bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fuzzy Geodesics and Consistent Sparse Correspondences For: eformable Shapes
Authors: Sun Jian , Chen Xiaobai , Funkhouser Thomas A. 
Published: September 2010

AbstractA geodesic is a parameterized curve on a Riemannian manifold governed by a second order partial differential equation. Geodesics are notoriously unstable: small perturbations of the underlying manifold may lead to dramatic changes of the course of a geodesic. Such instability makes it difficult to use geodesics in many applications, in particular in the world of discrete geometry. In this paper, we consider a geodesic as the indicator function of the set of the points on the geodesic. From this perspective, we present a new concept called fuzzy geodesics and show that fuzzy geodesics are stable with respect to the Gromov‐Hausdorff distance. Based on fuzzy geodesics, we propose a new object called the intersection configuration for a set of points on a shape and demonstrate its effectiveness in the application of finding consistent correspondences between sparse sets of points on shapes differing by extreme deformations.
Persistent Heat Signature for Pose‐oblivious Matching of Incomplete Models
Authors: Dey T.K. , Li K. , Luo C. , Ranjan P. , Safa I. , Wang Y. 
Published: September 2010

AbstractAlthough understanding of shape features in the context of shape matching and retrieval has made considerable progress in recent years, the case for partial and incomplete models in presence of pose variations still begs a robust and efficient solution. A signature that encodes features at multi‐scales in a pose invariant manner is more appropriate for this case. The Heat Kernel Signature function from spectral theory exhibits this multi‐scale property. We show how this concept can be merged with the persistent homology to design a novel efficient pose‐oblivious matching algorithm for all models, be they partial, incomplete, or complete. We make the algorithm scalable so that it can handle large data sets. Several test results show the robustness of our approach.
One Point Isometric Matching with the Heat Kernel
Authors: Ovsjanikov Maks , Mérigot Quentin , Mémoli Facundo , Guibas Leonidas 
Published: September 2010

AbstractA common operation in many geometry processing algorithms consists of finding correspondences between pairs of shapes by finding structure‐preserving maps between them. A particularly useful case of such maps is isometries, which preserve geodesic distances between points on each shape. Although several algorithms have been proposed to find approximately isometric maps between a pair of shapes, the structure of the space of isometries is not well understood. In this paper, we show that under mild genericity conditions, a single correspondence can be used to recover an isometry defined on entire shapes, and thus the space of all isometries can be parameterized by one correspondence between a pair of points. Perhaps surprisingly, this result is general, and does not depend on the dimensionality or the genus, and is valid for compact manifolds in any dimension. Moreover, we show that both the initial correspondence and the isometry can be recovered efficiently in practice. This allows us to devise an algorithm to find intrinsic symmetries of shapes, match shapes undergoing isometric deformations, as well as match partial and incomplete models efficiently.
Iso‐geometric Finite Element Analysis Based on Catmull‐Clark : ubdivision Solids
Authors: Burkhart D. , Hamann B. , Umlauf G. 
Published: September 2010

AbstractWe present a volumetric iso‐geometric finite element analysis based on Catmull‐Clark solids. This concept allows one to use the same representation for the modeling, the physical simulation, and the visualization, which optimizes the design process and narrows the gap between CAD and CAE. In our method the boundary of the solid model is a Catmull‐Clark surface with optional corners and creases to support the modeling phase. The crucial point in the simulation phase is the need to perform efficient integration for the elements. We propose a method similar to the standard subdivision surface evaluation technique, such that numerical quadrature can be used.Experiments show that our approach converges faster than methods based on tri‐linear and tri‐quadratic elements. However, the topological structure of Catmull‐Clark elements is as simple as the structure of linear elements. Furthermore, the Catmull‐Clark elements we use are C2‐continuous on the boundary and in the interior except for irregular vertices and edges.
Polygonal mesh watermarking using Laplacian coordinates
Authors: Yang Y. , Ivrissimtzis I. 
Published: September 2010

