Academic literature on the topic 'Morphometric maps'

Le climat primitif martien fascine la recherche martienne. Identifier avec le plus de précision possible les conditions primitives martiennes permettrait de contraindre les différents états de l’eau au cours de l’histoire martienne. Aujourd’hui deux hypothèses font débat, la première est celle d’un climat chaud et humide régnant à la surface de Mars à la fin du Noachien/début Héspérien. La deuxième, à l’inverse, semble indiquer que le climat aurait été froid et englacé sur les plus hautes altitudes martiennes. Néanmoins, cette deuxième hypothèse est souvent contestée, car contrairement à la présence de marqueur d’eau liquide à la surface de Mars, aucune morphologie de surface attestant d’un climat froid n’avait été identifiée. Au cours de cette thèse, nous avons étudié de manière morphométrique les structures et morphologies à la surface de Terra Sabaea, qui constitue 1% de la superficie totale de la planète. Ces structures constituent des héritages morphologiques des activités climatiques passées. Afin de caractériser au mieux l’origine érosive de ces structures, nous avons créé une nouvelle méthode d’analyse morphométrique à partir de différentes méthodes terrestres et martiennes. Cette nouvelle méthode permet d’extraire plus de 20 données exploitables par vallée. Il a donc été question de mesurer un maximum de vallée afin d’établir une base de données que nous avons comparée avec des bases de données de morphologies terrestres et martiennes. Grâce à cette analyse, il a été possible de mettre en évidence, la présence d’un paysage glaciaire dans la région de Terra Sabaea. Ce paysage est composé de (1) vallées glaciaires liées avec (2) des cirques glaciaires. La source de cette glace semble être (3) des calottes de plateaux locales à des altitudes &gt; 3500 m. Nous avons donc démontré pour la première fois la présence de morphologies glaciaires attestant d’un climat froid il y a 3.6 Ga. Néanmoins, la présence de telles morphologies n’indique pas que l’ensemble de Terra Sabaea était englacé. L’analyse morphométrique a démontré la présence de morphologie fluviatile géographiquement proche des morphologies glaciaires et souvent à la même altitude, entre 1500 et 3500 m. Cette observation nous a permis de mettre en évidence (4) que la pente était un facteur qui influençait sur l’état de l’eau. En effet, pour une même altitude, les morphologies fluviatiles sont situées sur les pentes douces (&lt; 3°) alors que les morphologies glaciaires sont situées sur les remparts internes des cratères d’impacts présentant une forte pente (&gt; 10°). Cependant (5) l’altitude semble également être un facteur déterminant puisque l’on ne retrouve pas de morphologie glaciaire à des altitudes &lt; 1500 m. L’analyse des terrains de Terra Sabaea a également mis en évidence (6) qu’il existait un lien génétique entre les morphologies glaciaires de hautes altitudes et les vallées fluviatiles plus bas. En effet, il est possible de suivre une vallée qui prend sa source sur les hauts plateaux englacés en amont, jusqu’en aval où elle rejoint des morphologies témoignant d’une activité fluviatile. Cette continuité dans les morphologies glaciaires et fluviatiles permet (7) de mieux définir l’origine des vallées ramifiées, et notamment l’origine de Naktong vallis, et il semblerait que la fonte des glaces a joué un rôle dans leurs formations. De plus, cette continuité morphologique permet de supposer qu’il existait (8) un cycle de l’eau similaire à la Terre dans la région de Terra Sabaea il y a 3.6 Ga<br>The primitive Martian climate fascinates Martian research. Identifying Martian primitive conditions as accurately as possible would make it possible to constrain the different states of water during Martian history. Today two hypotheses are debated, the first is that of a hot and humid climate prevailing on the surface of Mars at the end of the Noachian / early Hesperian. The second, on the contrary, seems to indicate that the climate was cold and glacial on the highest Martian altitudes. Nevertheless, this second hypothesis is often disputed, because unlike the presence of liquid water marker on the surface of Mars, no surface morphology attesting to a cold climate had been identified. In this thesis, we studied morphometrically structures and morphologies on the surface of Terra Sabaea, which constitutes 1% of the total surface of the planet. These structures constitute morphological legacies of past climatic activities. In order to better characterize the erosive origin of these structures, we have created a new method of morphometric analysis from different