84 research outputs found
Functional and Behavior Models for the Supervision of an Intelligent and Autonomous System
The graphical approaches often have different backgrounds and view a system or an algebraic model from different perspectives in order to facilitate the communication and the understanding. These graphical approaches satisfy the modeling needs and give a clear and easily understandable overview of the behavioral and functional models and make easier to see what the process is, which vulnerabilities and asset that are involved and how the system works. The main goal of this paper is to develop and implement a methodology which combines the functional analysis and the bond graph (BG) tool for intelligent and autonomous systems. As a result, a supervisory interface is obtained, given under a finite automaton, displaying to the operators the possibilities the system has to achieve or not, its objectives. Each operating mode, corresponding to a vertex of the automaton, is associated with a set of services from a functional point-of-view and is defined accurately by a behavioral BG model. Furthermore, the service availability (associated to the BG elements) and the conditions for switching from one mode to another one are analyzed by fault detection and isolation algorithms generated on the basis of the structural and causal properties of the BG tool. Moreover, when a fault is not completely isolable some results can nevertheless be expressed in terms of available or unavailable services
Modelos de endemicidad a lo largo de un gradiente altitudinal en Sierra Nevada (España) y Lefka Ori (Creta, Grecia)
Aim: High mountains in the Mediterranean region of Europe are particularly rich in endemic vascular plants. We aimed to compare the altitudinal patterns of vascular plant species richness and the proportion of endemic species in two Mediterranean region: Lefka Ori on the island of Crete (Greece) and Sierra Nevada on the Iberian peninsula.
Location: Sierra Nevada, Granada (Spain); Lefka Ori, Crete (Greece).
Methods: Data from standardised permanent plots settings on summit sites (comprising eight plot sectors, covering the upeermost 10 altitudinal metres) of different elevations were used (GLORIA Multi-Summit approach; www.gloria.ac.at). Species numbers, rates of endemic species, and soils temperature were compared by means of ANCOVA and linear regression.
Results: The two regions, though climatically similar, showed strikingly different patterns: In Sierra Nevada, the proportion of endemic vascular plants (species restricted to Sierra Nevada) showed a stepwise increase from the lowest to the highest summit. In contrast, the proportion of endemic species restricted to Crete was not significantly different between the four summits in Lefka Ori. In both regions the observed trends were largely consistent with the altitudinal distribution of the endemic species obtained from standard floras.
Main conclusions: The geographic positions of the two regions, i.e. island versus mainland and the higher elevation of Sierra Nevada are suggested to be the primary causes of the observed differences.
The high degree of endemism in the cold environments of Mediterranean mountains’ upper bioclimatic zones indicates a pronounced vulnerability to the impacts of climate change. A continued and intensified species monitoring in the mountains around the Mediterranean basin, therefore, should be considered as a priority research task.Objetivo: Las zonas de alta montaña en la región mediterránea europea son particularmente ricas en plantas vasculares endémicas. Nuestro objetivo es comparar los modelos altitudinales para la riqueza de plantas vasculares y la proporción de endemismos en dos regiones mediterráneas: Lefka Ori en la isla de Creta (Grecia) y Sierra Nevada en la PenÃnsula Ibérica.
Localización: Sierra Nevada, Granada (España); Lefka Ori, Creta (Grecia).
Método: Los datos proceden de un muestreo estandarizado en varias cimas situadas a diferentes altitudes (GLORIA Multi-Summit approach; www.gloria.ac.at). El número de especies, tasas de endemicidad, y temperatura del suelo se compararon por medio de ANCOVA y regresión lineal.
Resultados: Las dos regiones objeto de análisis, aunque similares climáticamente, muestran patrones llamativamente diferentes: en Sierra Nevada, la proporción de plantas vasculares endémicas (especies restringidas a Sierra Nevada) muestra un incremento gradual desde la cima más baja a la más alta. En contraste, la proporción de endemismos restringidos a Creta no fue significativamente diferente entre las cuatro cimas de Lefka Ori. Las tendencias observadas en ambas regiones fueron en gran parte consistentes con la distribución de las especies endémicas obtenida de las floras para cada región.
Conclusiones principales: La posición geográfica de ambas regiones, por ejemplo. isla frente a continente, y la mayor elevación de Sierra Nevada se sugieren como las principales causas de las diferencias observadas.
El alto grado de endemicidad en los ambientes frÃos de las zonas bioclimáticas superiores de las montañas mediterráneas evidencia una marcada vulnerabilidad a los impactos del cambio climático. Por lo tanto, el seguimiento continuado e intensivo de las especies de montaña alrededor de la cuenca mediterránea, deberÃa considerarse como una tarea investigadora prioritaria.He set up of the permanent plots and data collection was supported by the FP-5 project GLORIA-Europe (2001-2003) No EVK2-2000-00056 of the European Commission
A survey of wild plant species for food use in Sicily (Italy) – results of a 3-year study in four Regional Parks
Compensation of the Backlash Effects in an Electrical Actuator
International audienceno abstrac
Compensation of Stick-Slip Phenomenon in an Electrical Actuator
International audienceno abstrac
Compensation of Stick-Slip Phenomenon in an Electrical Actuator
International audienceno abstrac
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