Two interesting properties of the distribution of spatially selective attention have been noted in the behavioral and electrophysiological literature. First, there is a graded field of attention that expands from the center of the attended area. Second, the size of the attended area can be adjusted to be either larger or smaller in order to match the demands of the current task. Five event-related potential (ERP) studies are presented that extend these findings in several important ways; 1) The time frame of these two distribution properties is different. Results are consistent with a two stage model of spatial attention in which visual processing is initially enhanced for all stimuli presented near the center of the attended area as indexed by the amplitude of the first negative peak in the waveform (N1). Subsequently, the effects of narrowing or expanding the attentional field to the relevant size affects visual processing as indexed by the amplitude of the second negative peak (N2). 2) Object boundaries had limited impact on either the spread of the initial gradient of spatial selection or the scale of attention. 3) When selecting visual stimuli for attentive processing based on features such as color and size there is also a gradient of facilitation, but the impact of this graded selection on visual processing is not observed until later in processing, and is indexed by the amplitude of the selection negativity (SN). Furthermore, similar to the lack of interaction between object boundaries and the range of cued locations, the gradients of feature-based selection are not affected by the range of cued features.

For evolution to occur over time, it is necessary for animals and plants to show phenotypic variation. If the individuals within populations of a species do not show observable differences among themselves, there will be a lack of driving force for natural selection to act on and decide which characteristic gets inherited from one generation to the next. It is hence important to study phenotypic variation, especially against environmental gradients such as latitude and altitude, which gives us an insight into the pattern of change according to essential factors such as temperature and length of seasons. The latter would impose time constraints on growing populations, leading to periods of unfavourable conditions limiting their growth and development. In many cases, such organisms would tend to compensate for the period of slow growth and catch up to the others that did not have to endure the same situation and grow to the same size as them. This study aims to find differences in three key larval life-history traits of the moor frog (Rana arvalis), namely metamorphic mass, larval period, and growth rate, and find what kind of pattern is observed in case of these phenotypic variations. It also aims to find differences in the strength of compensatory response between populations from lower and higher latitudes. A common garden experiment was conducted with populations originating from both sides of the Baltic Sea, ranging from southern Sweden and Latvia to central Finland and northern Sweden. It was expected that the northern populations would grow faster and show a countergradient variation pattern since they are faced with more strict time constraints at higher latitudes, but in most cases, we observed a co-gradient pattern, wherein the environmental effect amplifies the individual’s genetic predisposition instead of opposing it. We also observed a stronger compensatory response in the northern populations as compared to their southern counterparts. Effects of climate change and subsequent rise in temperatures making the environment unpredictable over time could be used to speculate about the reason behind the results obtained. Epigenetics could also be used as an approach to study long lasting changes in an organism’s gene expression to make it adapt better to changing conditions and hence show different patterns of variation from studies in the past. Studying such changes, expected or not, is important to keep up with the needs of the species that require conservation, and will help conservation biologists to formulate strategies that would be effective even in the face of constant change in the world.

Neural networks can perform an incredible array of complex tasks, but successfully training a network is difficult because it requires us to minimize a function about which we know very little. In practice, developing a good model requires both intuition and a lot of guess-and-check. In this dissertation, we study a type of fully-connected neural network that improves on standard rectifier networks while retaining their useful properties. We then examine this type of network and its loss function from a probabilistic perspective. This analysis leads to a new rule for parameter initialization and a new method for predicting effective learning rates for gradient descent. Experiments confirm that the theory behind these developments translates well into practice.

