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Design and characterisation of SPAD based CMOS analog pixels for photon-counting applications
No full textRecent advancements in biomedical research and imaging applications have ignited an intense interest in single-photon detection. Along with single-photon resolution, nanosecond or sub-nanosecond timing resolution and high sensitivity of the device must be achieved at the same time. Single- Photon Avalanche Diodes (SPADs) have proved their prospectives in terms of shot-noise limited operation, excellent timing resolution and wide spec- tral range. Nonetheless, the performance of recently presented SPAD based arrays has an issue of low detection efficiency by reason of the area on the substrate occupied by additional processing electronics.
This dissertation presents the design and experimental characteriza- tion of a few compact analog readout circuits for SPAD based arrays. Tar- geting the applications where the spatial resolution is the key requirement, the work is focused on the circuit compactness, that is, pixel fill factor re- finement. Consisting of only a few transistors, the proposed structures are remarkable for a small area occupation. This significant advancement has been achieved with the analog implementation of the additional circuitry instead of standard digital approach. Along with the compactness, the dis- tinguishing features of the circuits are low power consumption, low output non-linearity and pixel-to-pixel non-uniformity. In addition, experimental results on a time-gated operation have proved feasibility of a sub-nanosecond time window
Principles Matter: Humanitarian Assistance to Civilians under IHL
No full textThe provision of relief to civilians in armed conflict is a sensitive activity, subject to specific regulation in IHL treaties. Challenges emerged on the ground have questioned the comprehensive nature of this legal framework and generated debate on the concept of humanitarian assistance itself, the role of different kinds of actors (local/external, governmental/nongovernmental, armed/unarmed) in providing it, and the value and meaning of the principles traditionally associated to it—humanity, impartiality, neutrality, independence. This research, examining the evolution of State practice and opinio juris, provides a comprehensive analysis of the legal regime applicable to the provision of relief to civilians in armed conflict and the different categories of actors involved in it, identifying answers offered by international law (primarily IHL) to issues emerged in practice.
It is argued that humanitarian assistance is a well-defined and limited concept under IHL. Rules on this issue have been subject to progressive development, e.g. those on the protection of humanitarian workers in non-international armed conflict, but State practice has revealed that sovereignty remains important, and the principles of humanitarian assistance continue to embody the balance acceptable to States between military necessity and humanitarian considerations. No right to access or to provide humanitarian assistance without consent from the Parties concerned has developed, including no right to provide relief in non-international armed conflict in territory controlled by non-State armed groups without State consent. Participation in the provision of humanitarian assistance by local and external actors is not prohibited, but the level of protection they enjoy depends on their position under IHL. Different regimes are applicable to distinct armed actors (belligerents/peacekeepers/external armed forces/private security companies) but in all cases respect for the principle of distinction is central. In general, special protection for relief actions and actors remains connected to respect for the principles of humanitarian assistance. This has been confirmed by belligerents’ reactions to the increased engagement of humanitarian organisations in protection, as the second essential component of humanitarian action: belligerents have claimed their entitlement to require respect by humanitarian personnel also for the most contested principle—neutrality, meaning non-interference in hostilities and even abstention from involvement in politics
Le vie dello spiritualismo: Carlini, Guzzo e Sciacca interpreti di Rosmini
No full textLa tesi intende mostrare il collegamento tra il pensiero di Rosmini e quello degli spiritualisti della seconda fase, Carlini, Guzzo e Sciacca, attraverso l'analisi di alcuni temi specifici come: il sentimento fondamentale corporeo, la libertà, la teoria della conoscenza e i rapporti con la scolastica
The lex certa principle. From the Italian Constitution to the European Convention on Human Rights
Get PDFThe dissertation deals with the need for a precise definition in law of criminal offences (lex certa), and it analyses the current state of this need in the Italian legal system, in the light of the influences deriving from the case law of the European Court of Human Rights
USUS PUBLICUS: tutela interdittale e classificazione delle cose
No full textLa presente indagine rappresenta il tentativo di mettere a fuoco la nozione di usus publicus emergente dalla lettura delle fonti romane in tema di tutela interdittale di taluni beni pubblici chiamati perciò nelle fonti,perlomeno a partire dall'età augustea, res in usu publico
Decision making for bridge stock management
