2010
Authors
Reis, MGAD; Cabral, L; Peres, E; Bessa, M; Valente, A; Morais, R; Soares, S; Baptista, J; Aires, A; Escola, JJ; Bulas Cruz, JA; Reis, MJCS;
Publication
TURKISH ONLINE JOURNAL OF EDUCATIONAL TECHNOLOGY
Abstract
Technology has profoundly changed the way we learn and live. Indeed, such relationship appears to be quite complex, within IT contexts, and especially in socially and technologically rich learning environments, where related skills and learning are progressively required and fostered. Thus, if a satisfactory level of intellectual performance and social competence of a primary school pupil is indeed highly dependent on the type of participation that parents offer their children, IT, in general, and Internet, in particular, may well provide a new paradigm, setting forth that education and communication approach is truly more complex than ever before. It is on the basis of such paradigm that we therefore present a case study where a set of multimedia exercises were used in order to possibly improve the mathematical skills of pupils, one with mental retardation and another with cerebral palsy. Being part of a Web-based system to support students' learning, the referred set of multimedia exercises proved to be the children's favorite, rather than exercises in paper form, which also led the children to show a fair more positive attitude towards learning. Also, we observed that through the mentioned multimedia exercises, the children became far more autonomous, interested, persistent, happy, and able to easily absorb the material as well as more willingly to continue on working.
2010
Authors
Barbosa, MR; Solteiro Pires, EJS; Lopes, AM;
Publication
SOFT COMPUTING MODELS IN INDUSTRIAL AND ENVIRONMENTAL APPLICATIONS
Abstract
Parallel manipulators have attracted the attention of researchers from different areas such as: high-precision robotics, machine-tools, simulators and haptic devices. The choice of a particular structural configuration and its dimensioning is a central issue to the performance of these manipulators. A solution to the dimensioning problem, normally involves the definition of performance criteria as part of an optimization process. In this paper the kinematic design of a 6-dof parallel robotic manipulator for maximum dexterity is analyzed. The condition number of the inverse kinematic jacobian is defined as the measure of dexterity and solutions that minimize this criterion are found through a genetic algorithm formulation. Subsequently a neuro-genetic formulation is developed and tested. It is shown that the neuro-genetic algorithm can find close to optimal solutions for maximum dexterity, significantly reducing the computational load.
2010
Authors
Mestre, P; Serodio, C; Morais, R; Azevedo, J; Melo Pinto, P;
Publication
WORLD CONGRESS ON ENGINEERING, WCE 2010, VOL I
Abstract
Silvopastoralism is an activity with multiple benefits from both the ecological and economical points of view. Besides the potential cash flow to landowners, it has multiple environmental advantages and it can even help to reduce fire hazard in woodland. This hazard reduction is due to cattle grazing, and for it to become effective, it is needed to move herds to the correct place at the correct time. Only knowing when and where shrubs and sward are ready for grazing it is possible to make an effective management of herd placement. In loco inspection of the terrain can be time and resource consuming, as large areas must be verified. An automated system to detect the presence of shrubs and sward can help to improve the management of herds. Since Wireless Sensor Networks (WSN) have spread in the last years and, are becoming very popular in agricultural applications, the objective of this work is to analyse the effect of vegetation in radio-frequency (RF) signals propagation, and use it to detect plants growth. Experiments showed that by measuring and analysing the attenuation in wireless links it is possible to detect plants growth. Besides providing the infrastructure to transmit data from field wireless sensors, the network itself can be used as the sensor.
2010
Authors
Morais, R; Silva, N; Santos, P; Frias, C; Ferreira, J; Ramos, A; Simoes, J; Baptista, J; Reis, M;
Publication
EUROSENSORS XXIV CONFERENCE
Abstract
This paper describes an improved micro-power electric generator where energy harvested from human movements is used as an everlasting mechanical energy source to suffice smart hip implant electronics power needs. Its architecture is designed so that the mechanical energy promotes the movement of a combination of magnets and a spring embedded inside a Teflon tube, used to reduce friction. The changing magnetic field induces current in two coils so that the output of the generator is the sum of their signals. The end result is like a double generator in one casing. Produced electrical energy is stored in an energy reservoir handed over to a power management module. Experimental results shows that energy harvested from human walking can be used as an effective power source for hip prosthesis implants. (C) 2010 Published by Elsevier Ltd.
2010
Authors
Miranda, N; Morais, R;
Publication
Proceedings of the 17th International Conference - Mixed Design of Integrated Circuits and Systems, MIXDES 2010
Abstract
This article describes a new electrical conductance converter method suitable for very low power applications, where energy constraints prevails over speed and measurement accuracy. Method idea gather voltage time integration and shopper stabilization techniques to process noisy low amplitude signals and to overcome severe limitations of weak inversion channel CMOS circuitry. Main features and tradeoffs are exploited. A 1.2V ASIC implementation on standard 0.35µm CMOS schematics is also presented. Post-layout simulations shows a total power consumption lower than 900nW including current source excitation inherent to the conductance measurement. Such low power consumption allows the measurement of several physical parameters on self-powered wireless networks. © 2010 by Department of Microelectronics & Computer Science, Technical University of Lodz.
2010
Authors
Cunha, CR; Peres, E; Morais, R; Oliveira, AA; Matos, SG; Fernandes, MA; Ferreira, PJSG; Reis, MJCS;
Publication
COMPUTERS AND ELECTRONICS IN AGRICULTURE
Abstract
This paper describes a Viticulture Service-Oriented Framework (VSOF) which turns around context elements or tags that are placed in the field and which can be decoded by mobile devices such as mobile phones or PDAs. The tags are used to automatically associate a field location to the relevant database tables or records and also to access contextual information or services. By pointing a mobile device to a tag, the viticulturalist may download data such as climatic data or upload information such as disease and pest incidence in a simple way, without having to provide coordinates or any other references, and without having to return to a central office This work is part of an effort to implement a large-scale distributed cooperative network in the Douro Demarcated Region in Northeast Portugal, a region in which the effort makes particular sense due to the extremely variable topography and mesoclimates The possibility of exchanging contextualized information and accessing contextualized services in the field, using well-known devices such as cell phones, may contribute to increase the rate of adoption of information technology in viticulture, and contribute to more efficient and closer-to-the-crops practices.
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