Laser lithography has been implemented in many ways to pattern polymeric materials. By using a tightly focused laser beam we can induce sharp thermal gradients, exceeding 1,500,000 °C/cm, onto the surface of a thin polymer film. The temperature dependence of the surface tension in such a thermal field gives rise to a flow of material away from the center of the beam focus driven by the Marangoni or thermocapillary effect. The evolution of a film irradiated by a focused laser can be, in a general sense, predicted by a presented hydrodynamic model, which is based on simple fluid mechanics. However, the details of the individual evolution profiles show a more complicated behaviour. It has been shown that this complex behaviour can be explained by considering the optical interference effects of the thin polymer coating. An optical feedback control routine has been developed to compensate for the interference effect by monitoring and maintaining a constant absorbed laser power. This ensures that the temperature gradient that drives the lithography process is consistent during operation. Additional studies involving high laser power effects, different material systems and other thin film phenomena have revealed an interesting assortment of novel behaviours. The extension of these behaviours to the lithography process lead towards the development of applications in microfabriation and microfluidic devices. / Thesis / Master of Applied Science (MASc)

<p> A study of gradient optimization techniques, in particular as applied to system modelling problems, is made. Three efficient techniques are used to derive optimum second-order and third-order models for a seventh-order system. The optimization techniques are the Fletcher-Powell method, a more recent method proposed by Fletcher and a method based on a more general objective function proposed by Jacobson and Oksman.</p> <p> The approximation is carried out in the time domain. Least squares and least pth criteria are used, and almost minimax results are obtained for large values of p. Values of p up to 10^12 are successfully used. The results are compared with other minimax type algorithms.</p> / Thesis / Master of Engineering (MEngr)

<p> An exact analysis for the state of strain in a three dimensional rod continuum is presented. The exact geometrical description of the rod involves the evaluation of a power series expansion of the radius vector. It is shown however, that by a suitable choice of coordinates in the reference configuration and an interpretation of the deformation gradient as a material transformation, the strain tensor may be evaluated to the degree of accuracy inherent in using the full power series expansion of the radius vector without necessitating the explicit evaluation of the power series. Some concepts from the theory of multipolar media are used in order to make this three dimensional analysis compatible with the exact analysis of one dimensional rods.</p> / Thesis / Master of Engineering (MEngr)

Just over a hundred years ago, the First World War profoundly disrupted the landscape of Europe: from the fields of Galicia to the French plains, from the Alpine arc to the coasts of the Baltic Sea, position and trench warfare brought about transformations by etching the ground, carving out mountains, reorganizing territorial arrangements and original environmental ecosystems, leaving room for the stratification of new traces and meanings that, over time, have contributed to the construction of what is now universally recognized as a fragile cultural heritage of high complexity. If Law n.78 of 2001, as a synthesis of a very intense and fruitful debate, protects the remains of the First World War mainly intending to protect this particular historical heritage without altering “the material and historical characteristics” (in the Italian context), in the aftermath of the celebrations for the Centenary, and in light of numerous projects that have been applied to the restoration/recovery/evaluation of these assets, to return to investigate the “landscapes of war” means to set up a new research to understand how these remains can continue to narrate their “being in time” to future generations, stimulating “possibilities of memory” and representing at the same time substantial resources, cultural but also economic, for the future. A problem of scale clearly emerged following the analysis of the status quo of a representative sample of places and artifacts and concluded/ongoing projects at the international level. The pregnant force of the remains as a “system” deeply connected not only by a physical infrastructure of field fortifications, entrenchments, barracks, and obstacle courses but also by a dense network of intangible and visual relationships that substantiated