circularities in BCP's account of concept possession: a circularity in explaining concept possession in terms of the capacity to sort; and a circularity in explaining concept possession in terms of the capacity to draw inferences. We argue that neither of these circles is real. [ABSTRACT FROM AUTHOR]

The "New Synthesis" in cognitive science is committed to the computational theory of mind (CTM), massive modularity, nativism, and adaptationism. In The mind doesn't work that way, Jerry Fodor argues that CTM has problems explaining abductive or global inference, but that the New Synthesis offers no solution, since massive modularity is in fact incompatible with global cognitive processes. I argue that it is not clear how global human mentation is, so whether CTM is imperiled is an open question. Massive modularity also lacks some of the invidious commitments Fodor ascribes to it. Furthermore, Fodor's anti-adaptationist arguments are in tension with his nativism about the contents of modular systems. The New Synthesis thus has points worth preserving. [ABSTRACT FROM AUTHOR]

Indigenous peoples possess enormously rich and articulated knowledge of the natural world. A major goal of research in anthropology and ethnobiology as well as ecology, conservation biology, and development studies is to find ways of integrating this knowledge with that produced by academic and other institutionalized scientific communities. Here I present a challenge to this integration project. I argue, by reference to ethnographic and cross-cultural psychological studies, that the models of the world developed within specialized academic disciplines do not map onto anything existing within traditional beliefs and practices for coping with nature. Traditional ecological knowledge is distributed across a heterogeneous array of overlapping practices within Indigenous cultures, including spiritual and ritual practices that invoke categories, properties, and causal-explanatory models that do not in general converge with those of the academic sciences. In light of this divergence I argue that we should abandon the integration project, and conclude by sketching a notion of knowledge coordination as a possible successor framework. • Contrasts models of nature in traditional ecological knowledge (TEK) with those in academic ecological knowledge. • Shows that TEK does not overlap in structure and content with knowledge produced by institutionalized academic disciplines. • Argues that programs aiming to integrate TEK with academic knowledge face significant epistemic and ontological hurdles. • Develops a successor program of knowledge coordination that is pluralistic, local, provisional, and shallow. [ABSTRACT FROM AUTHOR]

We present an image-based approach to integrate state-of-the-art scientific visualization into virtual reality (VR) environments: the mint visualization/VR inter-operation system. We enable the integration of visualization algorithms from within their software frameworks directly into VR without the need to explicitly port visualization implementations to the underlying VR framework—thus retaining their capabilities, specializations, and optimizations. Consequently, our approach also facilitates enriching VR-based scientific data exploration with established or novel VR immersion and interaction techniques available in VR authoring tools. The separation of concerns enables researchers and users in different domains, like virtual immersive environments, immersive analytics, and scientific visualization, to independently work with existing software suitable for their domain while being able to interface with one another easily. We present our system architecture and inter-operation protocol (mint), an example of a collaborative VR environment implemented in the Unity engine (VRAUKE), as well as the integration of the protocol for the visualization frameworks Inviwo, MegaMol, and ParaView. Our implementation is publicly available as open-source software. [ABSTRACT FROM AUTHOR]

Visualization as a discipline has to investigate its practical implications in a world steadily moving toward greener computing methods. Quantifying the power consumption of visualization algorithms is thus essential, given the ever-increasing energy needs of GPUs. Previous approaches rely on integrated sensors or invasive methods that require modifications and special test setups. However, they still suffer from imprecision from low sampling rates and integration over time. Using a high-precision, high-frequency setup via steerable oscilloscopes, we can objectively measure the resulting quality of previous approaches. This is essential to establish a ground truth, pave the way for improved modeling of power consumption in general, and enable better estimates based on the output of lower-quality sensors. We finally discuss benefits that can be drawn from the additional insight of the higher-precision setup and which additional use cases can justify the incurred costs. [ABSTRACT FROM AUTHOR]

In architectural design optimization, fitness landscapes are used to visualize design space parameters in relation to one or more objective functions for which they are being optimized. In our design study with domain experts, we developed a visual analytics framework for exploring and analyzing fitness landscapes spanning data, projection, and visualization layers. Within the data layer, we employ two surrogate models and three sampling strategies to efficiently generate a wide array of landscapes. On the projection layer, we use star coordinates and UMAP as two alternative methods for obtaining a 2D embedding of the design space. Our interactive user interface can visualize fitness landscapes as a continuous density map or a discrete glyph-based map. We investigate the influence of surrogate models and sampling strategies on the resulting fitness landscapes in a parameter study. Additionally, we present findings from a user study (N = 12), revealing how experts' preferences regarding projection methods and visual representations may be influenced by their level of expertise, characteristics of the techniques, and the specific task at hand. Furthermore, we demonstrate the usability and usefulness of our framework by a case study from the architecture domain, involving one domain expert. [ABSTRACT FROM AUTHOR]

