3-D geometry reconstruction using a color image stereo pair and partial differential equations

[EN] In this work, we present a new model for a dense disparity estimation and the 3-D geometry reconstruction using a color image stereo pair. First, we present a brief introduction to the 3-D Geometry of a camera system. Next, we propose a new model for the disparity estimation based on an energy functional. We look for the local minima of the energy using the associate Euler-Langrage partial differential equations. This model is a generalization to color image of the model developed in, with some changes in the strategy to avoid the irrelevant local minima. We present some numerical experiences of 3-D reconstruction, using this method some real stereo pairs.

Aplicación para dispositivos móviles basados en Android para la consulta y gestión de reservas de vuelos de la aerolínea Canaryfly

[ES]El actual proyecto consiste en la implementación de un primer prototipo de la aplicación basada en dispositivos Android que la empresa Canaryfly, una aerolínea canaria, ofrecerá a sus clientes con el objetivo  de facilitarles información de sus vuelos y la posibilidad de gestionar sus reservas. La aplicación final pretende ser una extensión del sistema actual de Canaryfly, dado que el objetivo que se persigue  es el de ofrecer las mismas funcionalidades que ofrece la página web. Las funcionalidades desarrolladas para este proyecto han sido la creación de formularios para realizar la solicitud de presupuestos para vuelos especiales, dígase chárter y vuelos en grupo. También se ha creado un primer sistema de facturación online y otro formulario para la recuperación de datos de una reserva, además del formulario para la búsqueda de vuelos.

Elementi postmoderni nell'horror americano contemporaneo. Forme testuali e culturali della mutazione 1968-1998

This research argues for an analysis of textual and cultural forms in the American horror film (1968- 1998), by defining the so-called postmodern characters. The “postmodern” term will not mean a period of the history of cinema, but a series of forms and strategies recognizable in many American films. From a bipolar re-mediation and cognitive point of view, the postmodern phenomenon is been considered as a formal and epistemological re-configuration of the cultural “modern” system. The first section of the work examines theoretical problems about the “postmodern phenomenon” by defining its cultural and formal constants in different areas (epistemology, economy, mass-media): the character of convergence, fragmentation, manipulation and immersion represent the first ones, while the “excess” is the morphology of the change, by realizing the “fluctuation” of the previous consolidated system. The second section classifies the textual and cultural forms of American postmodern film, generally non-horror. The “classic narrative” structure – coherent and consequent chain of causal cues toward a conclusion – is scattered by the postmodern constant of “fragmentation”. New textual models arise, fragmenting the narrative ones into the aggregations of data without causal-temporal logics. Considering the process of “transcoding”1 and “remediation”2 between media, and the principle of “convergence” in the phenomenon, the essay aims to define these structures in postmodern film as “database forms” and “navigable space forms.” The third section applies this classification to American horror film (1968-1998). The formal constant of “excess” in the horror genre works on the paradigm of “vision”: if postmodern film shows a crisis of the “truth” in the vision, in horror movies the excess of vision becomes “hyper-vision” – that is “multiplication” of the death/blood/torture visions – and “intra-vision”, that shows the impossibility of recognizing the “real” vision from the virtual/imaginary. In this perspective, the textual and cultural forms and strategies of postmodern horror film are predominantly: the “database-accumulation” forms, where the events result from a very simple “remote cause” serving as a pretext (like in Night of the Living Dead); the “database-catalogue” forms, where the events follow one another displaying a “central” character or theme. In the first case, the catalogue syntagms are connected by “consecutive” elements, building stories linked by the actions of a single character (usually the killer), or connected by non-consecutive episodes about a general theme: examples of the first kind are built on the model of The Wizard of Gore; the second ones, on the films such as Mario Bava’s I tre volti della paura. The “navigable space” forms are defined: hyperlink a, where one universe is fluctuating between reality and dream, as in Rosemary’s Baby; hyperlink b (where two non-hierarchical universes are convergent, the first one real and the other one fictional, as in the Nightmare series); hyperlink c (where more worlds are separated but contiguous in the last sequence, as in Targets); the last form, navigable-loop, includes a textual line which suddenly stops and starts again, reflecting the pattern of a “loop” (as in Lost Highway). This essay analyses in detail the organization of “visual space” into the postmodern horror film by tracing representative patterns. It concludes by examining the “convergence”3 of technologies and cognitive structures of cinema and new media.

