Piezoelectric vibration energy harvesting from airflow in HVAC (Heating Ventilation and Air Conditioning) systems

This study focuses on the design and wind tunnel testing of a high efficiency Energy Harvesting device, based on piezoelectric materials, with possible applications for the sustainability of smart buildings, structures and infrastructures. The development of the device was supported by ESA (the European Space Agency) under a program for the space technology transfer in the period 2014-2016. The EH device harvests the airflow inside Heating, Ventilation and Air Conditioning (HVAC) systems, using a piezoelectric component and an appropriate customizable aerodynamic appendix or fin that takes advantage of specific airflow phenomena (vortex shedding and galloping), and can be implemented for optimizing the energy consumption inside buildings. Focus is given on several relevant aspects of wind tunnel testing: different configurations for the piezoelectric bender (rectangular, cylindrical and T-shaped) are tested and compared, and the effective energy harvesting potential of a working prototype device is assessed

OpenTED Browser: Insights into European Public Spendings

We present the OpenTED browser, a Web application allowing to interactively browse public spending data related to public procurements in the European Union. The application relies on Open Data recently published by the European Commission and the Publications Office of the European Union, from which we imported a curated dataset of 4.2 million contract award notices spanning the period 2006-2015. The application is designed to easily filter notices and visualise relationships between public contracting authorities and private contractors. The simple design allows for example to quickly find information about who the biggest suppliers of local governments are, and the nature of the contracted goods and services. We believe the tool, which we make Open Source, is a valuable source of information for journalists, NGOs, analysts and citizens for getting information on public procurement data, from large scale trends to local municipal developments.Comment: ECML, PKDD, SoGood workshop 201

Feature selection in high-dimensional dataset using MapReduce

This paper describes a distributed MapReduce implementation of the minimum Redundancy Maximum Relevance algorithm, a popular feature selection method in bioinformatics and network inference problems. The proposed approach handles both tall/narrow and wide/short datasets. We further provide an open source implementation based on Hadoop/Spark, and illustrate its scalability on datasets involving millions of observations or features

Why demand uncertainty curbs investment: Evidence froma a panel of Italian manufacturing firms

From a theoretical point of view, uncertainty over the demand for a firmÂ’s product may not have clear effects on investments, because of the influence of a number of factors, such as the production technology and the amount of competition in the product market.Until now, a deeper investigation of the interplay of different factors in the temporal dimension has not been possible because the empirical research has been based on cross-section analysis. This omission makes biased estimates of the investment-uncertainty relationship likely.The aim of this paper is to extend the findings of the empirical literature by using a panel of Italian firms over the period 1996-2004, covering a complete business cycle. The availability of a panel of survey data on companiesÂ’ investment plans, expected future sales and demand uncertainty allows us to account for unobservable individual firm differences, macroeconomic shocks and the temporal evolution of the investment-uncertainty relationship. A key finding of our paper concerns the role of the competition faced by Italian firms in 1996-2004. The gradual loss of market power experienced by Italian manufacturing firms along with the increasing flexibility of labour input may have weakened the negative effect of uncertainty on investment decisions. We show that, in repeated cross-section estimates, the omission of firm-specific effects together with the dynamic interplay described above, would have lead to misleading conclusions about the relevance of demand uncertainty in explaining investment decisions.planned investments, demand uncertainty, survey data, panel estimation.

