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1
Cruz, Shane Elliot 1979. "An investigation into better techniques for geo-targeting." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/87222.
Повний текст джерелаАнотація:
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references (p. 81-84).
by Shane Elliot Cruz.
M.Eng.
2
Picavet, Paul. "Les meules rotatives de la fin de l'Âge du Fer au haut Moyen Âge entre la Seine et le Rhin." Thesis, Lille, 2019. http://www.theses.fr/2019LIL3H005.
Повний текст джерелаАнотація:
Les meules, pièces maîtresses et les mieux conservées des moulins, sont emblématiques des questions relatives à l’histoire de l’économie et des techniques.De l’économie, parce que l’analyse des roches meulières révèle une chaîne complexe de recherche des ressources, d’extraction, de mise en forme, de distribution et d’utilisation qui dépend d’une série de facteurs qui ne concernent pas seulement les meules mais peuvent s’appliquer à toutes sortes de productions artisanales répondant à des besoins primaires de subsistance.Des techniques, parce que l’amélioration des procédés de mouture est le fruit d’une transmission des savoir-faire techniques alliée à une recherche constante de la meilleure réponse possible à des besoins alimentaires qui eux-mêmes évoluent. Cette notion de progrès technique, que l’on observe à la fois sur le temps long (ici plus d’un millénaire) et à l’occasion de brèves transitions politico-culturelles (la conquête romaine de la Gaule puis les migrations germaniques), est à l’origine de profonds changements socio-économiques.Sur la base de travaux de terrain (prospections thématiques), d’analyses d’objets (les meules) et d’un tour d’horizon bibliographique, cette thèse présente une synthèse régionale sur un type de mobilier modeste mais structurant des sociétés et des économies anciennesMillstones, as the centerpieces and the best preserved elements of mills, are characteristic of the questions relating to the history of techniques and economics.Of economics, because analysis of the rocks from which they are made reveal a complex chain including their research, extraction, shaping, distribution and use. The factors on which this chain depends don’t only concern querns and millstones but can be applied to all types of craft production that answer to primary needs of subsistence.Of techniques because the improving of milling processes is due to a transmission of technical savoir-faire, mixed with a constant research for the best solution to evolving food needs. This notion of technical progress is observed both over a long time scale (1000 years) and during brief political and cultural transitions (the Roman conquest of Gaul, and the Germanic migrations). This evolution is the basis of deep social and economic changes.Based on field surveys, artifact analysis (querns and millstones) and a literature survey, this thesis presents a regional synthesis on a modest but structuring element of ancient societies and their economies
3
Gao, Mengfei [Verfasser]. "Combining expansion microscopy with other super-resolution techniques / Mengfei Gao." Berlin : Freie Universität Berlin, 2020. http://d-nb.info/1205314776/34.
Повний текст джерела
4
Chini, Marco <1973>. "Radar and optical remote sensing techniques for earthquake damage mapping." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/863/1/Tesi_Chini_Marco.pdf.
Повний текст джерела
5
Chini, Marco <1973>. "Radar and optical remote sensing techniques for earthquake damage mapping." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/863/.
Повний текст джерела
6
Ferrara, Carlotta <1983>. "Ground penetrating radar early-time technique for soil electromagnetic parameters estimation." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6311/1/Ferrara_Carlotta_Tesi.pdf.
Повний текст джерелаАнотація:
In recent years, thanks to the technological advances, electromagnetic methods for non-invasive shallow subsurface characterization have been increasingly used in many areas of environmental and geoscience applications. Among all the geophysical electromagnetic methods, the Ground Penetrating Radar (GPR) has received unprecedented attention over the last few decades due to its capability to obtain, spatially and temporally, high-resolution electromagnetic parameter information thanks to its versatility, its handling, its non-invasive nature, its high resolving power, and its fast implementation.
The main focus of this thesis is to perform a dielectric site characterization in an efficient and accurate way studying in-depth a physical phenomenon behind a recent developed GPR approach, the so-called early-time technique, which infers the electrical properties of the soil in the proximity of the antennas. In particular, the early-time approach is based on the amplitude analysis of the early-time portion of the GPR waveform using a fixed-offset ground-coupled antenna configuration where the separation between the transmitting and receiving antenna is on the order of the dominant pulse-wavelength. Amplitude information can be extracted from the early-time signal through complex trace analysis, computing the instantaneous-amplitude attributes over a selected time-duration of the early-time signal. Basically, if the acquired GPR signals are considered to represent the real part of a complex trace, and the imaginary part is the quadrature component obtained by applying a Hilbert transform to the GPR trace, the amplitude envelope is the absolute value of the resulting complex trace (also known as the instantaneous-amplitude).
Analysing laboratory information, numerical simulations and natural field conditions, and summarising the overall results embodied in this thesis, it is possible to suggest the early-time GPR technique as an effective method to estimate physical properties of the soil in a fast and non-invasive way.
7
Ferrara, Carlotta <1983>. "Ground penetrating radar early-time technique for soil electromagnetic parameters estimation." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6311/.
Повний текст джерелаАнотація:
In recent years, thanks to the technological advances, electromagnetic methods for non-invasive shallow subsurface characterization have been increasingly used in many areas of environmental and geoscience applications. Among all the geophysical electromagnetic methods, the Ground Penetrating Radar (GPR) has received unprecedented attention over the last few decades due to its capability to obtain, spatially and temporally, high-resolution electromagnetic parameter information thanks to its versatility, its handling, its non-invasive nature, its high resolving power, and its fast implementation.
The main focus of this thesis is to perform a dielectric site characterization in an efficient and accurate way studying in-depth a physical phenomenon behind a recent developed GPR approach, the so-called early-time technique, which infers the electrical properties of the soil in the proximity of the antennas. In particular, the early-time approach is based on the amplitude analysis of the early-time portion of the GPR waveform using a fixed-offset ground-coupled antenna configuration where the separation between the transmitting and receiving antenna is on the order of the dominant pulse-wavelength. Amplitude information can be extracted from the early-time signal through complex trace analysis, computing the instantaneous-amplitude attributes over a selected time-duration of the early-time signal. Basically, if the acquired GPR signals are considered to represent the real part of a complex trace, and the imaginary part is the quadrature component obtained by applying a Hilbert transform to the GPR trace, the amplitude envelope is the absolute value of the resulting complex trace (also known as the instantaneous-amplitude).
Analysing laboratory information, numerical simulations and natural field conditions, and summarising the overall results embodied in this thesis, it is possible to suggest the early-time GPR technique as an effective method to estimate physical properties of the soil in a fast and non-invasive way.
8
Chen, Weiyi. "L'hétérogénéisation et l'altérité : Guo Xi, Giuseppe Castiglione et Xu Baihong. Ou la modification dans la peinture chinoise." Thesis, Université de Paris (2019-....), 2019. http://www.theses.fr/2019UNIP7007.
Повний текст джерелаАнотація:
Les images, les peintures montrent davantage ce qu’il y a d’inattendu, de surprenant dans la pensée de l’autre, elles nous aident à voir et à comprendre l’altérité. Cette recherche se présente comme une rétrospective de la transformation de la pensée chinoise à travers les œuvres de trois peintres qui sembleraient marquer des jalons dans l’histoire d’une rencontre avec l’autre : Guo Xi, Giuseppe Castiglione et Xu Beihong. Les œuvres nous serviront d’appui pour discuter sur la culture et sa transformation. Dans ce sens Guo Xi nous permettra de discuter sur l’altérité de la peinture et la pensée chinoises, Giuseppe Castiglione et Xu Beihong nous aideront à montrer comment la peinture européenne, qui est un autre pour la Chine, a transformé le champ visuel en Chine. Pourtant, une rétrospective est inévitablement anachronique : en essayant de situer les peintres dans leur époque, nous les voyons toujours à partir de la situation actuelle. Mais cet anachronisme fait en même temps tout l’intérêt d’une recherche qui a pour objectif de décrire la rencontre, l’hétérogénéisation et la globalisation comme un processus dans la durée. L’hétérogénéisation est comprise comme un enrichissement incessant au sein de la culture et la globalisation est comprise comme un processus où les cultures, chinoise et européenne, se trouvent en confrontation l’une avec l’autre. Ces deux termes sont les facettes de la rencontre entre la Chine et l’Occident, qui a marqué profondément l’histoire moderne et qui est toujours en train de se réaliser. L’objectif de ce travail est de montrer par où la Chine entre dans ce processus de la globalisation et de montrer l’issue intermédiaire de la confrontation de la peinture chinoise avec la peinture européenneThe images, paintings show what is unexpected, surprising in the thought of the other, they help us to see and understand otherness. This research presents itself as a retrospective of the transformation of the Chinese thought through the works of three painters who seem to mark milestones in the history of encountering with the other: Guo Xi, Giuseppe Castiglione and Xu Beihong. The artworks serve as support for the discussion of culture and its transformation. In this sense Guo Xi will allow us to discuss the otherness of the Chinese painting and thought, Giuseppe Castiglione and Xu Beihong will help us to show how the European painting, which is the other for China, has transformed the visual field in China. However, a retrospective is inevitably anachronistic: by trying to locate painters in their own context, we always see them from the current situation. But this anachronism is at the same time the very point of interest of the research that aims to describe the encounter, heterogenization and globalisation as a long-term process. Heterogenization is understood as an enrichment of culture and globalisation is understood as a process in which cultures, Chinese and European, are in confrontation with one another. These two terms are the facets of the encounter between China and the West, which has profoundly affected modern history and is still ongoing. The objective of this work is to show where China is entering this process of globalisation and show the intermediate outcome of the confrontation of the Chinese painting with the European painting
9
Ferrari, F. "ROCK MASS CHARACTERIZATION AND SPATIAL ESTIMATION OF GEOMECHANICAL PROPERTIES THROUGH GEOSTATISTICAL TECHNIQUES." Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/231572.
Повний текст джерелаАнотація:
This thesis deals with geostatistics, which is a branch of statistics focusing on spatial or spatiotemporal
datasets, and explores its possible application to rock mechanics, with particular reference to wide areas,
located in the Alpine context. The final objective of this work is the estimation (i.e. the prediction), through
geostatistical techniques, of the geomechanical parameters determining the quality of rock masses, starting
form punctual and scattered sampling locations.This thesis is a contribute in assessing how the rock mass features, in the Alpine geological context, can be
regarded as regionalized variables, and the geostatistical tool can be used to foresee the spatial structure of
rock masses. The main topic regards the estimation of rock mass properties, and their associated variations,
at regional scale, through geostatistical techniques. The estimation consists in forecasting the behaviour and
the values of a regionalized variable, in an area, starting form punctual and scattered measures.
