756 research outputs found
PER UN APPROCCIO DIDATTICO IN GEOGRAFIA: IL “PROGETTO IMPLICITO” DELLA CARTA
Se è vero che l’utilizzo delle carte è di fondamentale importanza per poter comunicare efficacemente
alcune delle conoscenze spaziali di un determinato fenomeno, occorre anche avere ben presente il
fatto che la carta geografica, intanto, non registra le forme del territorio in tutti i suoi dettagli, ma opera
delle selezioni; essa trasmette una concezione del mondo, ricostruisce quindi lo spazio che rappresenta
secondo uno schema culturale riconducendolo ai suoi tratti più significativi, veicola sempre nuove interpretazioni.
Dunque, la pluralità di significato di cui tutte le carte geografiche sono portatrici – da quello
immediato e superficiale, attinente alla localizzazione e descrizione morfologica degli elementi territoriali,
a quelli più profondi, esprimenti messaggi di natura culturale e politica – rende il loro impiego particolarmente
delicato in un contesto didattico. Grande infatti è la responsabilità dell’insegnante nel guidare
il processo di apprendimento spaziale, maneggiando consapevolmente il potenziale retorico e persuasivo
delle immagini cartografiche e al tempo stesso promuovendo l’acquisizione da parte degli allievi delle
capacità di lettura critica necessarie per un loro utilizzo consapevole. Ciò che si deve avere ben chiara
è, dunque, tale distinzione: la supposta oggettività della rappresentazione cartografica non deve essere
confusa con la sua efficacia rappresentativa. Caratteristica, quest’ultima, che senz’altro possiamo riconoscere
alla cartografia razionale, rilevando anzi che proprio da tale caratteristica deriva la sua straordinaria
utilità in ogni ambito disciplinare e non solo per ciò che attiene strettamente la geografia
THE MAPS IN THE ENHANCEMENT OF NATURAL AND CULTURAL ASSETS: THE CASE STUDY OF THE CITY WALLS OF VERONA
“La cartografia è l’insieme degli studi e delle operazioni scientifiche, artistiche e tecniche
che si svolgono a partire dai risultati delle osservazioni dirette o dalla utilizzazione di una
documentazione, al fine di elaborare ed allestire carte, piante e altri modi d’espressione,
nonché al fine del loro uso” (Associazione Internazionale di Cartografia, 1966). Si profila
così da questa definizione la possibilità di affidare quindi la salvaguardia del territorio,
oltre che ad interventi di natura vincolistica ai sensi della legislazione vigente in materia
di tutela storico-artistica e paesaggistica, anche e soprattutto ad un’oculata pianificazione
urbanistica, che mirasse alla conservazione non solo del “monumento”, ma anche del contesto
territoriale di appartenenza. Sulla base di queste premesse e con il fine di conoscere
e documentare gli elementi da tutelare, si rende quindi necessaria l’individuazione, la catalogazione
e la relativa rappresentazione cartografica di tutti i beni storici presenti in un
territorio: ne è un esempio significativo, la cinta muraria della città di Verona. Le mappe
della cinta muraria che si stanno valorizzando, realizzando e installando, hanno lo scopo
pratico di informare ma anche l’ambizione di “orientare” l'interesse di Verona verso il recupero
delle sue stesse mura. Tale saggio ha provato ad evidenziare proprio quel legame
che può e che dovrebbe esserci tra un territorio ed il proprio patrimonio e allo stesso tempo
ho cercato di mettere in risalto la centralità che assume la funzione della valorizzazione di
un bene culturale e naturale nell’ambito dello sviluppo locale.“The map is the set of studies and scientific operations, and artistic techniques that take
place from the results of direct observations or the use of documentation in order to
process and prepare maps, plans and other ways of expression, and the end of their use”
(International Cartographic Association, 1966). What then emerges from this definition
can then entrust the protection of the territory, well as interventions and constraints
under the existing legislation to protect the historic-artistic and landscape, and above all to ensure proper planning, that aimed conservation not only of the “monument”, but
also the context of territorial belonging. Based on these premises and in order to know
and document the elements to be protected, it is therefore necessary to identification,
cataloging and mapping of all its historical assets present in a territory: it is a significant
example, the city walls of Verona. The maps in the wall which are exploiting, producing
and installing, have the practical purpose to inform but also the ambition to “steer” the
interest of Verona to the recovery of his own walls. This paper has tried to highlight
that very bond that can and should exist between a territory and its own assets and at
the same time I tried to emphasize the centrality which assumes the function of the enhancement
of the cultural and natural context of local development
The Rationale and the Perils of Failing to Invoke State Responsibility for Cyber-Attacks: The Case of the EU Cyber Sanctions
Malicious cyber activities are on the rise. States and other relevant actors need to constantly adapt to the evolving cyber threat landscape, including by setting up effective deterrence mechanisms. This is what the European Union (EU) has done through the adoption of Common Foreign and Security Policy (CFSP) Decision 2019/797, which allows it to impose targeted sanctions to deter and respond to cyberattacks that constitute an external threat to the EU or its member states. However, in contrast to other horizontal regimes of restrictive measures in force within the EU, foreign governments are not included as potential targets of cyber sanctions. Moreover, the recital of the Decision specifies that the adoption of restrictive measures does not involve attribution of international responsibility for cyber-attacks to a third State. This article aims at identifying the rationale behind the inclusion of these distinctive features. It starts by considering the legal uncertainty that surrounds attribution of international responsibility for cyber operations. Next, it explains why the EU is not well placed to invoke third-State responsibility, and the reasons behind its reluctance to do so. It will then illustrate the risks inherent in the lack of a clear legal framework to attribute the responsibility of cyber-attacks to third countries. This may have serious consequences in terms of legal certainty when a cyber-attack amounts to a breach of the prohibition on the use of force in international relations. Then, we explore recent developments in EU legislation in the area of cyber security and the possibility to strenghten the powers of the European Union Agency for Cybersecurity (ENISA). We draw two conclusions: first, the Union might develop the capacity to attribute cyber attacks to specific actors and there is an interest to do so. However, Member States are probably still reticent to take this step. Two, despite the advantages of establishing a reliable attribution mechanisms, it is submitted that the majority of States prefers to take advantage of a regulative gap that allows them to react to cyber incidents as they see fit
On seed island generation and the non-linear self-consistent interaction of the tearing mode with electromagnetic gyro-kinetic turbulence
The multi-scale interaction of self-consistently driven magnetic islands with
electromagnetic turbulence is studied within the three dimensional, toroidal
gyro-kinetic framework. It can be seen that, even in the presence of
electromagnetic turbulence the linear structure of the mode is retained.
