Biodiesel and vegetable oil market in European Union: some evidences from threshold cointegration analysis

In this paper we analyse the long-run relationships between vegetable oils prices and conventional diesel price in EU during the period 2005- 2007. We utilise recent developments on threshold cointegration approach to investigate if asymmetric dynamic adjusting processes exist among rapeseed oil, sunflower oil, soybean oil and diesel prices. The results suggest that the two-regime threshold cointegration model exist only in favour of rapeseed oil-diesel price pair. Therefore, this vegetable oil price adjusts rapidly to its long run equilibrium, determined by fossil diesel prices, in an asymmetric manner when the divergence between the two prices is above a critical threshold. Consequently, rapeseed oil seems to be particularly exposed to exogenous shocks deriving from global political scenarios, suggesting to redefine the high quota (80%) of EU biodiesel produced by this vegetable oil through a sustainable development of international trade.Vegetable oils market, Biodiesel price, Threshold cointegration., Marketing, Resource /Energy Economics and Policy,

Time-Invariant Spatially Coupled Low-Density Parity-Check Codes with Small Constraint Length

We consider a special family of SC-LDPC codes, that is, time-invariant LDPCC codes, which are known in the literature for a long time. Codes of this kind are usually designed by starting from QC block codes, and applying suitable unwrapping procedures. We show that, by directly designing the LDPCC code syndrome former matrix without the constraints of the underlying QC block code, it is possible to achieve smaller constraint lengths with respect to the best solutions available in the literature. We also find theoretical lower bounds on the syndrome former constraint length for codes with a specified minimum length of the local cycles in their Tanner graphs. For this purpose, we exploit a new approach based on a numerical representation of the syndrome former matrix, which generalizes over a technique we already used to study a special subclass of the codes here considered.Comment: 5 pages, 4 figures, to be presented at IEEE BlackSeaCom 201

Heterodyne radiometer instrument concept studies

This report presents an analysis of the atmospheric characteristics in the terahertz spectral region (frequencies from 300 GHz to 10 THz, wavelengths from 30 μm to 1 mm), with particular attention in the range 1 to 5 THz. This interval is the spectral range of interest in the framework of DIAST project. Historically the THz spectral interval has been characterized by a relative lack of convenient radiation sources, detectors and transmission technology. This document considers the designs of different spectroradiometers and the simulation of their instrumental responses. The simulations take into account the scenarios presented in the document: “REPORT - DIAST Project 1 - Typical atmospheric scenarios in the 0.6 - 5 THz wavelength range”, in which the atmospheres have been chosen to be representative of a realistic working scenario in different acquisition geometries, taking into account the typical gaseous components and pollutants of terrestrial atmosphere

Design and Analysis of Time-Invariant SC-LDPC Convolutional Codes With Small Constraint Length

In this paper, we deal with time-invariant spatially coupled low-density parity-check convolutional codes (SC-LDPC-CCs). Classic design approaches usually start from quasi-cyclic low-density parity-check (QC-LDPC) block codes and exploit suitable unwrapping procedures to obtain SC-LDPC-CCs. We show that the direct design of the SC-LDPC-CCs syndrome former matrix or, equivalently, the symbolic parity-check matrix, leads to codes with smaller syndrome former constraint lengths with respect to the best solutions available in the literature. We provide theoretical lower bounds on the syndrome former constraint length for the most relevant families of SC-LDPC-CCs, under constraints on the minimum length of cycles in their Tanner graphs. We also propose new code design techniques that approach or achieve such theoretical limits.Comment: 30 pages, 5 figures, accepted for publication in IEEE Transactions on Communication

Compact QC-LDPC Block and SC-LDPC Convolutional Codes for Low-Latency Communications

Low decoding latency and complexity are two important requirements of channel codes used in many applications, like machine-to-machine communications. In this paper, we show how these requirements can be fulfilled by using some special quasi-cyclic low-density parity-check block codes and spatially coupled low-density parity-check convolutional codes that we denote as compact. They are defined by parity-check matrices designed according to a recent approach based on sequentially multiplied columns. This method allows obtaining codes with girth up to 12. Many numerical examples of practical codes are provided.Comment: 5 pages, 1 figure, presented at IEEE PIMRC 201

Efficient Search of Compact QC-LDPC and SC-LDPC Convolutional Codes with Large Girth

We propose a low-complexity method to find quasi-cyclic low-density parity-check block codes with girth 10 or 12 and shorter length than those designed through classical approaches. The method is extended to time-invariant spatially coupled low-density parity-check convolutional codes, permitting to achieve small syndrome former constraint lengths. Several numerical examples are given to show its effectiveness.Comment: 4 pages, 3 figures, 1 table, accepted for publication in IEEE Communications Letter

Weak Lensing Peaks in Simulated Light-Cones: Investigating the Coupling between Dark Matter and Dark Energy

In this paper, we study the statistical properties of weak lensing peaks in light-cones generated from cosmological simulations. In order to assess the prospects of such observable as a cosmological probe, we consider simulations that include interacting Dark Energy (hereafter DE) models with coupling term between DE and Dark Matter. Cosmological models that produce a larger population of massive clusters have more numerous high signal-to-noise peaks; among models with comparable numbers of clusters those with more concentrated haloes produce more peaks. The most extreme model under investigation shows a difference in peak counts of about $20\%$ with respect to the reference $\mathrm{\Lambda}$CDM model. We find that peak statistics can be used to distinguish a coupling DE model from a reference one with the same power spectrum normalisation. The differences in the expansion history and the growth rate of structure formation are reflected in their halo counts, non-linear scale features and, through them, in the properties of the lensing peaks. For a source redshift distribution consistent with the expectations of future space-based wide field surveys, we find that typically seventy percent of the cluster population contributes to weak-lensing peaks with signal-to-noise ratios larger than two, and that the fraction of clusters in peaks approaches one-hundred percent for haloes with redshift z$\leq$0.5. Our analysis demonstrates that peak statistics are an important tool for disentangling DE models by accurately tracing the structure formation processes as a function of the cosmic time.Comment: accepted in MNRAS, figures improved and text update

Information Demand and Agriculture Commodity Prices

This paper investigates the effect of information flow on corn futures price variability for the period January 2004 -July 2011. The theoretical framework is the Mixture Distribution Hypothesis, that posits a joint dependence of return volatility and information. The main contribution of this article is that we use two different proxy for the observed component of information flow that allow to separate the effect of supply (News) and demand (Internet Search Volume) of information.Empirical estimates highlight that: i) results support the MDH since observed volatility persistence appears to be related to the information flow; ii) variation in information demand has a significant effect on volatility of futures corn returns even controlling for variation in information supply and such result can be interpreted in light of behavioural finance

Is Wine a Financial Parachute?

This paper analyzes the relationship between Global Wine Industry Share Price Indexes and composite stock market indexes using a Threshold Vector Error Correction Model (TVECM), aiming to investigate if investments in the wine sector play a role in determining financial risk and return to investors who include it in their portfolio. Whilst in most of the literature analyses the return of investments of fine wine, this paper places the focus to “normal” (i.e. non fine) wine, using data from the Mediobanca database covering companies in the wine industry listed on regulated stock market in France, US, Australia, Chile and China . The dataset cover the time period going from January 1, 2001, to the end of February 2009. The estimates of the TVECM lead to the following results: i) in more mature markets, like France and the US, the presence of a threshold in the relationship between wine index and composite index permit informed investors to make gainful investments; ii) in less mature markets, like Chile and China, there is evidence suggest that wine is not used as a financial parachute