The main challenge is to understand if the geostatistical techniques, applied so successfully to local and
specific problems, can be applied also at regional scale (i.e. considering very wide portion of territory),
finding the best method useful to make estimation of that scale. Actually to have a tool able to predict the
rock mass parameters at regional scale can be very useful in areas interested by the planning and construction
of large-scale engineering works. The study areas, chosen to verify the applicability of geostatistical
methods at regional scale, are both located in the Central Alps: the first is the Italian Alpine Valley named
Valchiavenna (SO), while the second is in Switzerland, near the Grimselpass.The main innovative aspercts
of this thesis, respect to the previous works, are:
- the area involved in the estimations: very wide areas have been considered in order to verify if
geostatistics give good results also at regional scale;
- the geology of the site: hard rock masses outcropping on two different location of the Alpine chain
have been investigated: the first one is in the Italian Central Alps and the second one in the Swiss
Alps;- the starting measurements: data have been collected in situ using both direct and indirect measurements
(i.e. geomechanical survey in Valchiavenna, combined with photogrammetric analysis at
Grimsel test site).
10
Adani, Mario <1977>. "Reanalysis Techniques for the numerical modelling of the Mediterranean Sea Circulation." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/861/1/Tesi_Adani_Mario.pdf.
Повний текст джерела
11
Adani, Mario <1977>. "Reanalysis Techniques for the numerical modelling of the Mediterranean Sea Circulation." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/861/.
Повний текст джерела
12
Gualandi, Adriano <1987>. "Spatial and temporal characterisation of ground deformation recorded by geodetic techniques." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7093/1/Gualandi_Adriano_tesi.pdf.
Повний текст джерелаАнотація:
A critical point in the analysis of ground displacements time series is the development of data driven methods that allow the different sources that generate the observed displacements to be discerned and characterised. A widely used multivariate statistical technique is the Principal Component Analysis (PCA), which allows reducing the dimensionality of the data space maintaining most of the variance of the dataset explained. Anyway, PCA does not perform well in finding the solution to the so-called Blind Source Separation (BSS) problem, i.e. in recovering and separating the original sources that generated the observed data. This is mainly due to the assumptions on which PCA relies: it looks for a new Euclidean space where the projected data are uncorrelated. The Independent Component Analysis (ICA) is a popular technique adopted to approach this problem. However, the independence condition is not easy to impose, and it is often necessary to introduce some approximations. To work around this problem, I use a variational bayesian ICA (vbICA) method, which models the probability density function (pdf) of each source signal using a mix of Gaussian distributions. This technique allows for more flexibility in the description of the pdf of the sources, giving a more reliable estimate of them. Here I present the application of the vbICA technique to GPS position time series. First, I use vbICA on synthetic data that simulate a seismic cycle (interseismic + coseismic + postseismic + seasonal + noise) and a volcanic source, and I study the ability of the algorithm to recover the original (known) sources of deformation. Secondly, I apply vbICA to different tectonically active scenarios, such as the 2009 L'Aquila (central Italy) earthquake, the 2012 Emilia (northern Italy) seismic sequence, and the 2006 Guerrero (Mexico) Slow Slip Event (SSE).
13
Gualandi, Adriano <1987>. "Spatial and temporal characterisation of ground deformation recorded by geodetic techniques." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amsdottorato.unibo.it/7093/.
Повний текст джерелаАнотація:
A critical point in the analysis of ground displacements time series is the development of data driven methods that allow the different sources that generate the observed displacements to be discerned and characterised. A widely used multivariate statistical technique is the Principal Component Analysis (PCA), which allows reducing the dimensionality of the data space maintaining most of the variance of the dataset explained. Anyway, PCA does not perform well in finding the solution to the so-called Blind Source Separation (BSS) problem, i.e. in recovering and separating the original sources that generated the observed data. This is mainly due to the assumptions on which PCA relies: it looks for a new Euclidean space where the projected data are uncorrelated. The Independent Component Analysis (ICA) is a popular technique adopted to approach this problem. However, the independence condition is not easy to impose, and it is often necessary to introduce some approximations. To work around this problem, I use a variational bayesian ICA (vbICA) method, which models the probability density function (pdf) of each source signal using a mix of Gaussian distributions. This technique allows for more flexibility in the description of the pdf of the sources, giving a more reliable estimate of them. Here I present the application of the vbICA technique to GPS position time series. First, I use vbICA on synthetic data that simulate a seismic cycle (interseismic + coseismic + postseismic + seasonal + noise) and a volcanic source, and I study the ability of the algorithm to recover the original (known) sources of deformation. Secondly, I apply vbICA to different tectonically active scenarios, such as the 2009 L'Aquila (central Italy) earthquake, the 2012 Emilia (northern Italy) seismic sequence, and the 2006 Guerrero (Mexico) Slow Slip Event (SSE).
14
Corcoran, Jonathan. "Computational techniques for the geo-temporal analysis of crime and disorder data." Thesis, University of South Wales, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289394.
Повний текст джерела
15
Tas, Volkan. "Optimal Use of TDOA Geo-Location Techniques Within the Mountainous Terrain of Turkey." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/17467.
Повний текст джерелаАнотація:
Emitter location finding enables important functionality for both military and civilian applications. GPS is the most recognized and widely used positioning system, but it is a receiver location system that functions in a markedly different manner from emitter location. Many geo-location techniques predate and have been proposed as an alternative to GPS. Some of the more commonly used and exploited of these techniques are angle of arrival, time of arrival, frequency difference of arrival, and time difference of arrival (TDOA). This thesis is primarily focused on TDOA. These techniques are important for military applications. Location finding is a part of electronic warfare support, which is one of the main braches of electronic warfare. Because these techniques are platform independent, they can be used with any system or platform, such as UAVs, manned aircraft, ground locations, etc. In Turkey it is vitally important for the army conducting search and destroy operations against terrorists to locate emitters associated with these terrorists. The simulation developed in this thesis provides a better understanding of the accuracy of TDOA based geolocation systems. Combinations of receivers and techniques are explored to determine the optimal solutions. The factors of noise and distance have a linear effect on accuracy. The best combination of receivers is determined with consideration to using a combination of fixed and airborne platforms. The best distribution for highest accuracy is determined and discussed.
16
Li, Zhao. "Subsurface Simulation Using Stochastic Modeling Techniques for Reliability Based Design of Geo-structures." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1466691128.
Повний текст джерела
17
Mori, Guido <1978>. "The use of Ground Penetrating Radar and alternative geophysical techniques for assessing embankments and dykes safety." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2138/1/Mori_Guido_Tesi.pdf.
Повний текст джерелаАнотація:
The research is part of a survey for the detection of the hydraulic and geotechnical conditions of river embankments funded by the Reno River Basin Regional Technical Service
of the Region Emilia-Romagna. The hydraulic safety of the Reno River, one of the main rivers in North-Eastern Italy, is indeed of primary importance to the Emilia-Romagna regional administration. The large longitudinal extent of the banks (several hundreds of kilometres) has placed great
interest in non-destructive geophysical methods, which, compared to other methods such as drilling, allow for the faster and often less expensive acquisition of high-resolution data.
The present work aims to experience the Ground Penetrating Radar (GPR) for the detection of local non-homogeneities (mainly stratigraphic contacts, cavities and conduits) inside the Reno River and its tributaries embankments, taking into account supplementary data collected with traditional destructive tests (boreholes, cone penetration tests etc.). A comparison with non-destructive methodologies likewise electric resistivity tomography (ERT), Multi-channels Analysis of Surface Waves (MASW), FDEM induction, was also carried out in order to verify the usability of GPR and to provide integration of various geophysical methods in the process of regular maintenance and check of the embankments condition.
The first part of this thesis is dedicated to the explanation of the state of art concerning the geographic, geomorphologic and geotechnical characteristics of Reno River and its tributaries embankments, as well as the description of some geophysical applications provided on embankments belonging to European and North-American Rivers, which were used as bibliographic basis for this thesis realisation.
The second part is an overview of the geophysical methods that were employed for this research, (with a particular attention to the GPR), reporting also their theoretical basis and a deepening of some techniques of the geophysical data analysis and representation, when applied to river embankments.
The successive chapters, following the main scope of this research that is to highlight advantages and drawbacks in the use of Ground Penetrating Radar applied to Reno River and its tributaries embankments, show the results obtained analyzing different cases that could yield the formation of weakness zones, which successively lead to the embankment failure. As advantages, a considerable velocity of acquisition and a spatial resolution of the obtained data, incomparable with respect to other methodologies, were recorded. With regard to the drawbacks, some factors, related to the attenuation losses of wave propagation, due to different content in clay, silt, and sand, as well as surface effects have significantly limited the correlation between GPR profiles and geotechnical information and therefore compromised the embankment safety assessment.
Recapitulating, the Ground Penetrating Radar could represent a suitable tool for checking up river dike conditions, but its use has significantly limited by geometric and geotechnical characteristics of the Reno River and its tributaries levees. As a matter of facts, only the shallower part of the embankment was investigate, achieving also information just related to changes in electrical properties, without any numerical measurement. Furthermore, GPR application is ineffective for a preliminary assessment of embankment safety conditions,
while for detailed campaigns at shallow depth, which aims to achieve immediate results with optimal precision, its usage is totally recommended.
The cases where multidisciplinary approach was tested, reveal an optimal interconnection of the various geophysical methodologies employed, producing qualitative
results concerning the preliminary phase (FDEM), assuring quantitative and high confidential description of the subsoil (ERT) and finally, providing fast and highly detailed analysis (GPR). Trying to furnish some recommendations for future researches, the simultaneous
exploitation of many geophysical devices to assess safety conditions of river embankments is absolutely suggested, especially to face reliable flood event, when the entire extension of the embankments themselves must be investigated.
18
Mori, Guido <1978>. "The use of Ground Penetrating Radar and alternative geophysical techniques for assessing embankments and dykes safety." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/2138/.
Повний текст джерелаАнотація:
The research is part of a survey for the detection of the hydraulic and geotechnical conditions of river embankments funded by the Reno River Basin Regional Technical Service
of the Region Emilia-Romagna. The hydraulic safety of the Reno River, one of the main rivers in North-Eastern Italy, is indeed of primary importance to the Emilia-Romagna regional administration. The large longitudinal extent of the banks (several hundreds of kilometres) has placed great
interest in non-destructive geophysical methods, which, compared to other methods such as drilling, allow for the faster and often less expensive acquisition of high-resolution data.
The present work aims to experience the Ground Penetrating Radar (GPR) for the detection of local non-homogeneities (mainly stratigraphic contacts, cavities and conduits) inside the Reno River and its tributaries embankments, taking into account supplementary data collected with traditional destructive tests (boreholes, cone penetration tests etc.). A comparison with non-destructive methodologies likewise electric resistivity tomography (ERT), Multi-channels Analysis of Surface Waves (MASW), FDEM induction, was also carried out in order to verify the usability of GPR and to provide integration of various geophysical methods in the process of regular maintenance and check of the embankments condition.
The first part of this thesis is dedicated to the explanation of the state of art concerning the geographic, geomorphologic and geotechnical characteristics of Reno River and its tributaries embankments, as well as the description of some geophysical applications provided on embankments belonging to European and North-American Rivers, which were used as bibliographic basis for this thesis realisation.