Interactive visualization is a valuable tool for introductory or advanced courses in general relativity as well as for public outreach to provide a deeper understanding of the visual implications due to curved spacetime. In particular, the extreme case of a black hole where the curvature becomes so strong that even light cannot escape, benefits from an interactive visualization where students can investigate the distortion effects by moving objects around. However, the most commonly used technique of four-dimensional general-relativistic ray tracing is still too slow for interactive frame rates. Therefore, we propose an efficient and adaptive polygon rendering method that takes light deflection and light travel time into account. An additional advantage of this method is that it provides a natural demonstration of how multiple images occur and how light travel time affects them. Finally, we present our method using three example scenes: a triangle passing behind a black hole, a sphere orbiting a black hole and an accretion disk with different inclination angles. [ABSTRACT FROM AUTHOR]

Commercial videos are often used to familiarise potential buyers and users with new technologies and their possibilities. In addition, presenting visions of future applications is a way to configure users and define social worlds of technology use. We analyse 30 YouTube videos featuring augmented reality (AR) devices in industrial manufacturing and construction, to explore how these commercial videos situate AR technology and future users by showcasing techno-euphoric promises and imagined use cases. With a video analysis based on Grounded Theory and Situational Analysis, we untangle the promises of AR for manufacturing and construction work; second, we present two prevailing configurations of AR users: 'experts in situ' and 'smart dummies'; and third, we discuss how YouTube videos put forward developmental expectations. In addition, we identify discrepancies between expectations and foreseeable requirements in construction work. Finally, our research could contribute to a more holistic understanding of workplaces and socially robust AR applications. [ABSTRACT FROM AUTHOR]

We introduce a versatile density-based approach to label placement that aims to put labels in uncluttered areas of an underlying 2D visualization. Our novel, image-space algorithm constructs a density map by applying kernel density estimation to the input features, i.e., the locations of the points to be labeled. In order to find a suitable position for a label where it does not overlap any features or other labels, we move it following the gradient descent of this density map. This guides labels toward nearby areas of low feature density, resulting in a layout where labels are spread around feature-dense areas. The gradient descent trajectory can be used to draw curved leaders that connect the point features to their labels. Additionally, our approach supports prioritized label placement, user-defined label-to-label and label-to-feature margins, obstacle-constrained labeling, and arbitrarily shaped labels. The proposed method is conceptually simple and can easily be implemented using OpenCV and image-processing libraries. [ABSTRACT FROM AUTHOR]

Carey focuses her attention on a mechanism of concept learning called “Quinian bootstrapping.” I argue that this form of bootstrapping is not dependent upon language or other public representations, and outline a place for language in concept learning generally. Language, perception, and causal reasoning are all sources of evidence that can guide learners toward discovering new and potentially useful categories. [ABSTRACT FROM AUTHOR]

Data visualization relies on efficient rendering to allow users to interactively explore and understand their data. However, achieving interactive frame rates is often challenging, especially for high-resolution displays or large datasets. In computer graphics, several methods temporally reconstruct full-resolution images from multiple consecutive lower-resolution frames. Besides providing temporal image stability, they amortize the rendering costs over multiple frames and thus improve the minimum frame rate. We present a method that adopts this idea to accelerate 2D information visualization, without requiring any changes to the rendering itself. By exploiting properties of orthographic projection, our method significantly improves rendering performance while minimizing the loss of image quality during camera manipulation. For static scenes, it quickly converges to the full-resolution image. We discuss the characteristics and different modes of our method concerning rendering performance and image quality and the corresponding trade-offs. To improve ease of use, we provide automatic resolution scaling in our method to adapt to user-defined target frame rate. Finally, we present extensive rendering benchmarks to examine real-world performance for examples of parallel coordinates and scatterplot matrix visualizations, and discuss appropriate application scenarios and contraindications for usage. [ABSTRACT FROM AUTHOR]

In cloth simulation, the behavior of textiles largely depends on initial conditions, parameters, and simulation techniques. Usually, several combinations of those aspects are altered until a simulation setting is found to create a satisfying animation. However, if an initial condition, such as a collision object, is changed afterward or the cloth behavior is transferred to a different scene, the existing set of simulation parameters could no longer be suitable for the desired look. In this case, it is difficult to find a new configuration by changing parameters manually and to determine if it conforms the desired properties. This article introduces a feature vector that is used as a motion-shape signature to capture the spatiotemporal shape characteristics of cloth and can be applied as a similarity measure for physics-based cloth animations. [ABSTRACT FROM AUTHOR]

Graph visualizations encode relationships between objects. Abstracting the objects into group structures provides an overview of the data. Groups can be disjoint or overlapping, and might be organized hierarchically. However, the underlying graph still needs to be represented for analyzing the data in more depth. This work surveys research in visualizing group structures as part of graph diagrams. A particular focus is the explicit visual encoding of groups, rather than only using graph layout to indicate groups implicitly. We introduce a taxonomy of visualization techniques structuring the field into four main categories: visual node attributes vary properties of the node representation to encode the grouping, juxtaposed approaches use two separate visualizations, superimposed techniques work with two aligned visual layers, and embedded visualizations tightly integrate group and graph representation. The derived taxonomies for group structure and visualization types are also applied to group visualizations of edges. We survey group-only, group-node, group-edge and group-network tasks that are described in the literature as use cases of group visualizations. We discuss results from evaluations of existing visualization techniques as well as main areas of application. Finally, we report future challenges based on interviews we conducted with leading researchers of the field. [ABSTRACT FROM AUTHOR]

The article offers information on the 2009 Eurographics Symposium on Parallel Graphics and Visualization (EGPGV 2009) from March 29 to March 30, 2009 in Munich, Germany. The papers accepted for the symposium covered topics on computer graphics and visualization. Peter Shirley highlighted how desktop parallelism allows ray tracing to be an alternative to the traditional status quo of rasterization for interactive rendering while Matt Pharr identified how to control the parallel computing power of graphical architectures.