AbstractWe propose a watermarking algorithm for polygonal meshes based on the modification of the Laplacian coordinates. More specifically, we first compute the Laplacian coordinates (x,y,z) of the mesh vertices, then construct the histogram of the lengths of the (x,y,z) vectors, and finally, insert the watermark by altering the shape of that histogram. The watermark extraction is carried out blindly, with no reference to the host model. The proposed method is more robust than several existing high capacity watermarking algorithms. In particular, it is able to resist attacks such as translations, rotations, uniform scaling and vertex reordering, due to the invariance of the histogram of the Laplacian vector lengths under such transformations. Compared to the existing robust watermarking methods, our experiments show that the proposed method can better resist common mesh editing attacks, due to the good behaviour of the Laplacian coordinates under such operations.
Fast and Scalable CPU/GPU Collision Detection for Rigid and Deformable Surfaces
Authors: Pabst Simon , Koch Artur , Straßer Wolfgang 
Published: September 2010

AbstractWe present a new hybrid CPU/GPU collision detection technique for rigid and deformable objects based on spatial subdivision. Our approach efficiently exploits the massive computational capabilities of modern CPUs and GPUs commonly found in off‐the‐shelf computer systems. The algorithm is specifically tailored to be highly scalable on both the CPU and the GPU sides. We can compute discrete and continuous external and self‐collisions of non‐penetrating rigid and deformable objects consisting of many tens of thousands of triangles in a few milliseconds on a modern PC. Our approach is orders of magnitude faster than earlier CPU‐based approaches and up to twice as fast as the most recent GPU‐based techniques.
Feature Preserving Mesh Generation from 3D Point Clouds
Authors: Salman Nader , Yvinec Mariette , Merigot Quentin 
Published: September 2010

AbstractWe address the problem of generating quality surface triangle meshes from 3D point clouds sampled on piecewise smooth surfaces. Using a feature detection process based on the covariance matrices of Voronoi cells, we first extract from the point cloud a set of sharp features. Our algorithm also runs on the input point cloud a reconstruction process, such as Poisson reconstruction, providing an implicit surface. A feature preserving variant of a Delaunay refinement process is then used to generate a mesh approximating the implicit surface and containing a faithful representation of the extracted sharp edges. Such a mesh provides an enhanced trade‐off between accuracy and mesh complexity. The whole process is robust to noise and made versatile through a small set of parameters which govern the mesh sizing, approximation error and shape of the elements. We demonstrate the effectiveness of our method on a variety of models including laser scanned datasets ranging from indoor to outdoor scenes.
High Fidelity Scan Merging
Authors: Digne J. , Morel J.‐M. , Audfray N. , Lartigue C. 
Published: September 2010

AbstractFor each scanned object 3D triangulation laser scanners deliver multiple sweeps corresponding to multiple laser motions and orientations. The problem of aligning these scans has been well solved by using rigid and, more recently, non‐rigid transformations. Nevertheless, there are always residual local offsets between scans which forbid a direct merging of the scans, and force to some preliminary smoothing. Indeed, the tiling and aliasing effects due to the tiniest normal displacements of the scans can be dramatic. This paper proposes a general method to tackle this problem. The algorithm decomposes each scan into its high and low frequency components and fuses the low frequencies while keeping intact the high frequency content. It produces a mesh with the highest attainable resolution, having for vertices all raw data points of all scans. This exhaustive fusion of scans maintains the finest texture details. The method is illustrated on several high resolution scans of archeological objects.
Scales and Scale‐like Structures
Authors: Landreneau Eric , Schaefer Scott 
Published: September 2010

