1,721,267 research outputs found
Filamentos para la investigaciones en la visibilización de las subjetividades desde arqueológica y la genealógica
No full textFil: Martínez Posada, Jorge Eliécer. Universidad de la Salle; Universidad Javeriana
A Methodology for the Semantic Visualization of Industrial Plant CAD Models for Virtual Reality Walkthroughs
No full textThere are still many open questions and needs in important aspects of the scientific area of Large Model Visualization LMV- for Plant Design. Performance to achieve interactive rates in immersive virtual environments is certainly one of them, especially if resources are limited, but not anymore the most critical one. Surprisingly, the different processes used today to generate the walkthroughs experiences take into account very few explicit semantic considerations. The main approaches presented in the literature in the field of LMV are mainly related to algorithms and compression methods to be applied to the geometric entities that compose the CAD model. However, no sufficient attention is given to the following aspects: (i) These models actually belong to a special engineering domain with related standards; (ii) the different potential users have diverse backgrounds and intentions; and (iii) an adapted visualization walkthrough of the model can be different for a specific user and purpose in that context, in order to use in an optimal way the available resources and techniques. Therefore, the most common situation is that the generation of visual walkthrough experiences is typically not aware (in proprietary systems with links to PDM the situation is better to some extent) that the 3D CAD model of a plant is actually just a geometric representation of a complex engineering system, and this knowledge is not sufficiently exploited in the generation of the walkthrough experience. The consequence is to have advanced VR environments for the interactive exploration of models of millions of triangles, that have little explicit use of the knowledge and in many cases none- about the domain, users and visualization purposes involved. As a result, the main motivation for the present work is focused on one of this research lines not sufficiently covered so far: The explicit introduction of semantic aspects, pushed from an engineering domain perspective and strongly complemented with computer graphics and semantic technologies-, in the process of generating visual walkthrough experiences for specific users, visualization purposes and resources in the Plant Design domain.EG Graphics Dissertation Onlin
Actitud Esquizoanálitica. Esquizoanálisis, un método menor de descomposición del dispositivo capitalista
No full textFil: Martínez Posada, Jorge Eliécer. Universidad de la Salle; Universidad Javeriana.Fil: Ochoa Ordónez, Carolina. Corporación Universitaria Minuto de Dios
Cylindrical Transform Slicing of Revolute Parts with Overhangs for Laser Metal Deposition
No full textIn the context of Laser Metal Deposition (LMD), temporary support structures are needed to manufacture overhanging features. In order to limit the need for supports, multi-axis machines intervene in the deposition by sequentially repositioning the part. Under multi-axis rotations and translations, slicing and toolpath generation represent significant challenges. Slicing has been partially addressed by authors in multi-axis LMD. However, tool-path generation in multi-axis LMD is rarely touched. One of the reasons is that the required slices for LMD may be strongly non-developable. This fact produces a significant mismatch between the tool-path speeds and other parameters in Parametric space vs. actual Euclidean space. For the particular case of developable slices present in workpieces with cylindrical kernel and overhanging neighborhoods, this manuscript presents a methodology for LMD tool path generation. Our algorithm takes advantage of existing cylindrical iso-radial slicing by generating a path in the (?, z) parameter space and isometrically translating it into the R3 Euclidean space. The presented approach is advantageous because it allows the path-planning of complex structures by using the methods for conventional 2.5-axis AM. Our computer experiments show that the presented approach can be effectively used in manufacturing industrial/mechanical pieces (e.g., spur gears). Future work includes the generation of the machine g-code for actual LMD equipment.Spanish Computer Graphics Conference (CEIG)CAD, Simulation, and Graspin
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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