The second part is an overview of the geophysical methods that were employed for this research, (with a particular attention to the GPR), reporting also their theoretical basis and a deepening of some techniques of the geophysical data analysis and representation, when applied to river embankments.
The successive chapters, following the main scope of this research that is to highlight advantages and drawbacks in the use of Ground Penetrating Radar applied to Reno River and its tributaries embankments, show the results obtained analyzing different cases that could yield the formation of weakness zones, which successively lead to the embankment failure. As advantages, a considerable velocity of acquisition and a spatial resolution of the obtained data, incomparable with respect to other methodologies, were recorded. With regard to the drawbacks, some factors, related to the attenuation losses of wave propagation, due to different content in clay, silt, and sand, as well as surface effects have significantly limited the correlation between GPR profiles and geotechnical information and therefore compromised the embankment safety assessment.
Recapitulating, the Ground Penetrating Radar could represent a suitable tool for checking up river dike conditions, but its use has significantly limited by geometric and geotechnical characteristics of the Reno River and its tributaries levees. As a matter of facts, only the shallower part of the embankment was investigate, achieving also information just related to changes in electrical properties, without any numerical measurement. Furthermore, GPR application is ineffective for a preliminary assessment of embankment safety conditions,
while for detailed campaigns at shallow depth, which aims to achieve immediate results with optimal precision, its usage is totally recommended.
The cases where multidisciplinary approach was tested, reveal an optimal interconnection of the various geophysical methodologies employed, producing qualitative
results concerning the preliminary phase (FDEM), assuring quantitative and high confidential description of the subsoil (ERT) and finally, providing fast and highly detailed analysis (GPR). Trying to furnish some recommendations for future researches, the simultaneous
exploitation of many geophysical devices to assess safety conditions of river embankments is absolutely suggested, especially to face reliable flood event, when the entire extension of the embankments themselves must be investigated.
19
Rossi, Matteo. "Non invasive hydrogeophysical techniques for vadose zone hydrological characterization." Doctoral thesis, Università degli studi di Padova, 2010. http://hdl.handle.net/11577/3427485.
Повний текст джерелаАнотація:
Hydrogeophysics is a discipline that emerged and had a great development in the last two decades. The aim of this discipline is the subsurface hydrological and hydrogeological characterization via non-invasive geophysical techniques. Conventional sampling techniques, for characterizing or monitoring the shallow subsurface, are typically sparsely distributed or acquired at an inappropriate scale. Non-invasive geophysical datasets can provide more dense 2D/3D information. The present work focused on the hydrological characterization of the vadose zone, as it is a challenging issue that may be more deeply and extended understood.
The dependence of the geophysical response on changes in soil moisture content, e.g. via changes in electrical resistivity or dielectric properties, is the key mechanism that permits the use of non-invasive techniques to monitor the vadose zone in time-lapse mode, i.e. via repeated measurements over time. The use of these techniques in different configurations in the shallow and deep vadose zones can provide high-resolution images of hydrogeological structures and a detailed assessment of dynamic processes in the subsurface environment. The data from non-invasive techniques can subsequently be used to calibrate physical-mathematical models of water flow in the unsaturated zone. The understanding of fluid-dynamics is the key to all hydrologically-controlled environmental problems. The hydrogeophysical approach is based on links that can be established between geophysical quantities and hydrological variables, such as water content and solute concentration, generally in the form of empirical or semi-empirical petrophysical relationships.
The classical hydrogeophysical approach in hydraulic parameters evaluation starts from the measured geophysical data to estimate the hydrological state, albeit careful is need at this step: essential is the knowledge achievable from field data and the relative accuracy in the physical translation. Anyway this is the starting point for the hydrological simulation. Subsequently the hydrological modelled parameters may be compared and evaluated with the hydrological quantities obtained from geophysics through the petrophysical relationships. This approach can lead to erroneous parameter inference, if the spatial resolution of the geophysical techniques is not taking into account.
A different approach can be proceed, to overcome this issue. In spite of translating geophysical parameters in hydrological quantities, the comparison may be done directly on the not-inverted geophysical data. The geophysical surveys can be simulated with a forward model, starting from the hydrological modelled properties distribution and applying the petrophysical relationship to reconstruct the geophysical spatially-distributed parameters. At this point geophysical measured and simulated data can be compared, with the aim of calibrate and validate the hydrological model under examination. This second approach, not requiring geophysical inversions, is able to overcome artefacts deriving from the inversion procedure; but the resolution of the surveys must be considered, because an hydrological state should not be reproduced from geophysical methodologies, even if the two datasets, both simulated and measured, are in a perfect fitting.
The work is divided in two complementary parts. The first part is centred on the hydrological quasi-steady state characterization from cross-hole radar measurements. In many studies cross-borehole zero offset profiles (ZOP) are used to infer subsoil moisture content, which are a key topic in hydrological modelling and consequently in hydraulic parameters estimation. The principal aim of this work is to have a more complete view of how boreholes GPR ZOP measurements are informative of the subsoil geometry and distribution of relative permittivity. This is essential in moisture content estimation, uncertainty quantification and in the initial setting of parameters necessary for starting an hydrological model. For this purpose three different ZOP datasets are analysed: a synthetic dataset and two field-measured datasets.
The second part of the work is the hydrogeophysical inversion of a tracer test in the vadose zone, conducted at the Hatfield site (near Doncaster, UK). The path of a tracer in vadose zone may be masked from the variations of the physical status surrounding the dispersive plume; this could lead to erroneous interpretations of the evolving plume. The load of the new water, that moves under gravitational forces, produces the raising of the degree of saturation in the media just below the plume. This incidental effect could significantly contribute to geophysical signals and hydrological characterizations. The aim of this study is the recognition and distinction of the paths of the new injected fluid from the groundwater, already present in the system and activated from pressure variations, in a sort of “piston” effect. The discrimination between the new percolating water and the old pushed-down water is a key issue in aquifer vulnerability and soil pollution migrations, which can affect the vadose zone. In this second part the hydrogeophysical inversion is conducted: the simulated hydrological quantities are used to obtain a geophysical forward model of ZOP surveys, that should be compared with measured ZOP soundings. An estimation of the goodness of the hydrological model is then possible. A particle tracking code is then run to detect the exact evolution of the tracer plume in the subsurface. A comparison with the results from the inverted geophysical datasets is able to discriminate the tracer fluid from the old water of the system and to individuate where the geophysical imaging could be deceptive and misleading.
The present work is an example of the hydrogeophysical inversion methods, where great emphasis is focused on the characterization of the hydraulic state preceding the tracer injection test. Anyway the system must be stressed under artificial hydraulic states to force the parameters estimation and to limit the range of probable hydrological models.L’idrogeofisica è una disciplina che è emersa ed ha avuto un importante sviluppo nelle ultime due decadi. Lo scopo di questa disciplina è la caratterizzazione idrologica ed idrogeologica del sottosuolo attraverso tecniche geofisiche non invasive. Le tecniche di campionamento convenzionali sono di norma spazialmente distribuite ed acquisite ad una scala impropria. Le tecniche geofisiche invece permettono indagini spazialmente più fitte in 2D o 3D. Il presente lavoro si focalizza sulla caratterizzazione idrologica della zona vadosa. I dati ottenuti dalle tecniche geofisiche possono essere utilizzati per calibrare modelli fisico matematici del flusso nella zona del non-saturo. Tale approccio idrogeofisico è basato su relazioni petrofisiche che legano le quantità geofisiche con le variabili idrologiche. Il classico approccio idrogeofisico parte dalle misure geofisiche per ottenere una stima di parametri idrologici, che a loro volta vengono impiegati in modelli idraulici in grado di fornire ulteriori proprietà del sistema idraulico del sottosuolo. I modelli idrologici vengono successivamente validati e calibrati con i risultati delle inversioni geofisiche in time-lapse. Questo approccio prevede l’inversione del dato geofisico, metodo che può portare ad immagini del sottosuolo che contengono artefatti e che non tengono conto della risoluzione della tecnica applicata. Un approccio differente prevede che ai parametri stimati dai modelli idraulici siano applicate le relazioni petrofisiche, al fine di tradurre le quantità idrologiche in quantità geofisiche. A questo punto la simulazione di modelli geofisici diretti permette un confronto immediato con i dati misurati, senza l’ausilio dell’inversione geofisica. Il presente lavoro è suddiviso in due parti. La prima parte è centrata sulla caratterizzazione idrologica dello stato stazionario iniziale attraverso misure radar (GPR). Lo scopo principale del lavoro è quello di quantificare quanto le misure GPR a zero offset profiling (ZOP) siano informative delle geometrie del sottosuolo e delle relative condizioni di contenuto idraulico dei materiali. Questo lavoro è essenziale per ottenere una stima del contenuto idrico del sottosuolo e della relativa incertezza che ne deriva, poiché tali stime sono il punto di partenza delle simulazioni idrauliche. La seconda parte del lavoro è focalizzata sulla inversione idrogeofisica di un test con tracciante salino condotto ad Hatfield (UK). L’approccio idrogeofisico adottato è quello di simulare misure geofisiche direttamente dalla distribuzione dei parametri idrologici calcolati, per ottenere una calibrazione di quelle quantità idrologiche scopo della metodologia applicata. La ricostruzione dell’evoluzione di un plume iniettato nella zona vadosa è interessante ai fini di identificare i possibili percorsi di un contaminante nel sottosuolo. A tale scopo un codice di particle tracking è stato applicato ai risultati dell’inversione idrologica. Il codice di partcle tracking è in grado di distinguere i percorsi dell’acqua iniettata dall’acqua già presente nel sistema e movimentata del cambiamento di pressione in atto, ‘effetto pistone’. Le inversioni delle misure geofisiche non permettono di distinguere il fluido tracciante dai cambiamenti del contenuto idrico dei materiali adiacenti al plume iniettato.
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Shaik, Asif ur Rahman, Siril Yella, and Mark Dougherty. "Image processing technique to count the number of logs in a timber truck." Högskolan Dalarna, Datateknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:du-11790.
Повний текст джерелаАнотація:
This paper summarises the results of using image processing technique to get information about the load of timber trucks before their arrival using digital images or geo tagged images. Once the images are captured and sent to sawmill by drivers from forest, we can predict their arrival time using geo tagged coordinates, count the number of (timber) logs piled up in a truck, identify their type and calculate their diameter. With this information we can schedule and prioritise the inflow and unloading of trucks in the light of production schedules and raw material stocks available at the sawmill yard. It is important to keep all the actors in a supply chain integrated coordinated, so that optimal working routines can be reached in the sawmill yard.
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Svensson, Johan. "Waste water in the vehicle industry : A pre-study on Volvo GTO waste water treatment plant and its future conditions." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-161141.
