La questione percettiva in semiotica. Linee fondamentali e sviluppi della ricerca

This dissertation deals with the problems and the opportunities of a semiotic approach to perception. Is perception, seen as the ability to detect and articulate an coherent picture of the surrounding environment, describable in semiotic terms? Is it possibile, for a discipline wary of any attempt to reduce semiotic meaning to a psychological and naturalized issue, to come to terms with the cognitive, automatic and genetically hard-wired specifics of our perceptive systems? In order to deal with perceptive signs, is it necessary to modify basic assumptions in semiotics, or can we simply extend the range of our conceptual instruments and definitions? And what if perception is a wholly different semiotic machinery, to be considered as sui generis, but nonetheless interesting for a general theory of semiotics? By exposing the major ideas put forward by the main thinkers in the semiotic field, Mattia de Bernardis gives a comprehensive picture of the theoretical situation, adding to the classical dichotomy between structuralist and interpretative semiotics another distinction, that between homogeneist and etherogeneist theories of perception. Homogeneist semioticians see perception as one of many semiotic means of sign production, totally similar to the other ones, while heterogeneist semioticians consider perceptive meaning as essentially different from normal semiotic meaning, so much so that it requires new methods and ideas to be analyzed. The main example of etherogeneist approach to perception in semiotic literature, Umberto Eco’s “primary semiosis” is then presented, critically examined and eventually rejected and the homogeneist stance is affirmed as the most promising path towards a semiotic theory of perception.

Bayesian Analysis of Linear Inverse Problems with Applications in Economics and Finance

In my PhD thesis I propose a Bayesian nonparametric estimation method for structural econometric models where the functional parameter of interest describes the economic agent's behavior. The structural parameter is characterized as the solution of a functional equation, or by using more technical words, as the solution of an inverse problem that can be either ill-posed or well-posed. From a Bayesian point of view, the parameter of interest is a random function and the solution to the inference problem is the posterior distribution of this parameter. A regular version of the posterior distribution in functional spaces is characterized. However, the infinite dimension of the considered spaces causes a problem of non continuity of the solution and then a problem of inconsistency, from a frequentist point of view, of the posterior distribution (i.e. problem of ill-posedness). The contribution of this essay is to propose new methods to deal with this problem of ill-posedness. The first one consists in adopting a Tikhonov regularization scheme in the construction of the posterior distribution so that I end up with a new object that I call regularized posterior distribution and that I guess it is solution of the inverse problem. The second approach consists in specifying a prior distribution on the parameter of interest of the g-prior type. Then, I detect a class of models for which the prior distribution is able to correct for the ill-posedness also in infinite dimensional problems. I study asymptotic properties of these proposed solutions and I prove that, under some regularity condition satisfied by the true value of the parameter of interest, they are consistent in a "frequentist" sense. Once I have set the general theory, I apply my bayesian nonparametric methodology to different estimation problems. First, I apply this estimator to deconvolution and to hazard rate, density and regression estimation. Then, I consider the estimation of an Instrumental Regression that is useful in micro-econometrics when we have to deal with problems of endogeneity. Finally, I develop an application in finance: I get the bayesian estimator for the equilibrium asset pricing functional by using the Euler equation defined in the Lucas'(1978) tree-type models.

Toward a peripheral view of manufacturing networks

This doctoral thesis unfolds into a collection of three distinct articles that share an interest in supply firms, or “peripheral firms”. The three studies offer a novel theoretical perspective that I call the peripheral view of manufacturing networks. Building on the relational view literature, this new perspective identifies the supplier-based theoretical standpoint to analyze and explain the antecedents of relational rents in manufacturing networks. The first article, the namesake of the dissertation, is a theoretical contribution that explains the foundations of the “peripheral view of manufacturing networks”. The second article “Framing The Strategic Peripheries: A Novel Typology of Suppliers” is an empirical study with the aim to offer an interpretation of peripheries’ characteristics and dynamics. The third article, “What is Behind Absorptive Capacity? Dispelling the Opacity of R&D” presents an example of general theory development by using data from peripheral firms.

L'interpretazione del contratto internazionale

La ricerca ha ad oggetto l’analisi di clausole, contenute nei contratti del commercio internazionale, che sembrano finalizzate a fornire in anticipo una metodologia dell’interpretazione del contratto. L’elaborato pertanto analizza i profili di validità ed efficacia di singole e specifiche clausole, come le “clausole d’intero accordo”, le “clausole di non modificazione orale”, le clausole contenenti definizioni, e simili, alla luce delle regole giudiriche di derivazione eteronoma applicabili al contratto, siano esse rappresentate da una legge nazionale, da una convenzione internazionale di diritto materiale uniforme, o da fonti ulteriori c.d. di soft law, come i Principi Unidroit sui contratti del commercio internazionale. La ricerca ha pertanto rivelato che, diversamente da quanto possa apparire a prima vista, svariate tipologie di clausole analizzate non coinvolgono profili legati all'’nterpretazione del contratto, quanto piuttosto di documentazione e forma dello stesso. L’elaborato contiene infine alcune considerazioni di teoria generale del diritto.

