Wavelet Analysis and Denoising: New Tools for Economists

This paper surveys the techniques of wavelets analysis and the associated methods of denoising. The Discrete Wavelet Transform and its undecimated version, the Maximum Overlapping Discrete Wavelet Transform, are described. The methods of wavelets analysis can be used to show how the frequency content of the data varies with time. This allows us to pinpoint in time such events as major structural breaks. The sparse nature of the wavelets representation also facilitates the process of noise reduction by nonlinear wavelet shrinkage , which can be used to reveal the underlying trends in economic data. An application of these techniques to the UK real GDP (1873-2001) is described. The purpose of the analysis is to reveal the true structure of the data - including its local irregularities and abrupt changes - and the results are surprising.Wavelets, Denoising, Structural breaks, Trend estimation

Comparative Economic Cycles

The income cycles that have been experienced by six OECD countries over the past 24 years are analysed. The amplitude of the cycles relative to the level of aggregate income varies amongst the countries, as does the degree of the damping that affects the cycles. The study aims to reveal both of these characteristics. It also seeks to determine whether there exists a clear relationship between the degree of damping and the length of the cycles. In order to estimate the parameters of the cycles, the data have been subjected to the processes of detrending, anti-alias filtering and subsampling.Business cycles, Autoregressive models

Sustainable Development Policies in Europe

The objective of this paper is to investigate the actual situation in the shift towards the implementation of Sustainable Development Policies in Europe. The aim is to highlight the key role of the European Union in bringing about sustainable development within Europe and also on the wider global stage. It will show how the European Commission performs its commitment in reaching a sustainable regulation by issuing some documents and declarations. The paper frames the EU action into an international framework of strategies, agreements and policies on SD and, at the same time, provides an overview on experiences of SD strategy implementations at the national level, according to the commission pressing on MS to produce their own SD strategy and implement it. Indicators systems, issues of interest and fields of actions are compared: the analysis of these elements aims to highlight common scenarios of SD strategies that reveal the trends towards a more sustainable growth in the European Union.Sustainable Development, Globalization, Environment Policy, Strategy for Sustainable Development, Good Governance, Participation

Orthogonality Conditions for Non-Dyadic Wavelet Analysis

The conventional dyadic multiresolution analysis constructs a succession of frequency intervals in the form of ( π  / 2  j , π  / 2  j  - 1 ); j  = 1, 2, . . . ,  n of which the bandwidths are halved repeatedly in the descent from high frequencies to low frequencies. Whereas this scheme provides an excellent framework for encoding and transmitting signals with a high degree of data compression, it is less appropriate to the purposes of statistical data analysis.       A non-dyadic mixed-radix wavelet analysis is described that allows the wave bands to be defined more flexibly than in the case of a conventional dyadic analysis. The wavelets that form the basis vectors for the wave bands are derived from the Fourier transforms of a variety of functions that specify the frequency responses of the filters corresponding to the sequences of wavelet coefficients.Wavelets, Non-dyadic analysis, Fourier analysis

Testing for Contagion: a Time-Scale Decomposition

The aim of the paper is to test for ¯nancial contagion by estimating a simultaneous equation model subject to structural breaks. For this purpose, we use the Maximum Overlapping Discrete Wavelet Transform, MODWT, to decompose the covariance matrix of four asset returns on a scale by scale basis. This decomposition will enable us to identify the structural form model and to test for spillover e®ects between country speci¯c shocks during a crisis period. We distinguish between the case of the structural form model with a single dummy and the one with multiple dummies capturing shifts in the co-movement of asset returns occurring during periods of ¯nancial turmoil. The empirical results for four East Asian emerging stock markets show that, once we account for interdependence through an (unobservable) common factor, there is hardly any evidence of contagion during the 1997-1998 financial turbulence.wavelets; simultaneous equations model; financial contagion

Pasado y futuro en un presente convulso : dos revistas económicas catalanas ante la Gran Guerra