Rafael Moneo: la complessità del vuoto. Dalle matrici formali dell'opera di Oteiza e Chillida

The experience of void, essential to the production of forms and to make use them, can be considered as the base of the activities that attend to the formative processes. If void and matter constitutes the basic substances of architecture. Their role in the definition of form, the symbolic value and the constructive methods of it defines the quality of the space. This job inquires the character of space in the architecture of Moneo interpreting the meaning of the void in the Basque culture through the reading of the form matrices in the work of Jorge Oteiza and Eduardo Chillida. In the tie with the Basque culture a reading key is characterized by concurring to put in relation some of the theoretical principles expressed by Moneo on the relationship between place and time, in an unique and specific vision of the space. In the analysis of the process that determines the genesis of the architecture of Moneo emerges a trajectory whose direction is constructed on two pivos: on the one hand architecture like instrument of appropriation of the place, gushed from an acquaintance process who leans itself to the reading of the relations that define the place and of the resonances through which measuring it, on the other hand the architecture whose character is able to represent and to extend the time in which he is conceived, through the autonomy that is conferred to them from values. Following the trace characterized from this hypothesis, that is supported on the theories elaborated from Moneo, surveying deepens the reading of the principles that construct the sculptural work of Oteiza and Chillida, features from a search around the topic of the void and to its expression through the form. It is instrumental to the definition of a specific area that concurs to interpret the character of the space subtended to a vision of the place and the time, affine to the sensibility of Moneo and in some way not stranger to its cultural formation. The years of the academic formation, during which Moneo enters in contact with the Basque artistic culture, seem to be an important period in the birth of that knowledge that will leads him to the formulation of theories tied to the relationship between time, place and architecture. The values expressed through the experimental work of Oteiza and Chillida during years '50 are valid bases to the understanding of such relationships. In tracing a profile of the figures of Oteiza and Chillida, without the pretension that it is exhaustive for the reading of the complex historical period in which they are placed, but with the needs to put the work in a context, I want to be evidenced the important role carried out from the two artists from the Basque cultural area within which Moneo moves its first steps. The tie that approaches Moneo to the Basque culture following the personal trajectory of the formative experience interlaces to that one of important figures of the art and the Spanish architecture. One of the more meaningful relationships is born just during the years of his academic formation, from 1958 to the 1961, when he works like student in the professional office of the architect Francisco Sáenz de Oiza, who was teaching architectural design at the ETSAM. In these years many figures of Basque artists alternated at the professional office of Oiza that enjoys the important support of the manufacturer and maecenas Juan Huarte Beaumont, introduced to he from Oteiza. The tie between Huarte and Oteiza is solid and continuous in the years and it realizes in a contribution to many of the initiatives that makes of Oteiza a forwarder of the Basque culture. In the four years of collaboration with Oiza, Moneo has the opportunity to keep in contact with an atmosphere permeated by a constant search in the field of the plastic art and with figures directly connected to such atmosphere. It’s of a period of great intensity as in the production like in the promotion of the Basque art. The collective “Blanco y Negro”, than is held in 1959 at the Galería Darro to Madrid, is only one of the many times of an exhibition of the work of Oteiza and Chillida. The end of the Fifties is a period of international acknowledgment for Chillida that for Oteiza. The decade of the Fifties consecrates the hypotheses of a mythical past of the Basque people through the spread of the studies carried out in the antecedent years. The archaeological discoveries that join to a context already rich of signs of the prehistoric era, consolidate the knowledge of a strong cultural identity. Oteiza, like Chillida and other contemporary artists, believe in a cosmogonist conception belonging to the Basques, connected to their matriarchal mythological past. The void in its meaning of absence, in the Basque culture, thus as in various archaic and oriental religions, is equivalent to the spiritual fullness as essential condition to the revealing of essence. Retracing the archaic origins of the Basque culture emerges the deep meaning that the void assumes as key element in the religious interpretation of the passage from the life to the death. The symbology becomes rich of meaningful characters who derive from the fact that it is a chthonic cult. A representation of earth like place in which divine manifest itself but also like connection between divine and human, and this manipulation of the matter of which the earth it is composed is the tangible projection of the continuous search of the man towards God. The search of equilibrium between empty and full, that characterizes also the development of the form in architecture, in the Basque culture assumes therefore a peculiar value that returns like constant in great part of the plastic expressions, than in this context seem to be privileged regarding the other expressive forms. Oteiza and Chillida develop two original points of view in the representation of the void through the form. Both use of rigorous systems of rules sensitive to the physics principles and the characters of the matter. The last aim of the Oteiza’s construction is the void like limit of the knowledge, like border between known and unknown. It doesn’t means to reduce the sculptural object to an only allusive dimension because the void as physical and spiritual power is an active void, that possesses that value able to reveal the being through the trace of un-being. The void in its transcendental manifestation acts at the same time from universal and from particular, like in the atomic structure of the matter, in which on one side it constitutes the inner structure of every atom and on the other one it is necessary condition to the interaction between all the atoms. The void can be seen therefore as the action field that concurs the relations between the forms but is also the necessary condition to the same existence of the form. In the construction of Chillida the void represents that counterpart structuring the matter, inborn