their functioning, today is increasingly weakening. As a confirmation of this, it is evident, for example, how the fragmentation of the interventions and their management policies is also reflected in the greater attention paid by the majority of the carried out projects to the permanent fortifications compared to the entrenched articulated systems that surrounded them and were an integral part of them. To solve this interpretative-operative gap, the need to recover a systemic vision capable of moving at different scales and grasping the intangible wholeness of the system-vestiges, today apparently shattered, has emerged. This vision should focus attention not on the fragments as “remains of a whole that no longer exists”, but on the potential that they can still generate if put in tension with each other: a magnetic field capable of binding the different parts and recomposing their meanings. This has led to moving away from the specificity of individual disciplinary knowledge to embrace a transversal approach able to place the warscape at the core and analyze it in its entire nature and biography of landscape-palimpsest multi-layered in different times. In this perspective, the indissoluble symbiosis between physical “signs” and immaterial values (deposited over time) has turned out to be the specific peculiarity of the “character” of these “war landscapes”, thus recognizing the condition of fragility not as a point of weakness, but rather as their most “authentic” peculiarity. It was possible to identify different “ways of seeing” these warscapes through this simultaneously inductive and deductive knowledge-based process, studying not only the theoretical and methodological aspects of spatial analysis but also the relationships between the socio-cultural, historical, and anthropological factors that have defined its development and transformation. This approach focuses increasingly on the need to adopt a holistic vision to overcome the current fragmentation of this heritage and think about its future without betraying its authenticity. Operationally, this approach has been declined through two current levels of research. As an essential moment to consciously set up the future operative proposals, an order matrix was defined to reread the complexity recovering a systemic vision also in the analytical phase. By arranging the building typologies with the different morphologies of the territories, it was possible to identify some “war-scape classes”, useful to interpret the fragmentary nature of the different “war landscapes” through the identification both of the driving forces that had determined their construction, in different times, and of the same ones that can determine the trajectories of future change. By identifying the different “war-scape classes”, it was possible to critically reinterpret the status quo of places and artifacts through a “systemic look”. Based on what emerged, an articulate SWOT analysis was devolped to highlight the main potential and criticality of the remains at the system level. The second declination of this holistic approach focused on the meaning of the recognition of “war landscapes” as “places of memory”. Through the evolutionary study of the different phases of the “construction of the Great War memory”, which throughout a century have alternated multiple and polysense “practices of narration”, it was possible to better understand the processes that led to the recognition of the testimonial value of the remains. In this way, it was also possible to understand that specific “sense of place” that, metaphorically, identifies the different warscapes as “high capacity condensers of values”, in which the intensity of the potential (the meaningfulness of meanings/new re-significations) is directly proportional to the charge that is generated at the moment in which the relationships between the different poles (archipelago of vestiges as fragments) are strengthened. In this specific regard, it was possible to identify the physical space of the threshold between “the visible and the submerged” as a particularly dense and pregnant accumulation basin to be “poetically investigated” to unveil the permanence of the imprint of the war (manifested there as much on a physical level in the “matter marked” by the conflict as in the meanings assumed by such “signs”), still present today but “hidden” under the multiple layers of deposition that have stratified over time. The considerations obtained through the two levels of research have been combined with a theoretical reflection on the recognition of the “landscapes of war” as “heritage” understood in its various etymological meanings (legacy, inheritance, and patrimony). In this way, it was possible to better understand the meaning of the