Nonparametric modeling of carbon prices

This paper constitutes the first exercise of nonparametric modeling applied to carbon markets. The framework of analysis is carefully detailed, and the empirical application unfolds in the case of BlueNext spot and ECX futures prices. The data is gathered in daily frequency from April 2005 to April 2010. First, we document the presence of strong nonlinearities in the conditional mean functions. Second, the conditional volatility functions reveal an asymmetric and heteroskedastic behavior which is dramatically different between carbon spot and futures logreturns. The results for spot prices are also robust to subsamples' decomposition. Third, we show in an out-of-sample forecasting exercise that nonparametric modeling allows reducing the prediction error by almost 15% compared to linear AR models. This latter result is confirmed by the Diebold–Mariano pairwise test statistic.     

Implementation of food safety management systems in the UK

This paper reports the first stage of work being undertaken to understand the factors that have impacted on the current state of food safety in the UK food manufacturing sector. The paper first explores developments in international food safety regulation in general and in particular, the UK. Using a survey and case study methodology, the paper examines the response of food manufacturing enterprises to food safety regulation, and uses statistical techniques to investigate the effects of enterprise size on the drivers for, benefits of, and challenges to compliance. Further, the factors that influence the successful implementation of an integrated food safety management system are also examined. The results show a great deal of both statutory and private regulation that has incentivised enterprises. In response, enterprises have implemented integrated food safety management systems to proactively deal with the risks associated with food safety, however, enterprises claim that statutory regulations are biased towards consumers, without adequate impact assessments on all stakeholders within the chain, and hence causing industry to incur significant costs that could otherwise be avoided. Even though compliance with food safety regulation is burdensome, the cost of non-compliance will also be significant to enterprises. The findings also show that there is no significant effect of size of enterprise on the drivers, benefits and challenges to compliance with food safety regulation.     

A Survey of Desynchronization in a Polychronous Model of Computation

The synchronous hypothesis arose in the late Eighties as a conceptual framework for the computer-aided design of embedded systems. Along with this framework, the issue of desynchronization was simultaneously raised as the major topic of mapping the ideal communication and computation model of synchrony on realistic and distributed computer architectures.The aim of the present article is to survey the development of this topics in the particular yet promising model of one of the prominent environments that were build along these principles: Signal and its polychronous (synchronous multi-clocked) model of computation, before to give some hints and ideas about ongoing research addressing this issue.     

Mutational analysis of a satellite phage activator

A culture medium, named olive juice broth, which resembles the natural environment of Lactobacillus plantarum in the traditional Spanish-style green olive fermentation was obtained from green olives. In this medium, the bacteriocin-producing L. plantarum LPCO10 strain was able to produce bacteriocin throughout the incubation time (15 days). Bacteriocin purification from olive juice broth was achieved by a protocol including ammonium sulphate precipitation of cell-free, L. plantarum LPCO10 culture supernatants, and cation-exchange, hydrophobic-interaction and reversed-phase chromatographies. In a series of mixed cultures in olive juice broth, L. plantarum LPCO10 was able to dominate the bacteriocin-sensitive L. plantarum 128/2 strain, whereas the non-bacteriocin-producing, LPCO10 strain derivative, L. plantarum 55-1 strain did not show such capability. These results indicated that olive juice broth may be a valuable experimental substitute for olive fermentation brine in gaining more knowledge about the role of the bacteriocin-producing L. plantarum strains in the control of the Spanish-style green olive fermentation.     

Sufficient LMI stability conditions for Lur’e type systems governed by a control law designed on their Euler approximate model

In this paper, the stability issue of Lur’e systems governed by a control law stabilising their forward Euler approximate model is investigated. More specifically, the considered control law is obtained by exploiting the advantages of a new Lur’e type Lyapunov function with disconnected level sets. This Lyapunov function is adapted to discrete-time Lur’e systems and to the structure of the forward Euler approximate model. The main result consists of linear matrix inequality conditions allowing to guarantee that the continuous-time Lur’e system associated with the proposed digital control law is globally asymptotically stable. The relevance of this approach is illustrated using a numerical example.