in it, the element in absence of which wouldn’t be variations neither distinctive characters to define the phenomenal variety of the world. The physics laws become the subject of the sculptural representation, the void are the instrument that concurs to catch up the equilibrium. Chillida dedicate himself to experience the space through the senses, to perceive of the qualities, to tell the physics laws which forge the matter in the form and the form arranges the places. From the artistic experience of the two sculptors they can be transposed, to the architectonic work of Moneo, those matrices on which they have constructed their original lyric expressions, where the void is absolute protagonist. An ambit is defined thus within which the matrices form them drafts from the work of Oteiza and Chillida can be traced in the definition of the process of birth and construction of the architecture of Moneo, but also in the relation that the architecture establishes with the place and in the time. The void becomes instrument to read the space constructed in its relationships that determine the proportions, rhythms, and relations. In this way the void concurs to interpret the architectonic space and to read the value of it, the quality of the spaces constructing it. This because it’s like an instrument of the composition, whose role is to maintain to the separation between the elements putting in evidence the field of relations. The void is that instrument that serves to characterize the elements that are with in the composition, related between each other, but distinguished. The meaning of the void therefore pushes the interpretation of the architectonic composition on the game of the relations between the elements that, independent and distinguished, strengthen themselves in their identity. On the one hand if void, as measurable reality, concurs all the dimensional changes quantifying the relationships between the parts, on the other hand its dialectic connotation concurs to search the equilibrium that regulated such variations. Equilibrium that therefore does not represent an obtained state applying criteria setting up from arbitrary rules but that depends from the intimate nature of the matter and its embodiment in the form. The production of a form, or a formal system that can be finalized to the construction of a building, is indissolubly tied to the technique that is based on the acquaintance of the formal vocation of the matter, and what it also can representing, meaning, expresses itself in characterizing the site. For Moneo, in fact, the space defined from the architecture is above all a site, because the essence of the site is based on the construction. When Moneo speaks about “birth of the idea of plan” like essential moment in the construction process of the architecture, it refers to a process whose complexity cannot be born other than from a deepened acquaintance of the site that leads to the comprehension of its specificity. Specificity arise from the infinite sum of relations, than for Moneo is the story of the oneness of a site, of its history, of the cultural identity and of the dimensional characters that that they are tied to it beyond that to the physical characteristics of the site. This vision is leaned to a solid made physical structure of perceptions, of distances, guideline and references that then make that the process is first of all acquaintance, appropriation. Appropriation that however does not happen for directed consequence because does not exist a relationship of cause and effect between place and architecture, thus as an univocal and exclusive way does not exist to arrive to a representation of an idea. An approach that, through the construction of the place where the architecture acquires its being, searches an expression of its sense of the truth. The proposal of a distinction for areas like space, matter, spirit and time, answering to the issues that scan the topics of the planning search of Moneo, concurs a more immediate reading of the systems subtended to the composition principles, through which is related the recurrent architectonic elements in its planning dictionary. From the dialectic between the opposites that is expressed in the duality of the form, through the definition of a complex element that can mediate between inside and outside as a real system of exchange, Moneo experiences the form development of the building deepening the relations that the volume establishes in the site. From time to time the invention of a system used to answer to the needs of the program and to resolve the dual character of the construction in an only gesture, involves a deep acquaintance of the professional practice. The technical aspect is the essential support to which the construction of the system is indissolubly tied. What therefore arouses interest is the search of the criteria and the way to construct that can reveal essential aspects of the being of the things. The constructive process demands, in fact, the acquaintance of the formative properties of the matter. Property from which the reflections gush on the relations that can be born around the architecture through the resonance produced from the forms. The void, in fact, through the form is in a position to constructing the site establishing a reciprocity relation. A reciprocity that is determined in the game between empty and full and of the forms between each other, regarding around, but also with regard to the subjective experience. The construction of a background used to amplify what is arranged on it and to clearly show the relations between the parts and at the same time able to tie itself with around opening the space of the vision, is a system that in the architecture of Moneo has one of its more effective applications in the use of the platform used like architectonic element. The spiritual force of this architectonic gesture is in the ability to define a place whose projecting intention is perceived and shared with who experience and has lived like some instrument to contact the cosmic forces, in a delicate process that lead to the equilibrium with them, but in completely physical way. The principles subtended to the construction of the form taken from the study of the void and the relations that it concurs, lead to express human values in the construction of the site. The validity of these principles however is tested from the time. The time is what Moneo considers as filter that every architecture is subordinate to and the survival of architecture, or any of its formal characters, reveals them the validity of the principles that have determined it. It manifests thus, in the tie between the spatial and spiritual dimension, between the material and the worldly dimension, the state of necessity that leads, in the construction of the architecture, to establish a contact with the forces of the universe and the intimate world, through a process that translate that necessity in elaboration of a formal system.

