7,080 research outputs found

    Requirements for Topology in 3D GIS

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    Topology and its various benefits are well understood within the context of 2D Geographical Information Systems. However, requirements in three-dimensional (3D) applications have yet to be defined, with factors such as lack of users' familiarity with the potential of such systems impeding this process. In this paper, we identify and review a number of requirements for topology in 3D applications. The review utilises existing topological frameworks and data models as a starting point. Three key areas were studied for the purposes of requirements identification, namely existing 2D topological systems, requirements for visualisation in 3D and requirements for 3D analysis supported by topology. This was followed by analysis of application areas such as earth sciences and urban modelling which are traditionally associated with GIS, as well as others including medical, biological and chemical science. Requirements for topological functionality in 3D were then grouped and categorised. The paper concludes by suggesting that these requirements can be used as a basis for the implementation of topology in 3D. It is the aim of this review to serve as a focus for further discussion and identification of additional applications that would benefit from 3D topology. © 2006 The Authors. Journal compilation © 2006 Blackwell Publishing Ltd

    The Digital Anatomist Information System and Its Use in the Generation and Delivery of Web-Based Anatomy Atlases

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    Advances in network and imaging technology, coupled with the availability of 3-D datasets such as the Visible Human, provide a unique opportunity for developing information systems in anatomy that can deliver relevant knowledge directly to the clinician, researcher or educator. A software framework is described for developing such a system within a distributed architecture that includes spatial and symbolic anatomy information resources, Web and custom servers, and authoring and end-user client programs. The authoring tools have been used to create 3-D atlases of the brain, knee and thorax that are used both locally and throughout the world. For the one and a half year period from June 1995–January 1997, the on-line atlases were accessed by over 33,000 sites from 94 countries, with an average of over 4000 ‘‘hits’’ per day, and 25,000 hits per day during peak exam periods. The atlases have been linked to by over 500 sites, and have received at least six unsolicited awards by outside rating institutions. The flexibility of the software framework has allowed the information system to evolve with advances in technology and representation methods. Possible new features include knowledge-based image retrieval and tutoring, dynamic generation of 3-D scenes, and eventually, real-time virtual reality navigation through the body. Such features, when coupled with other on-line biomedical information resources, should lead to interesting new ways for managing and accessing structural information in medicine

    The path to precision: comparison analysis of automated neural morphology reconstruction software

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    The differences in the shape, form and location of neurons are closely linked to their function. Being able to accurately and efficiently reconstruct neurons digitally in a three-dimensional space is necessary for the acquisition of knowledge in this research field. Automation through software helps optimise efficiency, yet manual reconstructions are often preferred. This thesis therefore aims to help standardise the research field more and facilitate communication and collaborative efforts by evaluating three software, Vaa3D, Neutube and NCTracer, in regards to the reconstruction algorithms' accuracy, efficiency, consistency and user experience with the user interface in order to deduce their advantages and shortcomings. A downloadable and executable Java program, which compares similarities between two reconstructions, and scripts were written to measure these parameters. Vaa3D had higher accuracy and a significantly lower execution time, but Neutube and NCTracer showcased more stability and consistent results. Additionally, NCTracer proved to be more intuitive to use. All software exhibited their own drawbacks, but the information presented can aid in improving the software or the development of new software surpassing prior ones

    Reconstructing the History of Marriage Strategies in Indo-European–Speaking Societies: Monogamy and Polygyny

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    Explanations for the emergence of monogamous marriage have focused on the cross-cultural distribution of marriage strategies, thus failing to account for their history. In this paper I reconstruct the pattern of change in marriage strategies in the history of societies speaking Indo-European languages, using cross-cultural data in the systematic and explicitly historical framework afforded by the phylogenetic comparative approach. The analysis provides evidence in support of Proto-Indo-European monogamy, and that this pattern may have extended back to Proto-Indo- Hittite. These reconstructions push the origin of monogamous marriage into prehistory, well beyond the earliest instances documented in the historical record; this, in turn, challenges notions that the cross-cultural distribution of monogamous marriage reflects features of social organization typically associated with Eurasian societies, and with “societal complexity” and “modernization” more generally. I discuss implications of these findings in the context of the archaeological and genetic evidence on prehistoric social organization. Pay-Per-View Download To access this article as a PDF pay-per-view download via BioOne, please click here

