1,628 research outputs found
Analysis and Market Prospects of a Traditional Calabrian Product
The strategies for exploiting typical production represents a theme of great interest, above all in the measure in which exploitation brought about via adequate marketing strategies allows these products to shed their anonymity. This paper constitutes a contribution in this direction, since it analyses the potential of a traditional product ('Nduja) using multivariate analysis techniques on a sample of consumers, identified by a specific market research survey. This made it possible to define the main characteristics of the type of consumer of this product and to define suitable market segmentation strategies.Traditional product, Rural development, Marketing strategies, Factor Analysis, Consumer/Household Economics,
Forced response of shrouded blades with a coupled static/dynamic approach
A coupled static-dynamic method is proposed and applied to bladed disks with shrouds, in order to calculate the nonlinear forced response in presence of friction damping in the frequency domain. The novel approach allows to improve the already existing methods, which require a preliminary static analysi
Global and local expansion of magnetic clouds in the inner heliosphere
Observations of magnetic clouds (MCs) are consistent with the presence of
flux ropes detected in the solar wind (SW) a few days after their expulsion
from the Sun as coronal mass ejections (CMEs). Both the \textit{in situ}
observations of plasma velocity profiles and the increase of their size with
solar distance show that MCs are typically expanding structures. The aim of
this work is to derive the expansion properties of MCs in the inner heliosphere
from 0.3 to 1 AU.We analyze MCs observed by the two Helios spacecraft using
\textit{in situ} magnetic field and velocity measurements. We split the sample
in two subsets: those MCs with a velocity profile that is significantly
perturbed from the expected linear profile and those that are not. From the
slope of the \textit{in situ} measured bulk velocity along the Sun-Earth
direction, we compute an expansion speed with respect to the cloud center for
each of the analyzed MCs. We analyze how the expansion speed depends on the MC
size, the translation velocity, and the heliocentric distance, finding that all
MCs in the subset of non-perturbed MCs expand with almost the same
non-dimensional expansion rate (). We find departures from this general
rule for only for perturbed MCs, and we interpret the departures as the
consequence of a local and strong SW perturbation by SW fast streams, affecting
the MC even inside its interior, in addition to the direct interaction region
between the SW and the MC. We also compute the dependence of the mean total SW
pressure on the solar distance and we confirm that the decrease of the total SW
pressure with distance is the main origin of the observed MC expansion rate. We
found that was for non-perturbed MCs while was
for perturbed MCs, the larger spread in the last ones being due
to the influence of the environment conditions on the expansion
Expansion of magnetic clouds in the outer heliosphere
A large amount of magnetized plasma is frequently ejected from the Sun as
coronal mass ejections (CMEs). Some of these ejections are detected in the
solar wind as magnetic clouds (MCs) that have flux rope signatures. Magnetic
clouds are structures that typically expand in the inner heliosphere. We derive
the expansion properties of MCs in the outer heliosphere from one to five
astronomical units to compare them with those in the inner heliosphere. We
analyze MCs observed by the Ulysses spacecraft using insitu magnetic field and
plasma measurements. The MC boundaries are defined in the MC frame after
defining the MC axis with a minimum variance method applied only to the flux
rope structure. As in the inner heliosphere, a large fraction of the velocity
profile within MCs is close to a linear function of time. This is indicative
of} a self-similar expansion and a MC size that locally follows a power-law of
the solar distance with an exponent called zeta. We derive the value of zeta
from the insitu velocity data. We analyze separately the non-perturbed MCs
(cases showing a linear velocity profile almost for the full event), and
perturbed MCs (cases showing a strongly distorted velocity profile). We find
that non-perturbed MCs expand with a similar non-dimensional expansion rate
(zeta=1.05+-0.34), i.e. slightly faster than at the solar distance and in the
inner heliosphere (zeta=0.91+-0.23). The subset of perturbed MCs expands, as in
the inner heliosphere, at a significantly lower rate and with a larger
dispersion (zeta=0.28+-0.52) as expected from the temporal evolution found in
numerical simulations. This local measure of the expansion also agrees with the
distribution with distance of MC size,mean magnetic field, and plasma
parameters. The MCs interacting with a strong field region, e.g. another MC,
have the most variable expansion rate (ranging from compression to
over-expansion)