Persistent currents in quantum rings

In this thesis, three different types of quantum rings arestudied. These are quantum rings with diamagnetic,paramagnetic or spontaneous persistent currents. It turns out that the main observable to characterizequantum rings is the Drude weight. Playing a key role inthis thesis, it will be used to distinguish betweendiamagnetic (positive Drude weight) and paramagnetic(negative Drude weight) ring currents. In most models, theDrude weight is positive. Especially in the thermodynamiclimit, it is positive semi-definite. In certain modelshowever, intuitivelysurprising, a negative Drude weight is found. This rareeffect occurs, e.g., in one-dimensional models with adegenerate ground state in conjunction with the possibilityof Umklapp scattering. One aim of this thesis is to examineone-dimensional quantum rings for the occurrence of anegative Drude weight. It is found, that the sign of theDrude weight can also be negative, if the band structurelacks particle-hole symmetry. The second aim of this thesis is the modeling of quantumrings intrinsically showing a spontaneous persistentcurrent. The construction of the model starts from theextended Hubbard model on a ring threaded by anAharonov-Bohm flux. A feedback term through which thecurrent in the ring can generate magnetic flux is added.Another extension of the Hamiltonian describes the energystored in the internally generated field. This model isevaluated using exact diagonalization and an iterativescheme to find the minima of the free energy. The quantumrings must satisfy two conditions to exhibit a spontaneousorbital magnetic moment: a negative Drude weight and aninductivity above the critical level. The magneticproperties of cyclic conjugated hydrocarbons likebenzene due to electron delocalization [magnetic anisotropy,magnetic susceptibility exaltation, nucleus-independent chemical shift (NICS)]---that have become important criteriafor aromaticity---can be examined using this model. Corrections to the presented calculations are discussed. Themost substantial simplification made in this thesis is theneglect of the Zeeman interaction of the electron spins withthe magnetic field. If a single flux tube threads a quantumring, the Zeeman interaction is zero, but in mostexperiments, this situation is difficult to realize. In themore realistic situation of a homogeneous field, the Zeemaninteraction has to be included, if the electrons have atotal spin component in the direction of the magnetic field,or if the magnetic field is strong.

La tutela del disoccupato nel mercato del lavoro. Dal sostegno del reddito ai servizi per l'occupazione

La tesi affronta il tema degli istituti e degli strumenti di tutela della condizione di disoccupazione. In mancanza d’una nozione giuridica generale di disoccupazione, l’obiettivo è quello di ricercare gli elementi comuni ai differenti istituti in grado di definire l’ambito della protezione garantita alla persona priva d’impiego. Lo studio fornisce, dapprima, una complessiva ricognizione storico-critica degli strumenti per il sostegno del reddito nelle ipotesi di mancanza di lavoro. L’esame dei modelli d’intervento legislativo evidenzia finalità, caratteristiche e criticità dei singoli istituti, sia di quelli più consolidati, che degli interventi più recenti. La seconda parte della tesi si propone d’integrare la ricognizione delle forme di tutela economica con l’analisi delle politiche attive nel mercato del lavoro e degli interventi a sostegno all’occupabilità. L’intento è di verificare le modalità attraverso le quali l’ordinamento tenta di collegare tutela del reddito e promozione dell’occupazione. La ricerca affronta anche la questione dei limiti alla libertà di circolazione nell’Unione Europea dei cittadini non lavoratori, nonché il condizionamento determinato dalle misure che riducono o scoraggiano l’esportabilità delle prestazioni previdenziali negli altri Paesi europei. La parte finale si propone d’individuare gli elementi che caratterizzano il complesso degli istituti analizzati, al fine di verificare a quale evento giuridico l’ordinamento offra protezione. Lo studio identifica due elementi rilevanti: la condizione di “mancanza di lavoro”, che accomuna l’intervento per la disoccupazione e quello a favore dei rapporti di lavoro sospesi, nonché l’attualità dello stato di disoccupazione, parametro generale per gli interventi protettivi. L’analisi svolta sottolinea, però, che i meccanismi di c.d. condizionalità per l’accesso alle prestazioni economiche e ai servizi per l’impiego non consentono un’adeguata promozione della qualità del lavoro e della professionalità del lavoratore. La tesi individua un possibile terreno di sviluppo della protezione della condizione del disoccupato nell’integrazione tra strumenti di sostegno all’impiego e interventi a base universalistica.

