Search results for "Computer Aided Design"
showing 10 items of 40 documents
CAD of complex passive devices composed of arbitrarily shaped waveguides using Nyström and BI-RME methods
2004
In this paper, a novel computer-aided design (CAD) tool of complex passive microwave devices in waveguide technology is proposed. Such a tool is based on a very efficient integral-equation analysis technique that provides a full-wave characterization of discontinuities between arbitrarily shaped waveguides defined by linear, circular, and/or elliptical arcs. For solving the modal analysis of such arbitrary waveguides, a modified version of the well-known boundary integral-resonant-mode expansion (BI-RME) method using the Nyström approach, instead of the traditional Galerkin version of the method of moments, is proposed, thus providing significant savings on computational costs and implement…
SPICE model for resistive gas and odour sensors
1999
A generalised PSPICE model of resistive gas/odour sensors is presented. The model simulates the response of both polymeric and metal oxide devices, as well as an integrated resistive heater that is used to set the operating temperature. In both cases there was good agreement between the observed responses and the PSPICE simulated responses to rectangular pulses of gases. The PSPICE model is not only simpler and faster to use than analytical solutions, but also should permit the rapid prototyping of associated drive circuitry.
A new design approach for customised medical devices realized by additive manufacturing
2020
AbstractThe aim of this work is the design of a new customised elbow orthosis completely realized by Additive Manufacturing and the development of generative algorithms for parametric modelling and creation of 3D patterns to be adapted to the CAD model. This work describes a method to perfect the design of a custom elbow orthosis. A reverse engineering approach has been used to digitalize the patient’s arm and the subsequent CAD modelling of the structure of the custom elbow orthosis has been performed. In particular, two algorithms have been implemented for the creation of 3D patterns and Voronoi tessellations. Subsequently, FEM analyses have been carried out to validate the design. Finall…
Analysis of the depth of field of integral imaging displays based on wave optics.
2013
In this paper, we analyze the depth of field (DOF) of integral imaging displays based on wave optics. With considering the diffraction effect, we analyze the intensity distribution of light with multiple micro-lenses and derive a DOF calculation formula for integral imaging display system. We study the variations of DOF values with different system parameters. Experimental results are provided to verify the accuracy of the theoretical analysis. The analyses and experimental results presented in this paper could be beneficial for better understanding and designing of integral imaging displays.
EM Based Synthesis and Design of Bandpass Waveguide Filters Including Manufacturing Effects with FEST3D
2011
This article aims at the industry interest on automated design tools that are able to take into account manufacturing effects. First, an efficient design strategy for bandpass waveguide filters including the rounded corners arising from low-cost manufacturing procedures is presented. This technique is based on a recent enhanced prototype and synthesis methodology able to consider the real structure parts. Using the resulting electromagnetic (EM)-based synthesis technique, an excellent structure is extracted, which requires, at most, only a slight final EM optimization. Second, this article presents analytical expressions providing error estimates for the different filter performances in ter…
Using Semantics to Manage 3D Scenes in Web Platforms
2005
Computer graphics has widely spread out into various computer applications. After the early wire-frame computer generated images of the 60s, spatial representation of objects improved in the 70s with Boundary Representation (B-Rep) modeling, Constructive Solid Geometry (CSG) objects, and free-form surfaces. Realistic rendering in the 90s, taking into account sophisticated dynamic interactions (between objects or between objects and human actors, physical interactions with light, etc.) now make 3D-scenes much better than simple 3D representations of the real world. Indeed, they are a way to conceive products (industrial products, art products, etc.) and to modify them over time, either inter…
Cognitive intelligent sensory system for vision-based quality control
2003
This paper presents an original approach for a vision-based quality control system, built around a cognitive intelligent sensory system. The principle of the approach relies on two steps. First, a so-called initialization phase leads to structural knowledge on image acquisition conditions, type of illumination sources, etc. Second, the image is iteratively evaluated using this knowledge and complementary information (e.g., CAD models, and tolerance information). Finally, the information describing the quality of the piece under evaluation is extracted. A further aim of the approach is to enable building strategies that determine for instance the “next best view” required for completing the …
Methods for optimal shape design of electrical devices
1996
Often the primary problem facing designers of structural systems is determining the shape of the structure. In spite of graphical work stations and modern software for analyzing the structure, finding the best geometry for the structure by “trial and error” is still a very tedious and timeconsuming task. The goal in optimal shape design (structural optimization, or redesign) is to computerize the design process and therefore shorten the time it takes to design new products or improve the existing design. Structural optimization is already used in many applications in industry. In general, however, structural optimization is just beginning to penetrate the industrial community. Integrating F…
A PROGRAM FOR THE AUTOMATIC COMPUTING OF SOLAR GAIN OF A PARALLELEPIPED VOLUME CONSIDERING THE SHADOWS CAST ON IT BY ANY SYSTEM OF SURROUNDING PARALL…
1985
A program is given, that computes solar gain on a parallelepiped volume taking in to consideration the shadows cast by any system of surrounding parallelepiped. It contains an algorithm for the quick discarding of non shadowing volumes, for the construction of the union polygon, without repetition of overlapping shadows, and for the intersection polygon of formerly found union polygon with the shadowed faces.
Information Systems Architecture and Technology: Proceedings of 38th International Conference on Information Systems Architecture and Technology – IS…
2018
This three-volume set of books presents advances in the development of concepts and techniques in the area of new technologies and contemporary information system architectures. It guides readers through solving specific research and analytical problems to obtain useful knowledge and business value from the data. Each chapter provides an analysis of a specific technical problem, followed by the numerical analysis, simulation and implementation of the solution to the problem. The books constitute the refereed proceedings of the 2017 38th International Conference “Information Systems Architecture and Technology,” or ISAT 2017, held on September 17–19, 2017 in Szklarska Poręba, Poland. The con…