Crisi economiche, sostenibilità ambientale e politiche pubbliche: il ruolo del legislatore e della pubblica amministrazione

Il presente lavoro analizza il ruolo ricoperto dal legislatore e dalla pubblica amministrazione rispettivamente nel delineare e attuare politiche pubbliche volte alla promozione di modelli di sviluppo economico caratterizzati da un elevato tasso di sostenibilità ambientale. A tal fine, il lavoro è suddiviso in quattro capitoli. Nel primo capitolo vengono presi in considerazione i principali elementi della teoria generale che costituiscono i piani di lettura del tema trattato. Questa prima fase della ricerca è incentrata, da un lato, sull’analisi (storico-evolutiva) del concetto di ambiente alla luce della prevalente elaborazione giuridica e, dall’altro, sulla formazione del concetto di sviluppo sostenibile, con particolare riguardo alla sua declinazione in chiave ambientale. Nella parte centrale del lavoro, costituita dal secondo e dal terzo capitolo, l’analisi è rivolta a tre settori d’indagine determinanti per l’inquadramento sistematico delle politiche pubbliche del settore: il sistema di rapporti che esiste tra i molteplici soggetti (internazionali, nazionali e locali) coinvolti nella ricerca di soluzioni alla crisi sistemica ambientale; l’individuazione e la definizione dell’insieme dei principi sostanziali che governano il sistema di tutela ambientale e che indirizzano le scelte di policy nel settore; i principali strumenti (giuridici ed economici) di protezione attualmente in vigore. Il quarto ed ultimo capitolo prende in considerazione le politiche relative alle procedure di autorizzazione alla costruzione e all’esercizio degli impianti per la produzione di energia alimentati da fonti energetiche rinnovabili, analizzate quale caso specifico che può essere assunto a paradigma del ruolo ricoperto dal legislatore e dalla pubblica amministrazione nel settore delle politiche di sviluppo sostenibile. L’analisi condotta mostra un elevato tasso di complessità del sistema istituzionale e organizzativo, a cui si aggiungono evidenti limiti di efficienza per quanto riguarda il regime amministrativo delle autorizzazioni introdotto dal legislatore nazionale.

Multidimensional item response theory models with general and specific latent traits for ordinal data

The aim of the thesis is to propose a Bayesian estimation through Markov chain Monte Carlo of multidimensional item response theory models for graded responses with complex structures and correlated traits. In particular, this work focuses on the multiunidimensional and the additive underlying latent structures, considering that the first one is widely used and represents a classical approach in multidimensional item response analysis, while the second one is able to reflect the complexity of real interactions between items and respondents. A simulation study is conducted to evaluate the parameter recovery for the proposed models under different conditions (sample size, test and subtest length, number of response categories, and correlation structure). The results show that the parameter recovery is particularly sensitive to the sample size, due to the model complexity and the high number of parameters to be estimated. For a sufficiently large sample size the parameters of the multiunidimensional and additive graded response models are well reproduced. The results are also affected by the trade-off between the number of items constituting the test and the number of item categories. An application of the proposed models on response data collected to investigate Romagna and San Marino residents' perceptions and attitudes towards the tourism industry is also presented.

Quantum Correlations in Field Theory and Integrable Systems

In this thesis we will investigate some properties of one-dimensional quantum systems. From a theoretical point of view quantum models in one dimension are particularly interesting because they are strongly interacting, since particles cannot avoid each other in their motion, and you we can never ignore collisions. Yet, integrable models often generate new and non-trivial solutions, which could not be found perturbatively. In this dissertation we shall focus on two important aspects of integrable one- dimensional models: Their entanglement properties at equilibrium and their dynamical correlators after a quantum quench. The first part of the thesis will be therefore devoted to the study of the entanglement entropy in one- dimensional integrable systems, with a special focus on the XYZ spin-1/2 chain, which, in addition to being integrable, is also an interacting model. We will derive its Renyi entropies in the thermodynamic limit and its behaviour in different phases and for different values of the mass-gap will be analysed. In the second part of the thesis we will instead study the dynamics of correlators after a quantum quench , which represent a powerful tool to measure how perturbations and signals propagate through a quantum chain. The emphasis will be on the Transverse Field Ising Chain and the O(3) non-linear sigma model, which will be both studied by means of a semi-classical approach. Moreover in the last chapter we will demonstrate a general result about the dynamics of correlation functions of local observables after a quantum quench in integrable systems. In particular we will show that if there are not long-range interactions in the final Hamiltonian, then the dynamics of the model (non equal- time correlations) is described by the same statistical ensemble that describes its statical properties (equal-time correlations).

