Analisi di un Algoritmo di Inversione per dati di Risonanza Magnetica Nucleare (NMR)

La stesura del presente elaborato si è occupata di analizzare la robustezza di un metodo di inversione per dati bidimensionali provenienti da Risonanza Magnetica Nucleare (NMR) chiamato I2DUPEN. L’algoritmo senza alcuna informazione a priori riguardante il rumore, indissolubilmente legato al segnale elettromagnetico, fornisce un’approssimazione della distribuzione dei valori dei tempi di rilassamento longitudinale e trasversale delle popolazioni di spin e l’insieme dei valori dei coefficienti di regolarizzazione del metodo di inversione per mezzo dell’utilizzo di metodi iterativi. Infatti, per costruzione, riuscire ad ottenere questi risultati significa risolvere un problema malposto che necessita di approcci specifici, come ad esempio l’aggiunta di un termine di regolarizzazione. L’algoritmo I2DUPEN utilizza alcuni parametri specifici (β0,βp,βc) per calcolare il termine di regolarizzazione, i cui valori determinano la sua capacità di ottenere affidabili distribuzioni NMR. La sua implementazione numerica richiede l’utilizzo di una serie di algoritmi iterativi. Tali algoritmi sono caratterizzati da parametri specifici, diversi da quelli richiesti dal calcolo della regolarizzazione; si tratta in particolare di tolleranze che controllano le iterazioni. L’obiettivo della presente tesi è stato quello di individuare un set di parametri per gli algoritmi numerici indipendente dai dati processati e dai valori dei parametri di I2DUPEN. Oltre a ricercare questo insieme di parametri, si è investigato sull’eventuale correlazione esistente tra i parametri esaminati e sulla loro distinzione in parametri che dipendono dalla natura del campione e parametri che invece non dipendono dalla sua natura. La sperimentazione numerica è stata realizzata utilizzando il software 2DUpenWin, che realizza l’algoritmo I2DUPEN. In questo modo è stato possibile fornire un insieme di parametri di default, utile per un eventuale sviluppo commerciale del software

The northern question : Italy\u27s participation in the European Economic Community and the Mezzogiorno\u27s underdevelopment.

This dissertation attempts to explain underdevelopment by analyzing the underdevelopment of the economic system of Southern Italy, the Mezzogiorno, in the context of Italy\u27s participation in the European Economic Community (EEC). Underdevelopment is not opposed to development; it is a type of development. Underdevelopment is opposed to, and organically united with, its other : positive, balanced development. The distribution of power among political actors determines the consequences of the integration of their economic systems. The strong benefit at the expense of the weak and determine preponderantly their destiny. With regard to the development of integrating economic systems, the systems of the strong experience generally positive, balanced development at the expense of the weak; the former cause the latter to underdevelop. The unification of Italy under the Kingdom of Sardinia transformed the organic development of capitalism in southern Italy, under way long before the country\u27s unification, into the Mezzogiorno\u27s underdevelopment. The Kingdom of Sardinia\u27s ruling class became Italy\u27s ruling class, identified its interests territorially with the economic system of northwestern Italy (most of which belonged to the Kingdom of Sardinia) and placed the Mezzogiorno in a subaltern position in the Italian economy. The United States, hegemonic over Western Europe, attempts to maintain the international balance of power in part by giving political and economic predominance in the EEC to West Germany and France, Western Europe\u27s two most important states in the strategic equilibrium between the United States and the Soviet Union. The predominance of West Germany and France in the EEC induces Italy\u27s current ruling class, heir to the Kingdom of Sardinia\u27s, to protect its traditional position of dominance and its interests by intensifying the Mezzogiorno\u27s underdevelopment to the advantage and benefit of the economic system of northwestern Italy