No full textBridges in service in most Western Countries were built according to codes with design loads that are now inconsistent with today’s traffic demands. Currently, transportation agencies do not know how to respond to transit applications on their bridges. This thesis focuses on the legal issues entailed by overweight/oversize load permits issued by transportation agencies. Indeed, correct decision-making should consider the legal liabilities involved in possible catastrophic events. In this thesis I illustrate how this problem is guided by the Department of Transportation of the Italian Autonomous Province of Trento (APT’s DoT), a medium-sized agency managing approximately one thousand bridges across its territory. In the basic approach, it does not authorize movement of overweight loads unless it is demonstrated that their effect is less than that of the nominal design load. When this condition is not satisfied, a formal evaluation is carried out in an attempt to assess a higher load rating for the bridge. If, after the reassessment, the rating is still insufficient, the bridge is classified as sub-standard and a formal evaluation of the operational risk is performed to define a priority ranking for future reinforcement or replacement
Numerical methods for advection-diffusion-reaction equations and medical applications
No full textThe purpose of this thesis is twofold, firstly, the study of a relaxation procedure for numerically solving advection-diffusion-reaction equations, and secondly, a medical application. Concerning the first topic, we extend the applicability of the Cattaneo relaxation approach to reformulate time-dependent advection-diffusion-reaction equations, that may include stiff reactive terms, as hyperbolic balance laws with stiff source terms. The resulting systems of hyperbolic balance laws are solved by extending the applicability of existing high-order ADER schemes, including well-balanced and non-conservative schemes. Moreover, we also present a new locally implicit version of the ADER method to solve general hyperbolic balance laws with stiff source terms. The relaxation procedure depends on the choice of a relaxation parameter . Here we propose a criterion for selecting in an optimal manner, relating the order of accuracy of the numerical scheme used, the mesh size and the chosen . This results in considerably more efficient schemes than some methods with the parabolic restriction reported in the current literature. The resulting present methodology is validated by applying it to a blood flow model for a network of viscoelastic vessels, for which experimental and numerical results are available. Convergence-rates assessment for some selected second-order model equations, is carried out, which also validates the applicability of the criterion to choose the relaxation parameter. The second topic of this thesis concerns the numerical study of the haemodynamics impact of stenoses in the internal jugular veins. This is motivated by the recent discovery of a range of extra cranial venous anomalies, termed Chronic CerbroSpinal Venous Insufficiency (CCSVI) syndrome, and its potential link to neurodegenerative diseases, such as Multiple Sclerosis. The study considers patient specific anatomical configurations obtained from MRI data. Computational results are compared with measured data
Numerical Methods for Optimal Control Problems with Application to Autonomous Vehicles
No full textIn the present PhD thesis an optimal problem suite is proposed as benchmark for the test of numerical solvers. The problems are divided in four categories, classic, singular, constrained and hard problems. Apart from the hard problems, where it is not possible to give the analytical solution but only some details, all other problems are supplied with the derivation of the solution. The exact solution allows a precise comparison of the performance of the considered software. All of the proposed problems were taken from published papers or books, but it turned out that an analytic exact solution was only rarely provided, thus a true and reliable comparison among numerical solvers could not be done before. A typical wrong conclusion when a solver obtains a lower value of the target functional with respect to other solvers is to claim it better than the others, but it is not recognized that it has only underestimated the true value.
In this thesis, a cutting edge application of optimal control to vehicles is showed: the optimization of the lap time in a race circuit track considering a number of realistic constraints. A new algorithm for path planning is completely described for the construction of a quasi G2 fitting of the GPS data with a clothoid spline in terms of the G1 Hermite interpolation problem. In particular the present algorithm is proved to work better than state of the art algorithms in terms of both efficiency and precision
The role of Sustainability in Development Analysis: a case study of Laos
No full textThe main purpose of this thesis is to identify the role of sustainable development in Laos, based on the integration of three factors, economic growth, social development, and the environmental dimension. Annual time series data are used for the period 1980-2010. In order to generate the most appropriate regression, relevant theoretical and empirical studies are reviewed. This thesis contributes to the on-going research issue about key determinants influencing sustainable development in developing countries. Firstly, this study uses the first different of logarithm form to identify the determinants of economic growth, the impacts of growth on poverty and environmental conditions in Laos. However, using the multiple regressions, serious problems of multicollinearity were encountered and those results became less reliable. Principal components analysis (PCA) is a technique to handle the problem of multicollinearity and produce stable and meaningful estimates for regression coefficients.