Повний текст джерелаАнотація:
This thesis aims to investigate and assess the future conditions for Volvo GTO Umeå after the installation of a new pre-treatment facility. The treatment method used is physical-chemical precipitation. Its function is to precipitate contaminants such as nickel, zinc and phosphorus, make them flocculate by adding a coagulant and separate the flocs by sedimentation. An investigation was carried out at the Volvo plant to locate the major inflow of waste water. These major inflows was analyzed and future scenarios was predicted by estimating a lower pre-treatment flow volume. The future scenarios showed that the volume and content will be greatly lowered. This will change many of the treatment plants performance factors, such as residence time, metal ion concentration and how much chemicals needed to treat the contaminants. Volvos physical-chemical precipitation plant was compared to the best available technique document drawn up in the framework of the implementation of the Industrial Emission Directive (2010/75/EU). The findings in the comparison showed that the Volvo plant works at a desirable degree and that the plant itself is considered best available technique when treating the current and future contaminants. Thus the physical-chemical precipitation technique can be used to treat the future waste water flows if the treatment plants performance factors are adjusted for.
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Cosoli, Simone <1976>. "Inference of the three-dimensional flow field in shallow water environments: application of the "Velocity Projection Technique" to the Northern Adriatic sea." Doctoral thesis, Università Ca' Foscari Venezia, 2007. http://hdl.handle.net/10579/735.
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Islam, Faiz ul. "In-Depth Analysis of Texas Accidents Using Data-Mining Techniques and Geo-Statistical Analyst Tools." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/28779.
Повний текст джерелаАнотація:
Traffic accidents have been a consistently growing problem in the United States. The road-safety issues have not been completely resolved and pose danger to people driving on the roadways. This research used various approaches and techniques to evaluate and analyze the Texas State traffic-accident dataset profoundly and meticulously. Data-mining techniques were used to analyze the accident dataset for Texas statistically, and information were collected. The resulting information from the analysis suggested that the city of Houston, Texas, was the point of persistent accidents and accounted for most accidents in all Texas cities. Therefore, Houston was analyzed further by using the geostatistical and geo-analyst tools in ArcGIS. The Geostatistical Analysis tools including Space-Time identified the key hotspot locations within the city to study the overall behavior, and developed prediction maps from the kriging tool. A similar approach can apply to other parts of Texas and any location in the United States.
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Buschmann, Stefan [Verfasser], and Jürgen [Akademischer Betreuer] Döllner. "A software framework for GPU-based geo-temporal visualization techniques / Stefan Buschmann ; Betreuer: Jürgen Döllner." Potsdam : Universität Potsdam, 2018. http://d-nb.info/1219515310/34.
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Van, den Dool Riaan. "Onboard image geo-referencing for LEO satellites." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1252.
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Butenschon, Momme <1973>. "Numerical simulations of the coastal marine ecosystem dynamics: integration techniques and data assimilation in a complex physical-biogeochemical model." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/552/1/butenschon.pdf.
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Butenschon, Momme <1973>. "Numerical simulations of the coastal marine ecosystem dynamics: integration techniques and data assimilation in a complex physical-biogeochemical model." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/552/.
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Smorti, Nathaniel Mark James. "How does it go? An investigation into interpretive options of selected clarinet works." Thesis, Griffith University, 2018. http://hdl.handle.net/10072/380573.
Повний текст джерелаАнотація:
This submission examines and compares different approaches to preparing and performing a specific programme of Western concert clarinet repertoire. Historic and modern sources concerning contrasting performance approaches are used to inform preparation, performance, and evaluation of multiple concerts of identical repertoire yet differing approach. The paper reflects on the implications of these approaches on the performer, clarinet technique, musical outcomes, and interactions with other parties.
An introductory chapter provides insight into the background of the researcher, details the research process, and compares the project to existing literature. Following this introduction is an autoethnographic narrative which details the data-gathering stage of the project. This leads into a discussion of the implications of the project and recommendations for future research. The submission consists of this paper and the accompanying three audio-visual recordings.
Those who will benefit most from this study include music teachers, students, and performers who hope to develop awareness of the range of interpretive options available when approaching repertoire of this kind. While clarinet repertoire formed the basis of the action research portion of the study the issues the project deals with, and its conclusions, have application for the wider musical community.Thesis (Masters)
Master of Music Research (MMusRes)
Queensland Conservatorium
Arts, Education and Law
Full Text
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Pisano, Andrea <1977>. "Development of oil spill detection techniques for satellite optical sensors and their application to monitor oil spill discharge in Mediterranean sea." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3520/1/A.PisanoTesi.pdf.
Повний текст джерелаАнотація:
Satellite remote sensing has proved to be an effective support in timely detection and monitoring of marine oil pollution, mainly due to illegal ship discharges. In this context, we have developed a new methodology and technique for optical oil spill detection, which make use of MODIS L2 and MERIS L1B satellite top of atmosphere (TOA) reflectance imagery, for the first time in a highly automated way. The main idea was combining wide swaths and short revisit times of optical sensors with SAR observations, generally used in oil spill monitoring. This arises from the necessity to overcome the SAR reduced coverage and long revisit time of the monitoring area. This can be done now, given the MODIS and MERIS higher spatial resolution with respect to older sensors (250-300 m vs. 1 km), which consents the identification of smaller spills deriving from illicit discharge at sea. The procedure to obtain identifiable spills in optical reflectance images involves removal of oceanic and atmospheric natural variability, in order to enhance oil-water contrast; image clustering, which purpose is to segment the oil spill eventually presents in the image; finally, the application of a set of criteria for the elimination of those features which look like spills (look-alikes). The final result is a classification of oil spill candidate regions by means of a score based on the above criteria.Oil Spill Detection, MODIS, MERIS, Destriping, Clustering, Feature extraction; Classification
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Pisano, Andrea <1977>. "Development of oil spill detection techniques for satellite optical sensors and their application to monitor oil spill discharge in Mediterranean sea." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3520/.
Повний текст джерелаАнотація:
Satellite remote sensing has proved to be an effective support in timely detection and monitoring of marine oil pollution, mainly due to illegal ship discharges. In this context, we have developed a new methodology and technique for optical oil spill detection, which make use of MODIS L2 and MERIS L1B satellite top of atmosphere (TOA) reflectance imagery, for the first time in a highly automated way. The main idea was combining wide swaths and short revisit times of optical sensors with SAR observations, generally used in oil spill monitoring. This arises from the necessity to overcome the SAR reduced coverage and long revisit time of the monitoring area. This can be done now, given the MODIS and MERIS higher spatial resolution with respect to older sensors (250-300 m vs. 1 km), which consents the identification of smaller spills deriving from illicit discharge at sea. The procedure to obtain identifiable spills in optical reflectance images involves removal of oceanic and atmospheric natural variability, in order to enhance oil-water contrast; image clustering, which purpose is to segment the oil spill eventually presents in the image; finally, the application of a set of criteria for the elimination of those features which look like spills (look-alikes). The final result is a classification of oil spill candidate regions by means of a score based on the above criteria.Oil Spill Detection, MODIS, MERIS, Destriping, Clustering, Feature extraction; Classification
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Christodoulou, Klitos. "On techniques for pay-as-you-go data integration of linked data." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/on-techniques-for-payasyougo-data-integration-of-linked-data(67d1273f-8b08-4f7b-9dd2-c45815c024e6).html.
Повний текст джерелаАнотація:
It is recognised that nowadays, users interact with large amounts of data that exist in disparate forms, and are stored under different settings. Moreover, it is true that the amount of structured and un-structured data outside a single well organised data management system is expanding rapidly. To address the recent challenges of managing large amounts of potentially distributed data, the vision of a dataspace was introduced. This data management paradigm aims at reducing the complexity behind the challenges of integrating heterogeneous data sources. Recently, efforts by the Linked Data (LD) community gave rise to a Web of Data (WoD) that interweaves with the current Web of documents in a way that it is useful for data consumption by both humans and computational agents. On the WoD, datasets are structured under a common data model and published as Web resources following a simple set of guidelines that enables them to be linked with other pieces of data, as well as, to be annotated with useful meta data that help determine their semantics. The WoD is an evolving open ecosystem including specialist publishers as well as community efforts aiming at re-publishing isolated databases as LD on the WoD, and annotating them with meta data. The WoD raises new opportunities and challenges. However, currently it mostly relies on manual efforts for integrating the large amounts of heterogeneous data sources on the WoD. This dissertation makes the case that several techniques from the dataspaces research area (aiming at on-demand integration of data sources in a pay-as-you-go fashion) can support the integration of heterogeneous WoD sources. In so doing, this dissertation explores the opportunities and identifies the challenges of adapting existing pay-as-you-go data integration techniques in the context of LD. More specifically, this dissertation makes the following contributions: (1) a case-study for identifying the challenges when existing pay-as-you-go data integration techniques are applied in a setting where data sources are LD; (2) a methodology that deals with the 'schema-less' nature of LD sources by automatically inferring a conceptual structure from a given RDF graph thus enabling downstream tasks, such as the identification of matches and the derivation of mappings, which are, both, essential for the automatic bootstrapping of a dataspace; and (3) a well-defined, principled methodology that builds on a Bayesian inference technique for reasoning under uncertainty to improve pay-as-you-go integration. Although the developed methodology is generic in being able to reason with different hypothesis, its effectiveness has only been explored on reducing the uncertain decisions made by string-based matchers during the matching stage of a dataspace system.
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PARISATTO, MATTEO. "APPLICATIONS OF X-RAY TOMOGRAPHIC TECHNIQUES TO THE STUDY OF CEMENT-BASED MATERIALS." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3421653.
Повний текст джерелаАнотація:
The knowledge of the microstructural properties of cement-based materials plays a fundamental role in predicting their macroscopic behaviour in terms of performance and durability. However, due to the intrinsic microstructural and chemical complexity of such materials, a multi-disciplinary approach is often required. Most classical experimental techniques such as XRD, XRF or mercury porosimetry (MIP) only provide overall information about selected properties (phase and chemical composition, porosity, etc.) but give no indications about their real spatial distribution within the investigated sample. Over the past decades, modern experimental methods for microstructural analysis such as SEM imaging have lead to great advances in our understanding of the complex mechanisms occurring during cement hydration. However, the lack of access to three-dimensional (3D) information represents the main limitation of SEM and other 2D imaging techniques. Furthermore, as sample preparation is often quite invasive, the microstructure of cement may result completely altered. For such reasons, the development of non-destructive techniques for the 3D microstructural investigation of materials has become necessary. Nowadays X-ray computed micro-tomography (X-μCT) provides a totally non-invasive tool to investigate in a three-dimensional way the inner structure of materials, with a spatial resolution reaching the sub-μm level when the most advanced systems are employed. X-μCT allows to reconstruct 3D maps of the variations of the X-ray linear attenuation coefficient (μ) within a sample without perturbing its structure.
The aim of this research project is to assess the potential of X-μCT for the microstructural study of several features of interest in cementitious materials. The evolution of the microstructure during setting and hardening, the effects of water-cement ratio (w/c), the role of superplasticizers and the pore space properties are among the major topics that have been investigated. The results obtained from X-μCT at the microscopic scale can then be correlated with the corresponding macroscopic properties observed in real applications.
