105,025 research outputs found
Migraña en población pediátrica : caracterización demográfica y clínica en el Hospital San José entre enero 2010 a julio 2011.
No full textVENCES Balta, Aldo Dantón. Migraña en población pediátrica : caracterización demográfica y clínica en el Hospital San José entre enero 2010 a julio 2011. Trabajo de Investigación (Especialista en Neurología). Lima, Perú: Universidad Nacional Mayor de San Marcos, Facultad de Medicina Humana, Escuela de Post-Grado, 2014. 55 h
THREE DIMENSIONAL MODELING VIA PHOTOGRAPHS FOR DOCUMENTATION OF A VILLAGE BATH
No full textThe aim of this study is supporting the conceptual discussions of architectural restoration with three dimensional modeling of
monuments based on photogrammetric survey. In this study, a 16th century village bath in Ulamış, Seferihisar, and Izmir is modeled
for documentation. Ulamış is one of the historical villages within which Turkish population first settled in the region of Seferihisar –
Urla. The methodology was tested on an antique monument; a bath with a cubical form. Within the limits of this study, only the
exterior of the bath was modeled. The presentation scale for the bath was determined as 1 / 50, considering the necessities of
designing structural interventions and architectural ones within the scope of a restoration project. The three dimensional model
produced is a realistic document presenting the present situation of the ruin. Traditional plan, elevation and perspective drawings
may be produced from the model, in addition to the realistic textured renderings and wireframe representations. The model
developed in this study provides opportunity for presenting photorealistic details of historical morphologies in scale. Compared to
conventional drawings, the renders based on the 3d models provide an opportunity for conceiving architectural details such as color,
material and texture. From these documents, relatively more detailed restitution hypothesis can be developed and intervention
decisions can be taken. Finally, the principles derived from the case study can be used for 3d documentation of historical structures
with irregular surfaces
Semi-Automated 3D Registration for Heterogeneous Unmanned Robots Based on Scale Invariant Method
No full textThis paper addresses the problem of 3D registration of outdoor environments combining heterogeneous datasets acquired from unmanned aerial (UAV) and ground (UGV) vehicles. In order to solve this problem, we introduced a novel Scale Invariant Registration Method (SIRM) for semi-automated registration of 3D point clouds. The method is capable of coping with an arbitrary scale difference between the point clouds, without any information about their initial position and orientation. Furthermore, the SIRM does not require having a good initial overlap between two heterogeneous datasets. Our method strikes an elegant balance between the existing fully automated 3D registration systems (which often fail in the case of heterogeneous datasets and harsh outdoor environments) and fully manual registration approaches (which are labour-intensive). The experimental validation of the proposed 3D heterogeneous registration system was performed on large-scale datasets representing unstructured and harsh outdoor environments, demonstrating the potential and benefits of the proposed 3D registration system in real-world environments
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
3D registration and integrated segmentation framework for heterogeneous unmanned robotic systems
No full textThe paper proposes a novel framework for registering and segmenting 3D point clouds of large-scale natural terrain and complex environments coming from a multisensor heterogeneous robotics system, consisting of unmanned aerial and ground vehicles. This framework involves data acquisition and pre-processing, 3D heterogeneous registration and integrated multi-sensor based segmentation modules. The first module provides robust and accurate homogeneous registrations of 3D environmental models based on sensors' measurements acquired from the ground (UGV) and aerial (UAV) robots. For 3D UGV registration, we proposed a novel local minima escape ICP (LME-ICP) method, which is based on the well known iterative closest point (ICP) algorithm extending it by the introduction of our local minima estimation and local minima escape mechanisms. It did not require any prior known pose estimation information acquired from sensing systems like odometry, global positioning system (GPS), or inertial measurement units (IMU). The 3D UAV registration has been performed using the Structure from Motion (SfM) approach. In order to improve and speed up the process of outliers removal for large-scale outdoor environments, we introduced the Fast Cluster Statistical Outlier Removal (FCSOR) method. This method was used to filter out the noise and to downsample the input data, which will spare computational and memory resources for further processing steps. Then, we co-registered a point cloud acquired from a laser ranger (UGV) and a point cloud generated from images (UAV) generated by the SfM method. The 3D heterogeneous module consists of a semi-automated 3D scan registration system, developed with the aim to overcome the shortcomings of the existing fully automated 3D registration approaches. This semi-automated registration system is based on the novel Scale Invariant Registration Method (SIRM). The SIRM provides the initial scaling between two heterogenous point clouds and provides an adaptive mechanism for tuning the mean scale, based on the difference between two consecutive estimated point clouds' alignment error values. Once aligned, the resulting homogeneous ground-aerial point cloud is further processed by a segmentation module. For this purpose, we have proposed a system for integrated multi-sensor based segmentation of 3D point clouds. This system followed a two steps sequence: ground-object segmentation and color-based region-growing segmentation. The experimental validation of the proposed 3D heterogeneous registration and integrated segmentation framework was performed on large-scale datasets representing unstructured outdoor environments, demonstrating the potential and benefits of the proposed semi-automated 3D registration system in real-world environments
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Populist attitudes and conspiratorial thinking
No full textWhat happens to the anti-establishment sentiments of pro-incumbent voters for a populist force that is in government and thus controls the political system? This article examines this question utilizing the case of Turkey, a country in which a populist force has been in power for more than a decade. By analyzing populist attitudes among a nationally representative sample, we demonstrate that while the voters of the incumbent populist party (AKP) are less likely, compared to everyone else, to hold populist sentiments, the same voters are also substantially more likely to endorse conspiracy theories that center on malign foreign powers. This finding is relevant beyond Turkey, because it demonstrates that populist forces might be able to maintain popular support and thus stay in power for a long stretch of time by employing government propaganda to fuel an antagonism against conspiratorial foreign and global forces.Fondo Nacional de Desarrollo Cientifico y Tecnologico (FONDECYT Project) ; Observatory for Socioeconomic Transformations (ANID/PCI/Max Planck Institute for the Study of Societies
Dynamic numerical modelling of co-seismic landslides using the 3D distinct element method: Insights from the Balta rockslide (Romania)
No full textAncient landslides of unknown origin can be found in large numbers in mountainous regions; some represent valid markers of (pre-)historic natural regimes referring to either long-term evolution or short-term peak events of climatic and seismotectonic nature. An example is represented by the Balta rockslide in the Romanian Carpathian Mountains. Its location in the seismically active Vrancea-Buzau region, as well as its morphological features, deep-seated rupture surface and large debris volume, raise the question of its failure history with regard to a possible co-seismic triggering. A 3D volume based reconstruction of the slope morphology together with field measurements of elasto-plastic in-situ rock properties allow to estimate pre-failure conditions of the slope, with special regards to the geological, i.e. flysch bedrock of poor to fair rock quality, and structural settings, i.e. anti-dip slope bedding crossed by the main joint family. The reconstructed slope behaviour was tested under static and dynamic forces with the 3D distinct element code 3DEC, subsequently used to simulate a failure scenario with a 120 s long real earthquake record that leads to the realistic post-failure morphology of Balta. For the latter, we observe a principally joint-controlled failure combined with internal fracturing of the undamaged rock mass. After 230 s of simulated time, the landslide debris reaches the valley bottom with maximum displacements of 1350 m and is marked by a lateral expansion to a broader extent than the source zone width, as observed in the field. Extension of this work to other pre-historic slope failures in the valleys of Vrancea-Buzau yield valuable new information for future seismic hazard estimations of the region
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
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