Dimensionamento e Analisi di un motore a riluttanza mediante un modello FEM

Questo elaborato si propone di dimensionare e analizzare un motore sincrono a riluttanza (SynRM - Synchronous Reluctance Machine) validando il modello con prove sperimentali sullo stesso. Il progetto è stato sviluppato partendo da un motore già in produzione, che è stato sezionato allo scopo di avere misure precise della geometria interna, sia di statore che di rotore; sono state poi effettuare scansioni della superficie e delle misure sull’intera macchina. Questi dati, opportunamente elaborati mediante un software di editing di immagini, sono stati importati in un software agli elementi finiti (FEM - Finite Element Method). Data la possibilità di avere una macchina fisica, si è proceduto a fare un confronto diretto fra le prove sperimentali e i risultati delle simulazioni, al fine di validare il modello creato via software, verificando che quest’ultimo risponda nel modo più simile possibile alla macchina reale. Con l’obiettivo di realizzare un software che sia utile alla progettazione di macchine sincrone a riluttanza è stato implementato un file Excel che si interfaccia al modello FEM mediante la scrittura di un codice in VBA (Visual Basic Applications) che sia in grado di dialogare con il software di simulazione. I vari fogli del file Excel, servono come interfaccia grafica per l'inserimento dei dati di ingresso, geometrie e dati di targa della macchina, ma anche come centro di controllo per le varie simulazioni. Lo scopo è quello di creare uno strumento versatile per la progettazione e l'analisi delle macchine a riluttanza. Inoltre, i risultati elaborati dal software, vengono direttamente importati in Excel sotto forma di tabelle e grafici; questo è stato ottenuto sfruttando sempre simulazioni statiche che hanno permesso di avere elaborazioni relativamente veloci, dell’ordine di pochi minuti. Viceversa, poiché le simulazioni dinamiche richiedono tempi molto lunghi è stato deciso di non renderle totalmente automatiche, dando la possibilità all’utente di lanciarle direttamente dal software. Per poter in qualche modo risolvere o quantomeno abbreviare i tempi di simulazione è stata implementata anche la possibilità di creare solo un quarto di macchina, cosa pensata in modo specifico proprio per le simulazioni dinamiche. This elaborate it is proposed to dimension and analyze a Synchronous Reluctance Machine (SynRM), proving the model with experimental tests. The project has been developed starting from an motor already in production, which has been sectioned in order to obtain precise measurements of the internal geometry (stator and rotor). After that, we have made scans of the machine’s surface and the measures of the equipment. This data, appropriately processed by an image editing software, have been impor- ted into a finite element software. Therefore, we proceed to make a direct comparison between the experimental tests of the simulation results on the physical machine, in order to validate the model created by software. We are then ensured that it responds as closely as possible to the real machine with the relative limits and approximations. The purpose of this elaborate is to create a versatile tool for the design and analy- sis of Reluctance machines. The designed software uses a file excel that interfaces to the FEM model through a VBA code that is capable of dialoguing with the software simulation. The various sheets of the file excel serve as a graphical interface for the insertion of the input data, geometries and data plate of the machine, but also as the control center for the various simulations. Moreover, the software processes the results directly imported into excel in the form of tables and graphs; this makes the simulations more statics and have allowed to ob- tain elaborations relatively fast, of the order of a few minutes. Since these dynamic simulations require a very long time, it was decided not to make them fully automated allowing to launch them directly from the software. In order to solve, or at least shorten, the simulation time, it was also implemented the ability to create only a quarter of a machine, specifically thought for dynamic simulations. Just as has been implemented, the software allows use of nearly all its functions also to a user who is not in possession of the full version, because the model is 2D and all simulations are static

Condición juvenil, religión y movilización política en el Norte de África

In this essay I try to show that the political and religious change happened in Egypt and in some Maghreb countries (Morocco, Tunisia) can be interpreted from a multiple modernities perspective. The central claim of this essay is that the political modernization in these countries doesn’t follow the secularization paradigm of the West relying on a separation of religion and state. In these North African countries the processes of political subjectivization show a strong connection to the transformation of religious identity and the development of arenas of religious discussion, both in pluralist that in fundamentalist point of view. I will show that the new condition of youth is an important factor in this change. Young people plays the main role/are key players in the re-Islamization of society, started in the 1980s. The strong connection between politics and religion emerged from the Arab Spring is not the result of a traditionalist and antimodern resistance but it’s due to a multiplicity of causes relying on the development of modern forms of life.En este artículo intento demostrar que el cambio político y religioso que se ha dado en Egipto y en algunos países del Magreb (Marruecos, Túnez) puede interpretarse bajo una perspectiva de modernidad múltiple. El tema central de este artículo es que la modernización política en estos países no sigue el paradigma de la secularización de Occidente basándose en la separación entre religión y Estado. En estos países del Norte de África, los procesos de subjetivización política muestran un enlace muy fuerte con la transformación de la identidad religiosa y el desarrollo de anfiteatros de discusión religiosa, tanto desde un punto de vista pluralista como fundamentalista. Voy a poner en evidencia que la nueva condición juvenil es un factor importante en este cambio. Los jóvenes juegan el papel principal y son los protagonistas de la reislamización de la sociedad, empezada en 1980. La relación muy fuerte entre política y religión aparecida gracias a la primavera árabe no es el resultado de una resistencia tradicionalista y antimoderna, sino que se debe a una multiplicidad de causas que dependen del desarrollo de formas de vida modernas