In order to compare the capabilities of the two most common types of X-μCT setups, experiments were carried out using both conventional laboratory instruments and synchrotron-based systems. A synchrotron study of cement evolution during the early hydration stages was successfully performed, focusing the attention on the effect of superplasticizers (chapter 4). The high spatial resolution achievable allowed to follow the evolution of porosity and anhydrous cement fraction as a function of hydration time. In chapter 5, conventional laboratory X-μCT was applied to the study of cement paste samples prepared at different w/c ratios in order to get insights on the microstructural features that determine the variations of strengths in macroscopic samples with varying water contents (chapter 5).
In addition, the capabilities of a novel experimental technique (diffraction tomography, XRD-CT) were tested for the first time on cementitious samples (chapter 6). By combining the principles of X-ray micro-diffraction with those of tomographic reconstruction, XRD-CT allows to map the distribution of selected crystalline or amorphous phases within a sample in a totally non invasive manner. In this way, one of the main limitations of X-μCT, related to the poor sensitivity to small absorption variations between different phases can be overcome. Despite the fact that data analysis is not straightforward and requires further developments, the preliminary results presented in this thesis show that crystalline and amorphous phases growing during cement hydration such as ettringite and C-S-H can be successfully mapped without perturbing the system.
In the last part of the thesis (chapter 7), a practical application example of X-μCT is reported. The tomographic technique was employed to characterize the pore space properties and the microstructure of cementitious granular materials produced from the solidification and stabilization process (S/S) of soils contaminated by heavy metals. The results of X-μCT analyses were then combined with those obtained using other established experimental methods (e.g. MIP, physico-mechanical and leaching tests) in order to evaluate the performances and environmental compatibility of an innovative method of contaminated grounds remediation.La conoscenza delle proprietà microstrutturali dei materiali cementizi gioca un ruolo fondamentale nel predire il loro comportamento macroscopico in termini di prestazioni e durabilità. Tuttavia, a causa dell’intrinseca complessità microstrutturale e chimica di tali materiali, un approccio multi disciplinare è spesso richiesto. La maggior parte delle tecniche sperimentali classiche come XRD, XRF o la porosimetria a mercurio (MIP) forniscono solamente informazioni complessive riguardo determinate proprietà (composizione mineralogica e chimica, porosità, etc.) ma non danno alcuna indicazione sulla loro reale distribuzione spaziale all’interno del campione studiato. Nel corso degli ultimi decenni, i moderni metodi sperimentali per l’analisi microstrutturale come la microscopia elettronica a scansione (SEM) hanno portato ad importanti avanzamenti delle nostre conoscenze sui complessi meccanismi che avvengono nel corso dell’idratazione del cemento. Tuttavia, l’impossibilità di accedere ad informazioni tridimensionali (3D) rappresenta la principale limitazione della tecnica SEM e degli altri metodi di imaging 2D. Inoltre, poiché la preparazione del campione è spesso piuttosto invasiva, la microstruttura del cemento può risultare completamente alterata. Per tali ragioni, si è reso necessario lo sviluppo di tecniche non distruttive per lo studio microstrutturale in 3D dei materiali. Oggigiorno, la micro-tomografia computerizzata a raggi X (X-μCT) fornisce uno strumento totalmente non invasivo per studiare in modo tridimensionale la struttura interna dei materiali, con una risoluzione spaziale che può raggiungere il livello sub-micrometrico quando vengono utilizzati i sistemi più avanzati. La X-μCT consente di ricostruire mappe in 3D delle variazioni del coefficiente di attenuazione lineare dei raggi X (μ) all’interno di un campione senza perturbarne la struttura. Lo scopo di questo progetto di ricerca è quello di verificare le potenzialità della X-μCT per lo studio microstrutturale di diversi aspetti di interesse nei materiali cementizi. Tra le principali tematiche che sono state affrontate vi sono l’evoluzione della microstruttura durante la presa e l’indurimento, gli effetti del rapporto acqua-cemento, il ruolo degli additivi superfluidificanti e le proprietà dello spazio poroso. I risultati ottenuti dalla X-μCT alla scala microscopica possono essere correlati con le corrispondenti proprietà microscopiche osservate nelle applicazioni reali. Al fine di confrontare le potenzialità delle due principali tipologie di strumenti per X-μCT, sono stati effettuati esperimenti utilizzando sia sistemi convenzionali da laboratorio sia sistemi da sincrotrone. Uno studio al sincrotrone sull’evoluzione del cemento nel corso degli stadi iniziali dell’idratazione è stato portato a termine con successo, ponendo l’attenzione sull’effetto dei superfluidificanti (cap. 4). L’elevata risoluzione spaziale ottenibile ha consentito di seguire l’evoluzione della porosità e della frazione di cemento anidro in funzione del tempo di idratazione. Nel capitolo 5, la X-μCT convenzionale da laboratorio è stata applicata allo studio di campioni di paste di cemento preparati a diverso rapporto acqua-cemento al fine di ottenere indicazioni sui parametri microstrutturali che determinano le variazioni delle resistenze meccaniche in campioni macroscopici al variare del contenuto d’acqua. Inoltre, le potenzialità di una tecnica sperimentale recentemente sviluppata (diffraction tomography, XRD-CT) sono state testate per la prima volta su campioni cementizi (cap. 6). La tecnica della XRD-CT, combinando i principi della micro-diffrazione a raggi X con quelli della ricostruzione tomografica, consente di mappare la distribuzione di determinate fasi cristalline o amorfe all’interno di un campione in una maniera del tutto non invasiva. In questo modo, una delle principali limitazioni della X-μCT legata alla scarsa sensibilità nei confronti di ridotte variazioni di assorbimento tra diverse fasi può essere superata. Nonostante l’analisi dei dati non sia semplice e richieda ulteriori sviluppi, i risultati preliminari presentati in questa tesi mostrano che alcune fasi, sia cristalline sia amorfe, che si sviluppano nel corso dell’idratazione del cemento (come ad esempio l’ettringite o il C-S-H), possono essere mappate con successo senza perturbare il sistema. Nell’ultima parte del lavoro è riportato un esempio pratico di applicazione della X-μCT. La tecnica tomografica è stata utilizzata per caratterizzare la porosità e la microstruttura di materiali cementizi granulari prodotti dal processo di solidificazione e stabilizzazione (S/S) di suoli contaminati da metalli pesanti. I risultati delle analisi di X-μCT sono stati poi combinati con quelli ottenuti usando altri metodi sperimentali classici (ad esempio MIP, test fisico-meccanici e di cessione) al fine di valutare le prestazioni e la compatibilità ambientale di un metodo innovativo di bonifica dei terreni inquinati.
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Shiburi, Piet Thapedi. "Tshekatsheko ya diteng le poloto ya Go ša Baori ka D.P.S. Monyaise." Diss., University of Pretoria, 2007. http://hdl.handle.net/2263/26561.
Повний текст джерелаАнотація:
A representative example of Monyaise’s work is his novel Go ša Baori, published in 1970. A survey of the literature reveals that this novel has already been investigated, by Malope R.M and (1986), Shole J. S.S (1988) who analysed only the dream found in this novel. The chief aim of this investigation is thus to critically analyse the structure of the novel Go ša Baori at the level of content and plot, using two research methods, namely definition and interpretation, within the context of an adapted narratological model. This model conceives of a text according to three levels, namely content, plot and style, and focuses on the topic of the content, the theme of the plot and the atmosphere of the style. Thus this research study differs from the two previous investigations of Go ša Baori because it focuses on the content level of the text by examining the topic, and the plot level by analysing the theme. The content of a text is coordinated by the topic to form a unified entity. The topic of the novel we are investigating is reflected in its title, namely Go ša Baori. The topic is thus of vital importance, and determines the arrangement and presentation of four important elements of content, namely character, time, place and events. These four elements are examined in more detail. The characters of the novel can be grouped into two categories, namely kind-hearted person (Olebile) and quarrelsome person (Wapeipi). These two content characters are investigated using the concepts of intention, patronage, resistance, assistance and success. Time and place together fall under setting. Setting can be defined as the natural and artificial environment in which characters in literature live and move (Roberts 1982:1).Time is then the period in which the events of the plot happen, and the order in which they happen. This can be expressed in various units, for example a day, month or year. Place denotes the geographical and topological position in which the characters in the story are situated and the events of the plot take place. Bal (1985: 8) regards the place within which the characters find themselves as the ‘frame’. The last of the four elements, the events, together make up the plot of the drama, which Strachan (1988: 20) and Magapa (1997: 11) describe as the second level of the text. Here theme is the key. The theme of the novel Go ša Baori centres on jealousy and competitive spirit. The plot is examined by focusing on the special functions in the plot of the protagonist Olebile and the antagonist Wapeipi, and the events related to them are classified as representing either good or evil. This study of Go ša Baori not only reveals how Monyaise creates his characters but also how he selects and shapes them for the purpose of dramatizing human life with all its varied manifestations. The actions that take place reveal essential character traits of the various characters, as do the words of the author as he describes Wapeipi as someone who makes up his mind at once and he is prepared to be hurt emotionally. While on the other hand, Olebile is a soft spoken man and very loving who shows his love to his fiancée by buying her a big diamond ring. The plot is then examined according to the conflicts that occur in its various stages, namely the exposition, the development, the climax and the denouement. There are twelve distinct conflicts that can be identified occurring between characters in the events of the plot. Monyaise using three techniques, namely repetition, elision and motif, presents the events of the exposition, which form the first conflict that sets the plot going. In the development, several other techniques are used to show the conflicting forces of character and events and to emphasize the message of the novel. The other conflicts, which are between other characters like the helpers, can be described as medium, and are not examined in great detail, though they are vital for creating suspense. In the climax phase the techniques of focus, idioms and motif are examined, particularly in the conflict between the protagonist and the antagonist, which leads to the death of the protagonist caused by emotions and complications. The conflict in the denouement phase is characterised by a very important technique, shadow to strengthen the theme of Go ša Baori. Here Monyaise uses this important technique, to strengthen the presentation of the theme of Go ša Baori. Overall, the most frequently used techniques are repetition, motif, idioms, elision, focus, rhetorical questions and foreshadowing. This novel can be classified as a tragic novel, because at the end, the antagonist dies. Using this tragic ending, Monyaise tries to caution his audience against jealousy and a competitive spirit. Thus it is the theme that holds the audience to the end of the novel.Dissertation (MA (African Languages))--University of Pretoria, 2007.
African Languages
MA (African Languages)
unrestricted
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Kurki, Saara. "How to let go : Different ways to detect and release tensions." Thesis, Kungl. Musikhögskolan, Institutionen för klassisk musik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kmh:diva-4186.
Повний текст джерелаАнотація:
The aim of my project was to find different ways to make playing easier and freer. What does it actually mean to let go and what could help to achieve more secure and relaxed feeling in your body when playing your instrument? I collected and experimented with exercises from a book The Inner Game of Music and Alexander Technique. I found out that knowing more precisely what to focus on and being more aware of the body can have a great effect. I discovered more gentle ways to teach myself and learned about the importance of how we are treating and using our bodies during practicing and in everyday situations.The sounding part consists of the following recording; Esa-Pekka Salonen: Pentatonic Étude.
