136 research outputs found

    Architectural Information Modelling in Construction History

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    The past few years show a significant increase in the usage of three-dimensional modelling and semantic description techniques for architectural research purposes. Where this increase has already shaped today’s design and construction industry, research in architectural and construction history can still improve its work methods and results through these techniques. Therefore, we propose a new conceptual approach for Architectural Information Modelling (AIM), which aims at describing historical information in construction and architecture directly related to design information and design practice. This paper will give an introduction into existing 3D modelling techniques and semantic description techniques, continuing with how these techniques are applied in the AIM approach. This investigation of 3D modelling and semantic technology shows promising results. However, in order to integrate these techniques into an AIM framework, more work is needed. Future work in this research project will therefore explore in further detail the semantic description scheme proposed below and the implementation of a proof-of-concept

    Where and when to inject low molecular weight heparin in hemodiafiltration? : a cross over randomised trial

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    Background and Objective : Low molecular weight heparins (LMWHs) are small enough to pass large pore dialysis membranes. Removal of LMWH if injected before the start of the session is possible during high-flux dialysis and hemodiafiltration. The aim of this study was to determine the optimal mode (place and time) of tinzaparin administration during postdilution hemodiafiltration. Study Design, Setting, Patients : In 13 chronic hemodiafiltration patients, 3 approaches of injection were compared in a randomised cross over trial: i) before the start of the session at the inlet blood line filled with rinsing solution (IN0), ii) 5 min after the start at the inlet line filled with blood (IN5) and iii) before the start of the session at the outlet blood line (OUT0). Anti-Xa activity, thrombin generation, visual clotting score and reduction ratios of urea and beta2microglobulin were measured. Results : Anti-Xa activity was lower with IN0 compared with IN5 and OUT0, and also more thrombin generation was observed with IN0. No differences were observed in visual clotting scores and no clinically relevant differences were observed in solute reduction ratio. An anti-Xa of 0.3 IU/mL was discriminative for thrombin generation. Anti-Xa levels below 0.3 IU/mL at the end of the session were associated with worse clotting scores and lower reduction ratio of urea and beta2microglobulin. Conclusions : Injection of tinzaparin at the inlet line before the start of postdilution hemodiafiltration is associated with loss of anticoagulant activity and can therefore not be recommended. Additionally, we found that an anti-Xa above 0.3 IU/mL at the end of the session is associated with less clotting and higher dialysis adequacy

    IFC-based calculation of the Flemish Energy Performance Standard

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    This paper illustrates our findings concerning space based design methodologies and interoperability issues for today's Building Information Modeling (BIM) environments. A method is elaborated which enables building designers to perform an automated energy use analysis, based oil an Industry Foundation Classes (IFC) model derived from a commercial BIM environment, in this case Autodesk Revit 9.1. A prototype application was built, which evaluates the building model as well as vendor-neutral exchange mechanisms, in accordance with the Flemish Energy Performance Regulation (EPR) standard. Several issues regarding the need for space-based building models are identified and algorithms are developed to overcome possible shortcomings

    Pattern-based access control in a decentralised collaboration environment

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    As the building industry is rapidly catching up with digital advancements, and Web technologies grow in both maturity and security, a data- and Web-based construction practice comes within reach. In such an environment, private project information and open online data can be combined to allow cross-domain interoperability at data level, using Semantic Web technologies. As construction projects often feature complex and temporary networks of stakeholder firms and their employees, a property-based access control mechanism is necessary to enable a flexible and automated management of distributed building projects. In this article, we propose a method to facilitate such mechanism using existing Web technologies: RDF, SHACL, WebIDs, nanopublications and the Linked Data Platform. The proposed method will be illustrated with an extension of a custom nodeJS Solid server. The potential of the Solid ecosystem has been put forward earlier as a basis for a Linked Data-based Common Data Environment: its decentralised setup, connection of both RDF and non-RDF resources and fine-grained access control mechanisms are considered an apt foundation to manage distributed building data

    Ontwikkeling van een Google SketchUp-plugin als ontwerpinstrument voor een energiezuinige architectuur

