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Sperimentazione di sistemi di structure from motion per la restituzione di apparati decorativi
No full textLa presente ricerca si colloca nell’ambito del rilievo indiretto e strumentale dell’architettura. In particolare la ricerca si focalizza sullo studio, attraverso una serie di sperimentazioni, di sistemi denominati di structure from motion che consentono di ricavare “automaticamente” dati tridimensionali e cromatici da un insieme di fotografie rappresentanti l’oggetto d’interesse
Logiche e dinamiche operative per la gestione delle trasformazioni urbane: il caso dei Large Scale Urban Development Projects
No full textThis research aims at investigate a topic probably not well examined by national and international literature, which is the one of the evolutions in operational rationales and patterns followed in contemporary urban planning. The hypothesis here discussed is that the transition from the so-called “modern” to the so-called “contemporary” city has engendered a number of issues, including a need for adjustment of a planning practice that is both not completed yet and can’t be longer avoided. In order to carry out such a survey two different case studies will be analyzed, the large scale urban development project of Paris Rive Gauche, in Paris, and King’s Cross Central, in London.
From the late ‘70s a number of factors, among which the research pinpoints the disappearance of manufacturing industry from large urban contexts, caused a deep physical and socio-economic restructuring process in many European cities. As a consequence, also the urban planning models followed during the previous decades faced a corresponding restructuring process. In particular, what fell in crisis was the traditional plan-led rationale that for at least three decades characterized urban planning in many European countries. Indeed this rationale was considered by many scholars and practitioners no longer suitable to respond to the increased complexity characterizing contemporary urban contexts.
During all the ‘80s a massive practice of deregulation has been proposed as the answer able to face such an issue. From the traditional plan-led model previously followed to implement urban strategies, the switch to the simplistic deregulation of real estate industry based on a property-led rationale knew a wide spread.
Despite such an ambition, even also this alternative led in turn to many critics, mainly related to the ability of such models to achieve social and sustainable goals. Therefore, in the late ‘90s and even more at the beginning of the new Century different operational rationales and patterns began to be established, in order to face both the initial and unsolved restructuring process and its first attempted reaction. The aim of this research is to better understand the progressive affirmation of this kind of operational patterns and to critical review them. In order to better conduct such a survey, the methodology is based on the analysis of two significant case studies, and more specifically a certain type of urban transformation known in the international literature with the diction of “large scale urban development projects”.
This research consists of four sections. In the first one will be described the background of the research, and then how this will be developed. By literature review will be discussed what caused the fall of a city that many other authors called “modern”, and the corresponding rise of a “contemporary” city, which will be analyzed. Then the research will focus on the discipline which has the city as its subject, that is urban planning. Therefore, it will be discussed how, in the different stages of urban evolution, urban planning met a corresponding evolution process, in order to understand different models followed by the discipline, but mainly to understand its ability to evolve in order to face always new issues. At the end of this first section, it will be discussed the framework of the whole research, in regards to what kind of methodology has been chosen, here based on case study research, and on how these case studies have been selected.
In the second section will be discussed the theoretical context of the research, by the review of national and international literature on the topic of operational rationales and patterns in urban planning. This survey will start from the analysis of different patterns in public decision-making, focusing on the process that brought form the rational model to the affirmation of the incremental model. Then it will be discussed how decision-making patterns in public and administrative context reflect in the urban planning discipline, and how this affects the operational patterns used to implement these different models.
As a second topic analysed in this section, it will be discussed the phenomenon of large scale urban development projects. Last two decades knew a wide spread of these kind of projects, whose success is commonly due to their ability in achieving a set of different purposes ranging from the redevelopment of large neglect urban areas to the improvement of competitiveness in metropolitan contexts. Moreover, these large projects permit to sum up some interesting trends in contemporary planning practice, because they are the result of important evolutions in the operational patterns followed their design and implementation.
The third section will deal with the analysis of the two case studies of Paris Rive Gauche and King’s Cross Central. Both these case studies are well known by national and international literature, but here it will be given an original interpretation which aims, for the French one, to retrace the events that brought to the affirmation of the patterns we are discussing about, and for the English one to carry out an in-depth review of the state of the art in implementation of large projects and in the interaction between the actors involved in this implementation.
