Cookies
O website necessita de alguns cookies e outros recursos semelhantes para funcionar. Caso o permita, o INESC TEC irá utilizar cookies para recolher dados sobre as suas visitas, contribuindo, assim, para estatísticas agregadas que permitem melhorar o nosso serviço. Ver mais
Aceitar Rejeitar
  • Menu
Publicações

Publicações por CRIIS

2011

Modeling and Control of a Dragonfly-Like Robot

Autores
Couceiro, MS; Fonseca Ferreira, NMF; Tenreiro Machado, JAT;

Publicação
COMPUTATIONAL INTELLIGENCE FOR ENGINEERING SYSTEMS: EMERGENT APPLICATIONS

Abstract
Dragonflies demonstrate unique and superior flight performances than most of the other insect species and birds. They are equipped with two pairs of independently controlled wings granting an unmatchable flying performance and robustness. In this paper it is studied the dynamics of a dragonfly-inspired robot. The system performance is analyzed in terms of time response and robustness. The development of computational simulation based on the dynamics of the robotic dragonfly allows the test of different control algorithms. We study different movement, the dynamics and the level of dexterity in wing motion of the dragonfly. The results are positive for the construction of flying platforms that effectively mimic the kinematics and dynamics of dragonflies and potentially exhibit superior flight performance than existing flying platforms.

2011

Application of Fractional Controllers for Quad Rotor

Autores
Lebres, C; Santos, V; Fonseca Ferreira, NMF; Tenreiro Machado, JAT;

Publicação
NONLINEAR SCIENCE AND COMPLEXITY

Abstract
This paper studies the application of fractional algorithms in the control of a quad-rotor rotorcraft. The development of a flight simulator provide the evaluation of the controller algorithm. Several basic maneuvers are investigated, namely the elevation and the position control.

2011

Remote sensing based indicators of changes in a mountain rural landscape of Northeast Portugal

Autores
Pocas, I; Cunha, M; Pereira, LS;

Publicação
APPLIED GEOGRAPHY

Abstract
Landscape metrics were used to analyze landscape changes and related driving forces in a mountain rural landscape of Northeast Portugal over three decades. This landscape has great heterogeneity, which favors high levels of diversity and provides for a variety of habitats. The landscape metrics were obtained from land cover maps derived from Landsat images of 1979, 1989 and 2002. Results indicate a trend for increased landscape fragmentation, decrease of annual crop fields (-43%) and, mainly, increase of meadows (+60%). Results relate with decline and aging of the rural population, and to several measures and policies of subsidies implemented in the region in application of the Common Agriculture Policy, which contributed to the replacement of annual crops by meadows. Results are potentially useful to base appropriate policies for landscape management and conservation planning.

2011

BEHAVIORAL AVOIDANCE TESTS TO EVALUATE EFFECTS OF CATTLE SLURRY AND DAIRY SLUDGE APPLICATION TO SOIL

Autores
Matos Moreira, M; Niemeyer, JC; Sousa, JP; Cunha, M; Carral, E;

Publicação
REVISTA BRASILEIRA DE CIENCIA DO SOLO

Abstract
The application of organic wastes to agricultural soils is not risk-free and can affect soil invertebrates. Ecotoxicological tests based on the behavioral avoidance of earthworms and springtails were performed to evaluate effects of different fertilization strategies on soil quality and habitat function for soil organisms. These tests were performed in soils treated with: i) slurry and chemical fertilizers, according to the conventional fertilization management of the region, ii) conventional fertilization + sludge and iii) unfertilized reference soil. Both fertilization strategies contributed to soil acidity mitigation and caused no increase in soil heavy metal content. Avoidance test results showed no negative effects of these strategies on soil organisms, compared with the reference soil. However, results of the two fertilization managements differed: Springtails did not avoid soils fertilized with dairy sludge in any of the tested combinations. Earthworms avoided soils treated with sludge as of May 2004 (DS1), when compared with conventional fertilization. Possibly, the behavioral avoidance of earthworms is more sensitive to soil properties (other than texture, organic matter and heavy metal content) than springtails

2011

Effects of Organic Fertilizers on Soil Physicochemistry and on the Yield and Botanical Composition of Forage over 3 Years

Autores
Matos Moreira, M; Elvira Lopez Mosquera, ME; Cunha, M; Sainz Oses, MJS; Rodriguez, T; Carral, EV;

Publicação
JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION

Abstract
Organic wastes have been reported to reduce saturation of the exchange complex by Al in Al-rich acid soils. For 3 years, the main soil fertility properties were studied in plots sown with mixed pasture species. These plots were fertilized with cattle slurry, dairy sludge (DS), or granulated broiler litter (BL) in comparison with mineral fertilizer. Al saturation levels were low after the initial inorganic liming treatment (19.00-33.71%) but tended to rise under all treatments (21.09-61.37%) except BL (8.45-30.98%), which was also associated with the highest average soil pH and the highest average levels of exchangeable Ca(2+), Mg(2+), and K(+). Treatment DS performed similarly to mineral fertilizer in most respects, but it led to greater available P levels. Under the dry conditions of the second and third years of the study, BL and DS treatments were associated with significantly greater forage yields than the other treatments. Under DS treatment, available P levels were too low to allow the maintenance of mixed pasture, clover being eliminated by the less P-dependent species.

2011

Association of financial or professional conflict of interest to research outcomes on health risks or nutritional assessment studies of genetically modified products

Autores
Diels, J; Cunha, M; Manaia, C; Sabugosa Madeira, B; Silva, M;

Publicação
FOOD POLICY

Abstract
Since the first commercial cultivation of genetically modified crops in 1994, the rapidly expanding market of genetically modified seeds has given rise to a multibillion dollar industry. This fast growth, fueled by high expectations towards this new commercial technology and shareholder trust in the involved industry, has provided strong incentives for further research and development of new genetically modified plant varieties. Considering, however, the high financial stakes involved, concerns are raised over the influence that conflicts of interest may place upon articles published in peer-reviewed journals that report on health risks or nutritional value of genetically modified food products. In a study involving 94 articles selected through objective criteria, it was found that the existence of either financial or professional conflict of interest was associated to study outcomes that cast genetically modified products in a favorable light (p = 0.005). While financial conflict of interest alone did not correlate with research results (p = 0.631), a strong association was found between author affiliation to industry (professional conflict of interest) and study outcome (p < 0.001). We discuss these results by comparing them to similar studies on conflicts of interest in other areas, such as biomedical sciences, and hypothesize on dynamics that may help explain such connections.

  • 319
  • 377