Spinpolarisierte Rastertunnelmikroskopie magnetischer Nanostrukturen am Beispiel von bcc-Co/Fe(110), Fe/Mo(110) und Kupfer-Phthalocyanin/Fe(110)

In dieser Arbeit werden, nach einer Einführung in die spinpolarisierte Rastertunnelmikroskopie und -spektroskopie als experimentelle Methode zur Untersuchung magnetischer Nanostrukturen, Ergebnisse zur spinpolarisierten elektronischen Struktur in Abhängigkeit von der Kristallstruktur am Beispiel ultradünner Co-Schichten sowie in Abhängigkeit von der Magnetisierungsrichtung für ultradünne Fe-Schichten vorgestellt. Hochaufgelöste Messungen zeigen die ortsabhängige Spinpolarisation auf einem einzelnen Kupfer-Phthalocyanin Molekül. rnrnKobalt wurde durch pseudomorphes Wachstum auf den (110)-Oberflächen der kubisch raumzentrierten Metalle Chrom und Eisen deponiert. Im Unterschied zu früheren Berichten in der Literatur lassen sich nur zwei Lagen Co in der kubisch raumzentrierten (bcc) Ordnung stabilisieren. Die bcc-Co Schichten auf der Fe(110)-Oberfläche zeigen keine Anzeichen von epitaktischen Verzerrungen. rnDickere Schichten rekonstruieren in eine dicht gepackte Struktur (hcp/fcc). Durch die bcc Ordnung wird die Spinpolarisation von Kobalt auf P=62% erhöht (hcp-Co: P=45%). rnrnDie temperaturabhängige Spinreorientierung (SRT) ultradünner Filme Fe/Mo(110) wurde mit spinpolarisierter Spektroskopie untersucht. Eine Neuausrichtung der Magnetisierung aus der senkrechten [110]-Achse in die in der Ebene liegenden [001]-Achse wird bei T=(13,2+-0,5)K festgestellt, wobei es sich um einen diskontinuierlichen Reorientierungsübergang handelt, d.h. die freie Energie weist innerhalb eines bestimmten Temperaturbereichs gleichzeitig zwei Minima auf. Weiterhin wird in der Mono- und Doppellage Fe/Mo(110 eine Abhängigkeit der elektronischen Struktur von der Ausrichtung der magnetisch leichten Achse und von der Magnetisierung beobachtet. rnrnDie Untersuchung des spinpolarisierten Ladungstransports durch ein Kupfer-Phthalocyanin-Molekül auf der Fe/Mo(110) Oberfläche liefert einen wesentlichen Beitrag zum Verständnis des Spintransports an der Grenzfläche zwischen Metall und organischem Molekül. Die HOMO-LUMO-Energielücke des freien Moleküls wird durch die Wechselwirkung mit der Metalloberfläche mit Grenzflächenzuständen gefüllt. Diese Zustände reduzieren die Spinpolarisation des durch das Molekül fließenden Tunnelstroms durch einen zusätzlichen unpolarisierten Strombeitrag um einen Faktor zwei. Spinpolarisierte hybridisierte Grenzflächenzustände mit größerem Abstand zur Fermi-Energie führen in Abhängigkeit von der Position auf dem Molekül zu weiteren Beiträgen zur effektiven Spinpolarisation. Diese Untersuchungen belegen die Möglichkeit einer effektiven Spininjektion in organische Halbleiter und damit das Potential dieser Materialien für die weitere Entwicklung von Spintronik-Bauteilen.

Charge-transport simulations in organic semiconductors

In this thesis we have extended the methods for microscopic charge-transport simulations for organic semiconductors. In these materials the weak intermolecular interactions lead to spatially localized charge carriers, and the charge transport occurs as an activated hopping process between diabatic states. In addition to weak electronic couplings between these states, different electrostatic environments in the organic material lead to a broadening of the density of states for the charge energies which limits carrier mobilities.rnThe contributions to the method development includern(i) the derivation of a bimolecular charge-transfer rate,rn(ii) the efficient evaluation of intermolecular (outer-sphere) reorganization energies,rn(iii) the investigation of effects of conformational disorder on intramolecular reorganization energies or internal site energiesrnand (iv) the inclusion of self-consistent polarization interactions for calculation of charge energies.These methods were applied to study charge transport in amorphous phases of small molecules used in the emission layer of organic light emitting diodes (OLED).rnWhen bulky substituents are attached to an aromatic core in order to adjust energy levels or prevent crystallization, a small amount of delocalization of the frontier orbital to the substituents can increase electronic couplings between neighboring molecules. This leads to improved charge-transfer rates and, hence, larger charge-mobility. We therefore suggest using the mesomeric effect (as opposed to the inductive effect) when attaching substituents to aromatic cores, which is necessary for example in deep blue OLEDs, where the energy levels of a host molecule have to be adjusted to those of the emitter.rnFurthermore, the energy landscape for charges in an amorphous phase cannot be predicted by mesoscopic models because they approximate the realistic morphology by a lattice and represent molecular charge distributions in a multipole expansion. The microscopic approach shows that a polarization-induced stabilization of a molecule in its charged and neutral states can lead to large shifts, broadening, and traps in the distribution of charge energies. These results are especially important for multi-component systems (the emission layer of an OLED or the donor-acceptor interface of an organic solar cell), if the change in polarizability upon charging (or excitation in case of energy transport) is different for the components. Thus, the polarizability change upon charging or excitation should be added to the set of molecular parameters essential for understanding charge and energy transport in organic semiconductors.rnWe also studied charge transport in self-assembled systems, where intermolecular packing motives induced by side chains can increase electronic couplings between molecules. This leads to larger charge mobility, which is essential to improve devices such as organic field effect transistors, where low carrier mobilities limit the switching frequency.rnHowever, it is not sufficient to match the average local molecular order induced by the sidernchains (such as the pitch angle between consecutive molecules in a discotic mesophase) with maxima of the electronic couplings.rnIt is also important to make the corresponding distributions as narrow as possible compared to the window determined by the closest minima of thernelectronic couplings. This is especially important in one-dimensional systems, where charge transport is limited by the smallest electronic couplings.rnThe immediate implication for compound design is that the side chains should assist the self-assemblingrnprocess not only via soft entropic interactions, but also via stronger specific interactions, such as hydrogen bonding.rnrnrnrn