The fourth section includes the conclusions of the research, where the literature review conducted in the second section will be compared with the report of the two cases, in order to answer to the research questions formulated during in the first section of the work. The topic of large urban development projects has been already discussed, especially in regard to the relationship between these and the affirmation of a new-liberalism in urban planning. However, not as many studies are specifically focused on the description of operational rationales and patterns in large scale projects, that on the contrary constitute probably the most original contribution of such projects. The spread of large projects could bring back up to the crisis of comprehensive plan, and to its inability in managing evolutions in contemporary cities. For these reasons, a broaden knowledge in evolutions of operational patterns can be useful in achieving a more effective planning practices
OPERATIONS RESEARCH: FROM COMPUTATIONAL BIOLOGY TO SENSOR NETWORK
No full textIn this dissertation we discuss the deployment of combinatorial optimization methods for modeling and solve real life problemS, with a particular emphasis to two biological problems arising from a common scenario: the reconstruction of the three-dimensional shape of a biological molecule from Nuclear Magnetic Resonance (NMR) data.
The fi rst topic is the 3D assignment pathway problem (APP) for a RNA molecule.
We prove that APP is NP-hard, and show a formulation of it based on edge-colored
graphs. Taking into account that interactions between consecutive nuclei in the NMR
spectrum are diff erent according to the type of residue along the RNA chain, each color
in the graph represents a type of interaction. Thus, we can represent the sequence of interactions as the problem of fi nding a longest (hamiltonian) path whose edges follow a given order of colors (i.e., the orderly colored longest path). We introduce three alternative IP formulations of APP obtained with a max flow problem on a directed graph with packing constraints over the partitions, which have been compared among themselves. Since the last two models work on cyclic graphs, for them we proposed an algorithm based on the solution of their relaxation combined with the separation of cycle inequalities in a Branch & Cut scheme.
The second topic is the discretizable distance geometry problem (DDGP), which is
a formulation on discrete search space of the well-known distance geometry problem
(DGP). The DGP consists in seeking the embedding in the space of a undirected graph, given a set of Euclidean distances between certain pairs of vertices. DGP has two important applications: (i) fi nding the three dimensional conformation of a molecule from a subset of interatomic distances, called Molecular Distance Geometry Problem, and (ii) the Sensor Network Localization Problem. We describe a Branch & Prune (BP) algorithm
tailored for this problem, and two versions of it solving the DDGP both in protein
modeling and in sensor networks localization frameworks. BP is an exact and exhaustive
combinatorial algorithm that examines all the valid embeddings of a given weighted
graph G=(V,E,d), under the hypothesis of existence of a given order on V. By
comparing the two version of BP to well-known algorithms we are able to prove the
e fficiency of BP in both contexts, provided that the order imposed on V is maintained.Institute of Systems Analysis and
Computer Science "A. Ruberti" of the Italian National Research Council (IASI-CNR
SEPARAZIONE PATRIMONIALE ENDOSOGGETTIVA E ATTIVITA' D'IMPRESA: UN'ANALISI COMPARATISTICA
No full textThe present study intends to investigate the issue of asset protection in the conduct of business activities, especially the internal credit structuring of a subject through the establishment of an endo-subjective segregation of assets, disconnected from the attribution of legal personality, creating a further limitation of liability of the entrepreneur that goes beyond the usual shareholders limited liability.
The reason for the growth of the asset segregation technique, both in civil law and common law systems, is linked to the economical need of isolating pools of assets committed to specific purposes and protecting them from claims of creditors other than the functional creditors of the purpose, reducing the establishment and management costs related to the creation of a new corporate structure and, in a perspective of corporate finance - according to the results of the law and economics studies - the financing cost.
As pointed out by Hansmann and Kraakman the assets partitioning, in the two different profiles of Affirmative and Defensive asset partitioning, represents an essential feature of organizational forms provided for the exercise of a business activity. But the phenomenon of asset partitioning is placed in a complex theoretical system, representing a transversal issue that affects not only the area of company law, but also fundamental concepts of private law as the debtor’s personal liability and the concept of legal person.
For this reason, the starting point of the this analysis (Chapter One) is the study of the theoretical foundations of common and civil law systems related to essential concepts such as the notion and the different theories about patrimony, the debtor’s personal liability, and the concept of legal person and legal entity (in connection with the so-called autonomia patrimoniale perfetta), highlighting similarities or differences and exploring their development until today.
After the analysis of these essential concepts, the study focuses (Chapter Two) on the use of asset partitioning in company law and, in particular, on the birth and the evolution of organizational forms arranged for the conduction of business activities in both systems. From the earliest forms of companies characterized by some form of assets partitioning and legal personality, to the last business forms, characterized by systems of endo-subjective asset segregation.