Turbulent fluctuations do not destroy the growing island early in its
development, which then maintains a coherent form as it grows.
The island is seeded by the electromagnetic turbulence fluctuations, which
provide an initial island structure through nonlinear interactions and which
grows at a rate significantly faster than the linear tearing growth rate. These
island structures saturate at a width that is approximately in size.
In the presence of turbulence the island then grows at the linear rate even
though the island is significantly wider than the resonant layer width, a
regime where the island is expected to grow at a significantly reduced
non-linear rate.
A large degree of stochastisation around the separatrix, and an almost
complete break down of the X-point is seen. This significantly reduces the
effective island width.Comment: Joint Varenna - Lausanne International Worksho
Photometric redshifts and selection of high redshift galaxies in the NTT and Hubble Deep Fields
We present and compare in this paper new photometric redshift catalogs of the
galaxies in three public fields: the NTT Deep Field, the HDF-N and the HDF-S.
Photometric redshifts have been obtained for thewhole sample, by adopting a
minimization technique on a spectral library drawn from the Bruzual
and Charlot synthesis models, with the addition of dust and intergalactic
absorption. The accuracy, determined from 125 galaxies with known spectroscopic
redshifts, is in the redshift intervals . The global redshift distribution of I-selected galaxies shows a
distinct peak at intermediate redshifts, z~0.6 at I_{AB}<26 and z~0.8 at
I_{AB}<27.5 followed by a tail extending to z~6. We also present for the first
time the redshift distribution of the total IR-selected sample to faint limits
( and ). It is found that the number density of galaxies
at 1.25<z<1.5 is ~ 0.1 /arcmin^22 at J<=21 and ~1./arcmin^2} at J<22, and drops
to 0.3/arcmin^2 (at J<22) at 1.5<z<2. The HDFs data sets are used to compare
the different results from color selection criteria and photometric redshifts
in detecting galaxies in the redshift range 3.5<z<4.5 Photometric redshifts
predict a number of high z candidates in both the HDF-N and HDF-S that is
nearly 2 times larger than color selection criteria, and it is shown that this
is primarily due to the inclusion of dusty models that were discarded in the
original color selection criteria by Madau et al 1998. In several cases, the
selection of these objects is made possible by the constraints from the IR
bands. Finally, it is shown that galactic M stars may mimic z>5 candidates in
the HDF filter set and that the 4 brightest candidates at in the HDF-S
are indeed most likely M stars. (ABRIDGED)Comment: Version accepted on July, 20, 2000. To appear on Astronomical
Journal, Nov 2000. The data and photometric redshift catalogs presented here
are available on line at http://www.mporzio.astro.it/HIGH
High redshift evolution of optically and IR-selected galaxies: a comparison with CDM scenarios
A combination of ground-based (NTT and VLT) and HST (HDF-N and HDF-S) public
imaging surveys have been used to collect a sample of 1712 I-selected and 319
galaxies. Photometric redshifts have been obtained for all these
galaxies. The results have been compared with the prediction of an analytic
rendition of the current CDM hierarchical models for galaxy formation. We focus
in particular on two observed quantities: the galaxy redshift distribution at
K<21 and the evolution of the UV luminosity density. The derived photometric
redshift distribution is in agreement with the hierarchical CDM prediction,
with a fraction of only 5% of galaxies detected at z>2. This result strongly
supports hierarchical scenarios where present-day massive galaxies are the
result of merging processes. The observed UV luminosity density in the
I-selected sample is confined within a factor of 4 over the whole range
0<z<4.5. CDM models in a critical Universe are not able to produce the density
of UV photons that is observed at z>3. CDM models in -dominated
universe are in better agreement at 3<z<4.5, but predict a pronounced peak at
z~1.5 and a drop by a factor of 8 from z=1.5 to z=4 that is not observed in the
data. We conclude that improvements are required in the treatment of the
physical processes directly related to the SFR, e.g. the starbust activity in
merger processes and/or different feedback to the star formation activity.Comment: Figures 2 and 3 modified to match the published versio
Progress in conceptual design of EU DEMO EC system
Since 2014 under the umbrella of EUROfusion Consortium the Work Package Heating and Current Drive (WPHCD) is performing the engineering design and R&D for the electron cyclotron (EC), ion cyclotron and neutral beam systems of the future fusion power plant DEMO. This presentation covers the activities performed in the last two years on the EC system conceptual design, as part of the WPHCD, focusing on launchers, transmission lines, system reliability and architecture
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