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Williams, Catherine F. M. "Diffusion-weighted magnetic resonance imaging techniques." Thesis, University of Aberdeen, 1998. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602003.
Повний текст джерелаАнотація:
The aim of this project was to compare and evaluate other, non-EPI, diffusion-weighted MRI (DWI) sequences, through imaging experiments, on a phantom and in vivo, (using a 0.95 T system) and computer simulations, and to develop improved DWI methodology which could be implemented on standard hardware. Pulsed gradient spin echo (PGSE) and diffusion-weighted STEAM are slow multiple shot sequences, with measurement times of several minutes. Both sequences are highly sensitive to patient motion, but motion artifact was virtually eliminated using navigator echo phase correction and EGG triggering when diffusion-sensitisation was in the phase-encoding direction. It was demonstrated that both sequences can provide high quality images and allow accurate and straightforward diffusion-coefficient measurement when an imaging time period in the region of 20-30 minutes is available and when diffusion-sensitisation is required in one or two directions. A third direction of diffusion-sensitisation may be feasible if more sophisticated immobilisation or phase correction techniques are employed. A choice between PGSE or STEAM for a given application should take account of the Ti and T2 values of the imaged tissues, since a higher SNR might be provided by STEAM when the T1T2 ratio is high. A diffusion-weighted CE-FAST sequence was implemented with the novel modification of acquisition of a navigator gradient-echo, which was shown to reduce motion artifact when diffusion-sensitisation was in the phase-encoding direction. However, it has been demonstrated by other workers that unknown signal losses due to motion-induced phase incoherence between signal components may remain. The SNR (normalised with respect to the square root of the imaging time) in the phantom and in white matter was similar to that obtained using PGSE, but an advantage of CE- FAST is that it can be performed in a fraction of the measurement time of PGSE. Diffusion-sensitivity was much higher than in other sequences and the diffusion- attenuation was found to agree with an analysis presented in the literature. However, a major disadvantage of the technique, which precludes its use for many DWI applications, is the requirement of accurate knowledge of Ti, T2 and flip angle in order to calculate the diffusion coefficient or tensor. Prior to a study of diffusion-weighted snapshot FLASH, the effects of magnetisation evolution during snapshot FLASH acquisition on image quality and parameter measurement accuracy were first investigated, through phantom experiments and computer simulations, in the context of a r2-weighted snapshot FLASH sequence. It was demonstrated that magnetisation evolution effects can lead to significant error in parameter measurement, but that this error can be eliminated by using crusher gradients to prevent evolved magnetisation from contributing to the acquired signal. However, qualitative effects are not entirely eliminated, since a significant degree of edge blurring may remain, and there is a 50% loss of SNR inherent to the crusher gradient technique. It was then shown, theoretically and experimentally, that in diffusion-weighted snapshot FLASH, the crusher gradient technique not only addresses the problem of magnetisation evolution, but also eliminates the effect of phase shifts arising during the diffusion-preparation sequence.
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Smith, Joshua Ryan. "Formulation of instrument noise analysis techniques and their use in the commissioning of the gravitational wave observatory, GEO 600." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=982491557.
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Guo, Qingchuan [Verfasser], Andreas [Akademischer Betreuer] Ostendorf, and Evgeny L. [Akademischer Betreuer] Gurevich. "Synthesis and fabrication of functional microstructures by laser direct writing techniques / Qingchuan Guo. Gutachter: Andreas Ostendorf ; Evgeny L. Gurevich." Bochum : Ruhr-Universität Bochum, 2016. http://d-nb.info/108242529X/34.
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ZUZUL, JOSIP. "Characterization of thunderstorm downburst winds through CFD techniques." Doctoral thesis, Università degli studi di Genova, 2022. http://hdl.handle.net/11567/1081542.
Повний текст джерелаАнотація:
The characteristic wind field of a certain region is mostly governed by the climatology of its larger scale area. In the case of mid-latitude regions (e.g. Europe), their climatology is determined by the extra-tropical cyclones at the larger synoptic scale. Atmospheric boundary layer (ABL) winds based on synoptic-scale structures are hence considered as the foundation for codes and standards used to assess the wind loading of structures and to design structures to prevent wind-related damage accordingly. In addition to the ABL winds, the mid-latitude regions are also prone to winds of a non-synoptic origin at the mesoscale level, with thunderstorm outflows or downbursts being the representative of such non-synoptic wind action. Since they are determined by a set of features that makes them fundamentally different from the ABL winds, downbursts can produce the corresponding wind action that is often fatal to low-rise and mid-rise structures. On these grounds, a comprehensive initiative to enable a better understanding of fundamental downburst flow features relevant for the structural loading was framed under the umbrella of the ERC THUNDERR Project. The present thesis, as the numerical modeling part of the THUNDERR Project framework, aims to address the physical characteristics of thunderstorm downbursts through the application of Computational Fluid Dynamics (CFD) technique. The focus of this work is placed on the CFD reconstruction of experimental tests of the reduced-scale thunderstorm downbursts carried out in the WindEEE Dome Research Institute (University of Western Ontario, Canada). Although they recreate the downburst flow field, the experimental analysis is restricted to the limited number of probe points. In that perspective, CFD allows expanding the analysis of experimental tests to the entire flow field, which can reveal phenomenological aspects that are either challenging or impossible to retrieve from experimental tests only. Two fundamental downburst scenarios were analyzed: (i) an isolated vertical downburst, and (ii) a downburst embedded inside the approaching ABL flow. For that purpose, three CFD approaches of a ranging complexity level were adopted. The unsteady Reynolds-Averaged Navier-Stokes (URANS), hybrid Scale-Adaptive Simulations (SAS), and Large-Eddy Simulations were used, and their overall reliability was examined. Theimplications of the WindEEE Dome specific geometrical features (i.e. bell-mouth inflow nozzle) on the downburst flow reconstruction by the facility were further discussed. The bulk of the thesis discusses the dominant flow features of the downburst with the particular emphasis on the dynamics of dominant vortex structures (i.e. primary vortex, secondary vortex, trailing ring vortices) and their spatio-temporal influence on the vertical profiles of radial velocity component. The non-dimensional flow characteristics of interest were evaluated such as the trajectory of the primary vortex and the spatial dependence of the velocity of primary vortex propagation. Analyses were further extended for the case of a joint downburst and ABL wind interaction to address the dynamics between two different wind fields, and the genesis of the worst condition in terms of the maximum radial velocity due to the ABL wind entrainment was discussed. The flow field was analyzed across various azimuth angles with respect to the ABL flow to report on the flow asymmetry, and general implications of such downburst configuration on spatio-temporal evolution of wind velocity profiles which can produce severe conditions for low-rise and mid-rise structures.
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Idir, Nadir. "Modélisation des commutations du thyristor GTO dans une structure hacheur série par la technique Bond-Graph : application au fonctionnement en interrupteur résonnant." Lille 1, 1993. http://www.theses.fr/1993LIL10144.
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Superchi, Laura. "The Vajont rockslide: new techniques and traditional methods to re-evaluate the catastrophic event." Doctoral thesis, Università degli studi di Padova, 2012. http://hdl.handle.net/11577/3425816.
Повний текст джерелаАнотація:
The Vajont landslide is one of the largest catastrophic slope failures of the past century. About 270 million m3 of limestones, mudstones and marls slid into the Vajont Reservoir on October 9, 1963, producing a displacement wave that overtopped the dam and killed over 2000 people in the valley below. Although the landslide has been extensively studied over the past several decades, its morphologic and structural controls, mechanisms, and dynamics are not completely understood yet. The first step in carrying out the research was the implementation of a bibliographic and geographic electronic geo-databases, including all existing bibliographic records. Published documents, theses, unpublished technical reports and maps were collected and indexed and they are available for the scientific community.
Afterwards, new techniques and technologies which were not available yet in the 60’s, were applied to this thesis in order to investigate more in detail the morpho-structural features and to better understand the different role that they played in the 1963 event, thus providing a more rigorous and less empirically based forecasting approach to the study of large catastrophic landslides.
In particular, the applied remote sensing techniques (DEM analyses, LIDAR technologies, photogrammetric analyses) allowed to characterize in detail the structure of inaccessible areas of the failure surface and, along with the geological and geomechanical field investigations, to clarify relevant aspects concerning the geological-structural setting of the northern slope of Mount Toc.
The geomechanical survey in 89 stations was performed in order to reach an accurate knowledge and in-depth evaluation of the characteristics of the rock masses outcropping on the Vajont area, both inside and outside the landslide.
The obtained results permitted the identification of the most significant parameters that influenced the rockslide triggering and displacement, so helping in the comprehension of both the phenomenon and the structural control on its development and collapse.
The implementation of laboratory tests Uniaxial and Triaxial on rock samples completed the geomechanical characterization of the rock-masses.
The amount of the collected data were used to characterize the rock mass quality, through the following different classifications : Rock Quality Designation (RQD) Rock Mass Rating System (RMR) and Slope Mass Rating (SMR).
In order to complete the knowledge of the deep geological structure of the rock masses two seismic reflection profiles were carried out. The results of their preliminary interpolation are still in progress.
The accurate and detailed results achieved of the above mentioned techniques, combined with field investigations, laboratory tests and ongoing geophysical surveys allowed to obtain a reliable 3D geological model.
