A novel map-matching procedure for low-sampling GPS data with applications to traffic flow analysis

An extensive sample (2%) of private vehicles in Italy are equipped with a GPS device that periodically measures their position and dynamical state for insurance purposes. Having access to this type of data allows to develop theoretical and practical applications of great interest: the real-time reconstruction of traffic state in a certain region, the development of accurate models of vehicle dynamics, the study of the cognitive dynamics of drivers. In order for these applications to be possible, we first need to develop the ability to reconstruct the paths taken by vehicles on the road network from the raw GPS data. In fact, these data are affected by positioning errors and they are often very distanced from each other (~2 Km). For these reasons, the task of path identification is not straightforward. This thesis describes the approach we followed to reliably identify vehicle paths from this kind of low-sampling data. The problem of matching data with roads is solved with a bayesian approach of maximum likelihood. While the identification of the path taken between two consecutive GPS measures is performed with a specifically developed optimal routing algorithm, based on A* algorithm. The procedure was applied on an off-line urban data sample and proved to be robust and accurate. Future developments will extend the procedure to real-time execution and nation-wide coverage.

Integrating new and traditional approaches for the estimate of slip-rates of active faults: examples from the Mw 6.3, 2009 L’Aquila earthquake area, Central Italy

This thesis is based on the integration of traditional and innovative approaches aimed at improving the normal faults seimogenic identification and characterization, focusing mainly on slip-rate estimate as a measure of the fault activity. The L’Aquila Mw 6.3 April 6, 2009 earthquake causative fault, namely the Paganica - San Demetrio fault system (PSDFS), was used as a test site. We developed a multidisciplinary and scale‐based strategy consisting of paleoseismological investigations, detailed geomorphological and geological field studies, as well as shallow geophysical imaging and an innovative application of physical properties measurements. We produced a detailed geomorphological and geological map of the PSDFS, defining its tectonic style, arrangement, kinematics, extent, geometry and internal complexities. The PSDFS is a 19 km-long tectonic structure, characterized by a complex structural setting and arranged in two main sectors: the Paganica sector to the NW, characterized by a narrow deformation zone, and the San Demetrio sector to SE, where the strain is accommodated by several tectonic structures, exhuming and dissecting a wide Quaternary basin, suggesting the occurrence of strain migration through time. The integration of all the fault displacement data and age constraints (radiocarbon dating, optically stimulated luminescence (OSL) and tephrochronology) helped in calculating an average Quaternary slip-rate representative for the PSDFS of 0.27 - 0.48 mm/yr. On the basis of its length (ca. 20 km) and slip per event (up to 0.8 m) we also estimated a max expected Magnitude of 6.3-6.8 for this fault. All these topics have a significant implication in terms of surface faulting hazard in the area and may contribute also to the understanding of the PSDFS seismic behavior and of the local seismic hazard.

Indoor and Outdoor Natural Radioactivity in the Vulsini Volcanic District (Central Italy): Estimation of Doses and Radiological Risks

Terrestrial radioactivity for most individual is the major contributor to the total dose and is mostly provided by 238U, 232Th and 40K radionuclides. In particular indoor radioactivity is principally due to 222Rn, a radioactive noble gas descendent of 238U, second cause of lung cancer after cigarettes smoking. Vulsini Volcanic District is a well known quaternary volcanic area located between the northern Latium and southern Tuscany (Central Italy). It is characterized by an high natural radiation background resulting from the high concentrations of 238U, 232Th and 40K in the volcanic products. In this context, subduction-related metasomatic enrichment of incompatible elements in the mantle source coupled with magma differentiation within the upper crust has given rise to U, Th and K enriched melts. Almost every ancient village and town located in this part of Italy has been built with volcanic rocks pertaining to the Vulsini Volcanic District. The radiological risk of living in this area has been estimated considering separately: a. the risk associated with buildings made of volcanic products and built on volcanic rock substrates b. the risk associated to soil characteristics. The former has been evaluated both using direct 222Rn indoor measurements and simulations of “standard rooms” built with the tuffs and lavas from the Vulsini Volcanic District investigated in this work. The latter has been carried out by using in situ measurements of 222Rn activity in the soil gases. A radon risk map for the Bolsena village has been developed using soil radon measurements integrating geological information. Data of airborne radioactivity in ambient aerosol at two elevated stations in Emilia Romagna (North Italy) under the influence of Fukushima plume have been collected, effective doses have been calculated and an extensive comparison between doses associated with artificial and natural sources in different area have been described and discussed.

