1,875 research outputs found

    From Big Data to Big Displays: High-Performance Visualization at Blue Brain

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    Blue Brain has pushed high-performance visualization (HPV) to complement its HPC strategy since its inception in 2007. In 2011, this strategy has been accelerated to develop innovative visualization solutions through increased funding and strategic partnerships with other research institutions. We present the key elements of this HPV ecosystem, which integrates C++ visualization applications with novel collaborative display systems. We motivate how our strategy of transforming visualization engines into services enables a variety of use cases, not only for the integration with high-fidelity displays, but also to build service oriented architectures, to link into web applications and to provide remote services to Python applications.Comment: ISC 2017 Visualization at Scale worksho

    XPath: Looking Forward

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    The location path language XPath is of particular importance for XML applications since it is a core component of many XML processing standards such as XSLT or XQuery. In this paper, based on axis symmetry of XPath, equivalences of XPath 1.0 location paths involving reverse axes, such as anc and prec, are established. These equivalences are used as rewriting rules in an algorithm for transforming location paths with reverse axes into equivalent reverse-axis-free ones. Location paths without reverse axes, as generated by the presented rewriting algorithm, enable efficient SAX-like streamed data processing of XPath

    Translating Universal Scene Descriptions into Knowledge Graphs for Robotic Environment

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    Robots performing human-scale manipulation tasks require an extensive amount of knowledge about their surroundings in order to perform their actions competently and human-like. In this work, we investigate the use of virtual reality technology as an implementation for robot environment modeling, and present a technique for translating scene graphs into knowledge bases. To this end, we take advantage of the Universal Scene Description (USD) format which is an emerging standard for the authoring, visualization and simulation of complex environments. We investigate the conversion of USD-based environment models into Knowledge Graph (KG) representations that facilitate semantic querying and integration with additional knowledge sources.Comment: 6 pages, 3 figures, ICRA 202

    A theoretical and computational basis for CATNETS

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    The main content of this report is the identification and definition of market mechanisms for Application Layer Networks (ALNs). On basis of the structured Market Engineering process, the work comprises the identification of requirements which adequate market mechanisms for ALNs have to fulfill. Subsequently, two mechanisms for each, the centralized and the decentralized case are described in this document. These build the theoretical foundation for the work within the following two years of the CATNETS project. --Grid Computing

    Using Timed-Release Cryptography to Mitigate Preservation Risk of Embargo Periods

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    This research defines Time-Locked Embargo, a framework designed to mitigate the Preservation Risk Interval: the preservation risk associated with embargoed scholarly material. Due to temporary access restrictions, embargoed data cannot be distributed freely and thus preserved via data refreshing during the embargo time interval. A solution to mitigate the risk of data loss has been developed by suggesting a data dissemination framework that allows data refreshing of encrypted instances of embargoed content in an open, unrestricted scholarly community. This framework has been developed by exploiting implementations of existing technologies to time-lock data using Timed-Release Cryptology (TRC) so that it can be deployed s digital resources encoded in the MPEG-21 Digital Item Description Language (DIDL) complex object format to harvesters interested in harvesting a local copy of content by utilizing The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH), a widely accepted interoperability standard for the exchange of metadata. The framework successfully demonstrates dynamic record identification, time-lock puzzle (TLP) encryption, encapsulation and dissemination as XML documents. This thesis dissertation presents the framework architecture and provides a quantitative analysis of an implementation. The framework demonstrates successful data harvest of time-locked embargoed data with minimum time overhead without compromising data security and integrity

    Automatic detection and removal of ineffective mutants for the mutation analysis of relational database schemas

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    Data is one of an organization’s most valuable and strategic assets. Testing the relational database schema, which protects the integrity of this data, is of paramount importance. Mutation analysis is a means of estimating the fault-finding “strength” of a test suite. As with program mutation, however, relational database schema mutation results in many “ineffective” mutants that both degrade test suite quality estimates and make mutation analysis more time consuming. This paper presents a taxonomy of ineffective mutants for relational database schemas, summarizing the root causes of ineffectiveness with a series of key patterns evident in database schemas. On the basis of these, we introduce algorithms that automatically detect and remove ineffective mutants. In an experimental study involving the mutation analysis of 34 schemas used with three popular relational database management systems—HyperSQL, PostgreSQL, and SQLite—the results show that our algorithms can identify and discard large numbers of ineffective mutants that can account for up to 24% of mutants, leading to a change in mutation score for 33 out of 34 schemas. The tests for seven schemas were found to achieve 100% scores, indicating that they were capable of detecting and killing all non-equivalent mutants. The results also reveal that the execution cost of mutation analysis may be significantly reduced, especially with “heavyweight” DBMSs like PostgreSQL

    Transforming structured descriptions to visual representations. An automated visualization of historical bookbinding structures.