concept of enhancement applied to this heritage, bringing to the surface some semantic nuclei that are currently critical concerning the strengthening and/or enhancement of which to consciously direct future orientations of priorities. The priority issue, which strongly emerged, was the pressing need to develop new operational strategies to facilitate the recognition, within the contemporary multi-layered landscape, of the different levels of permanence of the remains, including in particular the most fragile “signs” in terms of permanence, currently at greater “risk of loss”. In addition to this, the need to propose new strategies regarding the policies of coordination and management of processes with particular attention to the importance of participatory aspects (issues identified but not explored in detail in this research), and the need to better understand some aspects of construction technology (related to technological experiments of reinforced concrete of whose structural behavior little is known), also emerged. In an inter-scalar vision, these aspects have assumed even greater importance in the awareness that the ability to recognize different areas concerning which the vestiges remain in the contemporary world at different levels of semantic significance is a necessary prerequisite for future projects to operate recovering that systemic vision lost today, ensuring the system-vestiges, as such, different margins of design, preserving our “possibility of memory” through its evocative potential. In this perspective, the research has therefore elaborated and proposed a “method in complexity” proper to facilitate the recognition of what can have testimonial value at the landscape scale by identifying areas in which the vestiges of war persist at different temperatures. This is a new paradigm that, moving from the need to recover a systemic view capable of recognizing the permanence of even the most fragile remains, expands the meaning of “testimonial value” at the scale of the “warscape” by introducing the concept of “testimonial gradient”. This is a useful parameter to identify the different areas in which the degree of semantic significance of the vestiges and the related “possibilities of memory” are graduated according to the level of knowledge of specific indicators, such as the historical-identity aspects, the typological-constructive knowledge of the artifacts, the degree of community involvement and, above all, the legibility of the vestige-system. In addition to having defined at a conceptual level the meaning of these indicators, the research has also developed an analytical method based on a multi-criteria analysis to make operational the qualitative considerations expressed by the knowledge-based parameters previously identified and to obtain accurate fragility maps of the different warscapes. These documents are fascinating not only because they give an overall view of the semantic density of a given context, but because they are a fundamental proactive tool for future practices of “care”: the essential knowledge base on which to base future choices in terms of conservation, protection, and enhancement. In the light of the previous considerations, it has emerged the awareness of how necessary is the interdisciplinary collaboration for the definition of the indicators constituting the “testimonial gradient”: the last part of the present research has therefore been mainly focused on the elaboration of an operative method to facilitate the deepening of two of these indicators, in relation also to the criticalities previously emerged, linked to the issues of recognizability of the most fragile permanences, both from an overall point of view and of construction technology. Therefore, intending to contribute to the unveiling of the broad and deep information basin in which the complex system of visible but also “submerged” vestiges has been recognized, the research proposed the elaboration of a knowledge-based method called “stratigraphic telescope”, a methodological tool able to explore the processes of construction/transformation of war landscapes at different scales. This method proved to be a fertile contribution to place, side by side with the study of archival documents and manuals of fortifications, an indispensable store of knowledge to better understand the construction techniques, the technical and technological details, the materials used, and the tactical or planting solutions proposed. This method is clearly based on applying the interpretive code of architectural stratigraphy to the scale of the landscape, thus interpreting the history of artifacts as the result of processes of addition, subtraction, and transformation that have left physical traces linked together in a stratigraphic