Robust Energy Management for Green and Survivable IP Networks

Despite the growing necessity to make Internet greener, it is worth pointing out that energy-aware strategies to minimize network energy consumption must not undermine the normal network operation. In particular, two very important issues that may limit the application of green networking techniques concern, respectively, network survivability, i.e. the network capability to react to device failures, and robustness to traffic variations. We propose novel modelling techniques to minimize the daily energy consumption of IP networks, while explicitly guaranteeing, in addition to typical QoS requirements, both network survivability and robustness to traffic variations. The impact of such limitations on final network consumption is exhaustively investigated. Daily traffic variations are modelled by dividing a single day into multiple time intervals (multi-period problem), and network consumption is reduced by putting to sleep idle line cards and chassis. To preserve network resiliency we consider two different protection schemes, i.e. dedicated and shared protection, according to which a backup path is assigned to each demand and a certain amount of spare capacity has to be available on each link. Robustness to traffic variations is provided by means of a specific modelling framework that allows to tune the conservatism degree of the solutions and to take into account load variations of different magnitude. Furthermore, we impose some inter-period constraints necessary to guarantee network stability and preserve the device lifetime. Both exact and heuristic methods are proposed. Experimentations carried out with realistic networks operated with flow-based routing protocols (i.e. MPLS) show that significant savings, up to 30%, can be achieved also when both survivability and robustness are fully guaranteed

Energy management in communication networks: a journey through modelling and optimization glasses

The widespread proliferation of Internet and wireless applications has produced a significant increase of ICT energy footprint. As a response, in the last five years, significant efforts have been undertaken to include energy-awareness into network management. Several green networking frameworks have been proposed by carefully managing the network routing and the power state of network devices. Even though approaches proposed differ based on network technologies and sleep modes of nodes and interfaces, they all aim at tailoring the active network resources to the varying traffic needs in order to minimize energy consumption. From a modeling point of view, this has several commonalities with classical network design and routing problems, even if with different objectives and in a dynamic context. With most researchers focused on addressing the complex and crucial technological aspects of green networking schemes, there has been so far little attention on understanding the modeling similarities and differences of proposed solutions. This paper fills the gap surveying the literature with optimization modeling glasses, following a tutorial approach that guides through the different components of the models with a unified symbolism. A detailed classification of the previous work based on the modeling issues included is also proposed

Aerodynamic Optimization Using Add-On Devices: Comparison between CFD and Wind Tunnel Experimental Test

JUNO is an urban concept vehicle (developed at the Politecnico of Torino), equipped by an ethanol combustion engine, designed to obtain low consumptions and reduced environmental impact. For these goals the main requirements that were considered during the designing process were mass reduction and aerodynamic optimization, at first on the shape of the car body and then, thanks to add-on devices. JUNO's aerodynamic development follows a defined workflow: geometry definition and modelling, CFD simulations and analysis, and finally geometry changes and CFD new verification. In this paper the results of the CFD simulations (using STARCCM#x0002B; and RANS k-?) with a corresponding 1/1 scale wind tunnel tests made using the real vehicle. Particularly, the results in term of: total drag coefficient (Cx), total lift coefficient (Cz), the total pressure in the side and rear analyzing twenty different aerodynamics configurations made up of different combination of some aerodynamics add-on devices. From the analysis of the results is emerged that CFD simulations using RANS k-? methods are able to predict the trend of total drag coefficient and its absolute value. Regarding the trend and the absolute value for lift coefficient, much larger deviation than Cx has been identified. For total pressure scene, there is a high similarity between the two ways of testing, especially on the side and on the central rear zone. The CFD results simulations, RANS k-? model is correct to develop and test symmetrical wide body. The obtained results are in good agreement with experimental wind tunnel results but, with particular attention to geometry, that suddenly change the way of air-flow