Flash floods and their effects on the development in El-Qaá plain area in South Sinai, Egypt

The arid regions are dominated to a much larger degree than humid regions by major catastrophic events. Although most of Egypt lies within the great hot desert belt; it experiences especially in the north some torrential rainfall, which causes flash floods all over Sinai Peninsula. Flash floods in hot deserts are characterized by high velocity and low duration with a sharp discharge peak. Large sediment loads may be carried by floods threatening fields and settlements in the wadis and even people who are living there. The extreme spottiness of rare heavy rainfall, well known to desert people everywhere, precludes any efficient forecasting. Thus, although the limitation of data still reflects pre-satellite methods, chances of developing a warning system for floods in the desert seem remote. The relatively short flood-to-peak interval, a characteristic of desert floods, presents an additional impediment to the efficient use of warning systems. The present thesis contains introduction and five chapters, chapter one points out the physical settings of the study area. There are the geological settings such as outcrop lithology of the study area and the deposits. The alluvial deposits of Wadi Moreikh had been analyzed using OSL dating to know deposits and palaeoclimatic conditions. The chapter points out as well the stratigraphy and the structure geology containing main faults and folds. In addition, it manifests the pesent climate conditions such as temperature, humidity, wind and evaporation. Besides, it presents type of soils and natural vegetation cover of the study area using unsupervised classification for ETM+ images. Chapter two points out the morphometric analysis of the main basins and their drainage network in the study area. It is divided into three parts: The first part manifests the morphometric analysis of the drainage networks which had been extracted from two main sources, topographic maps and DEM images. Basins and drainage networks are considered as major influencing factors on the flash floods; Most of elements were studied which affect the network such as stream order, bifurcation ratio, stream lengths, stream frequency, drainage density, and drainage patterns. The second part of this chapter shows the morphometric analysis of basins such as area, dimensions, shape and surface. Whereas, the third part points the morphometric analysis of alluvial fans which form most of El-Qaá plain. Chapter three manifests the surface runoff through rainfall and losses analysis. The main subject in this chapter is rainfall which has been studied in detail; it is the main reason for runoff. Therefore, all rainfall characteristics are regarded here such as rainfall types, distribution, rainfall intensity, duration, frequency, and the relationship between rainfall and runoff. While the second part of this chapter concerns with water losses estimation by evaporation and infiltration which are together the main losses with direct effect on the high of runoff. Finally, chapter three points out the factors influencing desert runoff and runoff generation mechanism. Chapter four is concerned with assessment of flood hazard, it is important to estimate runoff and tocreate a map of affected areas. Therefore, the chapter consists of four main parts; first part manifests the runoff estimation, the different methods to estimate runoff and its variables such as runoff coefficient lag time, time of concentration, runoff volume, and frequency analysis of flash flood. While the second part points out the extreme event analysis. The third part shows the map of affected areas for every basin and the flash floods degrees. In this point, it has been depending on the DEM to extract the drainage networks and to determine the main streams which are normally more dangerous than others. Finally, part four presets the risk zone map of total study area which is of high inerest for planning activities. Chapter five as the last chapter concerns with flash flood Hazard mitigation. It consists of three main parts. First flood prediction and the method which can be used to predict and forecast the flood. The second part aims to determine the best methods which can be helpful to mitigate flood hazard in the arid zone and especially the study area. Whereas, the third part points out the development perspective for the study area indicating the suitable places in El-Qaá plain for using in economic activities.