This above mentioned 3D model firstly allowed to define the sliding surface depth and geometry more precisely than ever, and secondly to evaluate the landslide kinematics. These aspects represent the fundamental starting point for the future 3D modelling elaborations.La frana del Vajont è uno dei piu’ grandi eventi catastrofici del secolo scorso. Il 9 ottobre 1963, Circa 270 milioni di m3 di calcari, marnosi precipitarono nel bacino del Vajont .producendo un onda che oltrepasso’ la diga uccidendo piu’ di 2000 persone nella valle sottostante. Nonostante nei decenni passati la frana sia stata approfonditamente studiata, il controllo morfologico e strutturale, i meccanismi e le dinamiche non sono state ancora completamente chiarite. Il primo step del progetto di ricerca è stata la costruzione di un GIS-database contenente tutte le informazioni, edite ed inedite, collezionate sulla frana del Vajont (articoli, report, tesi e rapporti scientifici, carte geologiche e topografiche). Successivamente nuove tecniche e tecnologie non disponibili negli anni 60, sono state utilizzate nel presente lavoro per analizzare in dettaglio le caratteristiche morfo-strutturali e per megli comprendere il differente ruolo che hanno rivestito nell’evento del 1963, fornendo di conseguenza metodi di previsione piu’ scientificamente piu’rigorosi per la previsione delle grandi eventi catastrofici. In particolare, le tecniche remote sensing utilizzate (analisi DEM, tecnologie Lidar e analisi fotogrammetriche) hanno consetito di caratterizzare in dettaglio le caratteristiche strutturali di aree poco accessibili sulla superficie di scivolamento e, congiuntamente alle indagini di campagna, di chiarire gli aspetti rilevanti circa l’assetto geologico del versante Nord del Monte Toc. .Al fine di ottenere un’accurata conoscenza e una approfondita valutazione delle caratteristiche degli ammassi rocciosi affioranti fuori e dentro l’area della frana, le indagini geomeccaniche sono state condotte su 89 stazioni di misura. I risultati ottenuti hanno permesso di identificare i parametri più significativi che hanno influenzato l’innesco e l’evoluzione della frana favorendo così la comprensione del fenomeno in termini di sviluppo e collasso. L’implemetazione dei test di laboratorio, (prove uniassiali e triassiali) sui campioni di roccia hanno completato la caratterizzazione geomeccanica degli ammassi rocciosi. La consistente quantità di dati ottenuti è stata utilizzata per caratterizzare gli ammassi rocciosi attraverso differenti classificazioni standard tra cui RQD (Rock Quality Designation), (RMR) Rock Mass Rating System e SMR (Slope Mass Rating). Al fine di investigare sulla struttura geologica del versante Nord del Monte Toc, sono stati realizzati due profili ssismici. Attualmente è in corso l’analisi preliminare dell’interpolazione. Inoltre la costruzione del primo modello geologico 3D della frana ha permesso di analizzare dettagliatamente la cinematica della frana e di definire la geometria e la profondità della superficie di scivolamento. Gli accurati e dettagliati risultati raggiunti mediante l’utilizzo di nuove tecniche e di tradizionali indagini di campagna completate dai test di laboratorio ha permesso di ottenere un attendibile modello geologico 3D e un quadro completo delle caratteristiche geomeccaniche, che costituiscono una base fondamentale per l’elaborazione futura di modelli 3D
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Ramsay, Craig R. "Assessing the learning curves of health technologies." Thesis, University of Aberdeen, 2000. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU602014.
Повний текст джерелаАнотація:
Many health technologies exhibit some form of learning effect, and this represents a barrier to rigorous assessment by randomised controlled trials. There is reluctance to evaluate while the technique is being learnt, yet unwillingness to admit uncertainty once it has been learnt. In principle, statistical description of a learning curve and subsequent adjustment of an evaluation to take account of learning effects should solve this problem. Exactly how the analyses should be performed has been unclear. This thesis has three components: Systematic review of health technology assessment literature: a systematic description of studies that directly assessed the learning curve effect of health technologies. Systematic search of non-health technology assessment literature: a systematic identification of 'novel' statistical techniques applied to learning curve data in other fields, such as psychology and manufacturing. Testing of statistical methods: testing of these statistical techniques in sets of data describing a variety of health technologies where learning curve effects are known to exist.
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Affeltranger, Bastien. "Le contrôle de la vérité : (Géo)Politique de l'information hydrologique. Le cas du bassin du Mékong, Asie du Sud-Est." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25226/25226.pdf.
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Piovesan, Rebecca. "Archaometrical investigations on mortars and paintings at Pompeii and experiments for the determination of the painting technique." Doctoral thesis, Università degli studi di Padova, 2008. http://hdl.handle.net/11577/3426140.
Повний текст джерелаАнотація:
Archaeometrical investigations were performed on 127 samples collected from the Temple of Venus at Pompeii, by means of OM, SEM, ESEM, XRD, micro-ATR, FT-IR, Mössbauer spectroscopy, EMPA and image analysis. The materials analysed were composed of mortars (from walls, floors and hydraulic structures) and paintings. The main aim of the research was to characterise these materials to determine the preparation recipes, the technological knowledge and the provenance of the raw materials. To this aim the aggregates identified in the mortars were petrographically compared with eighteen samples of sand from the Neapolitan coastline and from borehole cores performed in the area that lies in front of the Temple of Venus. A correlation between functionality and age of the structures and recipes of samples was also carried out. Experiments were also performed in order to recognise an objective method for the recognition of the fresco and the mezzofresco painting techniques. Results from experiments were tested against samples of paintings from the Chiaravalle Abbey (XIV century) for which the use of fresco, dry finishing and mezzofresco is well documented, and then compared with the paintings of the Temple of Venus.Numerosi campioni di malta e finiture pittoriche (127) provenienti da ambienti funzionalmente e cronologicamente differenti sono stati prelevati dal sito archeologico del Tempio di Venere a Pompei e sottoposti ad indagini OM, SEM, ESEM, XRD, micro-ATR, FT-IR, spettroscopia Mössbauer, EMPA e analisi di immagine. Lo scopo principale dello studio è stato quello di caratterizzate tali materiali per ricavare informazioni riguardanti le ricette di preparazione, le conoscenze tecnologiche e la provenienza delle materie prime. A tale scopo, l’aggregato identificato nelle malte analizzate è stato confrontato da un punto di vista petrografico con diciotto campioni di sabbia provenienti dalla costa napoletana e da sondaggi eseguiti nell’area prospiciente il tempio di Venere. Le ricette riconosciute sono state inoltre correlate con la funzionalità e l’età delle strutture architettoniche di provenienza. Allo scopo di determinare una procedura analitica efficace per il riconoscimento delle tecniche pittoriche ad affresco e mezzofresco è stato inoltre svolto uno studio su campioni appositamente prodotti. I risultati di tale sperimentazione sono stati testati su cinque campioni provenienti dalla abbazia di Chiaravalle (Milano) per i quali dati storico-artistici confermano l’esecuzione secondo tecnica pittorica ad affresco, secco e mezzofresco. I criteri e la metodologia così ricavati sono stati applicati ai campioni di finiture pittoriche murarie provenienti dal tempio di Venere.
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Fraser, Stewart Ian. "Multiresolutional techniques for digital image filtering and watermarking." Thesis, University of Aberdeen, 2006. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU214436.
Повний текст джерелаАнотація:
This thesis examines the use of multiresolutional techniques in two areas of digital image processing: denoising (speckle reduction) and watermarking. A speckle reduction algorithm operating in the wavelet a irons domain is proposed. This novel algorithm iteratively approaches the difference between the estimated noise standard deviation (in an image.) and the removed noise standard deviation. A method for ascertaining the overall performance of a filter, based upon noise removal and edge; preservation, is presented. Comparisons between the novel denoising algorithm and existing denoising filters are carried out using test images and medical ultrasound images. Results show that the novel denoising algorithm reduces speckle drastically whilst maintaining sharp edges. Two distinct areas of digital image watermarking are addressed in this thesis: (1) the presentation of a novel watermarking system for copyright protection and (2) a fair comparison of the effects of incorporating Error Correcting Codes (ECC) into various watermarking systems. The newly proposed watermarking system is blind, quantization based and operates in the wavelet domain. Tests carried out on this novel system show it to be highly robust and reliable. An extensive and fair study of the effects of incorporating ECCs (Bose. Chaud-huri and Hoequenghem (BCI1) and repetition codes) into various watermarking systems is carried out. Spatial. Discrete Cosine Transform (I)CT) and wavelet based systems are tested. It is shown that it is not always beneficial to add ECCs into a watermarking system.
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Pop-Fanea, Laura. "MRI techniques for detection of developing inflammatory response." Thesis, University of Aberdeen, 2005. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU197393.
Повний текст джерелаАнотація:
Since at least 1552 BC, inflammatory eye disease have been acknowledged as a major threat to sight. There have been a limited number of studies of in vivo inflammatory eye disease in humans and more information is required to improve image interpretation. The aim of this study was to develop and evaluate MRI techniques for the in vivo investigation of retinal damage and macrophage activity in the rat eye affected by experimental autoimmune uveitis (EAU), an inflammatory and autoimmune mediated eye disease. Rat eye structures affected by EAU were visualised in vivo in MR images acquired using figure-of-eight or single loop copper surface coils. Retinal damage in EAU was detected in vivo by MRI at the early stages of EAU. Retinal thickening and detachment in the moderate and severe forms of EAU were monitored in vivo using the same MRI technique. Unlabelled macrophages infiltrating eye structures such as the retina, iris and ciliary body of the rat eye at peak of EAU were visualised in vivo by MRI using a newly-developed single loop, 2-turn surface coil. This study demonstrated that MRI, using specially designed surface coils, can be used for non-invasive in vivo monitoring and also for the in vivo investigation of macrophage activity during development of EAU and of eye disease involving retinal thickening and detachment. The MRI techniques investigated in this study have also demonstrated their potential for the evaluation of new therapies in inflammatory and autoimmune mediated eye disease. All these are non invasive and hence have potential for future possible clinical investigation of inflammatory and autoimmune mediated eye disease or in eye disease involving retinal thickening and detachment.
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CATALDI, LAURA. "Improving the quality of seismic monitoring by development of novel ground motion prediction techniques." Doctoral thesis, Università degli Studi di Trieste, 2021. http://hdl.handle.net/11368/2988359.
Повний текст джерелаАнотація:
L’attività di monitoraggio sismico è basata sull’uso di sismografi ricettivi per la registrazione del moto del suolo causato dai terremoti. Gli strumenti sviluppati nell’ambito del monitoraggio sismico permettono di studiare la sismicità a livello sia regionale che globale e trovano un uso strategico nel contesto della stima della pericolosità sismica. Uno sforzo continuo è necessario per migliorare gli strumenti al servizio del monitoraggio sismico e le conseguenti applicazioni, sia nel campo della stima della pericolosità che in contesti di protezione civile ed ingegneria sismica, come ad esempio nelle mappe di scuotimento del suolo.
Il primo fondamentale passo per migliorare gli strumenti e i modelli sviluppati nell’ambito del monitoraggio sismico è un corretto ed accurato trattamento dei dati. Un’attenta procedura di selezione ed elaborazione è stata seguita sulla base del tipo specifico di dati impiegati, differenziando tra dati strumentali, metadati e valori assegnati da esperti.
Una nuova definizione di intensità strumentale, la quale fornisce una previsione dell’intensità macrosismica sulla base del livello di scuotimento del suolo, viene proposta per il caso dell’Italia. Lo scopo è sostituire le equazioni lineari comunemente impiegate a tale scopo (Ground Motion to Intensity Equations, GMICE), che per loro natura non riescono a trattare in modo completamente corretto il dato dell’intensità macrosismica e la relativa incertezza. Un modello basato sulla tecnica dei classificatori di Bayes Gaussiani (Gaussian Naïve Bayes, GNB) è stato sviluppato e calibrato per un set di diversi parametri di moto del suolo. Tale modello fornisce stime di intensità su classi intere, in accordo con la definizione originaria di classi di intensità, ed una relativa probabilità associata. I risultati sono stati testati rispetto ad una formulazione delle più classiche GMICE calibrata sullo stesso gruppo di dati. L’intensità strumentale basata sulla definizione da GNB è risultata fornire prestazioni migliori in termini di applicazione su dati indipendenti e di capacità di catturare l’incertezza associata al dato. Le stime di intensità basate sull’uso di parametri di massimo moto del suolo (in velocità e in accelerazione) sono risultate le più adatte all’applicazione diretta nei prodotti di monitoraggio sismico e convertite in una scala spezzata adatta all’uso.