    The Nature and Use of Trimlines for Analysing 3-Dimensional Glacier Change in Rugged Terrain

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    Prava manjina i rano otklanjanje sukoba u Ruskoj Federaciji

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    The article provides a critical commentary to current use of the concept "minority" in Russia, particularly in academic and political discourse. The direct borrowing of the concept as it exists in international law or western social sciences is prevented by a number of limitations inherent to its meaning, the main limitation being that Russia could not be properly characterised as a democracy. The usage of the term "minority" in the context of the so-called "transitional societies" could be misleading, as the position of a particular group in a power hierarchy as well as its influence on political decision-making process here is not a function of a group\u27s numerical strength, but depends on such resources as the group\u27s wealth, access to education, and position in administrative institutions, security and army, effective monopoly of important sectors of social life and economy, group\u27s solidarity etc. Moreover, the conceptual field of in which the concept is situated is markedly different from its western analogues, where in such political concepts as "a titular nation", "an indigenous ethnos", "a state-founding people" remain virtually unknown and normally does not belong to semantic field of "minority". As the concept "minority" in Russia is firmly tied to ethnic reality interpretations, the current paradigms of ethnicity research are outlined. Finally, a description of contemporary attempts of minority rights monitoring within the framework of an early warning research is sketched.Članak kritički komentira pojam "manjina" što se rabi u ruskoj društvenoj znanosti i politici. Postoje mnoge poteškoće u vezi s izravnim preuzimanjem tog pojma iz jezika međunarodnog prava ili zapadne društvene znanosti. Među najvažnijima možemo navesti to što je pojam "manjina" najprikladniji u demokratskim državnim ustrojstvima. U tzv. "prijelaznim društvima" u kojima položaj skupine u sustavu odnosa vlasti ne ovisi toliko o njezinoj brojnosti, koliko o drugim resursima − bogatstvu, razini obrazovanja i grupne solidarnosti, dostupu do struktura moći i tijelima upravljanja, monopolu nad najvažnijim socijalnim i gospodarskim sferama itd. − uporaba pojma "manjina" manje je umjesna. Osim toga, koncepcijsko polje u koje rasprave u ruskoj znanosti i politici stavljaju "manjinu", oštro se razlikuje od zapadnih analogija. Ovdje se "manjina" suprotstavlja ne toliko "većini", koliko političkoj stvarnosti nepoznatoj na Zapadu kao što su "titularna nacija", "korijenska /indigena/ etnija", "državotvorni narod" i dr. Budući da je pojam "manjina" u Rusiji tijesno povezan s predodžbama o "etniji", znatno mjesto u članku nudi analizu paradigama istraživanja etničke stvarnosti. U zaključku opisani modeli za rano otklanjanje sukoba, sastavni su dio promatranja kako se prava manjina poštuju

    Polarisation photometric stereo

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    © 2017 This paper concerns a novel approach to fuse two-source photometric stereo (PS) data with polarisation information for complete surface normal recovery for smooth or slightly rough surfaces. PS is a well-established method but is limited in application by its need for three or more well-spaced and known illumination sources and Lambertian reflectance. Polarisation methods are less studied but have shown promise for smooth surfaces under highly controlled capture conditions. However, such methods suffer from inherent ambiguities and the depolarising effects of surface roughness. The method presented in this paper goes some way to overcome these limitations by fusing the most reliable information from PS and polarisation. PS is used with only two sources to deduce a constrained mapping of the surface normal at each point onto a 2D plane. Phase information from polarisation is used to deduce a mapping onto a different plane. The paper then shows how the full surface normal can be obtained from the two mappings. The method is tested on a range of real-world images to demonstrate the advantages over standalone applications of PS or polarisation methods
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