Search results for " Computer-Aided design"

On embedding Boolean as a subtype of integer

1990

Efficient estimation of tuned liquid column damper inerter (TLCDI) parameters for seismic control of base‐isolated structures

2022

This paper presents an enhanced base-isolation (BI) system equipped with a novel passive control device composed of a tuned liquid damper and an inerter (TLCDI). With the aim of reducing the seismic response of BI systems, this contribution focuses on the design of the TLCDI providing analytical solutions for the optimal TLCDI parameters, easily implementable in the design phase. The effectiveness of the proposed approach in terms of seismic response reduction and computational gain is validated by comparison with classical numerical optimization techniques. The control performance of two different base-isolated TLCDI-controlled structures is assessed by employing real-ground motion records…

An optimized mass storage FFT for vector computers

1995

Abstract The performance of a segmented FFT algorithm which allows the out-of-core computation of the Fourier transform of a very large mass storage data array is presented. The code is particularly optimized for vector computers. Tests performed mainly on a CONVEX C210 vector computer showed that, for very long transforms, tuning of the main parameters involved leads to computation speed and global efficiency better than for FFTs performed in-core. The use of tunable parameters allows optimization of the algorithm on machines with different configurations.

An efficient distributed algorithm for generating and updating multicast trees

2006

As group applications are becoming widespread, efficient network utilization becomes a growing concern. Multicast transmission represents a necessary lower network service for the wide diffusion of new multimedia network applications. Multicast transmission may use network resources more efficiently than multiple point-to-point messages; however, creating optimal multicast trees (Steiner Tree Problem in networks) is prohibitively expensive. This paper proposes a distributed algorithm for the heuristic solution of the Steiner Tree Problem, allowing the construction of effective distribution trees using a coordination protocol among the network nodes. Furthermore, we propose a novel distribut…

Representation of NURBS surfaces by Controlled Iterated Functions System automata

2019

Iterated Function Systems (IFS) are a standard tool to generate fractal shapes. In a more general way, they can represent most of standard surfaces like Bézier or B-Spline surfaces known as self-similar surfaces. Controlled Iterated Function Systems (CIFS) are an extension of IFS based on automata. CIFS are basically multi-states IFS, they can handle all IFS shapes but can also manage multi self-similar shapes. For example CIFS can describe subdivision surfaces around extraordinary vertices whereas IFS cannot. Having a common CIFS formalism facilitates the development of generic methods to manage interactions (junctions, differences...) between objects of different natures.This work focuses…

An advanced system for the simulation and planning of orthodontic treatment

2000

This paper presents a new system for three-dimensional (3-D) orthodontic treatment planning and movement of teeth. We describe a computer vision technique for the acquisition and processing of 3-D images of the profile of hydrocolloid dental imprints. Profile measurement is based on the triangulation method which detects deformation of the projection of a laser line on the dental imprints. The system is computer-controlled and designed to achieve depth and lateral resolutions of 0.1 and 0.2 mm, respectively, within a depth range of 40 mm. The 3-D image of the imprint is segmented in order to identify different teeth. Two operators are presented: one for the detection of molars and premolars…

A survey on geometrical reconstruction as a core technology to sketch-based modeling

2005

In this work, the background and evolution of three-dimensional reconstruction of line drawings during the last 30 years is discussed. A new general taxonomy is proposed to make apparent and discuss the historical evolution of geometrical reconstruction and their challenges. The evolution of geometrical reconstruction from recovering know-how stored in engineering drawings to sketch-based modeling for helping in the first steps of conceptual design purposes, and the current challenges of geometrical reconstruction are discussed too.

Car style-holon recognition in computer-aided design

2019

Abstract Multi-scale design can presumably stimulate greater intelligence in computer-aided design (CAD). Using the style-holon concept, this paper proposes a computational approach to address multi-scale style recognition for automobiles. A style-holon is both a whole—it contains sub-styles of which it is composed—as well as a part of a broader style. In this paper, we first apply a variable precision rough set-based approach to car evaluation and ranking. Secondly, we extracted and subsequently computed the each car's characteristic lines from the CAD models. Finally, we identified style-holons using the property of a double-headed style-holon. A style-holon is necessarily included in a t…

Corrigendum to “Intelligent agents for feature modelling in computer aided design” [J. Comput. Des. Eng. (2018) 19–40]

2018

Systems thinking and its contribution to understanding future designer thinking

2017

Design is changing in a radical way. The object of design is transforming from tangible objects into services and furthermore, into systems. Increasingly, new insights arise from the interfaces between diverse disciplines – such as art, science and technology – which through various discourses and paradigms have been specialized and driven apart. This discussion paper pinpoints the so-called systems thinkers, hybrid-people, whose methods and habits of work are constituted by the reconciliation of different disciplines. The article aims to bring more understanding to the kind of thinking that is needed in the complex and dynamic environment in which we create and use design today. This discu…