Search results for " Computer-Aided design"
showing 10 items of 232 documents
VisAdapt: A Visualization Tool to Support Climate Change Adaptation.
2017
In this article we present the design and implementation of the web-based visualization tool VisAdapt, developed to support homeowners in the Nordic countries to assess anticipated climate change and climate related risks which are expected to negatively impact their living conditions. The tool guides the user through a three-step visual exploration process to facilitate the exploration of risks and adaptation measures, specifically adapted to the user. VisAdapt has been developed over the course of two years in close collaboration with domain experts and end users to ensure the validity of the included data and the efficiency of the visual interface. Although VisAdapt is designed for Nordi…
A decade of research into player communities in online games
2013
The social dynamics of player communities in online games have been the subject of much research during the last decade. Following a systematic review of empirical research publications from 2000–2010, this article synthesizes the key methods and concepts researchers have used to study and characterize player communities. It also synthesizes the key aspects and operationalizations researchers have concentrated on. The analysis shows that qualitative approaches have been more common than quantitative ones. The concepts used to characterize player communities were often not clearly defined or overlapped in meaning. Yet they revealed a prevalence of micro (groups or teams), meso (guilds or org…
A collaborative virtual reality environment for liver surgery planning
2021
Abstract Surgical planning software is a key component in the treatment of tumor diseases. However, desktop-based systems provide only limited visualization and interaction opportunities. Moreover, collaborative planning among members of a surgical team is only possible to a limited extent. In this work, a collaborative virtual reality (VR) environment to assist liver surgeons in tumor surgery planning is presented. Our aim is to improve virtual resection planning between surgeons in a remote or co-located environment. The system allows surgeons to define and adjust virtual resections on patient-specific organ 3D surfaces and 2D image slices. Changes on both modalities are synchronized, whi…
Automatic segmentation and 3D reconstruction of intravascular ultrasound images for a fast preliminar evaluation of vessel pathologies.
2007
Abstract Intravascular ultrasound (IVUS) imaging is used along with X-ray coronary angiography to detect vessel pathologies. Manual analysis of IVUS images is slow and time-consuming and it is not feasible for clinical purposes. A semi-automated method is proposed to generate 3D reconstructions from IVUS video sequences, so that a fast diagnose can be easily done, quantifying plaque length and severity as well as plaque volume of the vessels under study. The methodology described in this work has four steps: a pre-processing of IVUS images, a segmentation of media–adventitia contour, a detection of intima and plaque and a 3D reconstruction of the vessel. Preprocessing is intended to remove …
A VR-based serious game for studying emotional regulation in adolescents
2015
[EN] We all use more or less adapted strategies to confront adverse emotional situations in our lives without being psychologically affected. Emotional Regulation (ER) strategies that we use determine the way in which we feel, express and behave. Moreover, ER strategies are particularly important in adolescents, a population in the age when the deficits of ER strategies can be linked to the appearance of numerous mental health disorders such as depression or anxiety, or disruptive behaviors. Thus, the early detection of dysfunctional ER strategies and the training in adaptive ER strategies will help us to prevent the future occurrence of possible behavioral and psychosocial disorders. In th…
A supervised learning framework of statistical shape and probability priors for automatic prostate segmentation in ultrasound images
2013
Prostate segmentation aids in prostate volume estimation, multi-modal image registration, and to create patient specific anatomical models for surgical planning and image guided biopsies. However, manual segmentation is time consuming and suffers from inter-and intra-observer variabilities. Low contrast images of trans rectal ultrasound and presence of imaging artifacts like speckle, micro-calcifications, and shadow regions hinder computer aided automatic or semi-automatic prostate segmentation. In this paper, we propose a prostate segmentation approach based on building multiple mean parametric models derived from principal component analysis of shape and posterior probabilities in a multi…
A spline-based non-linear diffeomorphism for multimodal prostate registration.
2012
This paper presents a novel method for non-rigid registration of transrectal ultrasound and magnetic resonance prostate images based on a non-linear regularized framework of point correspondences obtained from a statistical measure of shape-contexts. The segmented prostate shapes are represented by shape-contexts and the Bhattacharyya distance between the shape representations is used to find the point correspondences between the 2D fixed and moving images. The registration method involves parametric estimation of the non-linear diffeomorphism between the multimodal images and has its basis in solving a set of non-linear equations of thin-plate splines. The solution is obtained as the least…
Evaluation of prostate segmentation algorithms for MRI: The PROMISE12 challenge
2014
Contains fulltext : 137969.pdf (Publisher’s version ) (Open Access) Prostate MRI image segmentation has been an area of intense research due to the increased use of MRI as a modality for the clinical workup of prostate cancer. Segmentation is useful for various tasks, e.g. to accurately localize prostate boundaries for radiotherapy or to initialize multi-modal registration algorithms. In the past, it has been difficult for research groups to evaluate prostate segmentation algorithms on multi-center, multi-vendor and multi-protocol data. Especially because we are dealing with MR images, image appearance, resolution and the presence of artifacts are affected by differences in scanners and/or …
A Theoretical Approach to the Shift Mechanics of Rubber Belt Variators
2008
This paper proposes a theoretical description of the mechanical behavior of rubber belt variators during the speed ratio shift. Comparing with the steady operation, the mass conservation of the belt is completely reformulated considering an elementary dihedral control volume between two planes through the pulley axis and balancing the inside mass variation with the total mass flux through the control surface. On the other hand, the belt equilibrium conditions are similar to the steady case, as the inertia forces due to the shifting motion are negligible with respect to the other forces. Assuming a one-dimensional belt model, it is shown that adhesive regions may appear inside the arc of con…
The development of nature-inspired gripping system of a flat CFRP strip for stress-ribbon structural layout
2021
Abstract The elegant stress-ribbon systems are efficient in pedestrian bridges and long-span roofs. Numerous studies defined corrosion of the steel ribbons as the main drawback of these structures. Unidirectional carbon fiber-reinforced polymer (CFRP) is a promising alternative to steel because of lightweight, high strength, and excellent corrosion and fatigue resistance. However, the application of CFRP materials faced severe problems due to the construction of the anchorage joints, which must resist tremendous axial forces acting in the stress-ribbons. Conventional techniques, suitable for the typical design of the strips made from anisotropic material such as steel, are not useful for СF…