Embedding the DIRECT algorithm in a penalty approach for solving engineering design problems

Publicado em CD-ROMIn this paper we investigate the performance of DIRECT algorithm when solving constrained engineering design problems. For this purpose, the hyperbolic penalty approach is employed and the algorithm is modified in order to preserve feasibility of solutions. The algorithm is illustrated on six well–known engineering problems with promising results. Comparisons with other global optimization solvers are reported and discussed

Endo-cannibalism in the making of a recent British ancestor

Following his death in 1975, the ashes of Wally Hope, founder of Stonehenge People's Free Festival, were scattered in the centre of Stonehenge. When a child tasted the ashes the rest of the group followed this lead. In the following decades, as the festival increasingly became the site of contest about British heritage and culture, the story of Wally's ashes was told at significant times. His name continues to be invoked at gatherings today. This paper discusses these events as 'the making of an ancestor', and explores wider contexts in which they might be understood. These include Druidic involvement in the revival of cremation, Amazonian bone-ash endo-cannibalism, and popular means of speaking of and to dead relatives. In addition to considering the role of 'ancestors' in contemporary Britain, the paper contributes to considerations of 'ancestry' as a different way of being dead, of a particular moment in the evolution of an alternative religious neo-tribal movement, of the meanings of 'cannibalism', and of the ways in which human remains might be treated by the bereaved and by various other interested parties

Stereo vision calibration procedure for 3D surface measurements

In reverse engineering, rapid prototyping or quality control with complex 3D object surfaces, there is often the need to scan a complete 3D model using laser digitizers. Those systems usually use one camera and one laser,- using triangulation techniques; complex 3D objects can cause information gaps in the model obtained. To overcome this problem, another camera can be used. Traditional calibration procedures for those systems normally result in a full 3D camera calibration, involving individual implicit camera parameters, a rigid motion equation relating the explicit cameras parameters of each camera and the intersection with the laser line. This paper presents a new stereo vision laser strip calibration procedure for 3D surface measurements. In this calibration procedure the laser plane is the one that matters, only one set of laser-coplanar calibration points for camera calibration is needed, and a dead zone scan area is considered, since the digitalization arm is mounted in a 3 degree freedom machine PC-based Motion Control with multiple scan paths.Fundação para a Ciência e a Tecnologia (FCT

Calibration procedure for 3D surface measurements using stereo vision and laser stripe

This paper proposes a new stereo vision calibration procedure and laser strip detection for 3D surface measurements. In this calibration procedure the laser plane is the one that matters, only one set of laser-coplanar calibration points is needed for image cameras calibration; and a dead- zone scan area is considered, since the igitalization arm is assembled in a 3 degree-freedom machine PC-based Motion Control with multiple scan paths. It is also presented some algorithms for 3D surface treatment.Fundação para a Ciência e a Tecnologia (FCT

Automatic trajectory generation for the milling of sculpted surfaces acquired from laser scanning systems

The present work describes a set of algorithms for the milling of sculpted surfaces acquired from laser scanning systems. The milling operations cover three operations: roughing, semi-finishing and finishing. The developed algorithms use techniques ranging from computer vision to computer graphics following a different approach when compared with the usual milling techniques, usually feature based. The implementation of 3D path simulator was also described and testing of the different milling trajectories presented.Fundação para a Ciência e a Tecnologia (FCT

Integrated impact assessment of shares, automated and electric mobility

Major transformations in the road transportation sector such as vehicle automation, electrification, and shared mobility, create opportunities to tackle sector challenges. Despite the promising positive impact, little is known about the real potential and the effective sustainability of a combination oh these emerging mobility systems. The proposed doctoral research plan intends to understand and quantify the environmental and energy-related impacts of shared, fully automated, and electric mobility. A fundamental understanding of the upstream and downstream environmental impacts of a product and a system considering SAEVs fleet adjusted to different travel demands will be conducted in a life cycle assessment (LCA) approach. The assessment of potential environmental impact reduction has always been a research hotspot; however, most studies are only focused on operational impact. Moreover, the impact of SAEVs in the road network considering presence, routing, location, access to charging stations and scheduling will be addressed. Hence, automated driving decisions and distinguishing normal from recurring driving patterns are required to develop a framework for generating an automated mobility service. Attention will be given to the application of SAE mobility both at urban and inter-urban scales. The evaluation of the impacts of emerging mobility systems requires a comprehensive set of criteria. Results of the research intend to culminate into a feasibility study combining environmental, economic, and consumer perspective viability of the examined systems. The main research questions of this study are: 1) Which routing strategies should be adopted for energy-efficient driving decision?; 2) What are the impacts of SAEVs systems through a life cycle concept?; 3) What is the potential of SAEVs to manage traffic demand at urban and interurban scales?publishe

Calibration procedure for 3D measurement systems using two cameras and a laser line

Prova tipográficaIn order to ensure the precision of the measurement of complex 3D object surfaces using non-contact laser scanning systems, a novel stereo vision calibration procedure based on a laser line projection plane is presented. This calibration procedure can also be used in measurement systems based on a single camera and a laser line projection. This procedure, while using only laser-coplanar points, is oriented towards laser line detection and allows the matching of two images on the laser projection plane without the use of a rigid motion equation. These features make this procedure very precise, simple and, consequently, easier to implement.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/18155/200

Integração de um servidor web num sistema de pesagem

O presente artigo, descreve a integração das novas tecnologias de informação (TIs) via Web nos sistemas tradicionais de pesagem, dotando estes de grandes facilidades de interligação com outros sistemas ou equipamentos. Destas facilidades podem ser distinguidas as seguintes: leitura dos valores do peso local e remotamente; facilidades de ligação com sistemas de informação, bases de dados e outras formas de gestão e controlo centralizados; fácil ligação dos equipamentos em rede, possibilitando o controlo centralizado dos equipamentos e de todo o material por eles pesado; facilidades de teleassistência e telemanutenção

A new machine for acquire pavement texture

This paper presents a prototype machine for the acquisition and characterization of the macrotexture and megatexture of road surfaces. The development stages of the prototype machine involved: 3D data acquisition system configuration and calibration - based on laser triangulation technique, 3D surface reconstruction of the road surface and texture characterization using appropriated indicators, such as the Mean Profile Depth (MPD) and the Texture Profile Level (L), by applying different and complementary mathematical techniques. The prototype machine created is able to work in laboratory and in field, allowing an acquisition accuracy of 0.5 mm. The contribution of this research is in developing a prototype machine capable of acquiring an extensive area road surface with high precision 3D data.(undefined

3D surface profile equipment for the characterization of the pavement texture - TexScan

Loads from vehicles alter the functional and structural characteristics of road pavements that directly affect the loss of resistance of the pavement and the users’ comfort and safety. Those alterations require constant observation and analysis of an extensive area of road surface with high precision. For such it was developed a new scanning prototype machine capable of acquiring the 3D road surface data and characterize the road texture through two algorithms that allows calculate the Estimated Texture Depth (ETD) and Texture Profile Level (L) indicators. The experimental results obtained from nine road samples validate the developed algorithms for the texture analysis and showed good agreement between the scanning prototype equipment and the traditional Sand Patch Method.Fundação para a Ciência e a Tecnologia (FCT) through the PhD Grant referenced SFRH/BD/18155/200