Le Havre. Forme e caratteri dello spazio urbano nel progetto di Auguste Perret

Oggetto del presente studio è il progetto di ricostruzione del centro urbano di Le Havre ad opera di Auguste Perret. Suo obiettivo è il riconoscimento di quell’idea di città posta a fondamento del progetto, per il quale ci si propone di indagare il senso e le grammatiche costitutive della sua forma. Quella di Le Havre costituisce una dimostrazione di come una forma urbana ancora compatta ed evocativa della città storica possa definirsi a partire dalle relazioni stabilite con gli elementi della geografia fisica. Nei suoi luoghi collettivi e monumentali, che rimandano chiaramente a una cultura dell’abitare che affonda le proprie radici nella più generale esperienza della costruzione della città francese, la città riconosce un valore formale e sceglie di rappresentare il proprio mondo civico dinanzi a quei grandi elementi della geografia fisica che costituiscono l’identità del luogo nel quale questa si colloca. Sembra infatti possibile affermare che gli spazi pubblici della città atlantica riconoscano e traducano nella forma della Place de l’Hôtel de Ville le ripide pendici della falesia del Bec-de-Caux, in quella della Porte Océane l’orizzonte lontano dell’Oceano, e nel Front-de-mer Sud l’altra riva dell’estuario della Senna. Questa relazione fondativa sembra essere conseguita anche attraverso la definizione di un’appropriata grammatica dello spazio urbano, la cui significatività è nel fondarsi sull’assunzione, allo stesso tempo, del valore dello spazio circoscritto e del valore dello spazio aperto. La riflessione sullo spazio urbano investe anche la costruzione dell’isolato, sottoposto a una necessaria rifondazione di forma e significato, allo scopo di rendere intellegibile le relazioni tra gli spazi finiti della città e quelli infiniti della natura. La definizione dell’identità dello spazio urbano, sembra fondarsi, in ultima analisi, sulle possibilità espressive delle forme della costruzione che, connotate come forme dell’architettura, definiscono il carattere dei tipi edilizi e dello spazio da questi costruito.

Einsatz eines Aerosolmassenspektrometers während der CYPHEX-Kampagne und zur Methodenentwicklung einer Echtzeitquantifizierung gasförmiger Amine