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    In cultural heritage, the documentation of artefacts can be both iconographic and textual, i.e. both pictures and drawings on the one hand, and text and words on the other are used for documentation purposes. This research project aims to produce a methodology to transform automatically verbal descriptions of material objects, with a focus on bookbinding structures, into standardized and scholarly-sound visual representations. In the last few decades, the recording and management of documentation data about material objects, including bookbindings, has switched from paper-based archives to databases, but sketches and diagrams are a form of documentation still carried out mostly by hand. Diagrams hold some unique information, but often, also redundant information already secured through verbal means within the databases. This project proposes a methodology to harness verbal information stored within a database and automatically generate visual representations. A number of projects within the cultural heritage sector have applied semantic modelling to generate graphic outputs from verbal inputs. None of these has considered bookbindings and none of these relies on information already recorded within databases. Instead they develop an extra layer of modelling and typically gather more data, specifically for the purpose of generating a pictorial output. In these projects qualitative data (verbal input) is often mixed with quantitative data (measurements, scans, or other direct acquisition methods) to solve the problems of indeterminateness found in verbal descriptions. Also, none of these projects has attempted to develop a general methodology to ascertain the minimum amount ii of information that is required for successful verbal-to-visual transformations for material objects in other fields. This research has addressed these issues. The novel contributions of this research include: (i) a series of methodological recommendations for successful automated verbal-to-visual intersemiotic translations for material objects — and bookbinding structures in particular — which are possible when whole/part relationships, spatial configurations, the object’s logical form, and its prototypical shapes are communicated; (ii) the production of intersemiotic transformations for the domain of bookbinding structures; (iii) design recommendations for the generation of standardized automated prototypical drawings of bookbinding structures; (iv) the application — never considered before — of uncertainty visualization to the field of the archaeology of the book. This research also proposes the use of automatically generated diagrams as data verification tools to help identify meaningless or wrong data, thus increasing data accuracy within databases

    Theoretical and Computational Basis for Economical Ressource Allocation in Application Layer Networks - Annual Report Year 1

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    This paper identifies and defines suitable market mechanisms for Application Layer Networks (ALNs). On basis of the structured Market Engineering process, the work comprises the identification of requirements which adequate market mechanisms for ALNs have to fulfill. Subsequently, two mechanisms for each, the centralized and the decentralized case are described in this document. --Grid Computing

    Audio-Visual Resource Allocation for Bimodal Virtual Environments

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    Fidelity is of key importance if virtual environments are to be used as authentic representations of real environments. However, simulating the multitude of senses that comprise the human sensory system is computationally challenging. With limited computational resources it is essential to distribute these carefully in order to simulate the most ideal perceptual experience. This paper investigates this balance of resources across multiple scenarios where combined audio-visual stimulation is delivered to the user. A subjective experiment was undertaken where participants (N=35) allocated five fixed resource budgets across graphics and acoustic stimuli. In the experiment, increasing the quality of one of the stimuli decreased the quality of the other. Findings demonstrate that participants allocate more resources to graphics, however as the computational budget is increased, an approximately balanced distribution of resources is preferred between graphics and acoustics. Based on the results, an audiovisual quality prediction model is proposed and successfully validated against previously untested budgets and an untested scenario

    The Inhuman Overhang: On Differential Heterogenesis and Multi-Scalar Modeling

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    As a philosophical paradigm, differential heterogenesis offers us a novel descriptive vantage with which to inscribe Deleuze’s virtuality within the terrain of “differential becoming,” conjugating “pure saliences” so as to parse economies, microhistories, insurgencies, and epistemological evolutionary processes that can be conceived of independently from their representational form. Unlike Gestalt theory’s oppositional constructions, the advantage of this aperture is that it posits a dynamic context to both media and its analysis, rendering them functionally tractable and set in relation to other objects, rather than as sedentary identities. Surveying the genealogy of differential heterogenesis with particular interest in the legacy of Lautman’s dialectic, I make the case for a reading of the Deleuzean virtual that departs from an event-oriented approach, galvanizing Sarti and Citti’s dynamic a priori vis-à-vis Deleuze’s philosophy of difference. Specifically, I posit differential heterogenesis as frame with which to examine our contemporaneous epistemic shift as it relates to multi-scalar computational modeling while paying particular attention to neuro-inferential modes of inductive learning and homologous cognitive architecture. Carving a bricolage between Mark Wilson’s work on the “greediness of scales” and Deleuze’s “scales of reality”, this project threads between static ecologies and active externalism vis-à-vis endocentric frames of reference and syntactical scaffolding
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