2,997 research outputs found
An assessment of the impact of possible CAP reform scenarios on Romanian agriculture
Get PDFUsing a simplified model, with key-variable the prices of two different possible scenarios of CAP reform after 2013 (moderate and radical), this paper present a comparison between the price effects of implementation of each reform scenario at 2015 horizon on Romanian agriculture. This short analysis shows that, under the presented hypotheses, the net welfare effect, due to the price changes, for the selected products, is positive in both reform scenarios, yet greater in the case of the radical reform. Integrated in the large context of Romanian development, it seems that the influence of CAP reform upon agriculture and rural areas will be most likely a gradual one: an interpenetration between the two scenarios is foreseeable, starting with the moderate reform that will dominate the period around 2013, the reform measures acquiring a more radical character afterwards.CAP reform, Romania, welfare effects, Agricultural and Food Policy,
Rich, Sturmian, and trapezoidal words
Get PDFIn this paper we explore various interconnections between rich words, Sturmian words, and trapezoidal words. Rich words, first introduced by the second and third authors together with J. Justin and S. Widmer, constitute a new class of finite and infinite words characterized by having the maximal number of palindromic factors. Every finite Sturmian word is rich, but not conversely. Trapezoidal words were first introduced by the first author in studying the behavior of the subword complexity of finite Sturmian words. Unfortunately this property does not characterize finite Sturmian words. In this note we show that the only trapezoidal palindromes are Sturmian. More generally we show that Sturmian palindromes can be characterized either in terms of their subword complexity (the trapezoidal property) or in terms of their palindromic complexity. We also obtain a similar characterization of rich palindromes in terms of a relation between palindromic complexity and subword complexity
XBT, ARGO Float and Ship-Based CTD Profiles Intercompared under Strict Space-Time Conditions in the Mediterranean Sea: Assessment of Metrological Comparability
Get PDFAccurate measurement of temperature and salinity is a fundamental task with heavy
implications in all the possible applications of the currently available datasets, for example,
in the study of climate changes and modeling of ocean dynamics. In this work, the reliability
of measurements obtained by oceanographic devices (eXpendable BathyThermographs, Argo floats
and Conductivity-Temperature-Depth sensors) is analyzed by means of an intercomparison exercise.
As a first step, temperature profiles from XBT probes, deployed by commercial ships crossing the
Ligurian and Tyrrhenian seas during the Ship of Opportunity Program (SOOP), were matched
with profiles from Argo floats quasi-collocated in space and time. Attention was then paid to
temperature/salinity profiling Argo floats. Since Argo floats usually are not recovered and should last
up to five years without any re-calibration, their onboard sensors may suer some drift and/or oset.
In the literature, refined methods were developed to post-process Argo data, in order to correct the
response of their profiling CTD sensors, in particular adjusting the salinity drift. The core of this
delayed-mode quality control is the comparison of Argo data with reference climatology. At the
same time, the experimental comparison of Argo profiles with ship-based CTD profiles, matched
in space and time, is still of great importance. Therefore, an overall comparison of Argo floats
vs. shipboard CTDs was performed, in terms of temperature and salinity profiles in the whole
Mediterranean Sea, under space-time matching conditions as strict as possible. Performed analyses
provided interesting results. XBT profiles confirmed that below 100mdepth the accordance with Argo
data is reasonably good, with a small positive bias (close to 0.05 °C) and a standard deviation equal
to about 0.10 °C. Similarly, side-by-side comparisons vs. CTD profiles confirmed the good quality of
Argo measurements; the evidence of a drift in time was found, but at a level of about E-05 unit/day,
so being reasonably negligible on the Argo time-scale. XBT, Argo and CTD users are therefore
encouraged to take into account these results as a good indicator of the uncertainties associated with
such devices in the Mediterranean Sea, for the analyzed period, in all the climatological applications
Characterization Results for the Poset Based Representation of Topological Relations - I: Introduction and Models
No full text@article{DBLP:journals/informaticaSI/ForlizziN99,
author = {Luca Forlizzi and
Enrico Nardelli},
title = {Characterization Results for the Poset Based Representation
of Topological Relations - I: Introduction and Models.},
journal = {Informatica (Slovenia)},
volume = {23},
number = {2},
year = {1999},
bibsource = {DBLP, http://dblp.uni-trier.de}
Characterization Results for the Poset Based Representation of Topological Relations - II: Intersection and Union
No full text@article{DBLP:journals/informaticaSI/ForlizziN00,
author = {Luca Forlizzi and
Enrico Nardelli},
title = {Characterization Results for the Poset Based Representation
of Topological Relations - II: Intersection and Union.},
journal = {Informatica (Slovenia)},
volume = {24},
number = {1},
year = {2000},
bibsource = {DBLP, http://dblp.uni-trier.de}
System-on-chip Computing and Interconnection Architectures for Telecommunications and Signal Processing
No full textThis dissertation proposes novel architectures and design techniques targeting SoC building blocks for telecommunications and signal processing applications.
Hardware implementation of Low-Density Parity-Check decoders is approached at both the algorithmic and the architecture level. Low-Density Parity-Check codes are a promising coding scheme for future communication standards due to their outstanding error correction performance.