Bayesian space-time data fusion for real-time forecasting and map uncertainty

Environmental computer models are deterministic models devoted to predict several environmental phenomena such as air pollution or meteorological events. Numerical model output is given in terms of averages over grid cells, usually at high spatial and temporal resolution. However, these outputs are often biased with unknown calibration and not equipped with any information about the associated uncertainty. Conversely, data collected at monitoring stations is more accurate since they essentially provide the true levels. Due the leading role played by numerical models, it now important to compare model output with observations. Statistical methods developed to combine numerical model output and station data are usually referred to as data fusion. In this work, we first combine ozone monitoring data with ozone predictions from the Eta-CMAQ air quality model in order to forecast real-time current 8-hour average ozone level defined as the average of the previous four hours, current hour, and predictions for the next three hours. We propose a Bayesian downscaler model based on first differences with a flexible coefficient structure and an efficient computational strategy to fit model parameters. Model validation for the eastern United States shows consequential improvement of our fully inferential approach compared with the current real-time forecasting system. Furthermore, we consider the introduction of temperature data from a weather forecast model into the downscaler, showing improved real-time ozone predictions. Finally, we introduce a hierarchical model to obtain spatially varying uncertainty associated with numerical model output. We show how we can learn about such uncertainty through suitable stochastic data fusion modeling using some external validation data. We illustrate our Bayesian model by providing the uncertainty map associated with a temperature output over the northeastern United States.

Late Quaternary geological evolution of the Montenegro and Northern Albania continental margins

The object of this work has been the analysis of natural processes controlling the geological evolution of the Montenegro and Northern Albania Continental Margin (MACM) during the Late Quaternary. These include the modern sediment dispersal system and oceanographic regime, the building and shaping of the shelf margin at the scale of 100 kyr and relative to the most recent transition between glacial and interglacial periods. The analysis of the new data shows that the MACM is a shelf-slope system formed by a suite of physiographic elements, including: an inner and an outer continental shelf, separated by two tectonically-controlled morphological highs; a lobated drowned mid-shelf paleodelta, formed during the last sea level fall and low stand; an upper continental slope, affected by gravity-driven instability and a system of extensional faults with surficial displacement, featuring an orientation coherent with the regional tectonics. The stratigraphic study of the MACM shows a clear correspondence between the Late Pleistocene/Holocene mud-wedge and the low reflectivity sectors of the inner shelf. Conversely, most of the outer shelf and part of the continental slope expose deposits from the last sea level low stand, featuring a general sediment starving condition or the presence of a thin postglacial sediments cover. The MACM shows uplift in correspondence of the Kotor and Bar ridges, and subsidence in the outer shelf and upper slope sectors. In fact, seaward of these tectonic ridges, the sparker seismic profile show the presence of four well-defined seismo-stratigraphic sequences, interpreted as forced regression deposits, formed during the last four main glacial phases. In this way, the MACM records the 100 kyr scale sea level fluctuations on its seismo-stratigraphic architecture over the last 350 kyr. Over such time range, through the identification of the paleoshoreline deposits, we estimated an average subsidence rate of about 1.2 mm/yr.

Geological and hydrogeological features affecting migration, multi-phase partitioning and degradation of chlorinated hydrocarbons through unconsolidated porous media.

Chlorinated solvents are the most ubiquitous organic contaminants found in groundwater since the last five decades. They generally reach groundwater as Dense Non-Aqueous Phase Liquid (DNAPL). This phase can migrate through aquifers, and also through aquitards, in ways that aqueous contaminants cannot. The complex phase partitioning to which chlorinated solvent DNAPLs can undergo (i.e. to the dissolved, vapor or sorbed phase), as well as their transformations (e.g. degradation), depend on the physico-chemical properties of the contaminants themselves and on features of the hydrogeological system. The main goal of the thesis is to provide new knowledge for the future investigations of sites contaminated by DNAPLs in alluvial settings, proposing innovative investigative approaches and emphasizing some of the key issues and main criticalities of this kind of contaminants in such a setting. To achieve this goal, the hydrogeologic setting below the city of Ferrara (Po plain, northern Italy), which is affected by scattered contamination by chlorinated solvents, has been investigated at different scales (regional and site specific), both from an intrinsic (i.e. groundwater flow systems) and specific (i.e. chlorinated solvent DNAPL behavior) point of view. Detailed investigations were carried out in particular in one selected test-site, known as “Caretti site”, where high-resolution vertical profiling of different kind of data were collected by means of multilevel monitoring systems and other innovative sampling and analytical techniques. This allowed to achieve a deep geological and hydrogeological knowledge of the system and to reconstruct in detail the architecture of contaminants in relationship to the features of the hosting porous medium. The results achieved in this thesis are useful not only at local scale, e.g. employable to interpret the origin of contamination in other sites of the Ferrara area, but also at global scale, in order to address future remediation and protection actions of similar hydrogeologic settings.