The article discusses the highlights of the 2008 Eurographics Symposium on Parallel Graphics and Visualization (EGPGV 2008) held on April 14-15, 2008 in Crete, Greece. The first paper session was dedicated to volume rendering techniques, presenting multi-graphics processing units (GPU) methods, the second session focused on scientific visualization while the third session included parallel techniques for graph layout, mesh simplification and global illumination. The keynote address of Hans-Christian Hege focused on high performance computing.

A common enhancement of scatterplots represents points as small multiples, glyphs, or thumbnail images. As this encoding often results in overlaps, a general strategy is to alter the position of the data points, for instance, to a grid-like structure. Previous approaches rely on solving expensive optimization problems or on dividing the space that alter the global structure of the scatterplot. To find a good balance between efficiency and neighborhood and layout preservation, we propose Hagrid, a technique that uses space-filling curves (SFCs) to "gridify" a scatterplot without employing expensive collision detection and handling mechanisms. Using SFCs ensures that the points are plotted close to their original position, retaining approximately the same global structure. The resulting scatterplot is mapped onto a rectangular or hexagonal grid, using Hilbert and Gosper curves. We discuss and evaluate the theoretic runtime of our approach and quantitatively compare our approach to three state-of-the-art gridifying approaches, DGrid, Small multiples with gaps SMWG, and CorrelatedMultiples CMDS, in an evaluation comprising 339 scatterplots. Here, we compute several quality measures for neighborhood preservation together with an analysis of the actual runtimes. The main results show that, compared to the best other technique, Hagrid is faster by a factor of four, while achieving similar or even better quality of the gridified layout. Due to its computational efficiency, our approach also allows novel applications of gridifying approaches in interactive settings, such as removing local overlap upon hovering over a scatterplot. [ABSTRACT FROM AUTHOR]

Treating time as the third dimension of 2D time-dependent flow enables the application of a wide variety of visualization techniques for 3D stationary vector fields. In the resulting space-time representation, 3D streamlines represent 2D pathlines of the original field. In this paper, we investigate the application of different streamline-based visualization concepts to the 3D space-time representation of 2D time-dependent flow. As a consequence, we obtain from each streamline-based concept a Galilean-invariant counterpart that takes the time dependence of the original field explicitly into account. We show the advantages of the overall approach for vortex analysis and the analysis of the dynamics of material lines. In particular, we employ the concept for the extraction of vortex centers, vortex core regions, and the visualization of material line dynamics using streamsurface integration and line integral convolution in the space-time field. We exemplify the utility of our visualization approach using two 2D time-dependent datasets that exhibit vortical flow. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

We propose a novel method for the computation of Jacobi sets in 2D domains. The Jacobi set is a topological descriptor based on Morse theory that captures gradient alignments among multiple scalar fields, which is useful for multi-field visualization. Previous Jacobi set computations use piecewise linear approximations on triangulations that result in discretization artifacts like zig-zag patterns. In this paper, we utilize a local bilinear method to obtain a more precise approximation of Jacobi sets by preserving the topology and improving the geometry. Consequently, zig-zag patterns on edges are avoided, resulting in a smoother Jacobi set representation. Our experiments show a better convergence with increasing resolution compared to the piecewise linear method. We utilize this advantage with an efficient local subdivision scheme. Finally, our approach is evaluated qualitatively and quantitatively in comparison with previous methods for different mesh resolutions and across a number of synthetic and real-world examples. [ABSTRACT FROM AUTHOR]

It is difficult to explore and analyze eye gaze trajectories for commonly applied visual task solution strategies because such data shows complex spatio-temporal structure. In particular, the traditional eye gaze plots of scan paths fail for a large number of study participants since these plots lead to much visual clutter. To address this problem we introduce the AOI Rivers technique as a novel interactive visualization method for investigating time-varying fixation frequencies, transitions between areas of interest (AOIs), and the sequential order of gaze visits to AOIs in a visual stimulus of an eye tracking experiment. To this end, we extend the ThemeRiver technique by influents, effluents, and transitions similar to the concept of Sankey diagrams. The AOI Rivers visualization is complemented by linked spatial views of the data in the form of heatmaps, gaze plots, or display of the visual stimulus. The usefulness of our technique is demonstrated for gaze trajectory data recorded in a previously conducted eye tracking experiment. [ABSTRACT FROM AUTHOR]