The analysis about each organizational form, with particular attention to forms of companies characterized by the endo-subjective segregation, was conducted in a functional perspective, analyzing the presence or not of the legal personhood, the presence or not of the Affirmative and Defensive asset partitioning profiles, and the level of creditors protection that, in case of a further limitation of liability of the entrepreneur, assumes a crucial importance.
The data collected, particularly in relation to three essential legal systems - France and Italy for the civil law area and the United States for the common law area - show that in the last decade, despite the path-dependence of each legal system, the use of the endo-subjective segregation technique has grown in several countries of the Western Legal Tradition area.
Once observed differences and similarities between the new corporate structures, it was possible to show how the introduction of these new models of asset segregation produce identical problems in different jurisdictions, as the application of bankruptcy and tax law, generally related to the lack of legal personality.
The introduction of similar new company forms discloses the convergence of civil and common law systems, even if based on different theoretical foundations. This convergence is essentially due to several factors such as the globalization of markets and economies, which strengthens the attempt to the unification of commercial and company law towards a new lex mercatoria and encourages states to put in place legislation able to attract foreign investment in a competition and forum shopping perspective, increasing the spontaneous circulation of models.
From a theoretical point of view it has been possible to reach several conclusions. On one side, we note that in the context of the asset partitioning theory, the endo-subjective segregation (of series, PCCs and founds committed to a specific purpose) could lead to a peculiar configurations of Affirmative and Defensive asset partitioning: the production of a "Double Defensive asset partitioning" effect (a double shield for assets segregated into the internal cells of a company for both, specialized creditors of the cells or general creditors of the company), or a “Triple Defensive asset partitioning" only for Delaware series with different members; and a stronger Affirmative asset partitioning (considering beyond the general impossibility of personal shareholders’ creditors to reach company's assets, the further segregation of assets within each cell, that are committed only to the claims of specialized cell’s creditors), that could become “Double” for Delaware series with different members (series members’ personal creditors have no claims toward both, series assets and company assets).
On the other side, in terms of regulation, it can be noticed at first that it seems essential that the further limitation of liability of a subject, obtained through an endo-subjective segregation of assets, is supported by appropriate forms of disclosure in order to protect creditors, who must be aware of the structure of the company in terms of liability, and by a more penetrating system to protect involuntary creditors, in respect of which seems proper the expansion of liability to all company’s assets.
Moreover, for a greater diffusion of these new company structures a regulatory or courts intervention is necessary in both systems, to clarify and complete the current legislation, harmonizing it within the existing system, especially with the bankruptcy legislation, ensuring the efficiency and the compliance with their ratio, their essential nature of asset segregation and attribution of limited liability disjointed from the presence of legal personality, in order to preserve, also in case of dysfunction, the advantages of expanding financing channels and lowering the cost of debt capital as highlighted in the law and economics studies
Glycosylated cationic liposomes for specific drug delivery
No full textDevelopment and characterization of glycosylated cationic liposomes for drug delivery. These systems were characterized with an experimental e theoretical approach
Analisi dello svuotamento ventricolare sinistro mediante ecocardiografia tridimensionale in tempo reale prima e dopo terapia di resincronizzazione cardiaca (CRT)
No full textScopo del nostro studio è stato quello di analizzare mediante ecocardiografia tridimensionale (RT3DE) i seguenti parametri:
• la presenza e la distribuzione della dissincronia intraventricolare sinistra in pazienti sottoposti a terapia di resincronizzazione cardiaca (CRT), prima e dopo CRT mediante il calcolo dell’indice di dissincronia (SDI)
• la sequenza di svuotamento sistolico del ventricolo sinistro (VS) prima e dopo CRT
• Il potere predittivo dei due parametri sopra elencati (SDI e sequenza di svuotamento) nel predire la risposta alla CRT, singolarmente e in associazione.
La popolazione oggetto di studio comprendeva 166 pazienti sottoposti all’impianto di PM biventricolare secondo le attuali linee guida. Tutti i pazienti sono stati sottoposti a esame ecocardiografico 2D e 3D prima della CRT e dopo un intervallo di 6 mesi.