This work proposes a methodology for analyzing effects of finite precision arithmetic on error correction performance and hardware complexity. The methodology is throughout employed for co-designing the decoder. First, a low-complexity check node based on the P-output decoding principle is designed and characterized on a CMOS standard-cells library. Results demonstrate implementation loss below 0.2 dB down to BER of 10^{-8} and a saving in complexity up to 59% with respect to other works in recent literature. High-throughput and low-latency issues are addressed with modified single-phase decoding schedules. A new "memory-aware" schedule is proposed requiring down to 20% of memory with respect to the traditional two-phase flooding decoding. Additionally, throughput is doubled and logic complexity reduced of 12%. These advantages are traded-off with error correction performance, thus making the solution attractive only for long codes, as those adopted in the DVB-S2 standard. The "layered decoding" principle is extended to those codes not specifically conceived for this technique. Proposed architectures exhibit complexity savings in the order of 40% for both area and power consumption figures, while implementation loss is smaller than 0.05 dB.
Most modern communication standards employ Orthogonal Frequency Division Multiplexing as part of their physical layer. The core of OFDM is the Fast Fourier Transform and its inverse in charge of symbols (de)modulation. Requirements on throughput and energy efficiency call for FFT hardware implementation, while ubiquity of FFT suggests the design of parametric, re-configurable and re-usable IP hardware macrocells. In this context, this thesis describes an FFT/IFFT core compiler particularly suited for implementation of OFDM communication systems. The tool employs an accuracy-driven configuration engine which automatically profiles the internal arithmetic and generates a core with minimum operands bit-width and thus minimum circuit complexity. The engine performs a closed-loop optimization over three different internal arithmetic models (fixed-point, block floating-point and convergent block floating-point) using the numerical accuracy budget given by the user as a reference point. The flexibility and re-usability of the proposed macrocell are illustrated through several case studies which encompass all current state-of-the-art OFDM communications standards (WLAN, WMAN, xDSL, DVB-T/H, DAB and UWB). Implementations results are presented for two deep sub-micron standard-cells libraries (65 and 90 nm) and commercially available FPGA devices. Compared with other FFT core compilers, the proposed environment produces macrocells with lower circuit complexity and same system level performance (throughput, transform size and numerical accuracy).
The final part of this dissertation focuses on the Network-on-Chip design paradigm whose goal is building scalable communication infrastructures connecting hundreds of core. A low-complexity link architecture for mesochronous on-chip communication is discussed. The link enables skew constraint looseness in the clock tree synthesis, frequency speed-up, power consumption reduction and faster back-end turnarounds. The proposed architecture reaches a maximum clock frequency of 1 GHz on 65 nm low-leakage CMOS standard-cells library. In a complex test case with a full-blown NoC infrastructure, the link overhead is only 3% of chip area and 0.5% of leakage power consumption.
Finally, a new methodology, named metacoding, is proposed. Metacoding generates correct-by-construction technology independent RTL codebases for NoC building blocks. The RTL coding phase is abstracted and modeled with an Object Oriented framework, integrated within a commercial tool for IP packaging (Synopsys CoreTools suite). Compared with traditional coding styles based on pre-processor directives, metacoding produces 65% smaller codebases and reduces the configurations to verify up to three orders of magnitude
Satellite Altimetry and Seasonal Circulation in the Ligurian Sea
No full textSatellite altimetry observations are checked against in situ measurements to assess the capability of this remote sensing technique to describe the surface circulation in the Ligurian Sea. CTD profiles were collected during five oceanographic campaigns from 2017 and 2024 along the satellite track Jason 044, crossing the Ligurian Sea from the Corsica Channel to the coast close to Genoa. Eight months of ADCP surface currents from a fixed mooring were also used for the comparison with altimetric-derived geostrophic currents. Moreover, the possible contribution of ICESat-2 to oceanographic studies in the area is investigated. Altimetric measurements successfully reproduce the basic circulation features of the region and their seasonal variation and, despite the different nature of the used systems, can be well integrated with in situ observations. The results from the direct comparison with daily mean values of ADCP surface currents reported an RMSD of the same order as the standard deviation, which is consistent with similar investigations in other areas but evidences the need to define more appropriate metrics and methods
A General Formulation to Describe Empirical Rainfall Thresholds for Landslides
Get PDFAbstractIn this paper, a brief description of the Generalized FLaIR Model (GFM, De Luca and Versace, 2016) is provided, that is able to reproduce all the empirical thresholds proposed in literature, aimed to forecast landslides triggered by rainfall. In particular, this paper focuses on Antecedent Precipitation (AP) schemes. The paper demonstrates that these are particular solutions of the GFM and will exemplify this using AP schemes for NE Italy1, Seattle2 and Nicaragua - El Salvador3
The technological specialization of countries : an analysis of patent data
Get PDFNew methods of analysis of patent statistics allow assessing country profiles of technological specialization for the period 1990-2006. We witness a modest decrease in levels of specialization, which we show to be negatively influenced by country size and degree of internationalization of inventive activities
- …