AbstractWe present a method for generating scales and scale‐like structures on a polygonal mesh through surface replacement. As input, we require a triangular mesh that will be covered with scales and one or more proxy‐models to be used as the scale's shape. A user begins scale generation by drawing a lateral line on the model to control the distribution and orientation of scales on the surface. We then create a vector field over the surface to control an anisotropic Voronoi tessellation, which represents the region occupied by each scale. Next we replace these regions by cutting the proxy model to match the boundary of the Voronoi region and deform the cut model onto the surface. The result is a fully connected 2‐manifold that is suitable for subsequent post‐processing applications like surface subdivision.
Designing Quad‐dominant Meshes with Planar Faces
Authors: Zadravec Mirko , Schiftner Alexander , Wallner Johannes 
Published: September 2010

AbstractWe study the combined problem of approximating a surface by a quad mesh (or quad‐dominant mesh) which on the one hand has planar faces, and which on the other hand is aesthetically pleasing and has evenly spaced vertices. This work is motivated by applications in freeform architecture and leads to a discussion of fields of conjugate directions in surfaces, their singularities and indices, their optimization and their interactive modeling. The actual meshing is performed by means of a level set method which is capable of handling combinatorial singularities, and which can deal with planarity, smoothness, and spacing issues.
Closed‐form Blending of Local Symmetries
Authors: Ghosh Deboshmita , Amenta Nina , Kazhdan Michael 
Published: September 2010

AbstractWe present a closed‐form solution for the symmetrization problem, solving for the optimal deformation that reconciles a set of local bilateral symmetries. Given as input a set of point‐pairs which should be symmetric, we first compute for each local neighborhood a transformation which would produce an approximate bilateral symmetry. We then solve for a single global symmetry which includes all of these local symmetries, while minimizing the deformation within each local neighborhood. Our main motivation is the symmetrization of digitized fossils, which are often deformed by a combination of compression and bending. In addition, we use the technique to symmetrize articulated models.
Multi‐scale Geometric Modeling of Ambiguous Shapes with : oleranced Balls and Compoundly Weighted α‐shapes
Authors: Cazals Frédéric , Dreyfus Tom 
Published: September 2010

AbstractDealing with ambiguous data is a challenge in Science in general and geometry processing in particular. One route of choice to extract information from such data consists of replacing the ambiguous input by a continuum, typically a one‐parameter family, so as to mine stable geometric and topological features within this family. This work follows this spirit and introduces a novel framework to handle 3D ambiguous geometric data which are naturally modeled by balls.First, we introduce toleranced balls to model ambiguous geometric objects. A toleranced ball consists of two concentric balls, and interpolating between their radii provides a way to explore a range of possible geometries. We propose to model an ambiguous shape by a collection of toleranced balls, and show that the aforementioned radius interpolation is tantamount to the growth process associated with an additively‐multiplicatively weighted Voronoi diagram (also called compoundly weighted or CW). Second and third, we investigate properties of the CW diagram and the associated CW α‐complex, which provides a filtration called the λ‐complex. Fourth, we sketch a naive algorithm to compute the CW VD. Finally, we use the λ‐complex to assess the quality of models of large protein assemblies, as these models inherently feature ambiguities.
THE SWEDISH PAST PARTICIPLE: SOME ARGUMENTS FOR A LEXICAL REDUNDANCY RULE
Authors: Platzack Christer 
Published: September 2010

SummaryIn this paper, I have tried to give a description of the Swedish past participle which accounts for both the adjectival and the verbal character of this category. The past participle of a verb is envisaged as forming a lexical entry of its own, related to the lexical entry of the verb with the help of a lexical redundancy rule. To account for the various syntactic similarities between past participles and adjectives, the lexical entry of the past participle is marked + ADJ. The differences between an adjective and a past participle are claimed to be exclusively semantic. The crucial difference seems to be that the past participle focuses on the act referred to by the verb, whereas the adjective just denotes a state of affairs. To obtain the ‘verbal’ meaning of the past participle, I have proposed a description where the meaning of the verb functions as a restrictive modifier of the central meaning of the participle. Furthermore, I have claimed that this central meaning can always be inferred from the meaning of the verb. In section 3 of the paper, I give several arguments for a semantic description of the past participle.
MOTION AND EXTENT: TWO SIDES OF THE SAME COIN
Authors: Iwata Seizi 
Published: September 2010