Atmosphärische Aerosole haben einen starken Einfluss auf das Klima, der bisher nur grundlegend verstanden ist und weiterer Forschung bedarf. Das atmosphärische Verhalten der Aerosolpartikel hängt maßgeblich von ihrer Größe und chemischen Zusammensetzung ab. Durch Reflexion, Absorption und Streuung des Sonnenlichtes verändern sie den Strahlungshaushalt der Erde direkt und durch ihre Einflussnahme auf die Wolkenbildung indirekt. Besonders gealterte, stark oxidierte organische Aerosole mit großem Sauerstoff-zu-Kohlenstoff-Verhältnis wirken als effektive Wolkenkondensationskeime. Neben primären Aerosolpartikeln, die direkt partikelförmig in die Atmosphäre gelangen, spielen sekundäre Aerosolpartikel eine große Rolle, die aus Vorläufergasen in der Atmosphäre entstehen. Aktuelle Forschungsergebnisse legen nahe, dass kurzkettige aliphatische Amine bei Nukleationsprozessen beteiligt sind und somit die Partikelneubildung vielerorts mitsteuern. Um die Rolle von Aminen in der Atmosphäre besser erforschen und industrielle Emissionen kontrollieren zu können, bedarf es einer zuverlässigen Methode zur Echtzeitquantifizierung gasförmiger Amine mit hoher Zeitauflösung und niedriger Nachweisgrenze.rnDas hochauflösende Flugzeit-Aerosolmassenspektrometer (HR-ToF-AMS) bietet die Möglichkeit, atmosphärische Partikel in Echtzeit zu analysieren. Dabei werden Größe, Menge und grundlegende chemische Zusammensetzung erfasst. Anorganische Aerosolbestandteile können eindeutig zugeordnet werden. Es ist jedoch kaum möglich, einzelne organische Verbindungen in den komplizierten Massenspektren atmosphärischer Aerosole zu identifizieren und quantifizieren.rnIn dieser Arbeit wird atmosphärisches Aerosol untersucht, das im Westen Zyperns während der CYPHEX-Kampagne mit einem HR-ToF-AMS gemessen wurde. An diesem Standort ist vor allem stark gealtertes Aerosol vorzufinden, das aus Zentral- und Westeuropa stammt. Lokale Einflüsse spielen fast keine Rolle. Es wurde eine durchschnittliche Massenkonzentration von 10,98 μg/m3 gefunden, zusammengesetzt aus 57 % Sulfat, 30 % organischen Bestandteilen, 12 % Ammonium, < 1 % Nitrat und < 1 % Chlorid, bezogen auf das Gewicht. Der Median des vakuum-aerodynamischen Durchmessers betrug 446,25 nm. Es wurde sehr acides Aerosol gefunden, dessen anorganische Bestandteile weitgehend der Zusammensetzung von Ammoniumhydrogensulfat entsprachen. Tag-Nacht-Schwankungen in der Zusammensetzung wurden beobachtet. Die Sulfatkonzentration und die Acidität zeigten tagsüber Maxima und nachts Minima. Konzentrationsschwankungen an Nitrat und Chlorid zeigten einen weniger ausgeprägten Rhythmus, Maxima fallen aber immer mit Minima der Sulfatkonzentration, Aerosolacidität und Umgebungstemperatur zusammen. Organische Aerosolbestandteile entsprachen stark gealtertem, schwerflüchtigem oxidiertem organischem Aerosol. Es wurde eine interne Mischung der Partikel beobachtet, die ebenfalls meist bei alten Aerosolen auftritt.rnUm mit dem HR-ToF-AMS auch einzelne organische Verbindungen identifizieren und quantifizieren zu können, wurde eine Methode entwickelt, mit der man Amine der Gasphase selektiv in künstlich erzeugte Phosphorsäurepartikel aufnimmt und so für die HR-ToF-AMS-Messung zugänglich macht. Dadurch kombiniert man die Vorteile der Online-Messung des HR-ToF-AMS mit den Vorteilen klassischer Offline-Probenahmen. So können in Echtzeit sehr einfache Massenspektren gemessen werden, in denen störende Komponenten abgetrennt sind, während die Analyten eindeutig identifiziert werden können. Systeme dieser Art wurden GTRAP-AMS (Gaseous compound TRapping in Artificially-generated Particles – Aerosol Mass Spectrometry) genannt. Kalibrierungen für (Mono)Methylamin, Dimethylamin, Trimethylamin, Diethylamin und Triethylamin ergaben Nachweisgrenzen im ppt-Bereich bei einer Zeitauflösung von 3 min. Kammerexperimente zur Aminemission von Pflanzen zeigten eine gute Übereinstimmung des neu entwickelten Systems mit einer Gasdiffusionsabscheider-Offline-Probenahme und anschließender ionenchromatographischer Analyse. Beide Methoden zeigten Reaktionen der Pflanzen auf eine Veränderung der Lichtverhältnisse, während erhöhte Ozonkonzentrationen die Aminemission nicht veränderten. Die GTRAP-AMS-Methode eignet sich bereits für die Messung von Umgebungsluftkonzentrationen an einigen Orten, für die meisten Orte reicht die Nachweisgrenze allerdings noch nicht aus. Die Technik könnte bereits zur Echtzeitkontrolle industrieller Abgasemissionen eingesetzt werden.

How to Tango: a manual for implementing Spine Tango

The generic approach of the Spine Tango documentation system, which uses web-based technologies, is a necessity for reaching a maximum number of participants. This, in turn, reduces the potential for customising the Tango according to the individual needs of each user. However, a number of possibilities still exist for tailoring the data collection processes to the user's own hospital workflow. One can choose between a purely paper-based set-up (with in-house scanning, data punching or mailing of forms to the data centre at the University of Bern) and completely paper-free online data entry. Many users work in a hybrid mode with online entry of surgical data and paper-based recording of the patients' perspectives using the Core Outcome Measures Index (COMI) questionnaires. Preoperatively, patients can complete their questionnaires in the outpatient clinic at the time of taking the decision about surgery or simply at the time of hospitalisation. Postoperative administration of patient data can involve questionnaire completion in the outpatient clinic, the handing over the forms at the time of discharge for their mailing back to the hospital later, sending out of questionnaires by post with a stamped addressed envelope for their return or, in exceptional circumstances, conducting telephone interviews. Eurospine encourages documentation of patient-based information before the hospitalisation period and surgeon-based information both before and during hospitalisation; both patient and surgeon data should be acquired for at least one follow-up, at a minimum of three to six months after surgery. In addition, all complications that occur after discharge, and their consequences should be recorded.