Dopo 6 mesi di follow-up dall’impianto, il 62% dei pazienti (n=103) è stato classificato come responder alla CRT e il 38% (n=63) come non-responder. E’ stato effettuato un confronto tra le caratteristiche basali dei pazienti responder e non responder. La maggior parte dei pazienti responder presentava in condizioni basali entrambi i criteri 3D di dissincronia da noi proposti, cioè SDI elevato (> 5%) e assenza della sequenza di svuotamento apice-medio-base (n=82, 86.3%). Viceversa, la maggior parte dei pazienti non-responder non presentava in condizioni basali i due criteri ecocardiografici di dissincronia intraventricolare sinistra (n=32, 97%). L’analisi univariata e multivariata, effettuata per identificare i predittori di risposta alla CRT, ha mostrato che i valori basali di SDI elevati, l’assenza della sequenza di svuotamento apice-medio-base in condizioni basali e l’etiologia non ischemica erano gli unici parametri predittori indipendenti di risposta alla CRT.
L’utilizzo di entrambi i criteri di dissincronia intraventricolare sinistra (SDI + sequenza di svuotamento) ha un valore incrementale sulla sola valutazione clinica nel predire la risposta alla CRT (aumento del chi-square da 11.63 a 59.32, p<0.0001).
Nel gruppo dei responder abbiamo confrontato i parametri ecocardiografici basali e dopo CRT. E’ stata osservata la riduzione dei valori di SDI sotto la soglia del 5%, nonché la ricomparsa della fisiologica sequenza di svuotamento apice-medio-base, presente nel 72/103 pazienti (70%). Tale sequenza era presente in condizioni basali in 23/103 pazienti (22.3%). Quindi la risposta alla CRT comporta il recupero della fisiologica sequenza di svuotamento AMB e la sua assenza in condizioni basali è un parametro predittivo di risposta a medio termine. Viceversa, nel gruppo dei non responder, la sequenza apice-medio-base, è già presente in condizioni basali in 41/63 pazienti (65%).
Questa tecnica semplice e affidabile si aggiunge all’ampia gamma di metodiche che analizzano la presenza di dissincronia ventricolare, ma anzichè misurare il complesso movimento miocardico, valuta il suo prodotto finale, cioè lo svuotamento del ventricolo sinistro. Questi risultati confermano l’utilità del RT3DE nello studio della dissincronia intraventricolare sinistra e, in particolare, dimostrano che la combinazione di due indici differenti di dissincronia può identificare con maggior precisione i responder.nessun
Evaluation of stability and integrity of a steel truss bridge in a forensic investigation
No full textThe studies presented in this Thesis have been developed in the frame of the forensic
investigation into the causes of the collapse of the I-35West Bridge (I-35W) in Minneapolis,
Minnesota, USA that occurred on August 1
st, 2007. The failure of the I-35W represents a
major case-study for the evaluation of stability and integrity of a steel truss bridge.
The Thesis has been developed at Columbia University and at the engineering firm
Thornton Tomasetti (TT) which was hired by a national law firm, Robins, Kaplan, Miller &
Ciresi, to perform a forensic investigation into the cause of the catastrophic collapse.
According to the findings of the forensic investigation, the collapse was triggered by the
buckling of an element of the main truss bottom chord in the main span close to the pier.
The Thesis focused on technical aspects and did not attempt to assign responsibility among the
involved parties. In the first part of the thesis, the background and motivation for the
forensic investigation are presented together with a description of the I-35W Bridge. The
definition of bridge safety and related classifications are given. The concept of structural
stability and integrity of steel structures are discussed. The nature of structures and their
complexity are considered as well as the methodologies used to study them. An extensive
description of the structural decomposition method is presented and detailed for the case
study.
In this work, using the framework of a multilevel approach, the structural system has been
broken down in order to perform a detailed analysis and evaluate the system performances
at macro (global) and micro (local) levels. The effect of boundary conditions, thermal loads
on the global system and post buckling capacity of the main truss bottom chord built up
member on a local level have been studied.
First, a 3D finite element model has been developed in SAP2000 using frame elements. This
global-level model reproduces the entire bridge based on original drawings, design and
construction specifications. The model has been verified by comparing results with the
available original design calculations. Member forces and reactions based on the asdesigned
conditions with the specified design loads have been confirmed. The model served
to investigate the elastic behavior of the bridge and its overall response to various loading
and boundary conditions. In particular, from the global model it has been possible to
evaluate the static stress condition on the bridge showing how some of the temperature
changes and the possible deterioration of the designed supports could affect the demand on
the load carrying members. A specific lower chord member was identified as a critical
member for temperature loading in particular. Second, a 3D solid element model of the recognized critical load bearing member
comprised of a welded built up section with perforated cover plates was built in Abaqus.