Quality assessment of a landslide inventory map and its application to land‐use planning. A case study in the Northern Apennines (Emilia‐Romagna region, Italy)

Landslide hazard and risk are growing as a consequence of climate change and demographic pressure. Land‐use planning represents a powerful tool to manage this socio‐economic problem and build sustainable and landslide resilient communities. Landslide inventory maps are a cornerstone of land‐use planning and, consequently, their quality assessment represents a burning issue. This work aimed to define the quality parameters of a landslide inventory and assess its spatial and temporal accuracy with regard to its possible applications to land‐use planning. In this sense, I proceeded according to a two‐steps approach. An overall assessment of the accuracy of data geographic positioning was performed on four case study sites located in the Italian Northern Apennines. The quantification of the overall spatial and temporal accuracy, instead, focused on the Dorgola Valley (Province of Reggio Emilia). The assessment of spatial accuracy involved a comparison between remotely sensed and field survey data, as well as an innovative fuzzylike analysis of a multi‐temporal landslide inventory map. Conversely, long‐ and short‐term landslide temporal persistence was appraised over a period of 60 years with the aid of 18 remotely sensed image sets. These results were eventually compared with the current Territorial Plan for Provincial Coordination (PTCP) of the Province of Reggio Emilia. The outcome of this work suggested that geomorphologically detected and mapped landslides are a significant approximation of a more complex reality. In order to convey to the end‐users this intrinsic uncertainty, a new form of cartographic representation is needed. In this sense, a fuzzy raster landslide map may be an option. With regard to land‐use planning, landslide inventory maps, if appropriately updated, confirmed to be essential decision‐support tools. This research, however, proved that their spatial and temporal uncertainty discourages any direct use as zoning maps, especially when zoning itself is associated to statutory or advisory regulations.

A commutative higher cycle map into Deligne-Beilinson cohomology

Das Ziel dieser Arbeit ist die Konstruktion eines Homomorphismus von partiell definierten, graduiert-kommutativen Algebren, der nach Ubergang zu rationalen Kohomologiegruppen mit der Regulatorabbildung reg zwischen motivischer und Deligne-Beilinson Kohomologie übereinstimmt.rnZu Beginn der Arbeit werden verschiedene Komplexe beschrieben, mit denen sich die motivische und die Deligne-Beilinson Kohomologie berechnen lassen.rnIm ersten Kapitel wird der Komplex der höheren Chow Ketten und der Unterkomplex der "alternierenden" Ketten "in guter Lage" eingeführt, die beide die motivische Kohomologie berechnen (letzterer mit rationalen Koeffizienten).rnIn den folgenden beiden Kapiteln werden Komplexe C_D und P_D beschrieben, mit denen sich die (rationale) Deligne-Beilinson Kohomologie berechnen lässt. Diese sind aufgebaut aus sogenannten Strömen, die im zweiten Kapitel eingeführt werden. Verknüpft sind die beiden Komplexe durch eine Auswertungsabbildung ev, die für rationale Koeffizienten zu einem Quasi-Isomorphismus wird. Auf beiden Komplexen lassen sich (Schnitt-)Produkte definieren, von denen jedoch nur das Produkt auf P_D gleichzeitig assoziativ und graduiert-kommutativ ist.rnIm vierten Kapitel wird ganz allgemein für eine Familie von Komplexen, die einer Reihe an Anforderungen genügt, ein (partiell definierter) Homomorphismus (der Regulator) von dem Komplex der höheren Chow Ketten in eben diese Komplexe konstruiert. Die beiden oben genannten Komplexe erfüllen diese Anforderungen und liefern daher Regulatoren reg_C und reg_P

Mongodb tra i database non relazionali - focus su Map-Reduce e gestione della memoria

Panoramica delle caratteristiche dei database NoSQL, con dettaglio su MongoDB: filosofia di progettazione, modello dei dati, indicizzazione, algoritmo Map-Reduce e gestione della memoria.

Analisi di morfologie carsiche o crio-carsiche in relazione alla mobilizzazione di fluidi nella regione di Arabia Terra, Marte.