terrestrial and Martian methods. This new method makes it possible to extract more than 20 exploitable data per valley. It was therefore a question of measuring a valley maximum in order to establish a database that we compared with databases of terrestrial and Martian morphologies. Thanks to this analysis, it has been possible to highlight the presence of an ice landscape in the Terra Sabaea region. This landscape is composed of (1) glacial valleys linked or not with (2) glacial cirques. The source of this ice appears to be (3) local plateau caps at altitudes&gt; 3500 m. We thus demonstrated for the first time the presence of glacial morphologies attesting to a cold climate there are 3.6 Ga. Nevertheless, the presence of such morphologies does not indicate that the whole of Terra Sabaea was glaciated. Morphometric analysis has demonstrated the presence of fluvial morphology geographically close to glacial morphologies and often at the same altitude, between 1500 and 3500 m. This observation allowed us to highlight (4) that the slope was a factor influencing the state of the water. Indeed, for the same altitude, fluvial morphologies are located on gentle slopes (&lt;3 °) while glacial morphologies are located on the inner walls of impact craters with a steep slope (&gt; 10 °). However (5) altitude also seems to be a determining factor since we do not find glacial morphology at altitudes &lt;1500 m. Terra Sabaea land analysis also revealed (6) that there is a genetic link between high altitude glacial morphologies and lower river valleys. Indeed, it is possible to follow a valley that has its source on the highlands glaciers upstream, downstream where it joins morphologies testifying to a fluviatile activity. This continuity in glacial and fluvial morphologies makes it possible (7) to better define the origin of branched valleys, and in particular the origin of Naktong vallis, and it seems that melting ice has played a role in their formations. Moreover, this morphological continuity makes it possible to suppose that there existed (8) a cycle of water similar to the Earth in the region of Terra Sabaea there is 3.6 Ga

Une analyse bibliographique montre que si l'architecture des parties aeriennes est bien connue chez le mais, il n'en est pas de meme du systeme racinaire. Nous avons donc entrepris un travail de synthese a ce sujet. Dans la premiere partie de cette etude, les parametres descriptifs de la structure racinaire sont definis. Leur evolution au cours du cycle est ensuite caracterisee en conditions habituelles de culture, et, en rhizotrons. Quatre categories de racines primaires ont pu etre mises en evidence

Coastal waters have high biological productivity and provide goods and services with a high monetary value. Coasts are used by many different stakeholders and are often densely populated. These factors put coastal ecosystems under heavy environmental pressure and place high demands on politicians and coastal managers, who need suitable tools to facilitate decision-making. Geographic information systems and predictive mass balance models are two such tools, and the form of coastal areas (morphometry) is an important component of both tools in coastal management. In this thesis it was shown that the form and function of coastal areas are interrelated in a number of ways. Morphometric parameters can be used to identify coastal areas that are more sensitive to pollution, or that potentially have higher ecological value; and morphometric analysis is an essential part of mass balance modeling. New ways of using morphometry for estimation of benthic production potential were presented and tested. It was shown that there are great differences in benthic production potential among Swedish coastal areas and regions. Different morphometric descriptors of openness were developed and tested; these can be used in habitat mapping or for prediction of sediment bottom types. Significant correlation was found between the morphometric properties of coastal areas, the proportion of accumulation bottom areas and the critical depth. Statistical models for prediction of accumulation bottom areas and critical depth were also obtained using multiple regression. Large differences were found in empirical values of bottom dynamic conditions from two different sources. Algorithms from a well tested mass balance model were adapted for modeling salt in the Baltic Sea. This enabled calculation of water exchange between five basins on a monthly time scale, which can be of use in future modeling studies. The study included morphometric analysis for structuring the model and for calculation of input data.

