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The authors propose visual embedding as a model for automatically generating and evaluating visualizations. A visual embedding is a function from data points to a space of visual primitives that measurably preserves structures in the data (domain) within the mapped perceptual space (range). The authors demonstrate its use with three examples: coloring of neural tracts, scatterplots with icons, and evaluation of alternative diffusion tensor glyphs. They discuss several techniques for generating visual-embedding functions, including probabilistic graphical models for embedding in discrete visual spaces. They also describe two complementary approaches--crowdsourcing and visual product spaces--for building visual spaces with associated perceptual--distance measures. In addition, they recommend several research directions for further developing the visual-embedding model. [ABSTRACT FROM AUTHOR]

We propose a novel surface remeshing algorithm. While many remeshing algorithms are based on global parametrization or local mesh optimization, our algorithm is closely related to surface reconstruction techniques and it requires no explicit parameterization. Our approach is based on the advancing-front paradigm, and it can be used to both incrementally remesh the complete surface, or simply to remesh a portion of it with a high-quality mesh. It is accurate, fast, robust, and suitable for use with interactive mesh processing applications that require local remeshing. We show a number of applications, including matching the resolution of meshes when doing Boolean operations such as unions and intersections. We also show how to adapt the algorithm to blend and merge mixed-mode objects — for example, to compute the union of a point-set surface and a triangle mesh. [ABSTRACT FROM AUTHOR]

The explosive growth in integration technology and the parallel nature of rasterization-based graphics APIs (Application Programming Interface) changed the panorama of consumer-level graphics: today, GPUs (Graphics Processing Units) are cheap, fast and ubiquitous. We show how to harness the computational power of GPUs and solve the incompressible Navier-Stokes fluid equations significantly faster (more than one order of magnitude in average) than on CPU solvers of comparable cost. While past approaches typically used Stam's implicit solver, we use a variation of SMAC (Simplified Marker and Cell). SMAC is widely used in engineering applications, where experimental reproducibility is essential. Thus, we show that the GPU is a viable and affordable processor for scientific applications. Our solver works with general rectangular domains (possibly with obstacles), implements a variety of boundary conditions and incorporates energy transport through the traditional Boussinesq approximation. Finally, we discuss the implications of our solver in light of future GPU features, and possible extensions such as three-dimensional domains and free-boundary problems. [ABSTRACT FROM AUTHOR]

For an investigation of the relation between the morphology and the tectonics in the Macaronesian Islands (i.e. the geographical group of middle Atlantic Islands between 10°N and 40°N), orientation studies have been made of steeply dipping joints and, where possible, of the trends of valleys and ridges. A coincidence of the “preferred directions” of these features indicates a probable genetic relation between them. The results are: (1) Joint strikes, stream directions and ridge trends (where available) generally agree with each other on each individual island, indicating a common genetic (tectonic) origin of these features. Thus, the main result of this study is that the morphology of all Macaronesian Islands, although surficially of volcanic origin, has been significantly codesigend by tectonic processes. (2) The direction data for corresponding geomorphic features are essentially the same across each individual archipelago, certainly with regard to the joints, somewhat less so with regard to the links and ridges. (3) The Canary and the Madeira Islands Archipelago yield the same values for the direction maxima of joints and streams. (4) The compression (σ1)-axis indicated by the fault plane solution of the Canary earthquake of 9 May 1989 lines up with one of the bisectrices and not with one of the strike-maxima of the surrounding joints; this indicates that the joint directions may be indicative of the shear lines rather than of the principal stress directions of the neotectonic stress field in the area. (5) There is a steady anticlockwise rotation of corresponding morphotectonic directions as one moves from Africa westward from the Canary Islands through Madeira and the Cape Verde Islands to the Azores.This may be due to a general rotation of the area: whilst drifting N, Africa has been subject to an anticlockwise rotation (pole west of Madeira) owing to the drag caused by the eastward-spreading Atlantic Ocean floor. (6) The mid-Atlantic ridge seems to have no influence on the orientation of the joints/streams/ridges on the islands. In the plate-tectonic model, this lining up of joint orientations may be the consequence of the mirror reflection of the displacements away from the Ridge on its two sides. (7) The situation at the triple junction of the Eurasian, African and American plates is not clear; additional microplates (Azorean, Iberian) might even be present. The Azores might (i) have arisen around the triple junction from basaltic lava upwelling from a mantle hot spot to be carried away as islands on the moving plates; or (ii) they may represent a hot-spot trace on moving plates. Since trachytic/andesitic lava flows have been found on the islands, (iii) a tectonic control model has been proposed in the literature without recurrence to basaltic plates. The results of our morphometric studies would be able to conform to all three models. [Copyright &y& Elsevier]

Develops a theory of the lateral decrease of grain size and bed thickness with increasing distance of downwind transport for ash falls. Identification of sediment load density of a turbulent slug of fluid, a turbulent diffusivity coefficient and the decay of turbulent velocity fluctuations as basis of the theory.

Qualitative and quantitative observations show a general positive correlation between grain size and thickness of cross-bedded units. Greater sand-wave height correlates with greater turbulence which permits more and coarser grains to be transported. A theory is developed which qualitatively explains these relationships. [ABSTRACT FROM AUTHOR]

Data from Ordovician and Tertiary turbidites and from the Hekla ash fall show good correlation between bed thickness and grain size. Most of the thicker beds are coarser grained. The relation between bed thickness and grain size in graded beds can be explained by a theory which uses a sedimentation formula based on the decay law of turbulence in the deposition zone of a turbidity current. [ABSTRACT FROM AUTHOR]

Shows that non-multiple, continuously graded beds from turbidite sequences have size decline curves that are either convex, concave or straight. Fluid mechanics of turbulent transport; Formula relating both median and maximum-grain size to height above the base of the graded bed; Relation between the shape of the size decline curve in a continuously graded bed and the initial size distribution of particles.

Scientists study trajectory data to understand trends in movement patterns, such as human mobility for traffic analysis and urban planning. In this paper, we introduce a novel trajectory clustering technique whose central idea is to use vector fields to induce a notion of similarity between trajectories, letting the vector fields themselves define and represent each cluster. We present an efficient algorithm to find a locally optimal clustering of trajectories into vector fields, and demonstrate how vector-field k-means can find patterns missed by previous methods. We present experimental evidence of its effectiveness and efficiency using several datasets, including historical hurricane data, GPS tracks of people and vehicles, and anonymous cellular radio handoffs from a large service provider. [ABSTRACT FROM AUTHOR]

Summary: Current synteny visualization tools either focus on small regions of sequence and do not illustrate genome-wide trends, or are complicated to use and create visualizations that are difficult to interpret. To address this challenge, The Comparative Genomics Platform (CoGe) has developed two web-based tools to visualize synteny across whole genomes. SynMap2 and SynMap3D allow researchers to explore whole genome synteny patterns (across two or three genomes, respectively) in responsive, web-based visualization and virtual reality environments. Both tools have access to the extensive CoGe genome database (containing over 30 000 genomes) as well as the option for users to upload their own data. By leveraging modern web technologies there is no installation required, making the tools widely accessible and easy to use. [ABSTRACT FROM AUTHOR]