El presente artículo pretende analizar la lectura que hicieron dos importantes publicaciones económicas catalanas de los acontecimientos europeos entre 1914 y 1919. El intento es acercarse a la visión que sectores importantes de la clase dirigente del país -que, a la vez, producían y eran receptoras de dichas publicaciones- tuvieron del cambio de época representado por la Gran Guerra. Por ello, y más allá del debate general que recorrió también Catalunya en torno a las dos alianzas en lucha, el objeto principal será la capacidad de comprensión de los cambios sociales, económicos, políticos y culturales producidos por la confrontación militar más devastadora que el mundo conoció hasta aquel momento, tanto a nivel internacional como a nivel interno. Esta contribución focalizará especialmente la manera en que estas revistas recogieron y analizaron el debate sobre los tratados de paz y la reestructuración monetaria, considerando este último aspecto un indicador importante de la capacidad de análisis e interiorización de los cambios acaecidos en términos de relaciones de fuerza en el escenario internacional y más en general en las relaciones entre capital y trabajo.El present article pretén analitzar la lectura que van fer dues importants publicacions econòmiques catalanes dels esdeveniments europeus entre 1914 i 1919. L'intent és acostar-se a la visió que sectors importants de la classe dirigent del país -que, alhora, produïen i eren receptores d'aquestes publicacions- van tenir del canvi d'època representat per la Gran Guerra. Per això, i més enllà del debat general que va recórrer també Catalunya al voltant de les dues aliances en lluita, l'objecte principal serà la capacitat de comprensió dels canvis socials, econòmics, polítics i culturals produïts per la confrontació militar més devastadora que el món va conèixer fins a aquell moment, tant a nivell internacional com a nivell intern. Aquesta contribució se centrarà especialment en la manera com aquestes revistes van recollir i van analitzar el debat sobre els tractats de pau i la reestructuració monetària, tot considerant aquest últim aspecte com un indicador important de la capacitat d'anàlisi i interiorització dels canvis esdevinguts en termes de relacions de força en l'escenari internacional i més en general en les relacions entre capital i treball.This article aims to analyze how ​​two important catalan economic magazines read the events between 1914 and 1919. The core issue is to approach the vision that important sectors of the country's ruling class -both producing and receiving such publications- had about the epocale change represented by the Great War. Therefore, beyond the general debate around the two alliances fighting, the main focus will be catching the ability to understand social, economic, political and cultural change produced by the most devastating military conflict until then. This contribution will analize especially how these magazines collected and analyzed the debate about peace treaties and currency restructuring, considering this last element as an important indicator of the ability to analyze and internalize the changes in terms of power relations in international stage and more generally in the relations between capital and work

Pasado y futuro en un presente convulso: dos revistas económicas catalanas ante de la Gran Guerra

El present article pretén analitzar la lectura que van fer dues importants publicacions econòmiques catalanes dels esdeveniments europeus entre 1914 i 1919. L'intent és acostar-se a la visió que sectors importants de la classe dirigent del país –que, alhora, produïen i eren receptores d'aquestes publicacions– van tenir del canvi d'època representat per la Gran Guerra. Per això, i més enllà del debat general que va recórrer també Catalunya al voltant de les dues aliances en lluita, l'objecte principal serà la capacitat de comprensió dels canvis socials, econòmics, polítics i culturals produïts per la confrontació militar més devastadora que el món va conèixer fins a aquell moment, tant a nivell internacional com a nivell intern. Aquesta contribució se centrarà especialment en la manera com aquestes revistes van recollir i van analitzar el debat sobre els tractats de pau i la reestructuració monetària, tot considerant aquest últim aspecte com un indicador important de la capacitat d'anàlisi i interiorització dels canvis esdevinguts en termes de relacions de força en l'escenari internacional i més en general en les relacions entre capital i treball.This article aims to analyze how ​​two important catalan economic magazines read the events between 1914 and 1919. The core issue is to approach the vision that important sectors of the country's ruling class -both producing and receiving such publications- had about the epocale change represented by the Great War. Therefore, beyond the general debate around the two alliances fighting, the main focus will be catching the ability to understand social, economic, political and cultural change produced by the most devastating military conflict until then. This contribution will analize especially how these magazines collected and analyzed the debate about peace treaties and currency restructuring, considering this last element as an important indicator of the ability to analyze and internalize the changes in terms of power relations in international stage and more generally in the relations between capital and work.El presente artículo pretende analizar la lectura que hicieron dos importantes publicaciones económicas catalanas de los acontecimientos europeos entre 1914 y 1919. El intento es acercarse a la visión que sectores importantes de la clase dirigente del país –que, a la vez, producían y eran receptoras de dichas publicaciones– tuvieron del cambio de época representado por la Gran Guerra. Por ello, y más allá del debate general que recorrió también Catalunya en torno a las dos alianzas en lucha, el objeto principal será la capacidad de comprensión de los cambios sociales, económicos, políticos y culturales producidos por la confrontación militar más devastadora que el mundo conoció hasta aquel momento, tanto a nivel internacional como a nivel interno. Esta contribución focalizará especialmente la manera en que estas revistas recogieron y analizaron el debate sobre los tratados de paz y la reestructuración monetaria, considerando este último aspecto un indicador importante de la capacidad de análisis e interiorización de los cambios acaecidos en términos de relaciones de fuerza en el escenario internacional y más en general en las relaciones entre capital y trabajo

Virtual Element based formulations for computational materials micro-mechanics and homogenization

