The HyperBagGraph DataEdron: An Enriched Browsing Experience of Multimedia Datasets

Traditional verbatim browsers give back information in a linear way according to a ranking performed by a search engine that may not be optimal for the surfer. The latter may need to assess the pertinence of the information retrieved, particularly when s$\cdot$he wants to explore other facets of a multi-facetted information space. For instance, in a multimedia dataset different facets such as keywords, authors, publication category, organisations and figures can be of interest. The facet simultaneous visualisation can help to gain insights on the information retrieved and call for further searches. Facets are co-occurence networks, modeled by HyperBag-Graphs -- families of multisets -- and are in fact linked not only to the publication itself, but to any chosen reference. These references allow to navigate inside the dataset and perform visual queries. We explore here the case of scientific publications based on Arxiv searches.Comment: Extension of the hypergraph framework shortly presented in arXiv:1809.00164 (possible small overlaps); use the theoretical framework of hb-graphs presented in arXiv:1809.0019

Navigability Analysis of Natural Terrains with Fuzzy Elevation Maps from Ground-based 3D Range Scans

Mobile robot navigation through natural terrains is a challenging issue with applications such as planetary exploration or search and rescue. This paper proposes navigability assessment of natural terrains scanned from ground-based 3D laser rangefinders. A continuous model of the terrain is obtained as a fuzzy elevation map (FEM). Based on this model, the proposed solution incorporates terrain navigability both in terms of uncertainties of the 3D input data and slope of the fuzzy surface. Moreover, the paper discusses the application of this method for local path planning. For this purpose, the Bug algorithm has been adapted to compute local paths on the navigable region of the FEM. The method has been applied to actual 3D point clouds on two different experimental sites.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This work was partially supported by the Spanish CICYT project DPI 2011-22443 and the Andalusian project PE-2010 TEP-6101

Through a glass darkly: a case for the study of virtual space

This paper begins to examine the similarities and differences between virtual space and real space, as taken from anarchitectural (as opposed to a biological, psychological, geographic, philosophical or information theoretic)standpoint. It continues by introducing a number of criteria, suggested by the authors as being necessary for virtualspace to be used in a manner consistent with our experience of real space. Finally, it concludes by suggesting apedagogical framework for the benefits and associated learning outcomes of the study and examination of thisrelationship. This is accompanied by examples of recent student work, which set out to investigate this relationship

Through a glass darkly: a case for the study of virtual space

This paper begins to examine the similarities and differences between virtual space and real space, as taken from anarchitectural (as opposed to a biological, psychological, geographic, philosophical or information theoretic)standpoint. It continues by introducing a number of criteria, suggested by the authors as being necessary for virtualspace to be used in a manner consistent with our experience of real space. Finally, it concludes by suggesting apedagogical framework for the benefits and associated learning outcomes of the study and examination of thisrelationship. This is accompanied by examples of recent student work, which set out to investigate this relationship

Competition Among Public Schools: A Reply to Rothstein (2004)

Rothstein has produced two comments, Rothstein (2003) and Rothstein (2004), on Hoxby "Does Competition Among Public Schools Benefit Students and Taxpayers," American Economic Review, 2000. In this paper, I discuss every claim of any importance in the comments. I show that every claim is wrong. I also discuss a number of Rothstein's innuendos--that is, claims that are made by implication rather than with the support of explicit arguments or evidence. I show that, when held up against the evidence, each innuendo proves to be false. One of the major points of Rothstein (2003) is that lagged school districts are a valid instrumental variable for today's school districts. This is not credible. Another major claim of Rothstein (2003) is that it is better to use highly non-representative achievement data based on students' self-selecting into test-taking than to use nationally representative achievement data. This claim is wrong for multiple reasons. The most important claim of Rothstein (2004) is that the results of Hoxby (2000) are not robust to including private school students in the sample. This is incorrect. While Rothstein appears merely to be adding private school students to the data, he actually substitutes error-prone data for error-free data on all students, generating substantial attenuation bias. He attributes the change in estimates to the addition of the private school students, but I show that the change in estimates is actually due to his using erroneous data for public school students. Another important claim in Rothstein (2004) that the results in Hoxby (2000) are not robust to associating streams with the metropolitan areas through which they flow rather than the metropolitan areas where they have their source. This is false: the results are virtually unchanged when the association is shifted from source to flow. Since 93.5 percent of streams flow only in the metropolitan area where they have their source, it would be surprising if the results did change much. The comments Rothstein (2003) and Rothstein (2004) are without merit. All of the data and code used in Hoxby (2000) are available to other researchers. An easy-to-use CD provides not only extracts and estimation code, but all of the raw data and the code for constructing the dataset.

Survey-based naming conventions for use in OBO Foundry ontology development

A wide variety of ontologies relevant to the biological and medical domains are available through the OBO Foundry portal, and their number is growing rapidly. Integration of these ontologies, while requiring considerable effort, is extremely desirable. However, heterogeneities in format and style pose serious obstacles to such integration. In particular, inconsistencies in naming conventions can impair the readability and navigability of ontology class hierarchies, and hinder their alignment and integration. While other sources of diversity are tremendously complex and challenging, agreeing a set of common naming conventions is an achievable goal, particularly if those conventions are based on lessons drawn from pooled practical experience and surveys of community opinion. We summarize a review of existing naming conventions and highlight certain disadvantages with respect to general applicability in the biological domain. We also present the results of a survey carried out to establish which naming conventions are currently employed by OBO Foundry ontologies and to determine what their special requirements regarding the naming of entities might be. Lastly, we propose an initial set of typographic, syntactic and semantic conventions for labelling classes in OBO Foundry ontologies. Adherence to common naming conventions is more than just a matter of aesthetics. Such conventions provide guidance to ontology creators, help developers avoid flaws and inaccuracies when editing, and especially when interlinking, ontologies. Common naming conventions will also assist consumers of ontologies to more readily understand what meanings were intended by the authors of ontologies used in annotating bodies of data

Network Cosmology

Prediction and control of the dynamics of complex networks is a central problem in network science. Structural and dynamical similarities of different real networks suggest that some universal laws might accurately describe the dynamics of these networks, albeit the nature and common origin of such laws remain elusive. Here we show that the causal network representing the large-scale structure of spacetime in our accelerating universe is a power-law graph with strong clustering, similar to many complex networks such as the Internet, social, or biological networks. We prove that this structural similarity is a consequence of the asymptotic equivalence between the large-scale growth dynamics of complex networks and causal networks. This equivalence suggests that unexpectedly similar laws govern the dynamics of complex networks and spacetime in the universe, with implications to network science and cosmology

Investigating Primary Source Literacy

Primary source research requires students to acquire specialized research skills. This paper presents results from a user study testing the effectiveness of a Web guide designed to convey the concepts behind “primary source literacy”. The study also evaluated students’ strengths and weaknesses when conducting primary source research