177,355 research outputs found
Erratum to: Oculo-auriculo-vertebral spectrum: going beyond the first and second pharyngeal arch involvement (Neuroradiology, (2017), 59, 3, (305-316), 10.1007/s00234-017-1795-1)
No full textIn the article “Oculo-auriculo-vertebral spectrum: going beyond the first and second pharyngeal arch involvement”, the list of author names was incorrect. Author names were inverted with the surname preceding first name. Davide Brotto 1, Renzo Manara 2, Sara Ghiselli 1, Elisa Lovo 1, Rodica Mardari 3, Irene Toldo 4 , Alessandro Castiglione 1, Giovanni Schifano 1, Valentina Stritoni 1, Roberto Bovo 1, Patrizia Trevisi 1, Alessandro Martini 1
Photo-consistent planar patches from unstructured cloud of points
No full textPlanar patches are a very compact and stable intermediate representation of 3D scenes, as they are a good starting point for a complete automatic reconstruction of surfaces. This paper presents a novel method for extracting planar patches from an unstructured cloud of points that is produced by a typical structure and motion pipeline. The method integrates several constraints inside J-linkage, a robust algorithm for multiple models fitting. It makes use of information coming both from the 3D structure and the images. Several results show the effectiveness of the proposed approach
Robust multiple structures estimation with J-linkage
No full textThis paper tackles the problem of fitting multiple instances of a model to data corrupted by noise and outliers. The proposed solution is based on random sampling and conceptual data representation. Each point is represented with the characteristic function of the set of random models that fit the point. A tailored agglomerative clustering, called J-linkage, is used to group points belonging to the same model. The method does not require prior specification of the number of models, nor it necessitate parameters tuning. Experimental results demonstrate the superior performances of the algorithm
Image-consistent patches from unstructured points with J-linkage
No full textGoing from unstructured cloud of points to surfaces is a challenging problem. However, as points are produced by a structure-and-motion pipeline, image-consistency is a powerful clue that comes to the rescue. In this paper we present a method for extracting planar patches from an unstructured cloud of points, based on the detection of image-consistent planar patches with J-linkage, a robust algorithm for multiple models fitting. The method integrates several constraints inside J-linkage, optimizes the position of the points with regard to image-consistency and deploys a hierarchical processing scheme that decreases the computational load. With respect to previous work this approach has the advantage of starting from sparse data. Several results show the effectiveness of the proposed approach
Adaptive Toldo systems T̳M̳
No full textThesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections."February 2009." In title on title page, double scored "T̳M̳" appears as upper case.Includes bibliographical references (p. 94-96).This thesis investigates the structural, spatial, and climatic performance of the Toldo - a traditional lightweight street shading device, which is emblematic of Islamic cityscapes. Re-examining its historical roots along with its contextual, cultural and functional traits, the thesis aims at setting a framework on the basis of which to speculate its reincarnation within contemporary practice. Such framework provides the theoretical foundations and technological opportunities to reinvent the primitive Toldo as a commercial spin-off, which envisions its modernization in three steps. Firstly, a digital customization tool allows for intuitive, end-user generated designs; Secondly, energy-harvesting materials and microelectronics enhance the product's application range and enrich it with a functional flexibility such that it can be used as an architectural skin beyond street level; Thirdly, an online marketing platform coordinates worldwide communication of interdisciplinary subcontractors, while integrating the product's traditional economy and craftsmanship. Finally, different case studies in Cairo will demonstrate the widened scope of such architectural product and prove the system's reliability, as it confronts real life demands and various propensities for investment.by Simon Schleicher.M.Arch
Memórias que lutam por identidade: a demarcação da terra indígena Toldo Chimbangue (SC) - 1970 - 1986
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Filosofia e Ciências Humanas. Programa de Pós-Graduação em HistóriaEste trabalho pretende refletir acerca da identidade étnica dos Kaingáng da Terra Indígena Toldo Chimbangue, Chapecó - Santa Catarina, tomando como base as memórias coletivas desse grupo referentes à luta pela demarcação de suas terras entre as décadas de 1970 e 1980. Ao término desse estudo foi possível perceber, que a terra, e a experiência da luta por sua defesa, reforçam o sentimento de pertença e de identidade étnica. Assim, a luta pela demarcação é também uma luta por identidade
BENDING THE DOMING EFFECT IN STRUCTURE FROM MOTION RECONSTRUCTIONS THROUGH BUNDLE ADJUSTMENT
No full textStructure from Motion techniques provides low-cost and flexible methods that can be adopted in arial surveying to collect topographic
data with accurate results. Nevertheless, the so-called “doming effect”, due to unfortunate acquisition conditions or unreliable modeling
of radial distortion, has been recognized as a critical issue that disrupts the quality of the attained 3D reconstruction. In this paper we
propose a novel method, that works effectively in the presence of a nearly flat soil, to tackle a posteriori the doming effect: an automatic
ground detection method is used to capture the doming deformation flawing the reconstruction, which in turn is wrapped to the correct
geometry by iteratively enforcing a planarity constraint through a Bundle Adjustment framework. Experiments on real word datasets
demonstrate promising results
Visual vocabulary signature for 3D object retrieval and partial matching
No full textIn this paper a novel object signature is proposed for 3D object retrieval and partial matching. A part-based representation is obtained by partitioning the objects into subparts and by characterizing each segment with different geometric descriptors. Therefore, a Bag ofWords framework is introduced by clustering properly such descriptors in order to define the so called 3D visual vocabulary. In this fashion, the object signature is defined as a histogram of 3D visual word occurrences. Several examples on the Aim@Shape watertight dataset demonstrate the versatility of the proposed method in matching either 3D objects with articulated shape changes or partially occluded or compound objects. In particular, a comparison with the methods that participated to the Shape Retrieval contest 2007 (SHREC) reports satisfactory results for both object retrieval and partial matching
A bag of words approach for 3D object categorization
No full textIn this paper we propose a novel framework for 3D object categorization. The object is modeled it in terms of its sub-parts as an histogram of 3D visual word occurrences. We introduce an effective method for hierarchical 3D object segmentation driven by the minima rule that combines spectral clustering - for the selection of seed-regions - with region growing based on fast marching. The front propagation is driven by local geometry features, namely the Shape Index. Finally, after the coding of each object according to the Bag-of-Words paradigm, a Support Vector Machine is learnt to classify different objects categories. Several examples on two different datasets are shown which evidence the effectiveness of the proposed framewor
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