Differences in Internet Usage - Social Inequality and Informal Education

In the public debate the internet is regarded as a central resource for knowledge and information. Associated with this is the idea that everyone is able and even expected to serve himself or herself according to his or her own needs via this medium. Since more and more services are also delivered online the internet seems to allow its users to enjoy specific advantages in dealing with their everyday life. However, using the internet is based on a range of preconditions. New results of empirical and theoretical research indicate the rise of a social divide in this context. Within the internet, different ways of use can be identified alongside social inequalities. Boundaries of the "real life" are mirrored in the virtual space e.g. in terms of forms of communification and spaces for appropriation. These are not only shaped by invidual preferences but particularly by social structures and processes. In the context of the broader debate on education it is stated that formal educational structures are to be completed by arrangements which are structured in informal respectively nonformal ways. Particularly the internet is suggested to play an important role in this respect. However, the phenomenon of digital inequality points to limitations consolidated by effects of economic, social, and cultural ressources: Economical resources affect opportunities of access, priorities of everyday life shape respective intentions of internet use, social relationships have an impact on the support structures available and ways of appropriation reproduce a specific understanding of informal education ("informelle Bildung"). This produces an early stratification of opportunities especially for the subsequent generation and may lead to extensive inequalities regarding the distribution of advantages in terms of education. Thus the capacity of the virtual space in terms of participatory opportunities and democratic potentials raises concerns of major relevance with respect to social and educational policy. From the perspective of different disciplines involved in these issues it is essential to clarify this question in an empirical as well as in a theoretical way and to make it utilizable for a future-orientied practice. This article discusses central questions regarding young people's internet use and its implications for informal education and social service delivery on the basis of empirical findings. It introduces a methodological approach for this particular perspective and illustrates that the phenomena of digital divide and digital inequality are as much created by social processes as by technical issues.

Blind Deconvolution via Lower-Bounded Logarithmic Image Priors

In this work we devise two novel algorithms for blind deconvolution based on a family of logarithmic image priors. In contrast to recent approaches, we consider a minimalistic formulation of the blind deconvolution problem where there are only two energy terms: a least-squares term for the data fidelity and an image prior based on a lower-bounded logarithm of the norm of the image gradients. We show that this energy formulation is sufficient to achieve the state of the art in blind deconvolution with a good margin over previous methods. Much of the performance is due to the chosen prior. On the one hand, this prior is very effective in favoring sparsity of the image gradients. On the other hand, this prior is non convex. Therefore, solutions that can deal effectively with local minima of the energy become necessary. We devise two iterative minimization algorithms that at each iteration solve convex problems: one obtained via the primal-dual approach and one via majorization-minimization. While the former is computationally efficient, the latter achieves state-of-the-art performance on a public dataset.

Innovation Processes and Industrial Districts

In this survey, we examine the operations of innovation processes within industrial districts by exploring the ways in which differentiation, specialization, and integration affect the generation, diffusion, and use of new knowledge in such districts. We begin with an analysis of the importance of the division of labor and then investigate the effects of social embeddedness on innovation. We also consider the effect of forms of organization within industrial districts at various stages of product and process life, and we examine the negative aspects of embeddedness for innovation. We conclude with a discussion of the possible consequences of new information and communications technologies on innovation in industrial districts.

Depolarization-dependent synaptic potentiation and hyperexcitability induced by a Ca2+-independent trigger

Despite vast research efforts since Cajal's seminal thoughts on the adaptation of the nervous system, researchers have only recently begun to understand the diversity of forms of neuronal plasticity and its mechanisms. All known forms of activity-dependent neuronal plasticity utilize alterations in [Ca 2+]i as a signal of changes in the membrane voltage. Ca 2+ sensors trigger modifications in excitability or synaptic strength that last from seconds to weeks and presumably years. Intriguingly, Kunjilwar et al., (unpublished observations) discovered in peripheral sensory axons of Aplysia that the induction of depolarization-dependent long-term axonal hyperexcitability does not require Ca2+ transients. Here we show that induction of depolarization-dependent intermediate-term and long-term synaptic potentiation in Aplysia occurs in conditions that prevent Ca2+ entry through voltage-gated channels and elevation of [Ca2+]i. We found that the intermediate-term synaptic potentiation induced under conditions expected to prevent Ca 2+ transients is associated with increased excitability of sensory neuron axons near presynaptic terminals, suggesting that the synaptic potentiation involves a presynaptic locus. The Ca2+-independent intermediate- and long-term synaptic potentiation appeared similar to previously reported Ca2+-dependent modifications in Aplysia. ^