Le strategie di internazionalizzazione delle imprese distrettuali: un'analisi comparata di tre diversi sistemi locali di produzione in Emilia Romagna

Since the Nineties, the process of globalization has caused a sharp increase in the real and financial integration of the worldwide economy, reducing the obstacles to international trade and minimizing the cost of transaction. The entrance of foreign firms in the domestic market has deeply modified the competitive situation of Italian enterprises, which have been forced to change their strategies in order to cope with those of the new competitors. In this scenario, internationalization is no longer one of the different strategic options available for the firm, but it becomes a forced choice to maintain or acquire a competitive advantage sustainable over time. Internationalization strategies of SMEs, however, are hindered by the shortage of financial resources and entrepreneurial skills, therefore this kind of firms tends toward light forms of foreign expansion, like export and subcontracting. Despite this, many studies have demonstrated that the district localisation increases the firms’ productivity and innovative capacity, so their competiveness both at a domestic and international level. The majority of these empirical contributions has focused mainly on the analysis of commercial flows, confirming that district enterprises reach a superior international performance compared to their external competitors. On the contrary, only few works have tried to evaluate the existence of a district effect on the firms’ ability to invest abroad, but the obtained results are not straightforward. One of the reason of these conclusions is that the phenomena has been analysed without taking into account the differences existing between districts in terms of enterprises’ dimension, diffusion of industrial groups and, above all, the sector of productive specialization, because the technological content of production could improve the innovativeness of district firms, allowing them to adopt advanced forms of internationalisation as foreign direct investments (FDI). The aim of the thesis is to further investigate the district effect on internationalisation, trough an econometric analysis of the international strategies carried out by firms localised in three different local system of production characterised by different technological specialization.

Three Essays in Spatial Economics

This work contributes to the field of spatial economics by embracing three distinct modelling approaches, belonging to different strands of the theoretical literature. In the first chapter I present a theoretical model in which the changes in urban system’s degree of functional specialisation are linked to (i) firms’ organisational choices and firms’ location decisions. The interplay between firms’ internal communication/managing costs (between headquarters and production plants) and the cost of communicating with distant business services providers leads the transition process from an “integrated” urban system where each city hosts every different functions to a “functionally specialised” urban system where each city is either a primary business center (hosting advanced business services providers, a secondary business center or a pure manufacturing city and all this city-types coexist in equilibrium.The second chapter investigates the impact of free trade on welfare in a two-country world modelled as an international Hotelling duopoly with quadratic transport costs and asymmetric countries, where a negative environmental externality is associated with the consumption of the good produced in the smaller country. Countries’ relative sizes as well as the intensity of negative environmental externality affect potential welfare gains of trade liberalisation. The third chapter focuses on the paradox, by which, contrary to theoretical predictions, empirical evidence shows that a decrease in international transport costs causes an increase in foreign direct investments (FDIs). Here we propose an explanation to this apparent puzzle by exploiting an approach which delivers a continuum of Bertrand- Nash equilibria ranging above marginal cost pricing. In our setting, two Bertrand firms, supplying a homogeneous good with a convex cost function, enter the market of a foreign country. We show that allowing for a softer price competition may indeed more than offset the standard effect generated by a decrease in trade costs, thereby restoring FDI incentives.

Fault detection, diagnosis and active fault tolerant control for a satellite attitude control system

Modern control systems are becoming more and more complex and control algorithms more and more sophisticated. Consequently, Fault Detection and Diagnosis (FDD) and Fault Tolerant Control (FTC) have gained central importance over the past decades, due to the increasing requirements of availability, cost efficiency, reliability and operating safety. This thesis deals with the FDD and FTC problems in a spacecraft Attitude Determination and Control System (ADCS). Firstly, the detailed nonlinear models of the spacecraft attitude dynamics and kinematics are described, along with the dynamic models of the actuators and main external disturbance sources. The considered ADCS is composed of an array of four redundant reaction wheels. A set of sensors provides satellite angular velocity, attitude and flywheel spin rate information. Then, general overviews of the Fault Detection and Isolation (FDI), Fault Estimation (FE) and Fault Tolerant Control (FTC) problems are presented, and the design and implementation of a novel diagnosis system is described. The system consists of a FDI module composed of properly organized model-based residual filters, exploiting the available input and output information for the detection and localization of an occurred fault. A proper fault mapping procedure and the nonlinear geometric approach are exploited to design residual filters explicitly decoupled from the external aerodynamic disturbance and sensitive to specific sets of faults. The subsequent use of suitable adaptive FE algorithms, based on the exploitation of radial basis function neural networks, allows to obtain accurate fault estimations. Finally, this estimation is actively exploited in a FTC scheme to achieve a suitable fault accommodation and guarantee the desired control performances. A standard sliding mode controller is implemented for attitude stabilization and control. Several simulation results are given to highlight the performances of the overall designed system in case of different types of faults affecting the ADCS actuators and sensors.