Search results for "Form"

Essential oil crops for sustainable agriculture - A review

2009

Multifunctionality and diversification of farming systems, integration of agricultural practices both inter se and with the non-agricultural productive systems operating on the territory, biodiversity safeguards, and reduction in off-farm inputs, are key factors for all modern development strategies in agricultural areas. Such issues are valid worldwide, but are especially true in areas in which the cultivation of the more widespread and “classical” crops is constrained by factors of varying degree and importance. In Mediterranean areas, where many environmental and economic factors often reduce rural areas to marginal conditions, the search for new crop opportunities has become one of the …

Lagrangian matches between observations from aircraft, lidar and radar in a warm conveyor belt crossing orography

2021

Warm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to the formation of intense precipitation and the amplification of upper-level ridges. This study presents a case study that involves aircraft, lidar and radar observations in a WCB ascending from western Europe towards the Baltic Sea during the Hydrological Cycle in the Mediterranean Experiment (HyMeX) and T-NAWDEX-Falcon in October 2012, a preparatory campaign for the THORPEX North Atlantic Waveguide and Downstream Impact Experiment (TNAWDEX). Trajectories were used to link different observations along the WCB, that is, to establish so-called Lagrangian matches between observations. To this aim, a…

Fractional calculus approach for the representation of power spectral densities and correlation functions in wind engineering

2010

The paper deals with the digital simulation of wind velocity samples by Fractional Spectral Moment function. It is shown that such a function represents a third useful way to characterize a stationary Gaussian stochastic process, alongside the power spectral density and the correlation function. The method is applied to wind velocity fields whose power spectra is given by the Kaimal’s, the Davenport’s and the Solari’s representation. It is shown that by constructing a digital filter whose coefficients are the fractional spectral moments, it is possible to simulate samples of the target process as superposition of Riesz fractional derivatives of Gaussian white noise processes.

Performance Study of IEEE 802.11 DCF and IEEE 802.11e EDCA

2008

Learn to Cache: Machine Learning for Network Edge Caching in the Big Data Era

2018

The unprecedented growth of wireless data traffic not only challenges the design and evolution of the wireless network architecture, but also brings about profound opportunities to drive and improve future networks. Meanwhile, the evolution of communications and computing technologies can make the network edge, such as BSs or UEs, become intelligent and rich in terms of computing and communications capabilities, which intuitively enables big data analytics at the network edge. In this article, we propose to explore big data analytics to advance edge caching capability, which is considered as a promising approach to improve network efficiency and alleviate the high demand for the radio resou…

A Double Auction Mechanism for Virtual Resource Allocation in SDN-based Cellular Network

2016

The explosively growing demands for mobile traffic service bring both challenges and opportunities to wireless net- works, among which, wireless network virtualization is proposed as the main evolution towards 5G. In this paper, we first propose a Software Defined Network (SDN) based wireless virtualization architecture for enabling multi-flow transmission in order to save capital expenses (CapEx) and operation expenses (OpEx) significantly with multiple Infrastructures Providers (InPs) and multiple Mobile Virtual Network Operators (MVNOs). We for- mulate the virtual resource allocation problem with diverse QoS requirements as a social welfare maximization problem with transaction cost. Due…

Sparsity-aware multiple relay selection in large multi-hop decode-and-forward relay networks

2016

In this paper, we propose and investigate two novel techniques to perform multiple relay selection in large multi-hop decode-and-forward relay networks. The two proposed techniques exploit sparse signal recovery theory to select multiple relays using the orthogonal matching pursuit algorithm and outperform state-of-the-art techniques in terms of outage probability and computation complexity. To reduce the amount of collected channel state information (CSI), we propose a limited-feedback scheme where only a limited number of relays feedback their CSI. Furthermore, a detailed performance-complexity tradeoff investigation is conducted for the different studied techniques and verified by Monte …

Energy Efficient Optimization for Wireless Virtualized Small Cell Networks With Large-Scale Multiple Antenna

2017

Wireless network virtualization is envisioned as a promising framework to provide efficient and customized services for next-generation wireless networks. In wireless virtualized networks (WVNs), limited radio resources are shared among different services providers for providing services to different users with heterogeneous demands. In this paper, we propose a resource allocation scheme for an orthogonal frequency division multiplexing-based WVN, where one small cell base station equipped with a large number of antennas serves the users with different service requirements. In particular, with the objective to obtain the energy efficiency in the uplink, a joint power, subcarrier, and antenn…

Underwater Multirobot Cooperative Intervention MAC Protocol

2020

This work introduces a Medium Access Control (MAC) protocol designed to allow a group of underwater robots that share a wireless communication channel to effectively communicate with each other. The goal of the Underwater Multirobot Cooperative Intervention MAC (UMCI-MAC) protocol presented in this work is to minimize the end to end delay and the jitter. The access to the medium in UMCI-MAC follows a Time Division Multiple Access (TDMA) strategy which is arbitrated by a master, which also has the capability to prioritize the transmission of some nodes over the rest of the network. Two experiments have been carried out with a team of four Autonomous Underwater Vehicles (AUV) in order to comp…

The role of the agreement as a tool for management of property relations in cases of cross border marriages and civil unions/partnerships registered …

2021

The essay examines the role of the agreement as a tool for managing property relationships in crossborder marriages and registered partnerships, in light of EU Regulations 1103 and 1104 of 2016, on the property regimes of international married or registered couples. The main prerogative of such acts is the recognition of the parties? freedom to choose the court and the applicable law. The law governing the matrimonial property regimes, or the property consequences of registered partnerships, has universal scope. This agreement in the form envisaged, which is backed by the need for legal certainty and predictability of the applicable rules, means that the spouses, in family problems which ha…