Un algoritmo per la modellazione degli spettri di ampiezza di Fourier è stato sviluppato per effettuare un’inversione parametrica da cui ottenere stime di comportamento specifico al sito. Il relativo software è stato sviluppato in maniera flessibile per permettere un facile adattamento nella selezione dei modelli, degli stimatori di incertezza, dei coefficienti di peso, del sito di riferimento, della metodologia e del numero di passi usati nell’inversione. Sulla base di osservazioni sismotettoniche è stata individuata un’area nella regione del Nord-Est Italia, da usare come caso di studio per la stima dei parametri spettrali associati ad un gruppo di eventi e stazioni sismiche. Le curve di amplificazione al sito sono state ricostruite dall’analisi congiunta dei prodotti e dei residuali dell’inversione, ed è stato di conseguenza suggerito un gruppo di stazioni adatte ad essere usate come riferimento per il livello regionale di amplificazione su roccia. Il raffronto con la letteratura ha confermato l’affidabilità dei risultati ottenuti, in particolar modo per i termini relativi alle sorgenti sismiche e ai siti. La validazione rispetto a diverse scelte di parametrizzazione ha confermato la stabilità dell’algoritmo di inversione e fornito suggerimenti per migliorare la stima dei parametri legati all’attenuazione lungo il percorso sismico. Le stime ottenute per le curve di amplificazione sono adatte all’uso nei modelli di stima della pericolosità sismica.Seismic monitoring employs sensitive seismographs to record the ground motion generated by earthquakes. It provides tools to study regional and global seismicity that are fundamental when applied inside seismic hazard assessment. A continuous effort is necessary to improve monitoring for both hazard assessment and direct applications in civil protection and engineering contexts (e.g., shakemaps). The first step towards improving monitoring tools and models is to carefully select and handle data. A strict selection and processing procedure tailored to the specific kinds of employed data is followed to ensure the quality of the ensuing results. A novel definition of instrumental intensity for Italy is proposed, to provide a forecast of expected macroseismic intensity based on the ground motion shaking level. It is intended to substitute Ground Motion to Intensity Conversion Equations (GMICEs), which are linear relationships that do not correctly treat intensity and its associated uncertainty. A model based on Gaussian Naïve Bayes (GNB) classifiers is developed and calibrated for a set of ground shaking parameters, providing integer-valued intensity forecasts with a known, class-specific associated probability. The results are tested against a more classical GMICE formulation calibrated on the same dataset. Instrumental intensity based on GNB definition is proved to possess better performance on unseen data and better capability of capturing data uncertainty with respect to GMICEs. Forecasts based on peak ground parameters (velocity and acceleration) are selected as most suitable for direct application in seismic monitoring products and converted in a ready-to-use piecewise scale. An algorithm for Fourier amplitude spectra modelling is developed to perform parametric inversion and provide estimates of site-specific soil behaviour. A flexible software is developed that supports the customization of employed models, uncertainty estimators, weighting coefficients, reference settings, inversion techniques and number of inversion steps. A case study area in the North-Eastern Italy region is chosen based on seismo-tectonics considerations, and spectral parameters are estimated for a set of selected events and stations. Site-specific amplification curves are built from a combined analysis of inversion products and residuals, and a set of candidate stations to be used as regional rock amplification reference is suggested. Comparison with literature values reinforces the reliability of the results, especially in the case of source and site terms. Validation against different model parametrizations confirms the stability of the inversion algorithm and suggests additional steps to improve the estimate of path attenuation features. A case scenario is built to exemplify the possible use of the developed tools. Estimated amplification curves are found to be compatible with independent empirical observations and suitable for employment in hazard assessment models to better constrain site-specific response.
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Staff, Roger T. "The improvement of SPECT images using scatter correction techniques." Thesis, University of Aberdeen, 1994. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU552136.
Повний текст джерелаАнотація:
The removal of scattered radiation is recognised as one of the major goals to be achieved in SPECT. In this work three scatter removal techniques were investigated. These were dual window scatter subtraction, deconvolution using a Wiener filter and energy weighted acquisition (EWA) using a weighted acquisition module (WAM). In addition to this, the effects of simple background subtraction on SPECT images was also investigated. The techniques were investigated in both a semi-quantitative manner, in terms of the effects of each technique on the cold lesion contrast and image mottle, and qualitatively, in terms of the ability of observers to perform a detection task. This was done using Relative Operating Characteristic (ROC) experiments. Each technique is investigated individually to discover the parameters needed to optimise performance. The results showed that the optimum parameters for each scatter reduction technique was dependent on the measure of image quality used for optimisation and showed that all of the techniques investigated produced better results than those produced using the standard 20&'37 photopeak acquisition approach, however, in general no significant difference could be found between the techniques. The image noise produced by each technique was also evaluated by calculating the noise power spectra (NPS) produced by each technique. The calculated NPS showed the spatial content of the noise produced by each technique was different for each scatter reduction technique. The results in this work showed that empirically defined measures of image quality are poor predictors of observer performance.
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Abdullah, Saleh Mohammed S. "Blood group typing by molecular techniques : application to immunohaematology." Thesis, University of Aberdeen, 2004. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU486962.
Повний текст джерелаАнотація:
The initial aim was to establish conventional DNA typing technology for blood group typing using cell derived genomic DNA material from donors. Accordingly, blood samples were collected from 200 healthy, randomly selected, Aberdeen Regional blood donors. The DNA extracted from these samples was used to develop and validate PCR assays for RHD, RHDPsi, RHC/c, KEL1 and KEL2, Fya and Fyb and ABO blood group alleles. All samples were also phenotyped serologically for RH, KEL, Duffy and ABO blood groups. Complete concordance was observed between phenotype and genotype. The developed RHD, RHDPsi and Fya and Fyb genotyping assays were then applied to study the molecular basis of blood groups in a cohort of 170 native Saudi donors. This study demonstrated there was no significant difference between the Saudi and Scottish (Caucasian) populations with respect to the RHD or RHDPsi blood groups. However, a significant difference was recorded with respect to the molecular basis of the FY blood group in which 30.6% of the Saudi donors were typed as Fy/Fy. The Fyx allele was also observed in this cohort. Further study of the Scottish blood donor population was performed to define the molecular basis of Weak D in 58 SNBTS (Scottish National Blood Transfusion Services) blood donors. Weak D types 1 and 2 represented more than 95% of all Weak D types tested in this study. Of the rest, nine samples were typed as DVI type II, one sample typed as DVII, one sample typed as DVa type II and a new partial D was identified in one sample to be lodged with the Genbank DNA database. In the second part of the project, the overall aim was to develop fetal DNA typing from maternal plasma.
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Tiensing, Tinnakorn. "Novel techniques in assessing bioavailability of pollutants in soils." Thesis, University of Aberdeen, 2002. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU153957.
Повний текст джерелаАнотація:
Effective techniques for assessing soil environmental pollution are required to develop protective policy. Chemical methods have been traditionally used to determine total concentration of pollutants and biologically linked measurements have been used to assess the bioavailable fraction of pollutants. Bioluminescence-based microbial bioassays have been shown to respond to the bioavailable fractions. Growth and bioluminescence of lux-marked E. coli HB101 and P. fluorescens 10586r were characterised and optimised for freeze-drying culture. Freeze-drying cultures have been used effectively because of their ease of use, rapid assay response and sensitivity to a wide range of pollutants. An assessment of Zn and Cd amended soil was investigated. Two different techniques (centrifugation and Rhizon sampler) were used to obtain the interstitial pore water of soils. The concentrations of Zn and Cd were significantly higher in the soil solution extracted using the centrifugation technique compared to the Rhizon sampler technique. The biosensors responded to the free metal concentrations in the soil solution. An assessment of the toxicity of 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol, individually and in combinations, was tested in deionised water (pH 5.5), soil solutions, and soils using lux-marked E. coli HB101 and P. fluorescens 10586r. Toxicity interaction responses of the mixture chlorophenols were predicted using a model. Synergistic interactions were observed for the response of P. fluorescens 10586r pUCD60-7 to all combinations of chlorophenol tested, while the response of E. coli HB101 pUCD607 varied with the matrix solutions tested. Bioavailability of naphthalene was studied using cyclodextrin-based extractions caused to the luminescence response of Pseudomonas fluorescens KH44 pUTK21. Increasing the concentrations of beta-cyclodextrin (b-CD) and hydroxylpropyl-b-cyclodextrin (HPBC) in the extract solutions increased the apparent concentration of naphthalene in the soil solutions. The luminescence response of P. fluorescens HK44 was associated with bioavailable of naphthalene.
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Madrid, Carlos. "Etude critique de la technique des Gow-Gates pour l'anesthésie du nerf mandibulaire à la lumière de l'anatomie topographique de la région pterygo-mandibulaire." Toulouse 3, 1991. http://www.theses.fr/1991TOU30240.
Повний текст джерелаАнотація:
Les aspects anatomiques d'une technique d'anesthesie loco-regionale du nerf mandibulaire, decrite en 1973 par gow-gates, sont etudies. La specificite anatomique et l'utilisation clinique de cette technique, repandue dans les pays anglo-saxon motivent ce travail. Il constitue une simulation experimentale qui permet une evaluation des risques anatomiques particuliers de la technique. La caracteristique de la technique de gow-gates est de viser la face antero-mediale du condyle mandibulaire a distance du nerf mandibulaire a anesthesier. L'auteur determine comment la solution anesthesique parvient au nerf mandibulaire avec un taux d'efficacite superieur a celui de la technique au foramen mandibulaire. L'echantillon etudie comprend 44 pieces anatomiques humaines fraiches, centrees sur la region pterygo-mandibulaire. 40 pieces traitees selon differents protocoles ont ete reduites en coupes grace au scanigraphe, appareil de coupes a basse temperature par abrasion, concu dans le laboratoire par le prs combelles et boyer. 4 pieces ont ete traitees par digestion enzymatique par papaine activee. 583 cliches couleur de coupes et 117 cliches couleur a partir des pieces par digestion enzymatique, ont ete retenus pour etude. A partir de mesures prises sur 19 pieces, les dimensions et le volume de l'espace interpterygoidien, et ses rapports avec la region pterygo-mandibulaire qui le contient, sont determines. Deux facteurs determinent la diffusion d'une solution anesthesique dans cet espace fonctionnel, quelle que soit la technique regionale employee: le guidage des plans faisciaux interpterygoidiens, l'existence d'ouvertures potentielles de l'espace anatomique. Un modele de diffusion reproductible est decrit: il demontre que l'anesthesie ne resulte pas d'une diffusion aleatoire. L'etude des systemes vasculaires entourant le condyle mandibulaire montre que la cible de la technique de gow-gates est une zone hyper-vascularisee. Le risque d'injection vasculaire ou articulaire au cours de l'injection est mis en evidence. Ce risque specifique mis en balance avec ses avantages propres, condamne la technique proposee par gow-gates