This local-level model provided information on the post buckling behavior and capacity of
the load bearing member. The effects of the perforations and boundary conditions have
been outlined. Furthermore, the results have been compared against hand calculations
following the provisions of the Code of Standard Practice for Structural Steel Buildings and
Bridges (AISC, 2005) for built up members and the Timoshenko plate theory for columns
with perforated cover plates
Multi-frequency imagery based on the non-linearity of propagation. Applications to characterization of the seafloor.
No full textClassical acoustical surveying systems gather data about the seafloor usually on a narrow
frequency bandwidth: a single system does not provide frequency diversity in the collected
acoustic backscattered intensities. Gathering data at different frequencies has been revealed to
be an interesting asset for sea floor characterization. At the present time, to collect multi-
frequency information implies the use of different systems. Consequently, the acquired data
are not perfectly matched in time and space, and their fusion is problematic.
The feasibility of an original system that takes advantage of nonlinear propagation to achieve
a multi-frequency source is presented. The principle is to generate a harmonic pulse with
sufficient energy so that the saturation phenomenon emerges (Shooter et al., 1974). As a
result, a single source generates a whole set of beams at the harmonic frequencies, and all
these beams are perfectly superposed both in time and in space.
First, a preliminary study in which a simplistic theoretical model based on a generalized
Burgers’ equation is introduced. This was useful in the nonlinear propagation study and array
sizing. Three sources conceived in our laboratory have been tested in pool facilities to study
the multi-frequency emission feasibility. A special attention was focused on experimental
development; however a comparison between numerical and experimental results is made.
The research was then extended further to develop a Multi-frequency Side Scan Sonar
prototype. A broadband receiver was realized within the purpose of one-day sea trials. A
thorough analysis of the system and the future prospective are presented.Institut Français de Recherche pour l'Exploitation de la Mer - IFREME
La presentazione delle lingue: sulla dimensione semiotica del significare
No full textLa tesi indaga la sistematica e integrata correlazione degli aspetti tradizionalmente intesi come "paralinguistici" all'interno delle interazioni linguisticamente mediate e ne interroga gli aspetti pluri- e multimodali, dalla multisensorialità dei processi percettivi all'articolazione e configurazione delle caratteristiche dipendenti o indipendenti dai mezzi espressivi. L'analisi dei diversi approcci e metodi finora adottati negli studi linguistici e filosofici conduce alla proposta di rivalutare la presentazine delle lingue come dimensione propria del significare. Un approccio alla significazione che implica l'attenzione alle modalità espressive in quanto luoghi di manifestazione, se non di vera e propria genesi, del senso in un 'gioco linguistico' che intesse diverse semiotiche in maniera differente a seconda del mezzo utilizzato per l'espressione (orale, scritto, gestuale o multimediale), sostenendo con ciò che la competenza linguistica, nel senso di uso e conoscenza che i parlanti-scriventi-segnanti hanno della lingua, non solo non prescinda dalle condizioni enunciative ma si modelli nell'interazione con esse prevedendo (come elementi costitutivi del senso) le attività espressive a lungo marginalizzate negli studi linguistici
DECOMPOSITION ALGORITHMS FOR SVM TRAINING BASED ON THE FRANK-WOLFE METHOD
No full textThis work deals with the Support Vector Machine (SVM) learning process
which, as it is well-known, can be reduced to the solution of a quadratic problem
in the so-called feature space. For very large datasets there are practical
issues in the solution of this optimization problem. In particular it may be
impossible to store in memory the Hessian of the quadratic form. Decomposition
methods, such as the Sequential Minimal Optimization (SMO) method,
overcome this limit by operating with small working sets of indices. While
SMO methods use working sets of size two, we study SVM learning techniques
with high-dimensional working sets. At every step of the training algorithm,
we select a working set of cardinality possibly greater than two and we compute
a descent direction, in the working set, by defining a Frank-Wolfe type
linear sub-problem. We show that the latter sub-problem can be solved analytically
and propose a fast procedure for this purpose, the calculation of the
solution require only O(n log(n)) operations in the worst case. Two different
SVM training algorithms are proposed along this line and an extensive numerical
experimentation is carried out. Numerical results show that datasets such
that the training algorithm does not take advantage of second order information,
can be trained efficiently with first order information algorithms which
use high-dimensional working se