sequence. Operationally, this has been interpreted in understanding the archaeological transformation’s dynamics of the landscapes over time, comparing the impact of the war event with the current recognition of land uses and the permanence of the remains. This method founds itself mainly on analyzing, comparing, and interpreting historical documentation, period aerial photographs, current orthophotos, and data processing obtained by techniques of high-resolution (remote sensing). In this perspective, the use of software for the creation of Geographic Information Systems such as ArcGis and QuantumGis has been fundamental, as these work environments have allowed overall coordination of the entire cognitive process: from the integrated management of the different input datasets (georeferencing of historical maps of militarization and military aerial photographs) to the processing of the expected outputs. In this regard, the most innovative result of the research has been the important contribution that some specific visualization modalities of LIDAR data obtained through specific tools such as the Relief Tool Visualization (e.g., Hillshading from multiple directions and Sky-View-Factor visualization) have provided in the identification of different degrees of legibility of the footprint of the Great War within the topography of today’s landscape. The validation phase on specific case studies, for example, on the system of Austro-Hungarian forts in Trentino (Italy) and on the entrenched system around Fort Busa Verle (Altopiano di Vezzena, TN, Italy), has allowed us to verify the effectiveness of this method not only on a qualitative but also on a quantitative level. In conclusion, therefore, the elaboration of the tool “stratigraphic telescope”, in addition to the new possibilities of narration introduced by it, is a significant methodological contribution to the definition of the “testimonial gradient” previously described as a crucial moment to consciously set up future projects. The implementation of the proposed method on other case histories and the theoretical-operational deepening of the other identified indicators are the main directions towards which future research perspectives can be developed. / Poco più di cent’anni fa, il Primo Conflitto Mondiale ha profondamente sconvolto il paesaggio dell’intera Europa: dai campi di Galizia alle pianure francesi, dall’arco alpino sino alle coste del Mar Baltico, la guerra di posizione e di trincea ha determinato trasformazioni incidendo il terreno, scavando le montagne, riorganizzando gli assetti territoriali e gli ecosistemi ambientali originali, lasciando spazio alla stratificazione di nuove tracce e significati che, nel corso del tempo, hanno contribuito alla costruzione di quello che oggi è universalmente riconosciuto come un patrimonio culturale fragile ad alta complessità. Se la Legge n.78 del 2001, come sintesi di un dibattito molto intenso e fecondo, protegge le vestigia della Prima guerra mondiale principalmente con l’obiettivo di tutelare questo particolare patrimonio storico senza alterarne «le caratteristiche materiali e storiche» (in ambito italiano), all’indomani delle celebrazioni per il Centenario ed alla luce di numerosi progetti che, sino ad oggi, si sono applicati al restauro/recupero/valorizzazione di questi beni, tornare ad indagare i “paesaggi di guerra” significa impostare una nuova ricerca per comprendere in che modo tali vestigia possano continuare a narrare il loro “essere nel tempo” anche alle prossime generazioni, stimolando “possibilità di memoria” e rappresentando al tempo stesso concrete risorse, culturali ma anche economiche, per il futuro. A seguito dell’analisi dello status quo di un campione rappresentativo di luoghi e manufatti e di progettualità concluse e in atto, a livello internazionale, è chiaramente sorto un problema di scala: la forza pregnante delle vestigia in quanto “sistema” profondamente connesso non solo da un’infrastrutturazione fisica di fortificazioni campali, trinceramenti, baraccamenti e campi ad ostacoli, ma anche da una fitta rete di relazioni intangibili e visuali che ne sostanziavano il funzionamento, oggi si sta sempre più indebolendo. A conferma di ciò si evidenzia, ad esempio, come la frammentazione degli interventi e delle politiche di gestione degli stessi si riverberi anche nella maggior attenzione dedicata dalla maggioranza dei progetti realizzati alle fortificazioni permanenti rispetto agli articolati sistemi trincerati che le circondavano e ne costituivano parte integrante. Per risolvere tale gap interpretativo-operativo, è emersa la necessità di recuperare una visione sistemica in grado di muoversi alle diverse scale e cogliere l’intangibile interezza del sistema-vestigia, oggi apparentemente infranta, focalizzando