25 resultados para Ácaro fitófago
Resumo:
Amb el present treball es vol aprofundir en la manera que influeix l’organització d’espais, d’ambients i les característiques dels materials en el procés educatiu. A partir d’una recerca teòrica en base les necessitats educatives de la societat actual, les necessitats evolutives dels infants, i en base a l’observació i anàlisi d’escoles reggianes i catalanes referents que tenen en compte com a agent educador l’espai, els ambients i els materials, es volen reunir quines són les característiques bàsiques de l’organització dels espais, ambients i materials per garantir una educació de qualitat a l’etapa infantil (3-6).
Resumo:
A collection of slides from the authorpsilas seminar presentation is given
Resumo:
Ethernet is becoming the dominant aggregation technology for carrier transport networks; however, as it is a LAN technology, native bridged ethernet does not fulfill all the carrier requirements. One of the schemes proposed by the research community to make ethernet fulfill carrier requirements is ethernet VLAN-label switching (ELS). ELS allows the creation of label switched data paths using a 12-bit label encoded in the VLAN TAG control information field. Previous label switching technologies such as MPLS use more bits for encoding the label. Hence, they do not suffer from label sparsity issues as ELS might. This paper studies the sparsity issues resulting from the reduced ELS VLAN-label space and proposes the use of the label merging technique to improve label space usage. Experimental results show that label merging considerably improves label space usage
Resumo:
Recent developments in optical communications have allowed simpler optical devices to improve network resource utilization. As such, we propose adding a lambda-monitoring device to a wavelength-routing switch (WRS) allowing better performance when traffic is routed and groomed. This device may allow a WRS to aggregate traffic over optical routes without incurring in optical-electrical-optical conversion for the existing traffic. In other words, optical routes can be taken partially to route demands creating a sort of "lighttours". In this paper, we compare the number of OEO conversions needed to route a complete given traffic matrix using either lighttours or lightpaths
Resumo:
Wavelength division multiplexing (WDM) networks have been adopted as a near-future solution for the broadband Internet. In previous work we proposed a new architecture, named enhanced grooming (G+), that extends the capabilities of traditional optical routes (lightpaths). In this paper, we compare the operational expenditures incurred by routing a set of demands using lightpaths with that of lighttours. The comparison is done by solving an integer linear programming (ILP) problem based on a path formulation. Results show that, under the assumption of single-hop routing, almost 15% of the operational cost can be reduced with our architecture. In multi-hop routing the operation cost is reduced in 7.1% and at the same time the ratio of operational cost to number of optical-electro-optical conversions is reduced for our architecture. This means that ISPs could provide the same satisfaction in terms of delay to the end-user with a lower investment in the network architecture
Resumo:
Optical transport networks (OTN) must be prepared in terms of better resource utilization, for accommodating unicast and multicast traffic together. Light-trees have been proposed for supporting multicast connections in OTN. Nevertheless when traffic grooming is applied in light-trees, resources can be underutilized as traffic can be routed to undesirable destinations in order to avoid optical-electrical-optical (OEO) conversions. In this paper, a novel architecture named S/G light- tree for supporting unicast/multicast connections is proposed. The architecture allows traffic dropping and aggregation in different wavelengths without performing OEO conversions. A heuristic that routes traffic demands using less wavelengths by taking advantage of the proposed architecture is designed as well. Simulation results show that the architecture can minimize the number of used wavelengths and OEO conversions when compared to light-trees
Resumo:
In this article, a new technique for grooming low-speed traffic demands into high-speed optical routes is proposed. This enhancement allows a transparent wavelength-routing switch (WRS) to aggregate traffic en route over existing optical routes without incurring expensive optical-electrical-optical (OEO) conversions. This implies that: a) an optical route may be considered as having more than one ingress node (all inline) and, b) traffic demands can partially use optical routes to reach their destination. The proposed optical routes are named "lighttours" since the traffic originating from different sources can be forwarded together in a single optical route, i.e., as taking a "tour" over different sources towards the same destination. The possibility of creating lighttours is the consequence of a novel WRS architecture proposed in this article, named "enhanced grooming" (G+). The ability to groom more traffic in the middle of a lighttour is achieved with the support of a simple optical device named lambda-monitor (previously introduced in the RingO project). In this article, we present the new WRS architecture and its advantages. To compare the advantages of lighttours with respect to classical lightpaths, an integer linear programming (ILP) model is proposed for the well-known multilayer problem: traffic grooming, routing and wavelength assignment The ILP model may be used for several objectives. However, this article focuses on two objectives: maximizing the network throughput, and minimizing the number of optical-electro-optical conversions used. Experiments show that G+ can route all the traffic using only half of the total OEO conversions needed by classical grooming. An heuristic is also proposed, aiming at achieving near optimal results in polynomial time
Resumo:
Per diferents motius, l'acció de la justícia es troba permanentment d'actualitat. Una de les causes és la contínua novetat que prové de les propostes de modernització en els diversos àmbits, que tracten de pal·liar els dèficits amb els quals s'enfronta cada dia l'acció judicial. El debat és ja antic i permanent, sent que, simultàniament un ventall de projectes ha aparegut amb la intenció de dur a terme un canvi profund i determinant en la visió de l'estructura del Poder Judicial i dels serveis associats. En particular, la proposta de reforma de Llei Orgànica del Poder Judicial i de Demarcació i Planta, suposa la concentració de tots els jutjats a les capitals de província, amb el risc d'allunyament enfront dels ciutadans i problemes associats. L'esborrany de Codi Processal Penal aposta per un nou sistema de recerca a càrrec del Ministeri Fiscal, amb curts terminis taxats per a la finalització del procediment, promoció de la mediació i augment de les possibilitats de no continuació de la causa, a més una concentració i simplificació de totes les fases del procediment penal. D'altra banda, el Registre Civil ha estat retirat dels jutjats però, malgrat el transcurs del temps, no s'és capaç d'identificar a quin col·lectiu li correspondrà aquesta funció, amb la conseqüent generació d'una important inquietud social. Aquestes i altres novetats seran analitzades en profunditat, amb especial perspectiva des de l'àmbit de Catalunya, tractant d'aportar solucions i propostes de millora.
Resumo:
Analyzing the state of the art in a given field in order to tackle a new problem is always a mandatory task. Literature provides surveys based on summaries of previous studies, which are often based on theoretical descriptions of the methods. An engineer, however, requires some evidence from experimental evaluations in order to make the appropriate decision when selecting a technique for a problem. This is what we have done in this paper: experimentally analyzed a set of representative state-of-the-art techniques in the problem we are dealing with, namely, the road passenger transportation problem. This is an optimization problem in which drivers should be assigned to transport services, fulfilling some constraints and minimizing some function cost. The experimental results have provided us with good knowledge of the properties of several methods, such as modeling expressiveness, anytime behavior, computational time, memory requirements, parameters, and free downloadable tools. Based on our experience, we are able to choose a technique to solve our problem. We hope that this analysis is also helpful for other engineers facing a similar problem