This thesis concludes that there are several variables, both internal and external factors, which have influenced the current economic growth of Laos. Particularly the internal factors (domestic investment, government expenditure, and industry) show their strong correlation with economic growth, while the external factor (participation in ASEAN) also plays an important role in economic growth. On the other hand, the other external factors (FDI, AID and OPEN) show a weaker link to domestic growth of Laos. In the long run, to ensure the effectiveness of external factors on domestic growth, this research suggests exploiting more effectively the opportunities provided by foreign direct investment, through the openness of the system to globalization and international trade, together with better management of aid allocation. The impacts of economic growth on poverty and environmental conditions are then considered, questioning whether economic growth leads to the reduction of poverty and whether it produces a pressure on environmental conditions. This study found that those determinants not only have been dominant in economic growth, but they do indeed correlate with a reduction in the level of poverty. On the other hand, the increase in economic activities leads to increased environmental damage. This research supports continuing the adjustment of domestic activity investment, government expenditure, improving trade openness system, foreign direct investment, aid allocation, ASEAN, and so on. These factors can help the country to grow and poverty to diminish but we have also to pay attention to their impacts on the environment. Sustainable development would achieve its goal only if these internal and external factors contribute to economic growth, where this growth is distributed across the entire population, together with environmental protection conditions.
In order to attain the goal of sustainable development, strong environmental and natural resource protection policies are suggested. To maintain a high rate of economic growth, this study suggests considering the natural resources and the areas with the greatest potential to be utilized for growth; such as tourism sustainability, human resource improvement and trade policy improvement. To improve social development, reduce the development gap and eradicate extreme poverty, it is suggested that community participation development, gender promotion, and investment in social services be increased especially in rural areas
Equivalent Linearization Analysis Method for Base-isolated Buildings
No full textBase isolation system, as one of the most popular means to mitigate the seismic risks, often exhibits strong nonlinearity. To simplify the procedure of structural design, bilinear force-deformation behavior is recommended for isolation systems in
most modern structural codes. Although base isolation system can be analyzed through nonlinear time history method, solving of a system with a large number of degrees of freedom may require an exorbitant amount of time. As a substitute, the equivalent linearization method is frequently used. Apparently, under given earthquake ground motions, the accuracy of equivalent linearization analysis method is significantly related to the estimation of equivalent linear properties. How to improve the estimation accuracy of this approximate method constitutes a subject of wide and deep interest among researchers around the world.
In this research, the equivalent linearization analysis method for base-isolated
buildings was investigated. The literature survey on related aspects of base-isolated
buildings was carried out firstly. Then, the estimation accuracy of fifteen equivalent linearization methods selected from the literatures was evaluated when subjected to
twelve earthquake ground motions. After that, from simplicity to complexity, the
base-isolated buildings were modeled using single-degree-of-freedom (SDOF) systems and multi-degree-of-freedom (MDOF) systems, respectively. For both
considered systems, more comprehensive parametric analyses were performed
with varying the parameters selected from the isolation system and the superstructure. Accordingly, improved equivalent linearization methods were
derived for SDOF and MDOF systems to improve the prediction accuracy of the
maximum displacement of isolation systems.
Based on the proposed equivalent linearization methods, different analysis methods for base-isolated buildings were assessed, including equivalent static linear analysis, response spectral analysis, linear and nonlinear time history analyses. It was found
that with the proposed equivalent linearization methods equivalent linear analyses could yield more accurate results when compared with the equivalent linearization method recommended by structural codes. As a result, the proposed equivalent linearization
method could be potentially useful for the design and analysis of baseisolated buildings, as least in the preliminary stage of structural design