l’attenzione non ai frammenti in quanto “resti di un intero che ora non esiste più”, ma al potenziale che essi possono ancora generare se messi in tensione uno con l’altro: un campo magnetico in grado di legare le diverse parti e ricomporne i significati. Ciò ha portato ad allontanarsi dalla specificità dei singoli saperi disciplinari per abbracciare invece un approccio trasversale in grado di porre al centro il warscape ed analizzarlo nella sua intera natura e biografia di paesaggio-palinsesto pluristratifcato in tempi diversi. In questa prospettiva, l’indissolubile simbiosi tra “segni” fisici e valori immateriali depositatisi nel corso del tempo è risultata essere la peculiarità specifica del “carattere” di tali “paesaggi di guerra”, riconoscendo quindi la condizione di fragilità non quale punto di debolezza, quanto piuttosto come la loro peculiarità più “autentica”. Attraverso tale processo conoscitivo contemporaneamente induttivo e deduttivo, studiando non solo gli aspetti teorici e metodologici dell’analisi spaziale, ma anche le relazioni tra i fattori socio-culturali, storici ed antropologici che ne hanno definito sviluppo e trasformazioni, è stato quindi possibile individuare differenti “way of seeing” di questi warscapes, mettendo sempre più a fuoco la necessità di adottare una visione olistica per superare l’attuale frammentarietà di questo patrimonio e pensare al suo futuro senza tradirne l’autenticità. Operativamente questo approccio si è declinato attraverso due contemporanei livelli di ricerca. Per recuperare una visione sistemica anche in fase analitica, quale momento essenziale per impostare consapevolmente le future proposte operative, è stata definita una matrice d’ordine per rileggere la complessità: mettendo a sistema le tipologie costruttive con le differenti morfologie dei territori, è stato possibile identificare alcune “war-scape classes”, utili per interpretare la frammentarietà dei differenti “paesaggi di guerra” attraverso l’individuazione sia delle driving forces che ne avevano determinato la costruzione, in tempi diversi, sia delle stesse che ne possono determinare le traiettorie di cambiamento future. Attraverso l’individuazione delle differenti “war-scape classes” è stato possibile reinterpretare criticamente lo status quo di luoghi e manufatti attraverso uno “sguardo sistemico”. Sulla scorta di quanto emerso è stata quindi elaborata un’articolata analisi SWOT per mettere in luce le principali potenzialità e criticità delle vestigia a livello di sistema. La seconda declinazione dell’innovativo approccio olistico precedentemente proposto si è concentrata sul significato del riconoscimento dei “paesaggi di guerra” quali “luoghi della memoria”. Attraverso lo studio evolutivo delle diverse fasi di “costruzione della memoria della Grande Guerra”, che nel corso di tutto un secolo hanno alternato molteplici e polisense “pratiche di narrazione”, è stato possibile meglio comprendere i processi che hanno portato al riconoscimento del valore testimoniale delle vestigia, e quindi di quel “sense of place” specifico che, metaforicamente, identifica i differenti warscapes quali “condensatori di valori ad alta capacità”, in cui l’intensità del potenziale (la pregnanza di significati/nuove ri-significazioni) è direttamente proporzionale alla carica che si genera nel momento in cui vengono rafforzate le relazioni tra i diversi poli (arcipelago di vestigia in quanto frammenti). A questo specifico riguardo, è stato possibile individuare lo spazio fisico della soglia tra “il visibile e il sommerso” quale bacino di accumulo particolarmente denso e pregnante da “indagare poeticamente” per disvelare le permanenze dell’impronta della guerra (ivi manifestatasi tanto a livello fisico nella “materia signata” dal conflitto quanto nei significati assunti da tali “segni”), oggi ancora presente ma “nascosta” al di sotto dei molteplici layer deposizionali che si sono stratificati nel corso del tempo. Le considerazioni ottenute attraverso i due livelli di ricerca sopra descritti sono state messe a sistema con una riflessione a livello teorico rispetto al riconoscimento dei “paesaggi di guerra” in quanto “patrimonio” inteso nelle sue diverse accezioni etimologiche (legacy, inheritance e patrimony). In questo modo è stato possibile meglio constualizzare il significato del concetto di enhancement applicato a questo patrimonio, facendo affiorare alcuni nuclei semantici attualmente critici, rispetto al rafforzamento e/o valorizzazione dei quali indirizzare consapevolmente i futuri orientamenti di priorità. Oltre alla necessità di proporre nuove strategie riguardanti le policies di coordinamento e gestione dei processi con particolare attenzione all’importanza degli aspetti partecipativi (questioni individuate ma non approfondite