StreamCloud: An elastic and scalable data streaming system
Many applications in several domains such as telecommunications, network security, large scale sensor networks, require online processing of continuous data lows. They produce very high loads that requires aggregating the processing capacity of many nodes. Current Stream Processing Engines do not scale with the input load due to single-node bottlenecks. Additionally, they are based on static con?gurations that lead to either under or over-provisioning. In this paper, we present StreamCloud, a scalable and elastic stream processing engine for processing large data stream volumes. StreamCloud uses a novel parallelization technique that splits queries into subqueries that are allocated to independent sets of nodes in a way that minimizes the distribution overhead. Its elastic protocols exhibit low intrusiveness, enabling effective adjustment of resources to the incoming load. Elasticity is combined with dynamic load balancing to minimize the computational resources used. The paper presents the system design, implementation and a thorough evaluation of the scalability and elasticity of the fully implemented system
A scalable SIEM correlation engine and its application to the Olympic Games IT infrastructure
The security event correlation scalability has become a major concern for security analysts and IT administrators when considering complex IT infrastructures that need to handle gargantuan amounts of events or wide correlation window spans. The current correlation capabilities of Security Information and Event Management (SIEM), based on a single node in centralized servers, have proved to be insufficient to process large event streams. This paper introduces a step forward in the current state of the art to address the aforementioned problems. The proposed model takes into account the two main aspects of this ?eld: distributed correlation and query parallelization. We present a case study of a multiple-step attack on the Olympic Games IT infrastructure to illustrate the applicability of our approach
A big data platform for large scale event processing
To date, big data applications have focused on the store-and-process paradigm. In this paper we describe an initiative to deal with big data applications for continuous streams of events. In many emerging applications, the volume of data being streamed is so large that the traditional ‘store-then-process’ paradigm is either not suitable or too inefficient. Moreover, soft-real time requirements might severely limit the engineering solutions. Many scenarios fit this description. In network security for cloud data centres, for instance, very high volumes of IP packets and events from sensors at firewalls, network switches and routers and servers need to be analyzed and should detect attacks in minimal time, in order to limit the effect of the malicious activity over the IT infrastructure. Similarly, in the fraud department of a credit card company, payment requests should be processed online and need to be processed as quickly as possible in order to provide meaningful results in real-time. An ideal system would detect fraud during the authorization process that lasts hundreds of milliseconds and deny the payment authorization, minimizing the damage to the user and the credit card company
Meta-analysis of genes in commercially available nutrigenomic tests denotes lack of association with dietary intake and nutrient-related pathologies
Nutrigenomics is an emerging discipline that aims to investigate how individual genetic composition correlates with dietary intake, as well as how nutrition influences gene expression. Herein, the fundamental question relates to the value of nutrigenomics testing on the basis of the currently available scientific evidence. A thorough literature search has been conducted in PubMed scientific literature database for nutrigenomics research studies on 38 genes included in nutrigenomics tests provided by various private genetic testing laboratories. Data were subsequently meta-analyzed to identify possible associations between the genes of interest and dietary intake and/or nutrient-related pathologies. Data analysis occurred according to four different models due to data sparsity and inconsistency. Data from 524,592 individuals (361,153 cases and 163,439 controls) in a total of 1,170 entries were obtained. Conflicting findings indicated that there was a great incompatibility regarding the associations (or their absence) identified. No specific-and statistically significant-association was identified for any of the 38 genes of interest. In those cases, where a weak association was demonstrated, evidence was based on a limited number of studies. As solid scientific evidence is currently lacking, commercially available nutrigenomics tests cannot be presently recommended. Notwithstanding, the need for a thorough and continuous nutrigenomics research is evident as it is a highly promising tool towards precision medicine
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