This thesis tries to interpret the origin and evolution of karst-like forms present in Arabia Terra, a region of Mars that develops in the equatorial zone of the planet. The work has been carried out specifically in the craters Crommelin (4o 91’ N-10o 51’ E), 12000088 (3o 48’ N-1o 30’ E), NE 12000088 (4° 20’ N-2° 50’ E), C "2" (3° 54’ N-1° W), and in their surrounding areas. These craters contain layered deposits characterized by a high albedo and on which erosion is very pronounced. The area containing the craters is a plateau that has the same characteristics of albedo and texture. The preliminary morphological study has made use of instrumentation such as the Mars Reconnaissance Orbiter (MRO), in particular HiRISE images (High Resolution Imaging Science Experiment), CTX (Context Camera) and CRISM (Compact Reconnaissance Imaging Spectrometers for Mars). A regional geomorphological map has been drawn up containing the main morphotypes, and detailed geomorphological maps were prepared for different karst-like morphologies. The analysis of spectral data collected from CRISM instrumentation has allowed to identify the footprint of sulphate minerals in the external area. Data were collected for morphometric negative forms (karst-like) and positive forms (mud volcanoes, dikes and pingos). For the analysis of the relief forms DTMs (Digital Terrain Models) produced by the union of stereographic CTX couples or HiRISE were used. From the analysis of high-resolution images morphological footprints similar to periglacial environments have been identified, including the presence of patterned ground and polygonal cracks found all over the area of investigation, and relief structures similar to pingos present in the crater C "2". These observations allow us to imagine a geological past with a cold climate at the equator able to freeze the few fluids present in the Martian arid terrain. The development of karst-like landforms, on the other hand, can be attributed to a subsequent improval of the weather conditions that led to a normal climate regime for the equatorial areas, resulting in the degradation of the permafrost. The melt waters have thus allowed the partial dissolution of the sulphate layers. The karst-like forms look rather fresh suggesting them to be not that old.

Metodi di map-matching per l'identificazione degli itinerari dei ciclisti

Negli ultimi anni si è assistito al considerevole aumento della disponibilità di dati GPS e della loro precisione, dovuto alla diffusione e all’evoluzione tecnologica di smartphone e di applicazioni di localizzazione. Il processo di map-matching consiste nell’integrare tali dati - solitamente una lista ordinata di punti, identificati tramite coordinate geografiche ricavate mediante un sistema di localizzazione, come il GPS - con le reti disponibili; nell’ambito dell’ingegneria dei trasporti, l’obiettivo è di identificare il percorso realmente scelto dall’utente per lo spostamento. Il presente lavoro si propone l’obiettivo di studiare alcune metodologie di map-matching per l’identificazione degli itinerari degli utenti, in particolare della mobilità ciclabile. Nel primo capitolo è esposto il funzionamento dei sistemi di posizionamento e in particolare del sistema GPS: ne sono discusse le caratteristiche, la suddivisione nei vari segmenti, gli errori di misurazione e la cartografia di riferimento. Nel secondo capitolo sono presentati i vari aspetti del procedimento di map-matching, le sue principali applicazioni e alcune possibili classificazioni degli algoritmi di map-matching sviluppati in letteratura. Nel terzo capitolo è esposto lo studio eseguito su diversi algoritmi di map-matching, che sono stati testati su un database di spostamenti di ciclisti nell’area urbana di Bologna, registrati tramite i loro smartphone sotto forma di punti GPS, e sulla relativa rete. Si analizzano altresì i risultati ottenuti in un secondo ambiente di testing, predisposto nell’area urbana di Catania, dove sono state registrate in modo analogo alcune tracce di prova, e utilizzata la relativa rete. La comparazione degli algoritmi è eseguita graficamente e attraverso degli indicatori. Vengono inoltre proposti e valutati due algoritmi che forniscono un aggiornamento di quelli analizzati, al fine di migliorarne le prestazioni in termini di accuratezza dei risultati e di costo computazionale.

Three-dimensional electroanatomic entrainment map in atypical atrial flutter late after heart transplantation

Atrial flutter in the donor part of orthotopic heart transplants has been reported and successfully treated by radiofrequency ablation of the cavotricuspid isthmus, but mapping and ablation of atypical flutter circuits may be challenging.(1) Entrainment mapping has been used in combination with activation mapping to define the mechanism of atypical atrial flutter. Here, we report a case where colour-coded three-dimensional (3D) entrainment mapping allowed us to accurately determine and visualize the 3D location of the reentrant circuit and to plan the ablation of a left atrial flutter without the need for activation mapping.