Abstract. This paper examines the relationship between a motion sentence (e.g, Amy went from Denver to Indianapolis.) and an extent sentence (e.g., The road goes from Denver to Indianapolis.), building upon Jackendoft's (1983) analysis. It is shown that the semantic functions for motion and extent senses, respectively GO and GOExl, are distinct, but that they share a great deal of internal structure. While both functions express successive transition from one component state to the next, they differ in (a) the presence vs. absence of the passage of time, and (b) the identity of the mover through transition.The analysis presented here based on semantic functions comes closer to an overall characterization of the motion/extent contrast than the image‐schema‐based approach (Lakoff 1987) or the metaphor‐based approach (Lakoff & Turner 1989). It can also be easily extended to account for types of extent sentences that the literature has not focussed upon.
Morphological analysis of the hindlimb in apes and humans. I. Muscle architecture
Authors: Payne R. C. , Crompton R. H. , Isler K. , Savage R. , Vereecke E. E. , Günther M. M. , Thorpe S. K. S. , D’Août K. 
Published: September 2010

AbstractWe present quantitative data on the hindlimb musculature ofPan paniscus,Gorilla gorilla gorilla,Gorilla gorilla graueri,Pongo pygmaeus abelii and Hylobates larand discuss the findings in relation to the locomotor habits of each. Muscle mass and fascicle length data were obtained for all major hindlimb muscles. Physiological cross‐sectional area (PCSA) was estimated. Data were normalized assuming geometric similarity to allow for comparison of animals of different size/species. Muscle mass scaled closely to (body mass)1.0and fascicle length scaled closely to (body mass)0.3in most species. However, human hindlimb muscles were heavy and had short fascicles per unit body mass when compared with non‐human apes. Gibbon hindlimb anatomy shared some features with human hindlimbs that were not observed in the non‐human great apes: limb circumferences tapered from proximal‐to‐distal, fascicle lengths were short per unit body mass and tendons were relatively long. Non‐human great ape hindlimb muscles were, by contrast, characterized by long fascicles arranged in parallel, with little/no tendon of insertion. Such an arrangement of muscle architecture would be useful for locomotion in a three dimensionally complex arboreal environment.
The role of the endoderm in the development and evolution of the pharyngeal arches
Authors: Graham Anthony , Okabe Masataka , Quinlan Robyn 
Published: September 2010

AbstractThe oro‐pharyngeal apparatus has its origin in a series of bulges found on the lateral surface of the embryonic head, the pharyngeal arches. Significantly, the development of these structures is extremely complex, involving interactions between a number of disparate embryonic cell types: ectoderm, endoderm, mesoderm and neural crest, each of which generates particular components of the arches, and whose development must be co‐ordinated to generate the functional adult oro‐pharyngeal apparatus. In the past most studies have emphasized the role played by the neural crest, which generates the skeletal elements of the arches, in directing pharyngeal arch development. However, it is now apparent that the pharyngeal endoderm plays an important role in directing arch development. Here we discuss the role of the pharyngeal endoderm in organizing the development of the pharyngeal arches, and the mechanisms that act to pattern the endoderm itself and those which direct its morphogenesis. Finally, we discuss the importance of modification to the pharyngeal endoderm during vertebrate evolution. In particular, we focus on the emergence of the parathyroid gland, which we have recently shown to be the result of the internalization of the gills.
Regional regulation of palatal growth and patterning along the anterior–posterior axis in mice
Authors: Hilliard Sylvia A. , Yu Ling , Gu Shuping , Zhang Zunyi , Chen Yi Ping 
Published: September 2010

