1,720,966 research outputs found
Graph Model Simulation of Human Brain's Functional Activity at Resting State by Means of the FD Model
No full textIt is commonly accepted that the various parts of the human brain interact as a network at macroscopic, mesoscopic and microscopic level. Recently, different network models have been proposed to mime the brain behavior both at resting state and during tasks: Our study concerns one of those model that consider both the physical and functional connectivity as well as topological metrics of the brain networks. We provide evidence of the soundness of the model by means of a synthetic dataset based on the existing literature concerning the active cerebral areas at the resting state. Furthermore, we consider Ruzicka similarity measure in order to stress the predictive capability of the model and provide a thresholding criterium. Some network statistics are finally provided
Dynamic few-view X-ray imaging for inspection of CAD-based objects
Full text linkAbstract: X-ray 3D Computed Tomography (3DCT) has great potential for inspection of industrial products. Unfortunately, conventional CT-based workflows to inspect objects created from a CAD model involve a time-consuming acquisition process, computationally expensive image reconstruction, and multiple postprocessing steps, preventing them from inline usage. In this paper, we propose DynaPose, a fast and yet accurate workflow for 3D X-ray inspection of objects created from a CAD model. By exploiting prior knowledge of the CAD model, and relying on only very few radiographs, inspection can be performed in real-time. The DynaPose method allows automated 3D pose estimation of the object to be inspected while dynamically acquiring radiographs that are optimal for the detection task. Through simulation and real experiments, we show that our approach paves the way for inline inspection of manufactured objects
CAD-based defect inspection with optimal ROI selection based on polychromatic X-ray projection images
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
3D X-ray radiography-based inspection of manufactured objects
No full textAbstract: X-ray computed tomography (CT) is a widely used technique for the inspection of the external and internal components of industrial objects. It requires the acquisition of a large number of projections (usually from several hundred to a few thousand) at different angular views, from which a volumetric representation of the object is reconstructed. In industrial inspection based on CT, a triangular mesh is extracted from the CT reconstruction and registered to a nominal geometry for comparison. However, mainly due to the long acquisition time, this procedure does not apply to inline inspection, where each product must be analysed in a few seconds. For this reason, radiography-based methods that do not rely on tomographic reconstruction, are preferred for inline applications. However, most of these methods lack accuracy and 3D spatial information. The aim of this thesis is to search for effective methods which allow for 3D fast and automatic inline inspection from very few radiographs. The thesis is divided into four main parts. The first part is a general introduction to the basic knowledge required to understand the subsequent contents. It is divided into three chapters: quality control techniques (with a focus on X-ray radiography), image registration and neural networks. In the second part, an inspection method based on the analytic, dynamic registration between the acquired projections and simulated ones from the reference model of the object is presented. Subsequently, in the third part, a more generic method is proposed which uses a neural network to estimate the 3D pose of an object from one or multiple radiographs. Finally, as the final goal of inspection is to determine the quality of objects, a neural network is described to automatically classify objects as defective or not defective based on a single radiograph
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