Cáncer y tratamiento oncológico: Representaciones sociales de la población general, el paciente oncológico y miembros del equipo de salud

Se realizaron tres estudios cualitativos que tuvieron como propósito conocer las representaciones que ha construido la población general, los pacientes oncológicos y los profesionales de la salud, sobre el cáncer, la quimioterapia y el trasplante de médula ósea y realizar un análisis sobre las semejanzas y diferencias entre ellos. Se realizó en la ciudad de Bogotá (Colombia) con 55 personas: 20 pacientes con cáncer en proceso de trasplante de médula ósea, 20 personas no diagnosticadas con cáncer y 15 personas que trabajan en la atención de pacientes con cáncer. Se realizó una entrevista en profundidad con todos los participantes y asociaciones libres, clásicas y por sustitución sobre las palabras “cáncer”, “quimioterapia” y “trasplante de médula”. Los datos conseguidos se analizaron a la luz de la Teoría de las Representaciones Sociales (TRS). El análisis de la información siguió la técnica de análisis cualitativo de contenido para encontrar significados simbólicos y construir, denominar y definir categorías. Para los tres grupos el cáncer es una enfermedad terrible, que puede llevar a la muerte. El personal de salud y la población general creen que la enfermedad genera terror, angustia y miedo. Los pacientes tienen conciencia de la gravedad y del temor consecuente por una enfermedad que lo cambia todo, produce sufrimiento, dolor, obliga a depender de alguien y puede conducir a la muerte. El personal de salud considera que los pacientes lo pueden vivir como un castigo y la población general que puede ser la consecuencia de estilos de vida poco saludables. Para todos, la quimioterapia es un tratamiento para la enfermedad, que por un lado presenta efectos colaterales difíciles y visibles y que producen sentimientos negativos de temor y de angustia y al mismo tiempo constituye una opción y posibilidad de curación. El Trasplante de Médula Ósea representa para todos una oportunidad.

Max Abraham's and Tullio Levi-Civita's approach to Einstein Theory of Relativity

This work deals with the theory of Relativity and its diffusion in Italy in the first decades of the XX century. Not many scientists belonging to Italian universities were active in understanding Relativity, but two of them, Max Abraham and Tullio Levi-Civita left a deep mark. Max Abraham engaged a substantial debate against Einstein between 1912 and 1914 about electromagnetic and gravitation aspects of the theories. Levi-Civita played a fundamental role in giving Einstein the correct mathematical instruments for the General Relativity formulation since 1915. This work, which doesn't have the aim of a mere historical chronicle of the events, wants to highlight two particular perspectives: on one hand, the importance of Abraham-Einstein debate in order to clarify the basis of Special Relativity, to observe the rigorous logical structure resulting from a fragmentary reasoning sequence and to understand Einstein's thinking; on the other hand, the originality of Levi-Civita's approach, quite different from the Einstein's one, characterized by the introduction of a method typical of General Relativity even to Special Relativity and the attempt to hide the two Einstein Special Relativity postulates.

Essays on the Axiomatic Theory of Matching

This dissertation mimics the Turkish college admission procedure. It started with the purpose to reduce the inefficiencies in Turkish market. For this purpose, we propose a mechanism under a new market structure; as we prefer to call, semi-centralization. In chapter 1, we give a brief summary of Matching Theory. We present the first examples in Matching history with the most general papers and mechanisms. In chapter 2, we propose our mechanism. In real life application, that is in Turkish university placements, the mechanism reduces the inefficiencies of the current system. The success of the mechanism depends on the preference profile. It is easy to show that under complete information the mechanism implements the full set of stable matchings for a given profile. In chapter 3, we refine our basic mechanism. The modification on the mechanism has a crucial effect on the results. The new mechanism is, as we call, a middle mechanism. In one of the subdomain, this mechanism coincides with the original basic mechanism. But, in the other partition, it gives the same results with Gale and Shapley's algorithm. In chapter 4, we apply our basic mechanism to well known Roommate Problem. Since the roommate problem is in one-sided game patern, firstly we propose an auxiliary function to convert the game semi centralized two-sided game, because our basic mechanism is designed for this framework. We show that this process is succesful in finding a stable matching in the existence of stability. We also show that our mechanism easily and simply tells us if a profile lacks of stability by using purified orderings. Finally, we show a method to find all the stable matching in the existence of multi stability. The method is simply to run the mechanism for all of the top agents in the social preference.