In this thesis, a computational framework for microstructural modelling of transverse behaviour of heterogeneous materials is presented. The context of this research is part of the broad and active field of Computational Micromechanics, which has emerged as an effective tool both to understand the influence of complex microstructure on the macro-mechanical response of engineering materials and to tailor-design innovative materials for specific applications through a proper modification of their microstructure. While the classical continuum approximation does not account for microstructural details within the material, computational micromechanics allows detailed modelling of a heterogeneous material's internal structural arrangement by treating each constituent as a continuum. Such an approach requires modelling a certain material microstructure by considering most of the microstructure's morphological features. The most common numerical technique used in computational micromechanics analysis is the Finite Element Method (FEM). Its use has been driven by the development of mesh generation programs, which lead to the quasi-automatic discretisation of the artificial microstructure domain and the possibility of implementing appropriate constitutive equations for the different phases and their interfaces. In FEM's applications to computational micromechanics, the phase arrangements are discretised using continuum elements. The mesh is created so that element boundaries and, wherever required, special interface elements are located at all interfaces between material's constituents. This approach can be effective in modelling many microstructures, and it is readily available in commercial codes. However, the need to accurately resolve the kinematic and stress fields related to complex material behaviours may lead to very large models that may need prohibitive processing time despite the increasing modern computers' performance. When rather complex microstructure's morphologies are considered, the quasi-automatic discretisation process stated before might fail to generate high-quality meshes. Time-consuming mesh regularisation techniques, both automatic and operator-driven, may be needed to obtain accurate numeric results. Indeed, the preparation of high-quality meshes is today one of the steps requiring more attention, and time, from the analyst. In this respect, the development of computational techniques to deal with complex and evolving geometries and meshes with accuracy, effectiveness, and robustness attracts relevant interest. The computational framework presented in this thesis is based on the Virtual Element Method (VEM), a recently developed numerical technique that has proven to provide robust numerical results even with highly-distorted mesh. These peculiar features have been exploited to analyse two-dimensional representations of heterogeneous materials' microstructures. Ad-hoc polygonal multi-domain meshing strategies have been developed and tested to exploit the discretisation freedom that VEM allows. To further simplify the preprocessing stage of the analysis and reduce the total computational cost, a novel hybrid formulation for analysing multi-domain problems has been developed by combining the Virtual Element Method with the well-known Boundary Element Method (BEM). The hybrid approach has been used to study both composite material's transverse behaviour in the presence of inclusions with complex geometries and damage and crack propagation in the matrix phase. Numerical results are presented that demonstrate the potential of the developed framework

Energy management and guidelines to digitalisation of integrated natural gas distribution systems equipped with expander technology

In a swirling dynamic interaction, digital innovation, environment and anthropological evolution are swiftly shaping the smart grid scenario. Integration and flexibility are the keywords in this emergent picture characterised by a low carbon footprint. Digitalisation, within the natural limits imposed by the thermodynamics, seems to offer excellent opportunities for these purposes. Of course, here starts a new challenge: how digital technologies should be employed to achieve these objectives? How would we ensure a digital retrofit does not lead to a carbon emission increase? In author opinion, as long as it remains a generalised question, none answer exists: the need to contextualise the issue emerges from the variety of the characteristics of the energy systems and from their interactions with external processes. To address these points, in the first part of this research, the author presented a collection of his research contributions to the topic related to the energy management in natural gas pressure reduction station equipped with turbo expander technology. Furthermore, starting from the state of the art and the author's previous research contributions, the guidelines for the digital retrofit for a specific kind of distributed energy system, were outlined. Finally, a possible configuration of the ideal ICT architecture is extracted. This aims to achieve a higher level of coordination involving, natural gas distribution and transportation, local energy production, thermal user integration and electric vehicles charging. Finally, the barriers and the risks of a digitalisation process are critically analysed outlining in this way future research needs

In vivo assessment of class-specific inducible inhibitors of metalloproteinases in osteoarthritis

The role of articular cartilage is providing a painless and attrition-free surface for joints movements. Osteoarthritis (OA) is a debilitating multifactorial pathology characterized by progressive articular cartilage loss, exposition of the bone surface accompanied by pain, and final loss of joint functions. To date there is not an effective alternative to surgical replacement of damaged joints. Metalloproteinases (MPs) play an important role in cartilage remodelling both in physiological and pathological conditions. Among the metalloproteinases, the aggrecanase family was shown to be the major family responsible for aggrecan breakdown, while matrix metalloproteinases (MMPs) target preferentially the collagen molecules. Tissue inhibitor of metalloproteinases (TIMPs) are the endogenous regulators of those enzymes and in particular TIMP-3 was found to possess the broadest activity. So far all synthetic MP inhibitors failed in trials for OA treatment, and TIMP-3 may prove to be a possible alternative. Notably several synthetic mutants were generated to restrict its activity towards metalloproteinases. In order to test the potential therapeutic effects of these proteins, I decided to employ transgenic overexpressing mice. However I appreciated that it is of paramount importance to restrict the exogenous expression just to cartilage. Moreover because it was previously observed that overexpression of TIMP-3 in cartilage severely affects bone development and caused embryonic lethality, I decided to generate tissue specific inducible transgenic mice. I focused on the Aggrecan promoter in order to achieve specific cartilage expression and the Cre/loxP system to obtain inducible expression. Here I show the design and generation of a new aggrecan-driven Cre deleter mouse line. These mice can effectively target floxed genes in cartilage. I also show the generation of inducible TIMP-expressing mouse lines for both a cartilage-specific and ubiquitous expression. I aim to induce OA in those transgenic mice, after induction of TIMPs expression, to evaluate the inhibitors role in OA treatment.Open Acces