Les fonctionnelles de Minkowski définissent des mesures topologiques et géométriques d'ensembles, insuffisantes pour la caractérisation, des ensembles différents pouvant avoir les mêmes fonctionnelles. D'autres fonctionnelles de forme, géométriques et morphométriques, sont donc utilisées. Un diagramme de forme, défini grâce à deux fonctionnelles morphométriques, donne une représentation permettant d'étudier les formes d'ensembles. En analyse d'image, ces fonctionnelles et diagrammes sont souvent limités aux images binaires et déterminés de manière globale et mono-échelle. Les Voisinages Adaptatifs Généraux (VAG) simultanément adaptatifs avec les échelles d'analyse, structures spatiales et intensités des images, permettent de pallier ces limites. Une analyse locale, adaptative et multi-échelle des images à tons de gris est proposée sous forme de cartographies des fonctionnelles de forme à VAG.Les VAG, définis en tout point du support spatial d'une image à tons de gris, sont homogènes par rapport à un critère d'analyse représenté dans un modèle vectoriel, suivant une tolérance d'homogénéité. Les fonctionnelles de forme calculées pour chaque VAG de l'image définissent les cartographies des fonctionnelles de forme à VAG. Les histogrammes et diagrammes de ces cartographies donnent des distributions statistiques des formes des structures locales de l'image contrairement aux histogrammes classiques qui donnent une distribution globale des intensités de l'image. L'impact de la variation des critères axiomatiques des VAG est analysé à travers ces cartographies, histogrammes et diagrammes. Des cartographies multi-échelles sont construites, définissant des fonctions de forme à VAG<br>Minkowski functionals define set topological and geometrical measurements, insufficient for the characterization, because different sets may have the same functionals. Thus, other shape functionals, geometrical and morphometrical are used. A shape diagram, defined thanks to two morphometrical functionals, provides a representation allowing the study of set shapes. In quantitative image analysis, these functionals and diagrams are often limited to binary images and achieved in a global and monoscale way. The General Adaptive Neighborhoods (GANs) simultaneously adaptive with the analyzing scales, the spatial structures and the image intensities, enable to overcome these limitations. The GAN-based Minkowski functionals are introduced, which allow a gray-tone image analysis to be realized in a local, adaptive and multiscale way.The GANs, defined around each point of the spatial support of a gray-tone image, are homogeneous with respect to an analyzing criterion function represented in an algebraic model, according to an homogeneity tolerance. The shape functionals computed on the GAN of each point of the spatial support of the image, define the so-called GAN-based shape maps. The map histograms and diagrams provide statistical distributions of the shape of the gray-tone image local structures, contrary to the classical histogram that provides a global distribution of image intensities. The impact of axiomatic criteria variations is analyzed through these maps, histograms and diagrams. Thus, multiscale maps are built, defining GAN-based shape functions

<p>We introduce Hypoelliptic Diffusion Maps (HDM), a novel semi-supervised machine learning framework for the analysis of collections of anatomical surfaces. Triangular meshes obtained from discretizing these surfaces are high-dimensional, noisy, and unorganized, which makes it difficult to consistently extract robust geometric features for the whole collection. Traditionally, biologists put equal numbers of ``landmarks'' on each mesh, and study the ``shape space'' with this fixed number of landmarks to understand patterns of shape variation in the collection of surfaces; we propose here a correspondence-based, landmark-free approach that automates this process while maintaining morphological interpretability. Our methodology avoids explicit feature extraction and is thus related to the kernel methods, but the equivalent notion of ``kernel function'' takes value in pairwise correspondences between triangular meshes in the collection. Under the assumption that the data set is sampled from a fibre bundle, we show that the new graph Laplacian defined in the HDM framework is the discrete counterpart of a class of hypoelliptic partial differential operators.</p><p>This thesis is organized as follows: Chapter 1 is the introduction; Chapter 2 describes the correspondences between anatomical surfaces used in this research; Chapter 3 and 4 discuss the HDM framework in detail; Chapter 5 illustrates some interesting applications of this framework in geometric morphometrics.</p><br>Dissertation