in dettaglio nella presente ricerca), e all’esigenza di meglio comprendere alcuni aspetti di tecnologia costruttiva (legati alle sperimentazioni tecnologiche del cemento rinforzato del cui comportamento strutturale poco si conosce), la questione prioritaria, emersa con forza, è stata la stringente necessità di elaborare nuove strategie operative per facilitare il riconoscimento, all’interno del paesaggio contemporaneo pluri-stratificato, dei diversi livelli di permanenza delle vestigia, tra cui in particolare dei “segni” più fragili in quanto a permanenza, attualmente a maggior “rischio di perdita”. In una visione inter-scalare, questo aspetto ha assunto ancor maggior importanza nella consapevolezza che la capacità di riconoscere diverse aree rispetto cui le vestigia permangono nella contemporaneità a differenti livelli di pregnanza semantica, costituisce un presupposto necessario alle future progettualità per operare recuperando quella visione sistemica oggi perduta, garantendo al sistema-vestigia, proprio in quanto tale, diversi margini di progettabilità, conservando la nostra “possibilità di memoria” attraverso la sua potenzialità evocativa. In questa prospettiva, la ricerca ha quindi elaborato e proposto un “metodo nella complessità” utile per facilitare il riconoscimento di ciò che può avere valore testimoniale alla scala del paesaggio attraverso l’individuazione di aree in cui le vestigia della guerra permangono a differenti temperature. Si tratta a tutti gli effetti di un nuovo paradigma che, muovendo dalla necessità di recuperare uno sguardo sistemico in grado di riconoscere le permanenze anche delle vestigia più fragili, dilata il significato di “valore di testimonianza” alla scala del “warscape” introducendo il concetto di “gradiente testimoniale”. Si tratta di un parametro utile ad identificare i diversi ambiti nei quali il grado di pregnanza semantica delle vestigia e le relative “possibilità di memoria” risultano graduati in base al livello di conoscenza di specifici indicatori, quali gli aspetti storico-identitari, le conoscenze tipologico-costruttive dei manufatti, il grado di coinvolgimento delle comunità e, soprattutto, la leggibilità del sistema-vestigia. Oltre ad aver definito a livello concettuale il significato di tali indicatori, la ricerca ha sviluppato anche un metodo analitico basato su di un’analisi multicriteriale per rendere operative le considerazioni qualitative espresse dai parametri conoscitivi precedentemente individuati ed ottenere delle vere e proprie mappe della fragilità dei diversi warscapes. Tali elaborati sono particolarmente interessanti non solo perché restituiscono una visione complessiva della densità semantica di un dato contesto, ma in quanto costituiscono un vero e proprio strumento proattivo verso le future pratiche di “cura”, la base conoscitiva indispensabile su cui fondare le future scelte in termini di conservazione, protezione ed enhancement. Alla luce delle precedenti considerazioni è emersa la consapevolezza di quanto necessaria sia la collaborazione interdisciplinare per la definizione degli indicatori costituivi il “gradiente testimoniale”: l’ultima parte della presente ricerca si è quindi concentrata principalmente sull’elaborazione di un metodo operativo per facilitare l’approfondimento di due di questi indicatori, in relazioni anche alle criticità precedentemente emerse, legate alle questioni di riconoscibilità delle permanenze più fragili, sia da un punto di vista d’insieme che di tecnologia costruttiva. Con l’obiettivo quindi di contribuire al disvelamento del bacino informativo ampio e profondo quale è stato riconosciuto il complesso sistema di vestigia visibili ma anche “sommerse”, la ricerca ha proposto l’elaborazione di un metodo conoscitivo denominato “cannocchiale stratigrafico”, uno strumento metodologico in grado di esplorare i processi di costruzione/trasformazione dei paesaggi di guerra alle diverse scale. Tale metodo si è dimostrato essere un contributo conoscitivo molto fertile per affiancare allo studio dei documenti d’archivio e dei Manuali di fortificazioni, bagaglio conoscitivo irrinunciabile per meglio comprendere le tecniche costruttive, i dettagli tecnici e tecnologici, i materiali utilizzati e le soluzioni tattiche o d’impianto proposte, l’applicazione alla scala del paesaggio del codice interpretativo proprio della stratigrafia dell’architettura, che interpreta la storia dei manufatti come esito di processi di apporto, sottrazione e trasformazione che hanno lasciato tracce fisiche collegate tra loro in una sequenza stratigrafica. Operativamente ciò si è declinato nell’interpretazione delle dinamiche di trasformazione archeologica dei paesaggi nel corso del tempo, mettendo a confronto l’impatto dell’evento bellico di cent’anni fa