Search results for "Computer-aided design"
showing 10 items of 312 documents
Multiverse Ethnography: A Qualitative Method for Gaming and Technology Use Research
2021
This article introduces multiverse ethnography as a systematic team-based qualitative method for studying the mechanical, structural and experiential properties of video games and other technological artefacts. Instead of applying the ethnographic method to produce a single in-depth account, multiverse ethnography includes multiple researchers carrying out coordinated synergetic ethnographic work on the same research object, thus producing a multiverse of interpretations and perspectives. To test the method, 41 scholars carried out a multiverse ethnography on two video games, Cyberpunk 2077 and Among Us. Explorative thematic findings regarding both titles are reported and methodological imp…
Geometry control of the junction between two fractal curves
2012
International audience; The general objective of our work is to create a geometric modeller based on iterative processes. With this objective in mind, we have to provide tools that work with fractal objects in the same manner as with objects of classical topology. In this article we focus on the constructing of an intermediate curve between two other curves defined by different iterative construction processes. A similar problem often arises with subdivision surfaces, when the goal is to connect two surfaces with different subdivision masks. We start by dealing with curves, willing to later generalise our approach to surfaces. We formalise the problem with the Boundary Controlled Iterated F…
A Viscoelastic Model for the Long-Term Deflection of Segmental Prestressed Box Girders
2017
Most of segmental prestressed concrete box girders exhibit excessive multidecade deflections unforeseeable by past and current design codes. To investigate such a behavior, mainly caused by creep and shrinkage phenomena, an effective finite element (FE) formulation is presented in this article. This formulation is developed by invoking the stationarity of an energetic principle for linear viscoelastic problems and relies on the Bazant creep constitutive law. A case study representative of segmental prestressed concrete box girders susceptible to creep is also analyzed in the article, that is, the Colle Isarco viaduct. Its FE model, based on the aforementioned energetic formulation, was succ…
Precise and efficient parametric path analysis
2012
Hard real-time systems require tasks to finish in time. To guarantee the timeliness of such a system, static timing analyses derive upper bounds on the worst-case execution time (WCET) of tasks. There are two types of timing analyses: numeric and parametric. A numeric analysis derives a numeric timing bound and, to this end, assumes all information such as loop bounds to be given a priori. If these bounds are unknown during analysis time, a parametric analysis can compute a timing formula parametric in these variables. A performance bottleneck of timing analyses, numeric and especially parametric, is the so-called path analysis, which determines the path in the analyzed task with the longes…
Editorial for Special Issue “Fine Art Pattern Extraction and Recognition”
2021
Cultural heritage, especially the fine arts, plays an invaluable role in the cultural, historical, and economic growth of our societies [...]
A comparison study of evolutive algorithms for solving the partitioning problem in distributed virtual environment systems
2004
Fast Internet connections and the widespread use of high performance graphic cards are making Distributed Virtual Environment (DVE) systems very common nowadays. However, there are several key issues in these systems that should still be improved in order to design a scalable and cost-effective system. One of these key issues is the partitioning problem. This problem consists of efficiently assigning clients (3D avatars) to the servers in the system. In this paper, we present a comparison study of different modern heuristics for solving the partitioning problem in DVE systems, as an alternative to the ad hoc heuristic proposed in the literature. Performance evaluation results show that some…
A Qualitative-Quantitative Approach to V-Belt Mechanics
1996
A simplified formulation is adopted for the theoretical problem of tension distribution and radial penetration of a V-belt along the pulley groove. The trajectory portrait of the second order differential system describing the belt behavior is carefully analyzed and asymptotic approximations for the tension solutions are derived which are well suited for design purposes.
Helical Shift Mechanics of Rubber V-Belt Variators
2011
A very common configuration of V-belt variators for motorcycles considers the correction of the belt tensioning depending on the resistant torque by means of suitable helical-shaped tracks allowing the driven half-pulleys to close/open. The theoretical model for belt-pulley coupling is rather complex for this configuration, where one half-pulley may run in advance and the other one behind with respect to the belt, and requires the repeated numerical solution of a strongly nonlinear differential system by a sort of shooting technique, until all the operating conditions are fulfilled (angular contact extent, torque, and axial force). After solving the full equations, the present study develop…
Theoretical studies on cycloaddition reactions
2014
Cycloaddition reactions represent one of the most powerful processes in organic chemistry. The most common types of cycloaddition reactions are the Diels-Alder (DA) and the 1,3-dipolar cycloaddition reactions (1,3-DCs) which lead to five and six membered rings, respectively. In our ongoing efforts to contribute to the understanding of DA and 1,3-DCs; we studied the following using the B3LYP/6-31G(d) level of theory: 1. The 1,3-DCs of the pyridinium-3-olates and pyrazinium-3-olates with methyl acrylate and methyl methacrylate [1,2]. 2. The competitive hetero-DA and 1,3-DCs of methyl glyoxylate oxime and its tautomeric nitrone with cyclopentadiene in the absence and in the presence of BF3 as …
Impact of Wavelet Kernels on Predictive Capability of Radiomic Features: A Case Study on COVID-19 Chest X-ray Images
2023
Radiomic analysis allows for the detection of imaging biomarkers supporting decision-making processes in clinical environments, from diagnosis to prognosis. Frequently, the original set of radiomic features is augmented by considering high-level features, such as wavelet transforms. However, several wavelets families (so called kernels) are able to generate different multi-resolution representations of the original image, and which of them produces more salient images is not yet clear. In this study, an in-depth analysis is performed by comparing different wavelet kernels and by evaluating their impact on predictive capabilities of radiomic models. A dataset composed of 1589 chest X-ray ima…