In questa tesi descriviamo i metodi informatici e gli esperimenti eseguiti per l’applicazione della tecnologia whole body 3D scanner in supporto dell’antropometria. I body scanner restituiscono in uscita una nuvola di punti, solitamente trasformata in mesh triangolare mediante l’uso di algoritmi specifici per supportare la visualizzazione 3D della superficie e l’estrazione di misure e landmarks antropometrici significativi. L’antropometria digitale è già stata utilizzata con successo in vari studi per valutare importanti parametri medici. L’analisi antropometrica digitale è solitamente eseguita utilizzando soluzioni software fornite dai costruttori che sono chiuse e specifiche per il prodotto, che richiedono attenzione nell’acquisizione e dei forti limiti sulla posa assunta dal soggetto. Questo può portare a dei problemi nella comparazione di dati acquisiti in diversi luoghi, nella realizzazione di studi multicentrici su larga scala e nell’applicazione di metodi avanzati di shape analysis sui modelli acquisiti. L’obiettivo del nostro lavoro è di superare questi problemi selezionando e personalizzando strumenti di processing geometrico capaci di creare un sistema aperto ed indipendente dallo strumento per l’analisi di dati da body scanner. Abbiamo inoltre sviluppato e validato dei metodi per estrarre automaticamente dei punti caratteristici, segmenti corporei e misure significative che possono essere utilizzate nella ricerca antropometrica e metabolica. Nello specifico, presentiamo tre esperimenti. Nel primo, utilizzando uno specifico software per l’antropometria digitale, abbiamo valutato la performance dello scanner Breuckmann BodySCAN nelle misure antropometriche. I soggetti degli esperimenti sono 12 giovani adulti che sono stati sottoposti procedure di antropometria manuale e digitale tridimensionale (25 misurazioni) indossando abbigliamento intimo attillato. Le misure duplicate effettuate da un’antropometrista esperto mostrano una correlazione r=0.975-0.999; la loro media è significativamente (secondo il test t di Student) diversa su 4 delle 25 misure. Le misure digitali effettuate in duplicato da un antropometrista esperto e da due antropometristi non esperti, mostrano indici di correlazione individuali r che variano nel range 0.975-0.999 e medie che che erano significativamente diverse in una misurazione su 25. La maggior parte delle misure effettuate dall’antropometrista esperto, manuali e digitali, mostrano una correlazione significativa (coefficiente di correlazione intra-classe che variano nell’intervallo 0.855-0.995, p<0.0001). Concludiamo che lo scanner Breuckmann BodySCAN è uno strumento affidabile ed efficace per le misure antropometriche. In un secondo esperimento, compariamo alcune caratteristiche geometriche facilmente misurabili ottenute dalle scansioni di femmine obese (BMI>30) con i parametri di composizione corporea (misurata con una DXA) dei soggetti stessi, per investigare quali misure dei descrittori di forma correlavano meglio con il grasso del torso e corporeo. I risultati ottenuti mostrano che alcuni dei parametri geometrici testati presentano una elevata correlazione, mentre altri non correlano fortemente con il grasso corporeo. Questi risultati supportano il ruolo dell’antropometria digitale nell’indagine sulle caratteristiche fisiche rilevanti per la salute, ed incoraggiano la realizzazione di ulteriori studi che analizzino la relazione tra descrittori di forma e composizione corporea. Infine, presentiamo un nuovo metodo per caratterizzare le superfici tridimensionali mediante il calcolo di una funzione chiamata “Area projection transform”, la quale misura la possibilità dei punti dello spazio 3D di essere il centro di simmetria radiale della forma a predeterminati raggi. La trasformata può essere usata per rilevare e caratterizzare in maniera robusta i regioni salienti (approssimativamente parti sferiche e cilindriche) ed è, quindi, adatta ad applicazioni come la detection di caratteristiche anatomiche. In particolare, mostriamo che è possibile costruire grafi che uniscono questi punti seguendo i valori massimali della MAPT (Radial Simmetry Graphs) e che questi grafi possono essere usati per estrarre rilevanti proprietà della forma o definire corrispondenze puntuali robuste nei confronti di problematiche quali parti mancanti, rumore topologico e deformazioni articolate. Concludiamo che le potenziali applicazioni della tecnologia della scansione tridimensionale applicata all’antropometria sono innumerevoli, limitate solo dall’abilità della conoscienza scientifica di connettere il fenomeno biologico con le appropriate descrizioni matematiche/geometriche.