con la ricognizione attuale degli usi del suolo e delle permanenze delle vestigia, principalmente attraverso l’analisi, comparazione e relative interpretazioni tra documentazione storica, fotografie aree d’epoca, ortofoto attuali ed elaborazioni dei dati ottenuti da tecniche di telerilevamento ad alta risoluzione (remote sensing). In questa prospettiva, fondamentale è stato l’utilizzo di software per la creazione di Sistemi Geografici Informativi come ArcGis e QuantumGis in quanto tali ambienti di lavoro hanno permesso una coordinazione complessiva dell’intero processo conoscitivo: dalla gestione integrata dei diversi dataset di input (georeferenziazione di mappe storiche di militarizzazione e fotografie aeree militari) all’elaborazione degli outputs attesi. A questo riguardo, il risultato più innovativo ottenuto della ricerca è stato l’importante contributo che alcune specifiche modalità di visualizzazione dei dati LIDAR ottenute attraverso specifici tools quali il Relief Tool Visualization (ad esempio Hillshading from multiple directions e Sky-View-Factor visualization) hanno fornito nell’identificazione dei diversi gradi di leggibilità dell’impronta della Grande Guerra all’interno della topografia del paesaggio d’oggi. La fase di validazione su specifici casi-studio, ad esempio sul sistema dei forti austro-ungarici del Trentino (Italia) e sul sistema trincerato insistente nell’intorno di Forte Busa Verle (Altopiano di Vezzena, TN, Italy), ha permesso di verificare l’effettiva efficacia di tale metodo a livello non solo qualitativo ma anche quantitativo. In conclusione, quindi, l’elaborazione dello strumento “cannocchiale stratigrafico”, oltre alle nuove possibilità di narrazione da esso introdotte, costituisce un importante contributo metodologico per la definizione del “gradiente testimoniale” precedentemente descritto, quale momento necessario per impostare consapevolmente le future progettualità. L’implementazione del metodo proposto su altre casistiche e l’approfondimento teorico-operativo rispetto agli altri indicatori individuati costituiscono le principali direzioni verso cui possono essere sviluppate future prospettive di ricerca.

In this paper, a set of local radiosonde meteorological data, from 1990 to 2005, have been used to statistically analyze the refractivity gradient, DeltaN, at the lowest 65 m, 100 m and 1 km of the atmosphere above the surface of the Earth in the Gulf region. These three levels are the reference atmospheric layers in which the refractivity gradients have been evaluated by the ITU-R Recommendations P.453-10 and P.452-12The vertical variations of the refractivity profile aredisplayed through the cumulative distributions of the refractivity gradients at the targeted levels. The obtained results are compared for the three layers and also compared with the estimated values in the ITU maps and tables when available. Index Terms – Atmospheric refraction, Refractivity gradient.

Small scale renewable energy harvesting is an attractive solution to the growing need for power in remote technological applications. For this purpose, localized thermal gradients on-chip—created via radiative cooling—could be exploited to produce microscale renewable heat engines running on environmental heat. This could allow self-powering in small scale portable applications, thus reducing the need for non-renewable sources of electricity and hazardous batteries. In this work, we demonstrate the creation of a local thermal gradient on-chip by radiative cooling of a 90 nm thick freestanding silicon nitride nanomechanical resonator integrated on a silicon substrate at ambient temperature. The reduction in temperature of the thin film is inferred by tracking its mechanical resonance frequency, under high vacuum, using an optical fiber interferometer. Experiments were conducted on 15 different days during fall and summer months, resulting in successful radiative cooling in each case. Maximum temperature drops of 9.3 K and 7.1 K are demonstrated during the day and night, respectively, in close correspondence with our heat transfer model. Future improvements to the experimental setup could enhance the temperature reduction to 48 K for the same membrane, while emissivity engineering potentially yields a maximum theoretical cooling of 67 K with an ideal emitter. This thesis first elaborates a literature review on the field of radiative cooling, along with a theoretical review of relevant thermal radiation concepts. Then, a heat transfer model of the radiative cooling experiment is detailed, followed by the experimental method, apparatus, and procedures. Finally, the experimental and theoretical results are presented, along with future work and concluding remarks.

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