AbstractCleft palate is a congenital disorder arising from a failure in the multistep process of palate development. In its mildest form the cleft affects only the posterior soft palate. In more severe cases the cleft includes the soft (posterior) and hard (anterior) palate. In mice a number of genes show differential expression along the anterior–posterior axis of the palate. Mesenchymal heterogeneity is established early, as evident from Bmp4‐mediated induction ofMsx1and cell proliferation exclusively in the anterior and Fgf8‐specific induction ofPax9in the posterior palate alone. In addition, the anterior palatal epithelium has the unique ability to induceShox2expression in the anterior mesenchymein vivoand the posterior mesenchymein vitro. Therefore, the induction and competence potentials of the epithelium and mesenchyme in the anterior are clearly distinct from those in the posterior. Defective growth in the anterior palate ofMsx1−/–andFgf10−/–mice leads to a complete cleft palate and supports the anterior‐to‐posterior direction of palatal closure. By contrast, theShox2−/–mice exhibit incomplete clefts in the anterior presumptive hard palate with an intact posterior palate. This phenotype cannot be explained by the prevailing model of palatal closure. The ability of the posterior palate to fuse independent of the anterior palate inShox2−/–mice underscores the intrinsic differences along the anterior–posterior axis of the palate. We must hitherto consider the heterogeneity of gene expression and function in the palate to understand better the aetiology and pathogenesis of non‐syndromic cleft palate and the mechanics of normal palatogenesis.
Evolution of cranial development and the role of neural crest: insights from amphibians
Authors: Hanken James , Gross Joshua B. 
Published: September 2010

AbstractContemporary studies of vertebrate cranial development document the essential role played by the embryonic neural crest as both a source of adult tissues and a locus of cranial form and patterning. Yet corresponding and basic features of cranial evolution, such as the extent of conservation vs. variation among species in the contribution of the neural crest to specific structures, remain to be adequately resolved. Investigation of these features requires comparable data from species that are both phylogenetically appropriate and taxonomically diverse. One key group are amphibians, which are uniquely able to inform our understanding of the ancestral patterns of ontogeny in fishes and tetrapods as well as the evolution of presumably derived patterns reported for amniotes. Recent data support the hypothesis that a prominent contribution of the neural crest to cranial skeletal and muscular connective tissues is a fundamental property that evolved early in vertebrate history and is retained in living forms. The contribution of the neural crest to skull bones appears to be more evolutionarily labile than that of cartilages, although significance of the limited comparative data is difficult to establish at present. Results underline the importance of accurate and reliable homology assessments for evaluating the contrasting patterns of derivation reported for the three principal tetrapod models: mouse, chicken and frog.
Developmental studies of the lamprey and hierarchical evolutionary steps towards the acquisition of the jaw
Authors: Kuratani Shigeru 
Published: September 2010

AbstractThe evolution of animal morphology can be understood as a series of changes in developmental programs. Among vertebrates, some developmental stages are conserved across species, representing particular developmental constraints. One of the most conserved stages is the vertebrate pharyngula, in which similar embryonic morphology is observed and the Hox code is clearly expressed. The oral developmental program also appears to be constrained to some extent, as both its morphology and the the Hox‐code‐default state of the oropharyngeal region are well conserved between the lamprey and gnathostome embryos. These features do not by themselves explain the evolution of jaws, but should be regarded as a prerequisite for evolutionary diversification of the mandibular arch. By comparing the pharyngula morphology of the lamprey and gnathostomes, it has become clear that the oral pattern is not entirely identical; in particular, the positional differentiation of the rostral ectomesenchyme is shifted between these animals. Therefore, the jaw seems to have arisen as an evolutionary novelty by overriding ancestral constraints, a process in which morphological homologies are partially lost. This change involves the heterotopic shift of tissue interaction, which appears to have been preceded by the transition from monorhiny to diplorhiny, as well as separation of the hypophysis. When gene expression patterns are compared between the lamprey and gnathostomes, cell‐autonomously functioning genes tend to be associated with identical cell types or equivalent anatomical domains, whereas growth‐factor‐encoding genes have changed their expression domains during evolution. Thus, the heterotopic evolution may be based on changes in the regulation of signalling‐molecule‐encoding genes.