<br>In this thesis we describe the developed computer method and experiments performed in order to apply whole body 3D scanner technology in support to anthropometry. The output of whole body scanners is a cloud of points, usually transformed in a triangulated mesh through the use of specific algorithms in order to support the 3D visualization of the surface and the extraction of meaningful anthropometric landmarks and measurements. Digital anthropometry has been already used in various studies to assess important health-related parameters. Digital anthropometric analysis is usually performed using device-specific and closed software solutions provided by scanner manufacturers, and requires often a careful acquisition, with strong constraints on subject pose. This may create problems in comparing data acquired in different places and performing large-scale multi-centric studies as well as in applying advanced shape analysis tools on the captured models. The aim of our work is to overcome these problems by selecting and customizing geometrical processing tools able to create an open and device-independent method for the analysis of body scanner data. We also developed and validated methods to extract automatically feature points, body segments and relevant measurements that can be used in anthropometric and metabolic research. In particular we present three experiments. In the first, using specific digital anthropometry software, we evaluated the Breuckmann BodySCAN for performance in anthropometric measurement. Subjects of the experiment were 12 young adults underwent both manual and 3D digital anthropometry (25 measurements) wearing close-fitting underwear. Duplicated manual measurement taken by one experienced anthropometrist showed correlation r 0.975-0.999; their means were significantly different in four out of 25 measurements by Student’s t test. Duplicate digital measurements taken by one experienced anthropometrist and two naïve anthropometrists showed individual correlation coefficients r ranging 0.975-0.999 and means were significantly different in one out of 25 measurements. Most measurements taken by the experienced anthropometrist in the manual and digital mode showed significant correlation (intraclass correlation coefficient ranging 0.855-0.995, p<0.0001). We conclude that the Breuckmann BodyScan is reliable and effective tool for digital anthropometry. In a second experiment, we compare easily detectable geometrical features obtained from 3D scans of female obese (BMI > 30) subjects with body composition (measured with a DXA device) of the same subjects, in order to investigate which measurements on shape descriptors better correlate with torso and body fat. The results obtained show that some of the tested geometrical parameters have a relevant correlation, while other ones do not strongly correlate with body fat. These results support the role of digital anthropometry in investigating health-related physical characteristics and encourage the realization of further studies analyzing the relationships between shape descriptors and body composition. Finally, we present a novel method to characterize 3D surfaces through the computation of a function called Area Projection Transform, measuring the likelihood of points in the 3D space to be center of radial symmetry at selected scales (radii). The transform can be used to detect and characterize robustly salient regions (approximately spherical and cylindrical parts) and it is, therefore, suitable for applications like anatomical features detection. In particular, we show that it is possible to build graphs joining these points following maximal values of the MAPT (Radial Symmetry Graphs) and that these graphs can be used to extract relevant shape properties or to establish point correspondences on models robustly against holes, topological noise and articulated deformations. It is concluded that whole body scanning technology application to anthropometry are potentially countless, limited only by the ability of science to connect the biological phenomenon with the appropriate mathematical/geometrical descriptions.