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    Sinds 1 januari 2006 is in Vlaanderen de energieprestatieregelgeving van kracht. Vlaamse architecten, ontwerpers en ingenieurs worstelen met deze nieuwe wetgeving en zijn nog steeds op zoek naar een instrument waarmee ze reeds van in de beginfase van het onwerp het peil van energieprestatie kunnen bepalen. Deze paper behandelt het onderzoek naar en de ontwikkeling van een Google SketchUp-plugin, dat kadert in de masterscriptie van Tine Jonckheere. Er werd onderzocht wat de specifieke noden zijn van de architecten in Vlaanderen en welke oplossingen er reeds voorhanden zijn. Vervolgens werd een prototype van de SketchUp-plugin ontwikkeld en getoetst aan de eisen en noden van de architect

    Towards robust and reliable multimedia analysis through semantic integration of services

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    Thanks to ubiquitous Web connectivity and portable multimedia devices, it has never been so easy to produce and distribute new multimedia resources such as videos, photos, and audio. This ever-increasing production leads to an information overload for consumers, which calls for efficient multimedia retrieval techniques. Multimedia resources can be efficiently retrieved using their metadata, but the multimedia analysis methods that can automatically generate this metadata are currently not reliable enough for highly diverse multimedia content. A reliable and automatic method for analyzing general multimedia content is needed. We introduce a domain-agnostic framework that annotates multimedia resources using currently available multimedia analysis methods. By using a three-step reasoning cycle, this framework can assess and improve the quality of multimedia analysis results, by consecutively (1) combining analysis results effectively, (2) predicting which results might need improvement, and (3) invoking compatible analysis methods to retrieve new results. By using semantic descriptions for the Web services that wrap the multimedia analysis methods, compatible services can be automatically selected. By using additional semantic reasoning on these semantic descriptions, the different services can be repurposed across different use cases. We evaluated this problem-agnostic framework in the context of video face detection, and showed that it is capable of providing the best analysis results regardless of the input video. The proposed methodology can serve as a basis to build a generic multimedia annotation platform, which returns reliable results for diverse multimedia analysis problems. This allows for better metadata generation, and improves the efficient retrieval of multimedia resources

    Prepar√°ndonos para el impacto de la inteligencia artificial: ¬ŅC√≥mo evolucionar√° la formaci√≥n y la pr√°ctica de la radiolog√≠a?

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    La inteligencia artificial (IA) ha llegado a la Odontolog√≠a y promete quedarse. La constante escalada de la IA se remonta a casi diez a√Īos atr√°s. Aunque la mayor√≠a de los principios b√°sicos del aprendizaje autom√°tico y el aprendizaje profundo se desarrollaron a partir de 1980, las investigaciones en redes neuronales convolucionales (CNN) implementadas con unidades de procesamiento gr√°fico ganaron varios concursos en reconocimiento de im√°genes entre los a√Īos 2011-2012 1,2. No tom√≥ mucho tiempo para que sus aplicaciones en radiolog√≠a fueran exploradas 3. Unos a√Īos m√°s tarde, se publicaron los primeros estudios de investigaci√≥n con CNN para aplicaciones dentales 4,5

    Influence of head positioning during cone-beam CT imaging on the accuracy of virtual 3D models

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    Objective: Cone beam computed tomography (CBCT) images are being increasingly used to acquire three- dimensional (3D) models of the skull for additive manufacturing purposes. However, the accuracy of such models remains a challenge, especially in the orbital area. The aim of this study is to assess the impact of four different CBCT imaging positions on the accuracy of the resulting 3D models in the orbital area. Methods: An anthropomorphic head phantom was manufactured by submerging a dry human skull in silicon to mimic the soft tissue attenuation and scattering properties of the human head. The phantom was scanned on a ProMax 3D MAX CBCT scanner using 90 and 120 kV for four different field of view positions: standard; elevated; backwards tilted; and forward tilted. All CBCT images were subsequently converted into 3D models and geometrically compared with a "gold- standard" optical scan of the dry skull. Results: Mean absolute deviations of the 3D models ranged between 0.15 +/- 0.11 mm and 0.56 +/- 0.28 mm. The elevated imaging position in combination with 120 kV tube voltage resulted in an improved representation of the orbital walls in the resulting 3D model without compromising the accuracy. Conclusions: Head positioning during CBCT imaging can influence the accuracy of the resulting 3D model. The accuracy of such models may be improved by positioning the region of interest (e.g. the orbital area) in the focal plane (Figure 2a) of the CBCT X- ray beam.Peer reviewe
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