Design and Validation of a High-Level Controller for Automotive Active Systems

Active systems, from active safety to energy management, play a crucial role in the development of new road vehicles. However, the increasing number of controllers creates an important issue regarding complexity and system integration. This article proposes a high-level controller managing the individual active systems - namely, Torque Vectoring (TV), Active Aerodynamics, Active Suspension, and Active Safety (Anti-lock Braking System [ABS], Traction Control, and Electronic Stability Program [ESP]) - through a dynamic state variation. The high-level controller is implemented and validated in a simulation environment, with a series of tests, and evaluate the performance of the original design and the proposed high-level control. Then, a comparison of the Virtual Driver (VD) response and the Driver-in-the-Loop (DiL) behavior is performed to assess the limits between virtual simulation and real-driver response in a lap time condition. The main advantages of the proposed design methodology are its simplicity and overall cooperation of different active systems, where the proposed model was able to improve the vehicle behavior both in terms of safety and performance, giving more confidence to the driver when cornering and under braking. Some differences were discovered between the behavior of the VD and the DiL, especially regarding the sensitivity to external disturbances

Influence of Freeze-Thaw Aging on the Impact Performance of Damped Carbon Fiber Reinforced Plastics for Automotive Applications

The increasing use of composite materials in the automotive field requires more attention with regards to the appearance of noise, vibration and harshness (NVH) study in cars construction. However, in car door panels production, impact characteristics need to be evaluated in sandwich laminates. Furthermore, it is important to consider the effect of prolonged environmental aging on crashworthiness properties. The innovative content of the work is the hygrothermal effects evaluation on impact performance for two damped CFRP sandwich laminates. In this paper, two damping materials, Kraibon HHZ9578/99 and SUT9609/24, were used as core between two skins of CFRP for sandwich composite production. Freeze-Thaw aging treatment according to IEC 60068, specific for Automotive, was performed to investigate environmental effects on components. Up to 750 h, it was demonstrated that water absorption is regulated by Fick’s Law. The low-velocity impact behavior of the damped sandwiches has been studied according to ASTM D7136 throughout drop dart test equipment. Both main peak forces and energy absorption characteristics are negatively affected by aging condition. The introduction of damping core inside the composite structure of vehicle components can satisfy NVH constrictions. By contrast, at least same operating conditions must be assured in relation to not-damped components

Chemotherapy planning and multi-appointment scheduling: formulations, heuristics and bounds

The number of new cancer cases is expected to increase by about 50% in the next 20 years, and the need for chemotherapy treatments will increase accordingly. Chemotherapy treatments are usually performed in outpatient cancer centers where patients affected by different types of tumors are treated. The treatment delivery must be carefully planned to optimize the use of limited resources, such as drugs, medical and nursing staff, consultation and exam rooms, and chairs and beds for the drug infusion. Planning and scheduling chemotherapy treatments involve different problems at different decision levels. In this work, we focus on the patient chemotherapy multi-appointment planning and scheduling problem at an operational level, namely the problem of determining the day and starting time of the oncologist visit and drug infusion for a set of patients to be scheduled along a short-term planning horizon. We use a per-pathology paradigm, where the days of the week in which patients can be treated, depending on their pathology, are known. We consider different metrics and formulate the problem as a multi-objective optimization problem tackled by sequentially solving three problems in a lexicographic multi-objective fashion. The ultimate aim is to minimize the patient's discomfort. The problems turn out to be computationally challenging, thus we propose bounds and ad-hoc approaches, exploiting alternative problem formulations, decomposition, and $k$-opt search. The approaches are tested on real data from an Italian outpatient cancer center and outperform state-of-the-art solvers.Comment: 28 pages, 3 figure

Playing Three-Level Games in the Global Economy. Case Studies from the EU. College of Europe EU Diplomacy Paper 4/2008, May 2008

The case studies in this paper are a selection of essays that have been written in the framework of the compulsory first-semester course The EU in a Global Political Economy Context, taught by Professor Sieglinde Gstöhl, in the academic year 2007-2008 in the EU International Relations and Diplomacy Studies programme at the College of Europe. They all address recent cases of two- or three-level games played by the European Union in different policy fields of the global economy (reflecting the state of affairs at the end of 2007)